Develop Reference

Moving an object on imageview on zoom in and zoom out

There is a draggable object over the imageview which has been set as background in android. When the background imageview zooms, I want the object to stay in the same position as it was before.for example, if it was over a text called "smile" in that image then, it should stay there even after zooming.
I want the image works just like google maps when we add marker to a map the marker moves according to zoom in and out.

Use the below class of Framlayout for that, It will zoom all the content inside that.
public class ZoomableLayout extends FrameLayout {
public ZoomableLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
}
public ZoomableLayout(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
}
public ZoomableLayout(final Context context) {
super(context);
}
/**
* Zooming view listener interface.
*
* #author karooolek
*
*/
public interface ZoomViewListener {
void onZoomStarted(float zoom, float zoomx, float zoomy);
void onZooming(float zoom, float zoomx, float zoomy);
void onZoomEnded(float zoom, float zoomx, float zoomy);
}
// zooming
float zoom = 1.0f;
float maxZoom = 2.0f;
float smoothZoom = 1.0f;
float zoomX, zoomY;
float smoothZoomX, smoothZoomY;
private boolean scrolling; //
// minimap variables
private boolean showMinimap = false;
private int miniMapColor = Color.WHITE;
private int miniMapHeight = -1;
private String miniMapCaption;
private float miniMapCaptionSize = 10.0f;
private int miniMapCaptionColor = Color.WHITE;
// touching variables
private long lastTapTime;
private float touchStartX, touchStartY;
private float touchLastX, touchLastY;
private float startd;
private boolean pinching;
private float lastd;
private float lastdx1, lastdy1;
private float lastdx2, lastdy2;
// drawing
private final Matrix m = new Matrix();
private final Paint p = new Paint();
// listener
ZoomViewListener listener;
private Bitmap ch;
public float getZoom() {
return zoom;
}
public float getMaxZoom() {
return maxZoom;
}
public void setMaxZoom(final float maxZoom) {
if (maxZoom < 1.0f) {
return;
}
this.maxZoom = maxZoom;
}
public void setMiniMapEnabled(final boolean showMiniMap) {
this.showMinimap = showMiniMap;
}
public boolean isMiniMapEnabled() {
return showMinimap;
}
public void setMiniMapHeight(final int miniMapHeight) {
if (miniMapHeight < 0) {
return;
}
this.miniMapHeight = miniMapHeight;
}
public int getMiniMapHeight() {
return miniMapHeight;
}
public void setMiniMapColor(final int color) {
miniMapColor = color;
}
public int getMiniMapColor() {
return miniMapColor;
}
public String getMiniMapCaption() {
return miniMapCaption;
}
public void setMiniMapCaption(final String miniMapCaption) {
this.miniMapCaption = miniMapCaption;
}
public float getMiniMapCaptionSize() {
return miniMapCaptionSize;
}
public void setMiniMapCaptionSize(final float size) {
miniMapCaptionSize = size;
}
public int getMiniMapCaptionColor() {
return miniMapCaptionColor;
}
public void setMiniMapCaptionColor(final int color) {
miniMapCaptionColor = color;
}
public void zoomTo(final float zoom, final float x, final float y) {
this.zoom = Math.min(zoom, maxZoom);
zoomX = x;
zoomY = y;
smoothZoomTo(this.zoom, x, y);
}
public void smoothZoomTo(final float zoom, final float x, final float y) {
smoothZoom = clamp(1.0f, zoom, maxZoom);
smoothZoomX = x;
smoothZoomY = y;
if (listener != null) {
listener.onZoomStarted(smoothZoom, x, y);
}
}
public ZoomViewListener getListener() {
return listener;
}
public void setListner(final ZoomViewListener listener) {
this.listener = listener;
}
public float getZoomFocusX() {
return zoomX * zoom;
}
public float getZoomFocusY() {
return zoomY * zoom;
}
#Override
public boolean dispatchTouchEvent(final MotionEvent ev) {
// single touch
if (ev.getPointerCount() == 1) {
processSingleTouchEvent(ev);
}
// // double touch
if (ev.getPointerCount() == 2) {
processDoubleTouchEvent(ev);
}
// redraw
getRootView().invalidate();
invalidate();
return true;
}
private void processSingleTouchEvent(final MotionEvent ev) {
final float x = ev.getX();
final float y = ev.getY();
final float w = miniMapHeight * (float) getWidth() / getHeight();
final float h = miniMapHeight;
final boolean touchingMiniMap = x >= 10.0f && x <= 10.0f + w
&& y >= 10.0f && y <= 10.0f + h;
if (showMinimap && smoothZoom > 1.0f && touchingMiniMap) {
processSingleTouchOnMinimap(ev);
} else {
processSingleTouchOutsideMinimap(ev);
}
}
private void processSingleTouchOnMinimap(final MotionEvent ev) {
final float x = ev.getX();
final float y = ev.getY();
final float w = miniMapHeight * (float) getWidth() / getHeight();
final float h = miniMapHeight;
final float zx = (x - 10.0f) / w * getWidth();
final float zy = (y - 10.0f) / h * getHeight();
smoothZoomTo(smoothZoom, zx, zy);
}
private void processSingleTouchOutsideMinimap(final MotionEvent ev) {
final float x = ev.getX();
final float y = ev.getY();
float lx = x - touchStartX;
float ly = y - touchStartY;
final float l = (float) Math.hypot(lx, ly);
float dx = x - touchLastX;
float dy = y - touchLastY;
touchLastX = x;
touchLastY = y;
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
touchStartX = x;
touchStartY = y;
touchLastX = x;
touchLastY = y;
dx = 0;
dy = 0;
lx = 0;
ly = 0;
scrolling = false;
break;
case MotionEvent.ACTION_MOVE:
if (scrolling || (smoothZoom > 1.0f && l > 30.0f)) {
if (!scrolling) {
scrolling = true;
ev.setAction(MotionEvent.ACTION_CANCEL);
super.dispatchTouchEvent(ev);
}
smoothZoomX -= dx / zoom;
smoothZoomY -= dy / zoom;
return;
}
break;
case MotionEvent.ACTION_OUTSIDE:
case MotionEvent.ACTION_UP:
// tap
if (l < 30.0f) {
// check double tap
if (System.currentTimeMillis() - lastTapTime < 500) {
if (smoothZoom == 1.0f) {
smoothZoomTo(maxZoom, x, y);
} else {
smoothZoomTo(1.0f, getWidth() / 2.0f,
getHeight() / 2.0f);
}
lastTapTime = 0;
ev.setAction(MotionEvent.ACTION_CANCEL);
super.dispatchTouchEvent(ev);
return;
}
lastTapTime = System.currentTimeMillis();
performClick();
}
break;
default:
break;
}
ev.setLocation(zoomX + (x - 0.5f * getWidth()) / zoom, zoomY
+ (y - 0.5f * getHeight()) / zoom);
ev.getX();
ev.getY();
super.dispatchTouchEvent(ev);
}
private void processDoubleTouchEvent(final MotionEvent ev) {
final float x1 = ev.getX(0);
final float dx1 = x1 - lastdx1;
lastdx1 = x1;
final float y1 = ev.getY(0);
final float dy1 = y1 - lastdy1;
lastdy1 = y1;
final float x2 = ev.getX(1);
final float dx2 = x2 - lastdx2;
lastdx2 = x2;
final float y2 = ev.getY(1);
final float dy2 = y2 - lastdy2;
lastdy2 = y2;
// pointers distance
final float d = (float) Math.hypot(x2 - x1, y2 - y1);
final float dd = d - lastd;
lastd = d;
final float ld = Math.abs(d - startd);
Math.atan2(y2 - y1, x2 - x1);
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
startd = d;
pinching = false;
break;
case MotionEvent.ACTION_MOVE:
if (pinching || ld > 30.0f) {
pinching = true;
final float dxk = 0.5f * (dx1 + dx2);
final float dyk = 0.5f * (dy1 + dy2);
smoothZoomTo(Math.max(1.0f, zoom * d / (d - dd)), zoomX - dxk
/ zoom, zoomY - dyk / zoom);
}
break;
case MotionEvent.ACTION_UP:
default:
pinching = false;
break;
}
ev.setAction(MotionEvent.ACTION_CANCEL);
super.dispatchTouchEvent(ev);
}
private float clamp(final float min, final float value, final float max) {
return Math.max(min, Math.min(value, max));
}
private float lerp(final float a, final float b, final float k) {
return a + (b - a) * k;
}
private float bias(final float a, final float b, final float k) {
return Math.abs(b - a) >= k ? a + k * Math.signum(b - a) : b;
}
#Override
protected void dispatchDraw(final Canvas canvas) {
// do zoom
zoom = lerp(bias(zoom, smoothZoom, 0.05f), smoothZoom, 0.2f);
smoothZoomX = clamp(0.5f * getWidth() / smoothZoom, smoothZoomX,
getWidth() - 0.5f * getWidth() / smoothZoom);
smoothZoomY = clamp(0.5f * getHeight() / smoothZoom, smoothZoomY,
getHeight() - 0.5f * getHeight() / smoothZoom);
zoomX = lerp(bias(zoomX, smoothZoomX, 0.1f), smoothZoomX, 0.35f);
zoomY = lerp(bias(zoomY, smoothZoomY, 0.1f), smoothZoomY, 0.35f);
if (zoom != smoothZoom && listener != null) {
listener.onZooming(zoom, zoomX, zoomY);
}
final boolean animating = Math.abs(zoom - smoothZoom) > 0.0000001f
|| Math.abs(zoomX - smoothZoomX) > 0.0000001f
|| Math.abs(zoomY - smoothZoomY) > 0.0000001f;
// nothing to draw
if (getChildCount() == 0) {
return;
}
// prepare matrix
m.setTranslate(0.5f * getWidth(), 0.5f * getHeight());
m.preScale(zoom, zoom);
m.preTranslate(
-clamp(0.5f * getWidth() / zoom, zoomX, getWidth() - 0.5f
* getWidth() / zoom),
-clamp(0.5f * getHeight() / zoom, zoomY, getHeight() - 0.5f
* getHeight() / zoom));
// get view
final View v = getChildAt(0);
m.preTranslate(v.getLeft(), v.getTop());
// get drawing cache if available
if (animating && ch == null && isAnimationCacheEnabled()) {
v.setDrawingCacheEnabled(true);
ch = v.getDrawingCache();
}
// draw using cache while animating
if (animating && isAnimationCacheEnabled() && ch != null) {
p.setColor(0xffffffff);
canvas.drawBitmap(ch, m, p);
} else { // zoomed or cache unavailable
ch = null;
canvas.save();
canvas.concat(m);
v.draw(canvas);
canvas.restore();
}
// draw minimap
if (showMinimap) {
if (miniMapHeight < 0) {
miniMapHeight = getHeight() / 4;
}
canvas.translate(10.0f, 10.0f);
p.setColor(0x80000000 | 0x00ffffff & miniMapColor);
final float w = miniMapHeight * (float) getWidth() / getHeight();
final float h = miniMapHeight;
canvas.drawRect(0.0f, 0.0f, w, h, p);
if (miniMapCaption != null && miniMapCaption.length() > 0) {
p.setTextSize(miniMapCaptionSize);
p.setColor(miniMapCaptionColor);
p.setAntiAlias(true);
canvas.drawText(miniMapCaption, 10.0f,
10.0f + miniMapCaptionSize, p);
p.setAntiAlias(false);
}
p.setColor(0x80000000 | 0x00ffffff & miniMapColor);
final float dx = w * zoomX / getWidth();
final float dy = h * zoomY / getHeight();
canvas.drawRect(dx - 0.5f * w / zoom, dy - 0.5f * h / zoom, dx
+ 0.5f * w / zoom, dy + 0.5f * h / zoom, p);
canvas.translate(-10.0f, -10.0f);
}
// redraw
// if (animating) {
getRootView().invalidate();
invalidate();
// }
}
}
Add this to your xml as below,
<com.example.myapplication.Activities.Utils.ZoomableLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/zoom_layout"
>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
>
// Your contents here
</RelativeLayout>
</com.example.myapplication.Activities.Utils.ZoomableLayout>

Canvas getting wrong coordinates for finger drawing after pinch to zoom

I create canvas finger drawing app like line brush which is on https://play.google.com/store/apps/details?id=jp.naver.linebrush.android, I done pinch to zoom functionality but problem is after zoom in and zoom out, not drawing properly position on canvas area. For more understanding I share my View class for canvas drawing:
public class DrawingView extends View {
// Zooming Code 16-6-2015 4.12pm
private static final int INVALID_POINTER_ID = -1;
public Bitmap mMyChracter;
private float mPosX;
private float mPosY;
private float mLastTouchX;
private float mLastTouchY;
private int mActivePointerId = INVALID_POINTER_ID;
View currentView;
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
private float focusX;
private float focusY;
private float lastFocusX = -1;
private float lastFocusY = -1;
static final int IMG_WIDTH = 640;
static final int IMG_HEIGHT = 480;
static final int IMAGE_X_POS = 560;
static final int IMAGE_Y_POS = 20;
float sy;
float sx;
public static Context context;
// -------------------------------------
// ...................................
/*private final Bitmap bitmap;
private final int width;
private final int height;*/
private Matrix transform = new Matrix();
private Vector2D position = new Vector2D();
private float scale = 1;
private float angle = 0;
private TouchManager touchManager = new TouchManager(2);
private boolean isInitialized = false;
// Debug helpers to draw lines between the two touch points
private Vector2D vca = null;
private Vector2D vcb = null;
private Vector2D vpa = null;
private Vector2D vpb = null;
int mWidth;
int mHeight;
// ...............................
private final Paint mDefaultPaint;
private Paint mFillPaint;
float x, y;
private Canvas mLayerCanvas = new Canvas();
private Bitmap mLayerBitmap;
private Stack<DrawOp> mDrawOps = new Stack<>();
private Stack<DrawOp> mUndoOps = new Stack<>();
private SparseArray<DrawOp> mCurrentOps = new SparseArray<>(0);
// For Drag and Pan zoom Code initialization
private static float MIN_ZOOM = 1f;
private static float MAX_ZOOM = 2f;
private float scaleFactor = 1.f;
private static ScaleGestureDetector detector;
boolean mFlagDrawing;
private final Matrix mMatrix = new Matrix();
int y_old=0,y_new=0;int zoomMode=0;
float pinch_dist_old=0,pinch_dist_new=0;
int zoomControllerScale=1;//new and old pinch distance to determine Zoom scale
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
// We can be in one of these 3 states
static final int NONE = 0;
static final int PAN = 1;
static final int ZOOM = 2;
int mode = NONE;
private static final String TAG = "DebugTag";
// New Code
private Bitmap imgBitmap = null;
private int containerWidth;
private int containerHeight;
Paint background;
//Matrices will be used to move and zoom image
// Matrix matrix = new Matrix();
// Matrix savedMatrix = new Matrix();
// PointF start = new PointF();
float currentScale;
float curX;
float curY;
//We can be in one of these 3 states
// static final int NONE = 0;
// static final int DRAG = 1;
// static final int ZOOM = 2;
// int mode = NONE;
//For animating stuff
float targetX;
float targetY;
float targetScale;
float targetScaleX;
float targetScaleY;
float scaleChange;
float targetRatio;
float transitionalRatio;
float easing = 0.2f;
boolean isAnimating = false;
float scaleDampingFactor = 0.5f;
//For pinch and zoom
// float oldDist = 1f;
// PointF mid = new PointF();
private Handler mHandler = new Handler();
float minScale;
float maxScale = 8.0f;
float wpRadius = 25.0f;
float wpInnerRadius = 20.0f;
float screenDensity;
private GestureDetector gestureDetector;
public static final int DEFAULT_SCALE_FIT_INSIDE = 0;
public static final int DEFAULT_SCALE_ORIGINAL = 1;
private int defaultScale;
private static final String EXTRA_EVENT_LIST = "event_list";
private static final String EXTRA_STATE = "instance_state";
private ArrayList<MotionEvent> eventList = new ArrayList<MotionEvent>(100);
public DrawingView(Context context) {
this(context, null, 0);
}
public DrawingView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
// detector = new ScaleGestureDetector(getContext(), new ScaleListener());
}
public DrawingView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mDefaultPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mDefaultPaint.setStyle(Paint.Style.STROKE);
mDefaultPaint.setStrokeJoin(Paint.Join.ROUND);
mDefaultPaint.setStrokeCap(Paint.Cap.ROUND);
mDefaultPaint.setStrokeWidth(40);
mDefaultPaint.setColor(Color.GREEN);
/*mFillPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mFillPaint.setStyle(Paint.Style.STROKE);
mFillPaint.setStrokeJoin(Paint.Join.ROUND);
mFillPaint.setStrokeCap(Paint.Cap.ROUND);
mDefaultPaint.setStrokeWidth(40);
mFillPaint.setColor(Color.GREEN);*/
setFocusable(true);
setFocusableInTouchMode(true);
setBackgroundColor(Color.WHITE);
setLayerType(LAYER_TYPE_SOFTWARE, null);
setSaveEnabled(true);
// Code for Zoom start
// detector = new ScaleGestureDetector(getContext(), new ScaleListener());
// Code for Zoom finish
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
}
private static float getDegreesFromRadians(float angle) {
return (float)(angle * 180.0 / Math.PI);
}
// Single Touch Code
#Override
public boolean onTouchEvent(#NonNull MotionEvent event) {
vca = null;
vcb = null;
vpa = null;
vpb = null;
final int pointerCount = MotionEventCompat.getPointerCount(event);
switch (MotionEventCompat.getActionMasked(event)) {
// switch(event.getAction()){
// switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
// case MotionEventCompat.ACTION_POINTER_DOWN:
{
if (mFlagDrawing == true) {
/* final float xx = event.getX() / mScaleFactor;
final float yy = event.getY() / mScaleFactor;
mLastTouchX = xx;
mLastTouchY = yy;
mActivePointerId = event.getPointerId(0);*/
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
System.out.println("mFlagDrawing: " + mFlagDrawing);
// Code for Zoom start
// detector.onTouchEvent(event);
// mScaleDetector.onTouchEvent(event);
// Code for Zoom finish
} else if (mFlagDrawing == false) {
System.out.println("mFlagDrawing: " + mFlagDrawing);
for (int p = 0; p < pointerCount; p++) {
final int id = MotionEventCompat.getPointerId(event, p);
DrawOp current = new DrawOp(mDefaultPaint);
current.getPath().moveTo(event.getX(), event.getY());
mCurrentOps.put(id, current);
}
}
// mFlagZoom = true;
// }
}
break;
case MotionEvent.ACTION_MOVE: {
// for(int p = 0; p < pointerCount; p++){
if (mFlagDrawing == true) {
/* final int pointerIndex = event.findPointerIndex(mActivePointerId);
final float xx = event.getX(pointerIndex) / mScaleFactor;
final float yy = event.getY(pointerIndex) / mScaleFactor;
// Only move if the ScaleGestureDetector isn't processing a gesture.
if (!mScaleDetector.isInProgress()) {
final float dx = xx - mLastTouchX;
final float dy = yy - mLastTouchY;
mPosX += dx;
mPosY += dy;
invalidate();
}
mLastTouchX = xx;
mLastTouchY = yy;*/
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
// current.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
System.out.println("mFlagDrawing: " + mFlagDrawing);
// Code for Zoom start
// detector.onTouchEvent(event);
// mScaleDetector.onTouchEvent(event);
// Code for Zoom finish
} else if (mFlagDrawing == false) {
System.out.println("mFlagDrawing: " + mFlagDrawing);
final int id = MotionEventCompat.getPointerId(event, 0);
DrawOp current = mCurrentOps.get(id);
final int historySize = event.getHistorySize();
for (int h = 0; h < historySize; h++) {
x = event.getHistoricalX(h);
y = event.getHistoricalY(h);
current.getPath().lineTo(x, y);
}
x = MotionEventCompat.getX(event, 0);
y = MotionEventCompat.getY(event, 0);
current.getPath().lineTo(x, y);
// position.add(current.getPath());
// }
}
}
break;
case MotionEvent.ACTION_UP:
// case MotionEventCompat.ACTION_POINTER_UP:
// {
if (mFlagDrawing == true) {
// mActivePointerId = INVALID_POINTER_ID;
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
System.out.println("mFlagDrawing: " + mFlagDrawing);
// Code for Zoom start
// detector.onTouchEvent(event);
// mScaleDetector.onTouchEvent(event);
// Code for Zoom finish
} else if (mFlagDrawing == false) {
System.out.println("mFlagDrawing: " + mFlagDrawing);
for (int p = 0; p < pointerCount; p++) {
final int id = MotionEventCompat.getPointerId(event, p);
mDrawOps.push(mCurrentOps.get(id));
mCurrentOps.remove(id);
// }
updateLayer();
}
}
// }
break;
case MotionEvent.ACTION_CANCEL: {
if (mFlagDrawing == true) {
// mActivePointerId = INVALID_POINTER_ID;
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
position.add(touchManager.moveDelta(0));
}
else {
if (touchManager.getPressCount() == 2) {
vca = touchManager.getPoint(0);
vpa = touchManager.getPreviousPoint(0);
vcb = touchManager.getPoint(1);
vpb = touchManager.getPreviousPoint(1);
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
}
}
invalidate();
}
catch(Throwable t) {
// So lazy...
}
System.out.println("mFlagDrawing: " + mFlagDrawing);
// Code for Zoom start
// detector.onTouchEvent(event);
// mScaleDetector.onTouchEvent(event);
// Code for Zoom finish
} else if (mFlagDrawing == false) {
System.out.println("mFlagDrawing: " + mFlagDrawing);
for (int p = 0; p < pointerCount; p++) {
mCurrentOps
.remove(MotionEventCompat.getPointerId(event, p));
}
}
// mFlagZoom = true;
// }
}
break;
/*case MotionEvent.ACTION_POINTER_UP: {
final int pointerIndex = (event.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = event.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastTouchX = event.getX(newPointerIndex) / mScaleFactor;
mLastTouchY = event.getY(newPointerIndex) / mScaleFactor;
mActivePointerId = event.getPointerId(newPointerIndex);
}
break;
}*/
default:
return false;
}
invalidate();
return true;
}
#Override
protected void onSizeChanged(int w, int h, int oldW, int oldH) {
super.onSizeChanged(w, h, oldW, oldH);
/*mLayerBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mLayerCanvas.setBitmap(mLayerBitmap);*/
if(mLayerBitmap == null){
mLayerBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
}else{
Bitmap temporary = Bitmap.createScaledBitmap(mLayerBitmap, w, h, true);
mLayerBitmap = temporary;
}
mLayerCanvas = new Canvas(mLayerBitmap);
// mLayerCanvas.rotate(90);
/* matrix.setTranslate(1.5f,1.5f);
matrix.postRotate(90, 2.5f, 2.5f);*/
// updateLayer();
/* //Reset the width and height. Will draw bitmap and change
containerWidth = w;
containerHeight = h;
if(mLayerBitmap != null) {
int imgHeight = mLayerBitmap.getHeight();
int imgWidth = mLayerBitmap.getWidth();
float scale;
int initX = 0;
int initY = 0;
if(defaultScale == DrawingView.DEFAULT_SCALE_FIT_INSIDE) {
if(imgWidth > containerWidth) {
scale = (float)containerWidth / imgWidth;
float newHeight = imgHeight * scale;
initY = (containerHeight - (int)newHeight)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(0, initY);
}
else {
scale = (float)containerHeight / imgHeight;
float newWidth = imgWidth * scale;
initX = (containerWidth - (int)newWidth)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = scale;
minScale = scale;
}
else {
if(imgWidth > containerWidth) {
initY = (containerHeight - (int)imgHeight)/2;
matrix.postTranslate(0, initY);
}
else {
initX = (containerWidth - (int)imgWidth)/2;
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = 1.0f;
minScale = 1.0f;
}
invalidate();
}*/
}
private void updateLayer() {
mLayerCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
for (DrawOp drawOp : mDrawOps) {
if (drawOp != null) {
drawOp.draw(mLayerCanvas);
}
}
invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (isInEditMode()) {
return;
}
// if(mFlagDrawing == true){
if (!isInitialized) {
int w = getWidth();
int h = getHeight();
position.set(w / 2, h / 2);
isInitialized = true;
}
mWidth = mLayerBitmap.getWidth();
mHeight = mLayerBitmap.getHeight();
// Code for Zoom start
/* canvas.save();
canvas.scale(mScaleFactor, mScaleFactor, focusX, focusY);
canvas.translate(mPosX, mPosY);*/
// canvas.scale(scaleFactor, scaleFactor);
/*canvas.scale(mScaleFactor, mScaleFactor, super.getWidth() * 0.5f,
super.getHeight() * 0.5f);*/
// Code for Zoom finish
// canvas.save();
transform.reset();
transform.postTranslate(-mWidth / 2.0f, -mHeight / 2.0f);
// transform.postRotate(getDegreesFromRadians(angle));
transform.postScale(scale, scale);
transform.postTranslate(position.getX(), position.getY());
canvas.drawBitmap(mLayerBitmap, transform, null);
// }
// else if(mFlagDrawing == false){
// canvas.drawBitmap(mLayerBitmap, 0, 0, null);
for (int i = 0; i < mCurrentOps.size(); i++) {
DrawOp current = mCurrentOps.valueAt(i);
if (current != null) {
current.draw(canvas);
}
}
// }
// Code for Zoom
// canvas.restore();
}
public void operationClear() {
mDrawOps.clear();
mUndoOps.clear();
mCurrentOps.clear();
updateLayer();
}
public void operationUndo() {
if (mDrawOps.size() > 0) {
mUndoOps.push(mDrawOps.pop());
updateLayer();
}
}
public void operationRedo() {
if (mUndoOps.size() > 0) {
mDrawOps.push(mUndoOps.pop());
updateLayer();
}
}
public void setPaintStrokeWidth(float widthPx) {
mDefaultPaint.setStrokeWidth(widthPx);
}
public void setPaintOpacity(int percent) {
int alphaValue = (int) Math.round(percent * (255.0 / 100.0));
mDefaultPaint.setColor(combineAlpha(mDefaultPaint.getColor(),
alphaValue));
}
public void setPaintColor(String color) {
mDefaultPaint.setColor(combineAlpha(Color.parseColor(color), mDefaultPaint.getAlpha()));
}
public void setPaintColor(int color) {
mDefaultPaint.setColor(combineAlpha(color, mDefaultPaint.getAlpha()));
}
public void setPaintMaskFilter(MaskFilter filter) {
mDefaultPaint.setMaskFilter(filter);
}
public void setPaintShader(BitmapShader shader) {
mDefaultPaint.setShader(shader);
}
public void setPaintColorFilter(ColorFilter colorFilter) {
mDefaultPaint.setColorFilter(colorFilter);
}
private static int combineAlpha(int color, int alpha) {
return (color & 0x00FFFFFF) | ((alpha & 0xFF) << 24);
}
private static class DrawOp {
private float x,y;
private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
private final Path mPath = new Path();
public DrawOp(Paint paint) {
reset(paint);
}
/*public void add(Vector2D moveDelta) {
// TODO Auto-generated method stub
this.x += moveDelta.getX();
this.y += moveDelta.getY();
}*/
void reset(Paint paint) {
mPath.reset();
update(paint);
}
void update(Paint paint) {
mPaint.set(paint);
}
void draw(Canvas canvas) {
canvas.drawPath(mPath, mPaint);
}
public Path getPath() {
return mPath;
}
/* public DrawOp add(DrawOp value) {
this.x += value.getX();
this.y += value.getY();
return this;
}*/
/*public float getX() {
return x;
}
public float getY() {
return y;
}*/
}
public void fillShapeColor(){
}
// Code for Zoom
/* private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
scaleFactor *= detector.getScaleFactor();
scaleFactor = Math.max(MIN_ZOOM, Math.min(scaleFactor, MAX_ZOOM));
invalidate();
return true;
}
}*/
private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
// float x = detector.getFocusX();
// float y = detector.getFocusY();
lastFocusX = -1;
lastFocusY = -1;
return true;
}
#Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
focusX = detector.getFocusX();
focusY = detector.getFocusY();
if (lastFocusX == -1)
lastFocusX = focusX;
if (lastFocusY == -1)
lastFocusY = focusY;
mPosX += (focusX - lastFocusX);
mPosY += (focusY - lastFocusY);
Log.v("Hi Zoom", "Factor:" + mScaleFactor);
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.5f, Math.min(mScaleFactor, 2.0f));
lastFocusX = focusX;
lastFocusY = focusY;
invalidate();
return true;
}
}
/* #Override
public Parcelable onSaveInstanceState()
{
System.out.println("save instance");
Bundle bundle = new Bundle();
bundle.putParcelable(EXTRA_STATE, super.onSaveInstanceState());
bundle.putParcelableArrayList(EXTRA_EVENT_LIST, eventList);
return bundle;
}
#Override
public void onRestoreInstanceState(Parcelable state)
{
if (state instanceof Bundle)
{
Bundle bundle = (Bundle) state;
super.onRestoreInstanceState(bundle.getParcelable(EXTRA_STATE));
eventList = bundle.getParcelableArrayList(EXTRA_EVENT_LIST);
if (eventList == null) {
eventList = new ArrayList<MotionEvent>(100);
}
for (MotionEvent event : eventList) {
// performTouchEvent(event);
}
return;
}
super.onRestoreInstanceState(state);
}*/
public void setDrawingFlag(boolean flag) {
// System.out.println("Before Set mFlag " + mFlagDrawing);
this.mFlagDrawing = flag;
// System.out.println("After Set mFlag " + mFlagDrawing);
}
public void moveCanvas(float x, float y) {
float dx = x - mLastTouchX;
float dy = y - mLastTouchY;
// Adjust for zoom factor. Otherwise, the user's finger moving 10 pixels
// at 200% zoom causes the image to slide 20 pixels instead of perfectly
// following the user's touch
dx /= (mScaleFactor * 2);
dy /= (mScaleFactor * 2);
mPosX += dx;
mPosY += dy;
// Log.v(TAG, "moving by " + dx + "," + dy + " mScaleFactor: " +
// mScaleFactor);
}
}

I found mistake and correct it by my self. Below is my code.
public void resetZoom() {
mPanX = mPanY = 0;
final Matrix m = new Matrix();
m.postScale(1f / DENSITY, 1f / DENSITY);
setZoom(m);
invalidate();
}
public void setZoomPosNoInval(float x, float y) {
mPanX = x;
mPanY = y;
}
public void setZoomPos(float x, float y) {
setZoomPosNoInval(x, y);
invalidate();
}
public void setZoomPosNoInval(float[] pos) {
setZoomPosNoInval(pos[0], pos[1]);
}
public void setZoomPos(float[] pos) {
setZoomPosNoInval(pos);
invalidate();
}
public float[] getZoomPos(float[] pos) {
if (pos == null)
pos = new float[2];
pos[0] = mPanX;
pos[1] = mPanY;
return pos;
}
public float getZoomPosX() {
return mPanX;
}
public float getZoomPosY() {
return mPanY;
}
public Matrix getZoom() {
return mZoomMatrix;
}
public Matrix getZoomInv() {
return mZoomMatrixInv;
}
public void setZoom(Matrix m) {
mZoomMatrix.set(m);
mZoomMatrix.invert(mZoomMatrixInv);
}

Android pinch zoom imageview inside gallery

I'm creating lazy loaded photo gallery (like facebook)
i'm using cusotme gallery overriding Fling to the make single image paging
and using custume image view to make the pinch zoom
the result is that the image is working fine (zoom,move etc..) but i can't switch images
my code
SlowGallery:
public class SlowGallery extends Gallery {
public SlowGallery(Context context) {
super(context);
}
public SlowGallery(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SlowGallery(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
private boolean isScrollingLeft(MotionEvent e1, MotionEvent e2){
return e2.getX() > e1.getX();
}
#Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY){
Log.d("SlowGallery::onFling","onFinlg");
int kEvent;
if(isScrollingLeft(e1, e2)){ //Check if scrolling left
kEvent = KeyEvent.KEYCODE_DPAD_LEFT;
}
else{ //Otherwise scrolling right
kEvent = KeyEvent.KEYCODE_DPAD_RIGHT;
}
onKeyDown(kEvent, null);
return true;
}
}
ScaleImageView
public class ScaleImageView extends ImageView implements OnTouchListener {
private float MAX_SCALE = 2f;
private int DOUBLE_TAP_SECOND = 400;
private Matrix mMatrix;
private final float[] mMatrixValues = new float[9];
// display width height.
private int mWidth;
private int mHeight;
private int mIntrinsicWidth;
private int mIntrinsicHeight;
private float mScale;
private float mMinScale;
// double tap for determining
private long mLastTime = 0;
private boolean isDoubleTap;
private int mDoubleTapX;
private int mDoubleTapY;
private float mPrevDistance;
private boolean isScaling;
private int mPrevMoveX;
private int mPrevMoveY;
String TAG = "ScaleImageView";
public ScaleImageView(Context context, AttributeSet attr) {
super(context, attr);
initialize();
}
public ScaleImageView(Context context) {
super(context);
initialize();
}
#Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
this.initialize();
}
private void initialize() {
this.setScaleType(ScaleType.MATRIX);
this.mMatrix = new Matrix();
Drawable d = getDrawable();
if (d != null) {
mIntrinsicWidth = d.getIntrinsicWidth();
mIntrinsicHeight = d.getIntrinsicHeight();
setOnTouchListener(this);
}
}
#Override
protected boolean setFrame(int l, int t, int r, int b) {
mWidth = r-l;
mHeight = b-t;
mMatrix.reset();
mScale = (float) r / (float) mIntrinsicWidth;
int paddingHeight = 0;
int paddingWidth = 0;
// scaling vertical
if (mScale * mIntrinsicHeight > mHeight) {
mScale = (float) mHeight / (float) mIntrinsicHeight;
mMatrix.postScale(mScale, mScale);
paddingWidth = (r - mWidth) / 2;
paddingHeight = 0;
// scaling horizontal
} else {
mMatrix.postScale(mScale, mScale);
paddingHeight = (b - mHeight) / 2;
paddingWidth = 0;
}
mMatrix.postTranslate(paddingWidth, paddingHeight);
setImageMatrix(mMatrix);
mMinScale = mScale;
zoomTo(mScale, mWidth / 2, mHeight / 2);
cutting();
return super.setFrame(l, t, r, b);
}
protected float getValue(Matrix matrix, int whichValue) {
matrix.getValues(mMatrixValues);
return mMatrixValues[whichValue];
}
protected float getScale() {
return getValue(mMatrix, Matrix.MSCALE_X);
}
protected float getTranslateX() {
return getValue(mMatrix, Matrix.MTRANS_X);
}
protected float getTranslateY() {
return getValue(mMatrix, Matrix.MTRANS_Y);
}
protected void maxZoomTo(int x, int y) {
if (mMinScale != getScale() && (getScale() - mMinScale) > 0.1f) {
// threshold 0.1f
float scale = mMinScale / getScale();
zoomTo(scale, x, y);
} else {
float scale = MAX_SCALE / getScale();
zoomTo(scale, x, y);
}
}
protected void zoomTo(float scale, int x, int y) {
if (getScale() * scale < mMinScale) {
return;
}
if (scale >= 1 && getScale() * scale > MAX_SCALE) {
return;
}
mMatrix.postScale(scale, scale);
// move to center
mMatrix.postTranslate(-(mWidth * scale - mWidth) / 2,
-(mHeight * scale - mHeight) / 2);
// move x and y distance
mMatrix.postTranslate(-(x - (mWidth / 2)) * scale, 0);
mMatrix.postTranslate(0, -(y - (mHeight / 2)) * scale);
setImageMatrix(mMatrix);
}
public void cutting() {
int width = (int) (mIntrinsicWidth * getScale());
int height = (int) (mIntrinsicHeight * getScale());
if (getTranslateX() < -(width - mWidth)) {
mMatrix.postTranslate(-(getTranslateX() + width - mWidth), 0);
}
if (getTranslateX() > 0) {
mMatrix.postTranslate(-getTranslateX(), 0);
}
if (getTranslateY() < -(height - mHeight)) {
mMatrix.postTranslate(0, -(getTranslateY() + height - mHeight));
}
if (getTranslateY() > 0) {
mMatrix.postTranslate(0, -getTranslateY());
}
if (width < mWidth) {
mMatrix.postTranslate((mWidth - width) / 2, 0);
}
if (height < mHeight) {
mMatrix.postTranslate(0, (mHeight - height) / 2);
}
setImageMatrix(mMatrix);
}
private float distance(float x0, float x1, float y0, float y1) {
float x = x0 - x1;
float y = y0 - y1;
return FloatMath.sqrt(x * x + y * y);
}
private float dispDistance() {
return FloatMath.sqrt(mWidth * mWidth + mHeight
* mHeight);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
int touchCount = event.getPointerCount();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_1_DOWN:
case MotionEvent.ACTION_POINTER_2_DOWN:
if (touchCount >= 2) {
float distance = distance(event.getX(0), event.getX(1),
event.getY(0), event.getY(1));
mPrevDistance = distance;
isScaling = true;
} else {
if (System.currentTimeMillis() <= mLastTime + DOUBLE_TAP_SECOND) {
if (30 > Math.abs(mPrevMoveX - event.getX())
+ Math.abs(mPrevMoveY - event.getY())) {
isDoubleTap = true;
mDoubleTapX = (int) event.getX();
mDoubleTapY = (int) event.getY();
}
}
mLastTime = System.currentTimeMillis();
mPrevMoveX = (int) event.getX();
mPrevMoveY = (int) event.getY();
}
break;
case MotionEvent.ACTION_MOVE:
if (touchCount >= 2 && isScaling) {
float dist = distance(event.getX(0), event.getX(1),
event.getY(0), event.getY(1));
float scale = (dist - mPrevDistance) / dispDistance();
mPrevDistance = dist;
scale += 1;
scale = scale * scale;
zoomTo(scale, mWidth / 2, mHeight / 2);
cutting();
} else if (!isScaling) {
int distanceX = mPrevMoveX - (int) event.getX();
int distanceY = mPrevMoveY - (int) event.getY();
mPrevMoveX = (int) event.getX();
mPrevMoveY = (int) event.getY();
mMatrix.postTranslate(-distanceX, -distanceY);
cutting();
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_POINTER_2_UP:
if (event.getPointerCount() <= 1) {
isScaling = false;
if (isDoubleTap) {
if (30 > Math.abs(mDoubleTapX - event.getX())
+ Math.abs(mDoubleTapY - event.getY())) {
maxZoomTo(mDoubleTapX, mDoubleTapY);
cutting();
}
}
}
isDoubleTap = false;
break;
}
return true;
}
public boolean onTouch(View v, MotionEvent event) {
return super.onTouchEvent(event);
}
}
what am i missing ? thanks

Use ViewPager with you ImageView with Universal Image loader, I've already did and used your code for scaling image ;)

Double-tap to zoom and pinch to zoom on ImageView in android

I was looking for iphone like tap and pinch zooming with android ImageView. Mike Ortiz have done some excellent work on TouchImageView to detect boundaries. His code can be found here.
This code is missing only one thing, i.e., double-tap to zoom. Can anyone help add this feature to Mike Ortiz code?

It's old, but as no answer picked as correct, I would like to share it.
I've tweaked the TouchImageView class in this answer to support double tap for zooming in/out by implementing GestureDetector.OnGestureListener, GestureDetector.OnDoubleTapListener interfaces
import android.content.Context;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.ImageView;
public class TouchImageView extends ImageView implements GestureDetector.OnGestureListener, GestureDetector.OnDoubleTapListener {
Matrix matrix;
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float maxScale = 3f;
float[] m;
int viewWidth, viewHeight;
static final int CLICK = 3;
float saveScale = 1f;
protected float origWidth, origHeight;
int oldMeasuredWidth, oldMeasuredHeight;
ScaleGestureDetector mScaleDetector;
Context context;
public TouchImageView(Context context) {
super(context);
sharedConstructing(context);
}
public TouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
sharedConstructing(context);
}
GestureDetector mGestureDetector;
private void sharedConstructing(Context context) {
super.setClickable(true);
this.context = context;
mGestureDetector = new GestureDetector(context, this);
mGestureDetector.setOnDoubleTapListener(this);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
matrix = new Matrix();
m = new float[9];
setImageMatrix(matrix);
setScaleType(ScaleType.MATRIX);
setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
mScaleDetector.onTouchEvent(event);
mGestureDetector.onTouchEvent(event);
PointF curr = new PointF(event.getX(), event.getY());
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
last.set(curr);
start.set(last);
mode = DRAG;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
float deltaX = curr.x - last.x;
float deltaY = curr.y - last.y;
float fixTransX = getFixDragTrans(deltaX, viewWidth,
origWidth * saveScale);
float fixTransY = getFixDragTrans(deltaY, viewHeight,
origHeight * saveScale);
matrix.postTranslate(fixTransX, fixTransY);
fixTrans();
last.set(curr.x, curr.y);
}
break;
case MotionEvent.ACTION_UP:
mode = NONE;
int xDiff = (int) Math.abs(curr.x - start.x);
int yDiff = (int) Math.abs(curr.y - start.y);
if (xDiff < CLICK && yDiff < CLICK)
performClick();
break;
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
}
setImageMatrix(matrix);
invalidate();
return true; // indicate event was handled
}
});
}
public void setMaxZoom(float x) {
maxScale = x;
}
#Override
public boolean onSingleTapConfirmed(MotionEvent e) {
return false;
}
#Override
public boolean onDoubleTap(MotionEvent e) {
// Double tap is detected
Log.i("MAIN_TAG", "Double tap detected");
float origScale = saveScale;
float mScaleFactor;
if (saveScale == maxScale) {
saveScale = minScale;
mScaleFactor = minScale / origScale;
} else {
saveScale = maxScale;
mScaleFactor = maxScale / origScale;
}
matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
viewHeight / 2);
fixTrans();
return false;
}
#Override
public boolean onDoubleTapEvent(MotionEvent e) {
return false;
}
#Override
public boolean onDown(MotionEvent e) {
return false;
}
#Override
public void onShowPress(MotionEvent e) {
}
#Override
public boolean onSingleTapUp(MotionEvent e) {
return false;
}
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
return false;
}
#Override
public void onLongPress(MotionEvent e) {
}
#Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
return false;
}
private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
mode = ZOOM;
return true;
}
#Override
public boolean onScale(ScaleGestureDetector detector) {
float mScaleFactor = detector.getScaleFactor();
float origScale = saveScale;
saveScale *= mScaleFactor;
if (saveScale > maxScale) {
saveScale = maxScale;
mScaleFactor = maxScale / origScale;
} else if (saveScale < minScale) {
saveScale = minScale;
mScaleFactor = minScale / origScale;
}
if (origWidth * saveScale <= viewWidth
|| origHeight * saveScale <= viewHeight)
matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
viewHeight / 2);
else
matrix.postScale(mScaleFactor, mScaleFactor,
detector.getFocusX(), detector.getFocusY());
fixTrans();
return true;
}
}
void fixTrans() {
matrix.getValues(m);
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
float fixTransY = getFixTrans(transY, viewHeight, origHeight
* saveScale);
if (fixTransX != 0 || fixTransY != 0)
matrix.postTranslate(fixTransX, fixTransY);
}
float getFixTrans(float trans, float viewSize, float contentSize) {
float minTrans, maxTrans;
if (contentSize <= viewSize) {
minTrans = 0;
maxTrans = viewSize - contentSize;
} else {
minTrans = viewSize - contentSize;
maxTrans = 0;
}
if (trans < minTrans)
return -trans + minTrans;
if (trans > maxTrans)
return -trans + maxTrans;
return 0;
}
float getFixDragTrans(float delta, float viewSize, float contentSize) {
if (contentSize <= viewSize) {
return 0;
}
return delta;
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
viewWidth = MeasureSpec.getSize(widthMeasureSpec);
viewHeight = MeasureSpec.getSize(heightMeasureSpec);
//
// Rescales image on rotation
//
if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight
|| viewWidth == 0 || viewHeight == 0)
return;
oldMeasuredHeight = viewHeight;
oldMeasuredWidth = viewWidth;
if (saveScale == 1) {
// Fit to screen.
float scale;
Drawable drawable = getDrawable();
if (drawable == null || drawable.getIntrinsicWidth() == 0
|| drawable.getIntrinsicHeight() == 0)
return;
int bmWidth = drawable.getIntrinsicWidth();
int bmHeight = drawable.getIntrinsicHeight();
Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight);
float scaleX = (float) viewWidth / (float) bmWidth;
float scaleY = (float) viewHeight / (float) bmHeight;
scale = Math.min(scaleX, scaleY);
matrix.setScale(scale, scale);
// Center the image
float redundantYSpace = (float) viewHeight
- (scale * (float) bmHeight);
float redundantXSpace = (float) viewWidth
- (scale * (float) bmWidth);
redundantYSpace /= (float) 2;
redundantXSpace /= (float) 2;
matrix.postTranslate(redundantXSpace, redundantYSpace);
origWidth = viewWidth - 2 * redundantXSpace;
origHeight = viewHeight - 2 * redundantYSpace;
setImageMatrix(matrix);
}
fixTrans();
}
}
Usage:
You can replace your ImageView with TouchImageView in both XML & java
1. For XML
<?xml version="1.0" encoding="utf-8"?>
<com.example.android.myapp.TouchImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/imViewedImage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clickable="true"
android:focusable="true" />
2. For Java
TouchImageView imViewedImage = findViewById(R.id.imViewedImage);

Pinch Zoom on ImageView in Android with Orientation handling
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PointF;
import android.os.Handler;
import android.util.AttributeSet;
import android.util.FloatMath;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.GestureDetector.SimpleOnGestureListener;
public class ZoomableImageView extends View {
private static final String TAG = "ZoomableImageView";
private Bitmap imgBitmap = null;
private int containerWidth;
private int containerHeight;
Paint background;
//Matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
PointF start = new PointF();
float currentScale;
float curX;
float curY;
//We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
//For animating stuff
float targetX;
float targetY;
float targetScale;
float targetScaleX;
float targetScaleY;
float scaleChange;
float targetRatio;
float transitionalRatio;
float easing = 0.2f;
boolean isAnimating = false;
float scaleDampingFactor = 0.5f;
//For pinch and zoom
float oldDist = 1f;
PointF mid = new PointF();
private Handler mHandler = new Handler();
float minScale;
float maxScale = 8.0f;
float wpRadius = 25.0f;
float wpInnerRadius = 20.0f;
float screenDensity;
private GestureDetector gestureDetector;
public static final int DEFAULT_SCALE_FIT_INSIDE = 0;
public static final int DEFAULT_SCALE_ORIGINAL = 1;
private int defaultScale;
public int getDefaultScale() {
return defaultScale;
}
public void setDefaultScale(int defaultScale) {
this.defaultScale = defaultScale;
}
public ZoomableImageView(Context context) {
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
screenDensity = context.getResources().getDisplayMetrics().density;
initPaints();
gestureDetector = new GestureDetector(new MyGestureDetector());
}
public ZoomableImageView(Context context, AttributeSet attrs) {
super(context, attrs);
screenDensity = context.getResources().getDisplayMetrics().density;
initPaints();
gestureDetector = new GestureDetector(new MyGestureDetector());
defaultScale = ZoomableImageView.DEFAULT_SCALE_FIT_INSIDE;
}
private void initPaints() {
background = new Paint();
}
#Override
protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) {
super.onSizeChanged(width, height, oldWidth, oldHeight);
//Reset the width and height. Will draw bitmap and change
containerWidth = width;
containerHeight = height;
if(imgBitmap != null) {
int imgHeight = imgBitmap.getHeight();
int imgWidth = imgBitmap.getWidth();
float scale;
int initX = 0;
int initY = 0;
if(defaultScale == ZoomableImageView.DEFAULT_SCALE_FIT_INSIDE) {
if(imgWidth > containerWidth) {
scale = (float)containerWidth / imgWidth;
float newHeight = imgHeight * scale;
initY = (containerHeight - (int)newHeight)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(0, initY);
}
else {
scale = (float)containerHeight / imgHeight;
float newWidth = imgWidth * scale;
initX = (containerWidth - (int)newWidth)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = scale;
minScale = scale;
}
else {
if(imgWidth > containerWidth) {
initY = (containerHeight - (int)imgHeight)/2;
matrix.postTranslate(0, initY);
}
else {
initX = (containerWidth - (int)imgWidth)/2;
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = 1.0f;
minScale = 1.0f;
}
invalidate();
}
}
#Override
protected void onDraw(Canvas canvas) {
if(imgBitmap != null && canvas != null)
{
canvas.drawBitmap(imgBitmap, matrix, background);
}
}
//Checks and sets the target image x and y co-ordinates if out of bounds
private void checkImageConstraints() {
if(imgBitmap == null) {
return;
}
float[] mvals = new float[9];
matrix.getValues(mvals);
currentScale = mvals[0];
if(currentScale < minScale) {
float deltaScale = minScale / currentScale;
float px = containerWidth/2;
float py = containerHeight/2;
matrix.postScale(deltaScale, deltaScale, px, py);
invalidate();
}
matrix.getValues(mvals);
currentScale = mvals[0];
curX = mvals[2];
curY = mvals[5];
int rangeLimitX = containerWidth - (int)(imgBitmap.getWidth() * currentScale);
int rangeLimitY = containerHeight - (int)(imgBitmap.getHeight() * currentScale);
boolean toMoveX = false;
boolean toMoveY = false;
if(rangeLimitX < 0) {
if(curX > 0) {
targetX = 0;
toMoveX = true;
}
else if(curX < rangeLimitX) {
targetX = rangeLimitX;
toMoveX = true;
}
}
else {
targetX = rangeLimitX / 2;
toMoveX = true;
}
if(rangeLimitY < 0) {
if(curY > 0) {
targetY = 0;
toMoveY = true;
}
else if(curY < rangeLimitY) {
targetY = rangeLimitY;
toMoveY = true;
}
}
else {
targetY = rangeLimitY / 2;
toMoveY = true;
}
if(toMoveX == true || toMoveY == true) {
if(toMoveY == false) {
targetY = curY;
}
if(toMoveX == false) {
targetX = curX;
}
//Disable touch event actions
isAnimating = true;
//Initialize timer
mHandler.removeCallbacks(mUpdateImagePositionTask);
mHandler.postDelayed(mUpdateImagePositionTask, 100);
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if(gestureDetector.onTouchEvent(event)) {
return true;
}
if(isAnimating == true) {
return true;
}
//Handle touch events here
float[] mvals = new float[9];
switch(event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
if(isAnimating == false) {
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if(oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
matrix.getValues(mvals);
curX = mvals[2];
curY = mvals[5];
currentScale = mvals[0];
if(isAnimating == false) {
checkImageConstraints();
}
break;
case MotionEvent.ACTION_MOVE:
if(mode == DRAG && isAnimating == false) {
matrix.set(savedMatrix);
float diffX = event.getX() - start.x;
float diffY = event.getY() - start.y;
matrix.postTranslate(diffX, diffY);
matrix.getValues(mvals);
curX = mvals[2];
curY = mvals[5];
currentScale = mvals[0];
}
else if(mode == ZOOM && isAnimating == false) {
float newDist = spacing(event);
if(newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.getValues(mvals);
currentScale = mvals[0];
if(currentScale * scale <= minScale) {
matrix.postScale(minScale/currentScale, minScale/currentScale, mid.x, mid.y);
}
else if(currentScale * scale >= maxScale) {
matrix.postScale(maxScale/currentScale, maxScale/currentScale, mid.x, mid.y);
}
else {
matrix.postScale(scale, scale, mid.x, mid.y);
}
matrix.getValues(mvals);
curX = mvals[2];
curY = mvals[5];
currentScale = mvals[0];
}
}
break;
}
//Calculate the transformations and then invalidate
invalidate();
return true;
}
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x/2, y/2);
}
public void setImageBitmap(Bitmap b) {
if(b != null) {
imgBitmap = b;
containerWidth = getWidth();
containerHeight = getHeight();
int imgHeight = imgBitmap.getHeight();
int imgWidth = imgBitmap.getWidth();
float scale;
int initX = 0;
int initY = 0;
matrix.reset();
if(defaultScale == ZoomableImageView.DEFAULT_SCALE_FIT_INSIDE) {
if(imgWidth > containerWidth) {
scale = (float)containerWidth / imgWidth;
float newHeight = imgHeight * scale;
initY = (containerHeight - (int)newHeight)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(0, initY);
}
else {
scale = (float)containerHeight / imgHeight;
float newWidth = imgWidth * scale;
initX = (containerWidth - (int)newWidth)/2;
matrix.setScale(scale, scale);
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = scale;
minScale = scale;
}
else {
if(imgWidth > containerWidth) {
initX = 0;
if(imgHeight > containerHeight) {
initY = 0;
}
else {
initY = (containerHeight - (int)imgHeight)/2;
}
matrix.postTranslate(0, initY);
}
else {
initX = (containerWidth - (int)imgWidth)/2;
if(imgHeight > containerHeight) {
initY = 0;
}
else {
initY = (containerHeight - (int)imgHeight)/2;
}
matrix.postTranslate(initX, 0);
}
curX = initX;
curY = initY;
currentScale = 1.0f;
minScale = 1.0f;
}
invalidate();
}
else {
Log.d(TAG, "bitmap is null");
}
}
public Bitmap getPhotoBitmap() {
return imgBitmap;
}
private Runnable mUpdateImagePositionTask = new Runnable() {
public void run() {
float[] mvals;
if(Math.abs(targetX - curX) < 5 && Math.abs(targetY - curY) < 5) {
isAnimating = false;
mHandler.removeCallbacks(mUpdateImagePositionTask);
mvals = new float[9];
matrix.getValues(mvals);
currentScale = mvals[0];
curX = mvals[2];
curY = mvals[5];
//Set the image parameters and invalidate display
float diffX = (targetX - curX);
float diffY = (targetY - curY);
matrix.postTranslate(diffX, diffY);
}
else {
isAnimating = true;
mvals = new float[9];
matrix.getValues(mvals);
currentScale = mvals[0];
curX = mvals[2];
curY = mvals[5];
//Set the image parameters and invalidate display
float diffX = (targetX - curX) * 0.3f;
float diffY = (targetY - curY) * 0.3f;
matrix.postTranslate(diffX, diffY);
mHandler.postDelayed(this, 25);
}
invalidate();
}
};
private Runnable mUpdateImageScale = new Runnable() {
public void run() {
float transitionalRatio = targetScale / currentScale;
float dx;
if(Math.abs(transitionalRatio - 1) > 0.05) {
isAnimating = true;
if(targetScale > currentScale) {
dx = transitionalRatio - 1;
scaleChange = 1 + dx * 0.2f;
currentScale *= scaleChange;
if(currentScale > targetScale) {
currentScale = currentScale / scaleChange;
scaleChange = 1;
}
}
else {
dx = 1 - transitionalRatio;
scaleChange = 1 - dx * 0.5f;
currentScale *= scaleChange;
if(currentScale < targetScale) {
currentScale = currentScale / scaleChange;
scaleChange = 1;
}
}
if(scaleChange != 1) {
matrix.postScale(scaleChange, scaleChange, targetScaleX, targetScaleY);
mHandler.postDelayed(mUpdateImageScale, 15);
invalidate();
}
else {
isAnimating = false;
scaleChange = 1;
matrix.postScale(targetScale/currentScale, targetScale/currentScale, targetScaleX, targetScaleY);
currentScale = targetScale;
mHandler.removeCallbacks(mUpdateImageScale);
invalidate();
checkImageConstraints();
}
}
else {
isAnimating = false;
scaleChange = 1;
matrix.postScale(targetScale/currentScale, targetScale/currentScale, targetScaleX, targetScaleY);
currentScale = targetScale;
mHandler.removeCallbacks(mUpdateImageScale);
invalidate();
checkImageConstraints();
}
}
};
/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event) {
String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE", "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
StringBuilder sb = new StringBuilder();
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
sb.append("event ACTION_").append(names[actionCode]);
if (actionCode == MotionEvent.ACTION_POINTER_DOWN || actionCode == MotionEvent.ACTION_POINTER_UP) {
sb.append("(pid ").append(action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
sb.append(")");
}
sb.append("[");
for (int i = 0; i < event.getPointerCount(); i++) {
sb.append("#").append(i);
sb.append("(pid ").append(event.getPointerId(i));
sb.append(")=").append((int) event.getX(i));
sb.append(",").append((int) event.getY(i));
if (i + 1 < event.getPointerCount())
sb.append(";");
}
sb.append("]");
}
class MyGestureDetector extends SimpleOnGestureListener {
#Override
public boolean onDoubleTap(MotionEvent event) {
if(isAnimating == true) {
return true;
}
scaleChange = 1;
isAnimating = true;
targetScaleX = event.getX();
targetScaleY = event.getY();
if(Math.abs(currentScale - maxScale) > 0.1) {
targetScale = maxScale;
}
else {
targetScale = minScale;
}
targetRatio = targetScale / currentScale;
mHandler.removeCallbacks(mUpdateImageScale);
mHandler.post(mUpdateImageScale);
return true;
}
#Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
return super.onFling(e1, e2, velocityX, velocityY);
}
#Override
public boolean onDown(MotionEvent e) {
return false;
}
}
}

i know this is late but i have not seen any of the previous answers in kotlin
class ImageZoomingClass : AppCompatImageView, View.OnTouchListener,
GestureDetector.OnGestureListener, GestureDetector.OnDoubleTapListener {
//shared constructing
private var mContext: Context? = null
private var mScaleDetector: ScaleGestureDetector? = null
private var mGestureDetector: GestureDetector? = null
var mMatrix: Matrix? = null
private var mMatrixValues: FloatArray? = null
var mode = NONE
// all possible state
companion object {
const val NONE = 0
const val DRAG = 1
const val ZOOM = 2
}
// Scales
var mSaveScale = 1f
var mMinScale = 1f
var mMaxScale = 4f
// view dimensions
var origWidth = 0f
var origHeight = 0f
var viewWidth = 0
var viewHeight = 0
private var mLast = PointF()
private var mStart = PointF()
constructor(context: Context) : super(context) {
sharedConstructing(context)
}
constructor(context: Context, #Nullable attrs: AttributeSet?) : super(context, attrs) {
sharedConstructing(context)
}
constructor(context: Context?, attrs: AttributeSet?, defStyleAttr: Int) : super(
context!!,
attrs,
defStyleAttr
)
private fun sharedConstructing(context: Context) {
super.setClickable(true)
mContext = context
mScaleDetector = ScaleGestureDetector(context, ScaleListener())
mMatrix = Matrix()
mMatrixValues = FloatArray(9)
imageMatrix = mMatrix
scaleType = ScaleType.MATRIX
mGestureDetector = GestureDetector(context, this)
setOnTouchListener(this)
}
private inner class ScaleListener : ScaleGestureDetector.SimpleOnScaleGestureListener() {
override fun onScaleBegin(detector: ScaleGestureDetector): Boolean {
mode = ZOOM
return true
}
override fun onScale(detector: ScaleGestureDetector): Boolean {
var mScaleFactor = detector.scaleFactor
val prevScale = mSaveScale
mSaveScale *= mScaleFactor
if (mSaveScale > mMaxScale) {
mSaveScale = mMaxScale
mScaleFactor = mMaxScale / prevScale
} else if (mSaveScale < mMinScale) {
mSaveScale = mMinScale
mScaleFactor = mMinScale / prevScale
}
if (origWidth * mSaveScale <= viewWidth
|| origHeight * mSaveScale <= viewHeight
) {
mMatrix!!.postScale(
mScaleFactor, mScaleFactor, viewWidth / 2.toFloat(),
viewHeight / 2.toFloat()
)
} else {
mMatrix!!.postScale(
mScaleFactor, mScaleFactor,
detector.focusX, detector.focusY
)
}
fixTranslation()
return true
}
}
private fun fitToScreen() {
mSaveScale = 1f
val scale: Float
val drawable = drawable
if (drawable == null || drawable.intrinsicWidth == 0 || drawable.intrinsicHeight == 0) return
val imageWidth = drawable.intrinsicWidth
val imageHeight = drawable.intrinsicHeight
val scaleX = viewWidth.toFloat() / imageWidth.toFloat()
val scaleY = viewHeight.toFloat() / imageHeight.toFloat()
scale = scaleX.coerceAtMost(scaleY)
mMatrix!!.setScale(scale, scale)
// Center the image
var redundantYSpace = (viewHeight.toFloat()
- scale * imageHeight.toFloat())
var redundantXSpace = (viewWidth.toFloat()
- scale * imageWidth.toFloat())
redundantYSpace /= 2.toFloat()
redundantXSpace /= 2.toFloat()
mMatrix!!.postTranslate(redundantXSpace, redundantYSpace)
origWidth = viewWidth - 2 * redundantXSpace
origHeight = viewHeight - 2 * redundantYSpace
imageMatrix = mMatrix
}
fun fixTranslation() {
mMatrix!!.getValues(mMatrixValues) //put matrix values into a float array so we can analyze
val transX =
mMatrixValues!![Matrix.MTRANS_X] //get the most recent translation in x direction
val transY =
mMatrixValues!![Matrix.MTRANS_Y] //get the most recent translation in y direction
val fixTransX = getFixTranslation(transX, viewWidth.toFloat(), origWidth * mSaveScale)
val fixTransY = getFixTranslation(transY, viewHeight.toFloat(), origHeight * mSaveScale)
if (fixTransX != 0f || fixTransY != 0f) mMatrix!!.postTranslate(fixTransX, fixTransY)
}
private fun getFixTranslation(trans: Float, viewSize: Float, contentSize: Float): Float {
val minTrans: Float
val maxTrans: Float
if (contentSize <= viewSize) { // case: NOT ZOOMED
minTrans = 0f
maxTrans = viewSize - contentSize
} else { //CASE: ZOOMED
minTrans = viewSize - contentSize
maxTrans = 0f
}
if (trans < minTrans) { // negative x or y translation (down or to the right)
return -trans + minTrans
}
if (trans > maxTrans) { // positive x or y translation (up or to the left)
return -trans + maxTrans
}
return 0F
}
private fun getFixDragTrans(delta: Float, viewSize: Float, contentSize: Float): Float {
return if (contentSize <= viewSize) {
0F
} else delta
}
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
viewWidth = MeasureSpec.getSize(widthMeasureSpec)
viewHeight = MeasureSpec.getSize(heightMeasureSpec)
if (mSaveScale == 1f) {
// Fit to screen.
fitToScreen()
}
}
//OnTouch
override fun onTouch(view: View?, event: MotionEvent): Boolean {
mScaleDetector!!.onTouchEvent(event)
mGestureDetector!!.onTouchEvent(event)
val currentPoint = PointF(event.x, event.y)
when (event.action) {
MotionEvent.ACTION_DOWN -> {
mLast.set(currentPoint)
mStart.set(mLast)
mode = DRAG
}
MotionEvent.ACTION_MOVE -> if (mode == DRAG) {
val dx = currentPoint.x - mLast.x
val dy = currentPoint.y - mLast.y
val fixTransX = getFixDragTrans(dx, viewWidth.toFloat(), origWidth * mSaveScale)
val fixTransY = getFixDragTrans(dy, viewHeight.toFloat(), origHeight * mSaveScale)
mMatrix!!.postTranslate(fixTransX, fixTransY)
fixTranslation()
mLast[currentPoint.x] = currentPoint.y
}
MotionEvent.ACTION_POINTER_UP -> mode = NONE
}
invalidate()
imageMatrix = mMatrix
return false
}
//GestureListener
override fun onDown(motionEvent: MotionEvent): Boolean {
return false
}
override fun onShowPress(motionEvent: MotionEvent) {}
override fun onSingleTapUp(motionEvent: MotionEvent): Boolean {
return false
}
override fun onScroll(
motionEvent: MotionEvent,
motionEvent1: MotionEvent,
v: Float,
v1: Float
): Boolean {
return false
}
override fun onLongPress(motionEvent: MotionEvent) {}
override fun onFling(
motionEvent: MotionEvent,
motionEvent1: MotionEvent,
v: Float,
v1: Float
): Boolean {
return false
}
//onDoubleTap
override fun onSingleTapConfirmed(motionEvent: MotionEvent): Boolean {
return false
}
// zoom the image
// double tap again to return to normal
override fun onDoubleTap(e: MotionEvent): Boolean {
// Double tap is detected
Log.i("MAIN_TAG", "Double tap detected")
val origScale = mSaveScale
val mScaleFactor: Float
if (mSaveScale == mMaxScale) {
mSaveScale = mMinScale
mScaleFactor = mMinScale / origScale
} else {
mSaveScale = mMaxScale
mScaleFactor = mMaxScale / origScale
}
mMatrix?.postScale(
mScaleFactor, mScaleFactor, (viewWidth / 2).toFloat(), (
viewHeight / 2).toFloat()
)
fixTranslation()
return false
}
override fun onDoubleTapEvent(motionEvent: MotionEvent): Boolean {
return false
}
}
and your xml layout should look like this
<com.example.imagezooming.ImageZoomingClass
android:id="#+id/largeImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="2dp"
android:layout_marginEnd="2dp"
android:clickable="true"
android:focusable="true"
android:src="#drawable/theImageYouWant"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
happy Coding!!!

Here it works with both Pinch to Zoom and Double tap to Zoom:
import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Configuration;
import android.graphics.*;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Build.VERSION;
import android.os.Build.VERSION_CODES;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.OverScroller;
import android.widget.Scroller;
import androidx.appcompat.widget.AppCompatImageView;
public class TouchImageView extends AppCompatImageView {
private static final String DEBUG = "DEBUG";
//
// SuperMin and SuperMax multipliers. Determine how much the image can be
// zoomed below or above the zoom boundaries, before animating back to the
// min/max zoom boundary.
//
private static final float SUPER_MIN_MULTIPLIER = .75f;
private static final float SUPER_MAX_MULTIPLIER = 1.25f;
//
// Scale of image ranges from minScale to maxScale, where minScale == 1
// when the image is stretched to fit view.
//
private float normalizedScale;
//
// Matrix applied to image. MSCALE_X and MSCALE_Y should always be equal.
// MTRANS_X and MTRANS_Y are the other values used. prevMatrix is the matrix
// saved prior to the screen rotating.
//
private Matrix matrix, prevMatrix;
private static enum State {NONE, DRAG, ZOOM, FLING, ANIMATE_ZOOM}
;
private State state;
private float minScale;
private float maxScale;
private float superMinScale;
private float superMaxScale;
private float[] m;
private Context context;
private Fling fling;
private ScaleType mScaleType;
private boolean imageRenderedAtLeastOnce;
private boolean onDrawReady;
private ZoomVariables delayedZoomVariables;
//
// Size of view and previous view size (ie before rotation)
//
private int viewWidth, viewHeight, prevViewWidth, prevViewHeight;
//
// Size of image when it is stretched to fit view. Before and After rotation.
//
private float matchViewWidth, matchViewHeight, prevMatchViewWidth, prevMatchViewHeight;
private ScaleGestureDetector mScaleDetector;
private GestureDetector mGestureDetector;
private GestureDetector.OnDoubleTapListener doubleTapListener = null;
private OnTouchListener userTouchListener = null;
private OnTouchImageViewListener touchImageViewListener = null;
public TouchImageView(Context context) {
super(context);
sharedConstructing(context);
}
public TouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
sharedConstructing(context);
}
public TouchImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
sharedConstructing(context);
}
private void sharedConstructing(Context context) {
super.setClickable(true);
this.context = context;
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
mGestureDetector = new GestureDetector(context, new GestureListener());
matrix = new Matrix();
prevMatrix = new Matrix();
m = new float[9];
normalizedScale = 1;
if (mScaleType == null) {
mScaleType = ScaleType.FIT_CENTER;
}
minScale = 1;
maxScale = 3;
superMinScale = SUPER_MIN_MULTIPLIER * minScale;
superMaxScale = SUPER_MAX_MULTIPLIER * maxScale;
setImageMatrix(matrix);
setScaleType(ScaleType.MATRIX);
setState(State.NONE);
onDrawReady = false;
super.setOnTouchListener(new PrivateOnTouchListener());
}
#Override
public void setOnTouchListener(OnTouchListener l) {
userTouchListener = l;
}
public void setOnTouchImageViewListener(OnTouchImageViewListener l) {
touchImageViewListener = l;
}
public void setOnDoubleTapListener(GestureDetector.OnDoubleTapListener l) {
doubleTapListener = l;
}
#Override
public void setImageResource(int resId) {
super.setImageResource(resId);
savePreviousImageValues();
fitImageToView();
}
#Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
savePreviousImageValues();
fitImageToView();
}
#Override
public void setImageDrawable(Drawable drawable) {
super.setImageDrawable(drawable);
savePreviousImageValues();
fitImageToView();
}
#Override
public void setImageURI(Uri uri) {
super.setImageURI(uri);
savePreviousImageValues();
fitImageToView();
}
#Override
public void setScaleType(ScaleType type) {
if (type == ScaleType.FIT_START || type == ScaleType.FIT_END) {
throw new UnsupportedOperationException("TouchImageView does not support FIT_START or FIT_END");
}
if (type == ScaleType.MATRIX) {
super.setScaleType(ScaleType.MATRIX);
} else {
mScaleType = type;
if (onDrawReady) {
//
// If the image is already rendered, scaleType has been called programmatically
// and the TouchImageView should be updated with the new scaleType.
//
setZoom(this);
}
}
}
#Override
public ScaleType getScaleType() {
return mScaleType;
}
/**
* Returns false if image is in initial, unzoomed state. False, otherwise.
*
* #return true if image is zoomed
*/
public boolean isZoomed() {
return normalizedScale != 1;
}
/**
* Return a Rect representing the zoomed image.
*
* #return rect representing zoomed image
*/
public RectF getZoomedRect() {
if (mScaleType == ScaleType.FIT_XY) {
throw new UnsupportedOperationException("getZoomedRect() not supported with FIT_XY");
}
PointF topLeft = transformCoordTouchToBitmap(0, 0, true);
PointF bottomRight = transformCoordTouchToBitmap(viewWidth, viewHeight, true);
float w = getDrawable().getIntrinsicWidth();
float h = getDrawable().getIntrinsicHeight();
return new RectF(topLeft.x / w, topLeft.y / h, bottomRight.x / w, bottomRight.y / h);
}
/**
* Save the current matrix and view dimensions
* in the prevMatrix and prevView variables.
*/
private void savePreviousImageValues() {
if (matrix != null && viewHeight != 0 && viewWidth != 0) {
matrix.getValues(m);
prevMatrix.setValues(m);
prevMatchViewHeight = matchViewHeight;
prevMatchViewWidth = matchViewWidth;
prevViewHeight = viewHeight;
prevViewWidth = viewWidth;
}
}
#Override
public Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable("instanceState", super.onSaveInstanceState());
bundle.putFloat("saveScale", normalizedScale);
bundle.putFloat("matchViewHeight", matchViewHeight);
bundle.putFloat("matchViewWidth", matchViewWidth);
bundle.putInt("viewWidth", viewWidth);
bundle.putInt("viewHeight", viewHeight);
matrix.getValues(m);
bundle.putFloatArray("matrix", m);
bundle.putBoolean("imageRendered", imageRenderedAtLeastOnce);
return bundle;
}
#Override
public void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
Bundle bundle = (Bundle) state;
normalizedScale = bundle.getFloat("saveScale");
m = bundle.getFloatArray("matrix");
prevMatrix.setValues(m);
prevMatchViewHeight = bundle.getFloat("matchViewHeight");
prevMatchViewWidth = bundle.getFloat("matchViewWidth");
prevViewHeight = bundle.getInt("viewHeight");
prevViewWidth = bundle.getInt("viewWidth");
imageRenderedAtLeastOnce = bundle.getBoolean("imageRendered");
super.onRestoreInstanceState(bundle.getParcelable("instanceState"));
return;
}
super.onRestoreInstanceState(state);
}
#Override
protected void onDraw(Canvas canvas) {
onDrawReady = true;
imageRenderedAtLeastOnce = true;
if (delayedZoomVariables != null) {
setZoom(delayedZoomVariables.scale, delayedZoomVariables.focusX, delayedZoomVariables.focusY, delayedZoomVariables.scaleType);
delayedZoomVariables = null;
}
super.onDraw(canvas);
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
savePreviousImageValues();
}
/**
* Get the max zoom multiplier.
*
* #return max zoom multiplier.
*/
public float getMaxZoom() {
return maxScale;
}
/**
* Set the max zoom multiplier. Default value: 3.
*
* #param max max zoom multiplier.
*/
public void setMaxZoom(float max) {
maxScale = max;
superMaxScale = SUPER_MAX_MULTIPLIER * maxScale;
}
/**
* Get the min zoom multiplier.
*
* #return min zoom multiplier.
*/
public float getMinZoom() {
return minScale;
}
/**
* Get the current zoom. This is the zoom relative to the initial
* scale, not the original resource.
*
* #return current zoom multiplier.
*/
public float getCurrentZoom() {
return normalizedScale;
}
/**
* Set the min zoom multiplier. Default value: 1.
*
* #param min min zoom multiplier.
*/
public void setMinZoom(float min) {
minScale = min;
superMinScale = SUPER_MIN_MULTIPLIER * minScale;
}
/**
* Reset zoom and translation to initial state.
*/
public void resetZoom() {
normalizedScale = 1;
fitImageToView();
}
/**
* Set zoom to the specified scale. Image will be centered by default.
*
* #param scale
*/
public void setZoom(float scale) {
setZoom(scale, 0.5f, 0.5f);
}
/**
* Set zoom to the specified scale. Image will be centered around the point
* (focusX, focusY). These floats range from 0 to 1 and denote the focus point
* as a fraction from the left and top of the view. For example, the top left
* corner of the image would be (0, 0). And the bottom right corner would be (1, 1).
*
* #param scale
* #param focusX
* #param focusY
*/
public void setZoom(float scale, float focusX, float focusY) {
setZoom(scale, focusX, focusY, mScaleType);
}
/**
* Set zoom to the specified scale. Image will be centered around the point
* (focusX, focusY). These floats range from 0 to 1 and denote the focus point
* as a fraction from the left and top of the view. For example, the top left
* corner of the image would be (0, 0). And the bottom right corner would be (1, 1).
*
* #param scale
* #param focusX
* #param focusY
* #param scaleType
*/
public void setZoom(float scale, float focusX, float focusY, ScaleType scaleType) {
//
// setZoom can be called before the image is on the screen, but at this point,
// image and view sizes have not yet been calculated in onMeasure. Thus, we should
// delay calling setZoom until the view has been measured.
//
if (!onDrawReady) {
delayedZoomVariables = new ZoomVariables(scale, focusX, focusY, scaleType);
return;
}
if (scaleType != mScaleType) {
setScaleType(scaleType);
}
resetZoom();
scaleImage(scale, viewWidth / 2, viewHeight / 2, true);
matrix.getValues(m);
m[Matrix.MTRANS_X] = -((focusX * getImageWidth()) - (viewWidth * 0.5f));
m[Matrix.MTRANS_Y] = -((focusY * getImageHeight()) - (viewHeight * 0.5f));
matrix.setValues(m);
fixTrans();
setImageMatrix(matrix);
}
/**
* Set zoom parameters equal to another TouchImageView. Including scale, position,
* and ScaleType.
*
* #param
*/
public void setZoom(TouchImageView img) {
PointF center = img.getScrollPosition();
setZoom(img.getCurrentZoom(), center.x, center.y, img.getScaleType());
}
/**
* Return the point at the center of the zoomed image. The PointF coordinates range
* in value between 0 and 1 and the focus point is denoted as a fraction from the left
* and top of the view. For example, the top left corner of the image would be (0, 0).
* And the bottom right corner would be (1, 1).
*
* #return PointF representing the scroll position of the zoomed image.
*/
public PointF getScrollPosition() {
Drawable drawable = getDrawable();
if (drawable == null) {
return null;
}
int drawableWidth = drawable.getIntrinsicWidth();
int drawableHeight = drawable.getIntrinsicHeight();
PointF point = transformCoordTouchToBitmap(viewWidth / 2, viewHeight / 2, true);
point.x /= drawableWidth;
point.y /= drawableHeight;
return point;
}
/**
* Set the focus point of the zoomed image. The focus points are denoted as a fraction from the
* left and top of the view. The focus points can range in value between 0 and 1.
*
* #param focusX
* #param focusY
*/
public void setScrollPosition(float focusX, float focusY) {
setZoom(normalizedScale, focusX, focusY);
}
/**
* Performs boundary checking and fixes the image matrix if it
* is out of bounds.
*/
private void fixTrans() {
matrix.getValues(m);
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
float fixTransX = getFixTrans(transX, viewWidth, getImageWidth());
float fixTransY = getFixTrans(transY, viewHeight, getImageHeight());
if (fixTransX != 0 || fixTransY != 0) {
matrix.postTranslate(fixTransX, fixTransY);
}
}
/**
* When transitioning from zooming from focus to zoom from center (or vice versa)
* the image can become unaligned within the view. This is apparent when zooming
* quickly. When the content size is less than the view size, the content will often
* be centered incorrectly within the view. fixScaleTrans first calls fixTrans() and
* then makes sure the image is centered correctly within the view.
*/
private void fixScaleTrans() {
fixTrans();
matrix.getValues(m);
if (getImageWidth() < viewWidth) {
m[Matrix.MTRANS_X] = (viewWidth - getImageWidth()) / 2;
}
if (getImageHeight() < viewHeight) {
m[Matrix.MTRANS_Y] = (viewHeight - getImageHeight()) / 2;
}
matrix.setValues(m);
}
private float getFixTrans(float trans, float viewSize, float contentSize) {
float minTrans, maxTrans;
if (contentSize <= viewSize) {
minTrans = 0;
maxTrans = viewSize - contentSize;
} else {
minTrans = viewSize - contentSize;
maxTrans = 0;
}
if (trans < minTrans)
return -trans + minTrans;
if (trans > maxTrans)
return -trans + maxTrans;
return 0;
}
private float getFixDragTrans(float delta, float viewSize, float contentSize) {
if (contentSize <= viewSize) {
return 0;
}
return delta;
}
private float getImageWidth() {
return matchViewWidth * normalizedScale;
}
private float getImageHeight() {
return matchViewHeight * normalizedScale;
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Drawable drawable = getDrawable();
if (drawable == null || drawable.getIntrinsicWidth() == 0 || drawable.getIntrinsicHeight() == 0) {
setMeasuredDimension(0, 0);
return;
}
int drawableWidth = drawable.getIntrinsicWidth();
int drawableHeight = drawable.getIntrinsicHeight();
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
viewWidth = setViewSize(widthMode, widthSize, drawableWidth);
viewHeight = setViewSize(heightMode, heightSize, drawableHeight);
//
// Set view dimensions
//
setMeasuredDimension(viewWidth, viewHeight);
//
// Fit content within view
//
fitImageToView();
}
/**
* If the normalizedScale is equal to 1, then the image is made to fit the screen. Otherwise,
* it is made to fit the screen according to the dimensions of the previous image matrix. This
* allows the image to maintain its zoom after rotation.
*/
private void fitImageToView() {
Drawable drawable = getDrawable();
if (drawable == null || drawable.getIntrinsicWidth() == 0 || drawable.getIntrinsicHeight() == 0) {
return;
}
if (matrix == null || prevMatrix == null) {
return;
}
int drawableWidth = drawable.getIntrinsicWidth();
int drawableHeight = drawable.getIntrinsicHeight();
//
// Scale image for view
//
float scaleX = (float) viewWidth / drawableWidth;
float scaleY = (float) viewHeight / drawableHeight;
switch (mScaleType) {
case CENTER:
scaleX = scaleY = 1;
break;
case CENTER_CROP:
scaleX = scaleY = Math.max(scaleX, scaleY);
break;
case CENTER_INSIDE:
scaleX = scaleY = Math.min(1, Math.min(scaleX, scaleY));
case FIT_CENTER:
scaleX = scaleY = Math.min(scaleX, scaleY);
break;
case FIT_XY:
break;
default:
//
// FIT_START and FIT_END not supported
//
throw new UnsupportedOperationException("TouchImageView does not support FIT_START or FIT_END");
}
//
// Center the image
//
float redundantXSpace = viewWidth - (scaleX * drawableWidth);
float redundantYSpace = viewHeight - (scaleY * drawableHeight);
matchViewWidth = viewWidth - redundantXSpace;
matchViewHeight = viewHeight - redundantYSpace;
if (!isZoomed() && !imageRenderedAtLeastOnce) {
//
// Stretch and center image to fit view
//
matrix.setScale(scaleX, scaleY);
matrix.postTranslate(redundantXSpace / 2, redundantYSpace / 2);
normalizedScale = 1;
} else {
//
// These values should never be 0 or we will set viewWidth and viewHeight
// to NaN in translateMatrixAfterRotate. To avoid this, call savePreviousImageValues
// to set them equal to the current values.
//
if (prevMatchViewWidth == 0 || prevMatchViewHeight == 0) {
savePreviousImageValues();
}
prevMatrix.getValues(m);
//
// Rescale Matrix after rotation
//
m[Matrix.MSCALE_X] = matchViewWidth / drawableWidth * normalizedScale;
m[Matrix.MSCALE_Y] = matchViewHeight / drawableHeight * normalizedScale;
//
// TransX and TransY from previous matrix
//
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
//
// Width
//
float prevActualWidth = prevMatchViewWidth * normalizedScale;
float actualWidth = getImageWidth();
translateMatrixAfterRotate(Matrix.MTRANS_X, transX, prevActualWidth, actualWidth, prevViewWidth, viewWidth, drawableWidth);
//
// Height
//
float prevActualHeight = prevMatchViewHeight * normalizedScale;
float actualHeight = getImageHeight();
translateMatrixAfterRotate(Matrix.MTRANS_Y, transY, prevActualHeight, actualHeight, prevViewHeight, viewHeight, drawableHeight);
//
// Set the matrix to the adjusted scale and translate values.
//
matrix.setValues(m);
}
fixTrans();
setImageMatrix(matrix);
}
/**
* Set view dimensions based on layout params
*
* #param mode
* #param size
* #param drawableWidth
* #return
*/
private int setViewSize(int mode, int size, int drawableWidth) {
int viewSize;
switch (mode) {
case MeasureSpec.EXACTLY:
viewSize = size;
break;
case MeasureSpec.AT_MOST:
viewSize = Math.min(drawableWidth, size);
break;
case MeasureSpec.UNSPECIFIED:
viewSize = drawableWidth;
break;
default:
viewSize = size;
break;
}
return viewSize;
}
........
Ref: https://gist.github.com/myinnos/e14b750be9503a2b2611f5a5a74a9e6c
As SOF limit to 30000 characters it may miss the last line of code, Please take the class from the above link.
Use it in your XML like:
<com.mypackagename.TouchImageView
android:id="#+id/productImage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitCenter"/>

I have gone through almost 15+ libraries or JAVA classes so far to implement the pinch and double-tap zoom feature on ImageView.
But PhotoView is the best I've used and implemented in terms of functionality and memory management. Go and check this. If it helps you, give an upvote so that others can use it.

Zoomable imageview with singletap listener
import android.content.Context;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import it.sephiroth.android.library.imagezoom.ImageViewTouch;
public class MyZoomableImageViewTouch extends ImageViewTouch
{
static final float SCROLL_DELTA_THRESHOLD = 1.0f;
public MyZoomableImageViewTouch(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
init();
}
public MyZoomableImageViewTouch(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public MyZoomableImageViewTouch(Context context)
{
super(context);
init();
}
private void init() {
View.OnTouchListener listener = new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if (getScale() > 1f) {
getParent().requestDisallowInterceptTouchEvent(true);
} else {
getParent().requestDisallowInterceptTouchEvent(false);
}
return false;
}
};
setOnTouchListener(listener);
setDisplayType(DisplayType.FIT_TO_SCREEN);
}
#Override
protected float onDoubleTapPost(float scale, float maxZoom) {
if (scale != 1f) {
mDoubleTapDirection = 1;
return 1f;
}
if (mDoubleTapDirection == 1) {
mDoubleTapDirection = -1;
if ((scale + (mScaleFactor * 2)) <= maxZoom) {
return scale + mScaleFactor;
} else {
mDoubleTapDirection = -1;
return maxZoom;
}
} else {
mDoubleTapDirection = 1;
return 1f;
}
}
#Override
public boolean canScroll(int direction) {
RectF bitmapRect = getBitmapRect();
updateRect(bitmapRect, mScrollRect);
Rect imageViewRect = new Rect();
getGlobalVisibleRect(imageViewRect);
if (null == bitmapRect) {
return false;
}
if (Math.abs(bitmapRect.right - imageViewRect.right) < SCROLL_DELTA_THRESHOLD) {
if (direction < 0) {
return false;
}
}
if (Math.abs(bitmapRect.left - mScrollRect.left) < SCROLL_DELTA_THRESHOLD) {
if (direction > 0) {
return false;
}
}
return true;
}
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)
{
if (getScale() == 1f) return false;
if (distanceX != 0 && !canScroll((int) -distanceX)) {
getParent().requestDisallowInterceptTouchEvent(false);
return false;
} else {
getParent().requestDisallowInterceptTouchEvent(true);
mUserScaled = true;
scrollBy(-distanceX, -distanceY);
invalidate();
return true;
}
}
}
Use this method for single tap
imageView.setSingleTapListener(new ImageViewTouch.OnImageViewTouchSingleTapListener()
{
#Override
public void onSingleTapConfirmed()
{
}
}

Paint View Zoom with Image problem

anyone knows how to zoom paint view with image correctly?
At following code, I used canvas zoom in order to zoom paint view with image including using setImageMatrix().
But problem arised, that is entire screen became to zoom in/out but not paint view and image only.
So If anyone knows this issue, reply plz.
PaintScreen.java
public class PaintScreen extends Activity implements ColorPickerDialog.OnColorChangedListener{
Context mContext;
private Paint mPaint;
MaskFilter mEmboss;
MaskFilter mBlur;
private ImageView mImageView;
private LinearLayout mPaintBaseLayout;
private FrameLayout mTouchBaseLayout;
private PaintView mPaintView;
private int[] mPixels;
private Bitmap mBitmapImage;
private DisplayMetrics mDisplayMetrics = new DisplayMetrics();
MultiTouchListener multiTouchLitener = new MultiTouchListener(this);
private static final String TAG = "Touch";
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
Matrix savedMatrix2 = new Matrix();
private int WIDTH = 0;
private int HEIGHT = 1;
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int POINT2 = 2;
static final int ZOOM = 3;
int mode = NONE;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
float newDist;
float distanceOffset = 50f;
float minOffset = 50f;
float maxOffset = 10000f;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.paint_mode1_paint);
this.initialize();
this.PaintSet();
}
private void initialize()
{
mPaintBaseLayout = (LinearLayout) findViewById(R.id.paint_paint_base_layout);
mTouchBaseLayout = (FrameLayout) findViewById(R.id.paint_touch_base_layout);
mContext = this;
mPaint = new Paint();
mPaintView = new PaintView(mContext);
mPaintView.setBackgroundColor(Color.TRANSPARENT);
mPaintBaseLayout.addView(mPaintView, new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
mPaintBaseLayout.setBackgroundColor(Color.TRANSPARENT);
mPaintView.setScaleType(ScaleType.MATRIX);
mPaintView.setMPaint(mPaint);
Intent intent = getIntent();
Bundle itstr = intent.getExtras();
String imagePath = itstr.getString("image_path");
Drawable d = Drawable.createFromPath(imagePath);
mPaintView.setBackgroundDrawable(d);
mPaintView.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
dumpEvent(event);
PaintView view = (PaintView) v;
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
start.set(event.getX(), event.getY());
savedMatrix.set(matrix);
midPoint(mid, event);
mode = POINT2;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
distanceOffset = minOffset;
break;
case MotionEvent.ACTION_MOVE:
if (mode == POINT2)
{
newDist = spacing(event);
if (newDist - oldDist > 5f
|| newDist - oldDist < -5f) {
mode = ZOOM;
} else {
start.set(event.getX(), event.getY());
mode = DRAG;
}
} else
if (mode == DRAG) {
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x,
event.getY() - start.y);
}
else if (mode == ZOOM) {
newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
} else {
view.onTouchEvent(event);
}
break;
}
matrixTurning(matrix, view);
view.setImageMatrix(matrix);
view.cMatrix(matrix);
return true;
}
});
}
/** Show an event in the LogCat view, for debugging */
private static void dumpEvent(MotionEvent event) {
String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
"POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
StringBuilder sb = new StringBuilder();
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
sb.append("event ACTION_").append(names[actionCode]);
if (actionCode == MotionEvent.ACTION_POINTER_DOWN
|| actionCode == MotionEvent.ACTION_POINTER_UP) {
sb.append("(pid ").append(
action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
sb.append(")");
}
sb.append("[");
for (int i = 0; i < event.getPointerCount(); i++) {
sb.append("#").append(i);
sb.append("(pid ").append(event.getPointerId(i));
sb.append(")=").append((int) event.getX(i));
sb.append(",").append((int) event.getY(i));
if (i + 1 < event.getPointerCount())
sb.append(";");
}
sb.append("]");
Log.d(TAG, sb.toString());
}
/** Determine the space between the first two fingers */
private static float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
/** Calculate the mid point of the first two fingers */
private static void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
private void matrixTurning(Matrix matrix, ImageView view){
float[] value = new float[9];
matrix.getValues(value);
float[] savedValue = new float[9];
savedMatrix2.getValues(savedValue);
// view size
int width = view.getWidth();
int height = view.getHeight();
//image size
Drawable d = view.getDrawable();
if(d == null) return;
int imageWidth = d.getIntrinsicWidth();
int imageHeight = d.getIntrinsicHeight();
int scaleWidth = (int)(imageWidth*value[0]);
int scaleHeight = (int)(imageHeight*value[0]);
if(value[2] < width - scaleWidth) value[2] = width - scaleWidth;
if(value[5] < height - scaleHeight) value[5] = height - scaleHeight;
if(value[2] > 0) value[2] = 0;
if(value[5] > 0) value[5] = 0;
if(value[0] > 10 || value[4] > 10){
value[0] = savedValue[0];
value[4] = savedValue[4];
value[2] = savedValue[2];
value[5] = savedValue[5];
}
if(imageWidth > width || imageHeight > height){
if(scaleWidth < width && scaleHeight < height){
int target = WIDTH;
if(imageWidth < imageHeight) target = HEIGHT;
if(target == WIDTH) value[0] = value[4] = (float)width/imageWidth;
if(target == HEIGHT) value[0] = value[4] = (float)height/imageHeight;
scaleWidth = (int)(imageWidth*value[0]);
scaleHeight = (int)(imageHeight*value[4]);
if(scaleWidth == width) value[0] = value[4] = (float)width/imageWidth;
if(scaleHeight == height) value[0] = value[4] = (float)height/imageHeight;
}
}else{
if(value[0] < 1) value[0] = 1;
if(value[4] < 1) value[4] = 1;
}
scaleWidth = (int)(imageWidth*value[0]);
scaleHeight = (int)(imageHeight*value[4]);
if(scaleWidth < width){
value[2] = (float)width/2-(float)scaleWidth/2;
}
if(scaleHeight < height){
value[5] = (float)height/2-(float)scaleHeight/2;
}
matrix.setValues(value);
savedMatrix2.set(matrix);
}
public void PaintSet(){
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFFFF0000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(24);
getWindowManager().getDefaultDisplay().getMetrics(mDisplayMetrics);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 }, 0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(24, BlurMaskFilter.Blur.NORMAL);
}
public void colorChanged(int color) {
mPaint.setColor(color);
}
}
PaintView.java
public class PaintView extends ImageView {
private Context mContext;
private static final float MINP = 0.25f;
private static final float MAXP = 0.75f;
private Bitmap mBitmap;
private Bitmap testBitmap;
private Canvas mCanvas;
private Canvas tCanvas;
private Path mPath;
private Paint mBitmapPaint;
// onDraw
private Paint mPaint;
private MaskFilter mEmboss;
private MaskFilter mBlur;
// onTouch
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
public PaintView(Context context) {
this(context, null);
// TODO Auto-generated constructor stub
}
public PaintView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
mContext = context;
mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
//mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
#Override
protected void onDraw(Canvas canvas) {
//canvas.drawColor(0xFFAAAAAA);
super.onDraw(canvas);
mCanvas = canvas;
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
public void setMPaint(Paint paint) {
mPaint = paint;
}
private void touchStart(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touchMove(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touchUp() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
Log.d("PaintView", "ev ->" + event.getAction());
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touchStart(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touchMove(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touchUp();
invalidate();
break;
}
return true;
}
public void cMatrix(Matrix matrix) {
mCanvas.setMatrix(matrix);
}
}

#Override
protected void onDraw(Canvas canvas) {
//canvas.drawColor(0xFFAAAAAA);
super.onDraw(canvas);
mCanvas = canvas;
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
In this method you write, mCanvas = canvas; instead of this write, canvas = mCanvas.

Hello try with below code for paint and capture new bitmap with pain image.first zoom in/out image and on button click draw paint.then click on done button for save your final merge bitmap.Hop its helpful to you.
public class PaintScreen extends Activity {
Context mContext;
private Paint mPaint;
MaskFilter mEmboss;
MaskFilter mBlur;
private LinearLayout mPaintBaseLayout, mPaintBaseLayout2;
private PaintView mPaintView;
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix matrix1 = new Matrix();
Matrix savedMatrix = new Matrix();
Matrix savedMatrix2 = new Matrix();
Matrix dmMtrx = new Matrix();
private int WIDTH = 0;
private int HEIGHT = 1;
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int POINT2 = 2;
static final int ZOOM = 3;
int mode = NONE;
private static final float MIN_ZOOM = 0.0f;
private static final float MAX_ZOOM = 1.0f;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
float newDist;
float distanceOffset = 50f;
float minOffset = 50f;
float maxOffset = 10000f;
private boolean falg = true;
private int startval = 0;
Bitmap newbm;
private float finalscale;
Bitmap bm;
private float scaledImageOffsetX;
private float scaledImageOffsetY;
ImageView imageView;
ProgressDialog dialog;
private float[] matrixValues;
Bitmap temp;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_image_main);
this.initialize();
this.PaintSet();
imageView = (ImageView) findViewById(R.id.imageview1);
Button button = (Button) findViewById(R.id.btnzoom);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if (falg) {
getFlag(false);
} else {
getFlag(true);
}
}
});
Button btnset = (Button) findViewById(R.id.btnset);
btnset.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
startval = 1;
mPaintBaseLayout.setDrawingCacheEnabled(true);
/*newbm = Bitmap.createBitmap(bm.getWidth(),
bm.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(newbm);
mPaintBaseLayout.draw(canvas);*/
// mPaintView.clear();
/*
mPaintView.setScaleType(ScaleType.MATRIX);
mPaintView.setMPaint(mPaint);
mPaintView.setImageBitmap(newbm);*/
imageView.setVisibility(View.VISIBLE);
mPaintBaseLayout.setVisibility(View.GONE);
new SaveImageAsynk().execute();
}
});
imageView.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix1);
start.set(event.getX(), event.getY());
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
start.set(event.getX(), event.getY());
savedMatrix.set(matrix1);
midPoint(mid, event);
// mode = POINT2;
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
mode = NONE;
distanceOffset = minOffset;
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
distanceOffset = minOffset;
break;
case MotionEvent.ACTION_MOVE:
if (mode == POINT2) {
newDist = spacing(event);
if (newDist - oldDist > 5f
|| newDist - oldDist < -5f) {
mode = ZOOM;
} else {
start.set(event.getX(), event.getY());
mode = DRAG;
}
} else if (mode == DRAG) {
matrix1.set(savedMatrix);
matrix1.postTranslate(event.getX() - start.x,
event.getY() - start.y);
} else if (mode == ZOOM) {
newDist = spacing(event);
if (newDist > 10f) {
matrix1.set(savedMatrix);
float scale = newDist / oldDist;
matrix1.postScale(scale, scale, mid.x,
mid.y);
finalscale = scale;
}
}
break;
}
view.setImageMatrix(matrix1);
// matrixTurning(matrix1, view);
return true; // indicate event was handled
}
});
}
class SaveImageAsynk extends AsyncTask<String, String, String>{
Bitmap tempBm;
#Override
protected String doInBackground(String... params) {
temp = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), matrix, false);
newbm = Bitmap.createBitmap(mPaintBaseLayout.getWidth(),
mPaintBaseLayout.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(newbm);
mPaintBaseLayout.draw(canvas);
tempBm = combineImages(newbm, temp);
if (newbm != null) {
newbm = null;
}
if (temp != null) {
temp = null;
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
imageView.setImageBitmap(tempBm);
try {
dialog.dismiss();
if (dialog != null) {
dialog = null;
}
} catch (Exception e) {
}
}
#Override
protected void onPreExecute() {
super.onPreExecute();
dialog = new ProgressDialog(PaintScreen.this);
dialog.setMessage("Loading...");
dialog.show();
}
}
public Bitmap combineImages(Bitmap c, Bitmap s) {
Bitmap cs = null;
int width, height = 0;
if (c.getWidth() > s.getWidth()) {
width = c.getWidth();
height = c.getHeight() + s.getHeight();
} else {
width = s.getWidth();
height = c.getHeight() + s.getHeight();
}
Log.e("hw :", "X = "+width + " Y = "+height);
cs = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas comboImage = new Canvas(cs);
comboImage.drawBitmap(s,new Matrix(), null);
comboImage.drawBitmap(c,Math.abs(scaledImageOffsetX),Math.abs(scaledImageOffsetY), null);
return cs;
}
private void initialize() {
mPaintBaseLayout = (LinearLayout) findViewById(R.id.paint_paint_base_layout);
mPaintBaseLayout2 = (LinearLayout) findViewById(R.id.paint_paint_base_layout2);
mContext = this;
mPaint = new Paint();
mPaintView = new PaintView(mContext);
mPaintView.setBackgroundColor(Color.TRANSPARENT);
mPaintBaseLayout.addView(mPaintView, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
mPaintBaseLayout.setBackgroundColor(Color.TRANSPARENT);
// mPaintView.setScaleType(ScaleType.FIT_XY);
mPaintView.setAdjustViewBounds(true);
mPaintView.setMPaint(mPaint);
bm = BitmapFactory.decodeResource(getResources(), R.drawable.nat);
mPaintView.setImageBitmap(bm);
mPaintView.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
PaintView view = (PaintView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
if (falg) {
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
} else {
view.onTouchEvent(event);
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
if (falg) {
oldDist = spacing(event);
if (oldDist > 10f) {
start.set(event.getX(), event.getY());
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
}
break;
case MotionEvent.ACTION_UP:
if (falg) {
mode = NONE;
distanceOffset = minOffset;
}
case MotionEvent.ACTION_POINTER_UP:
if (falg) {
mode = NONE;
distanceOffset = minOffset;
}
break;
case MotionEvent.ACTION_MOVE:
if (falg) {
if (mode == POINT2) {
newDist = spacing(event);
if (newDist - oldDist > 5f
|| newDist - oldDist < -5f) {
mode = ZOOM;
} else {
start.set(event.getX(), event.getY());
mode = DRAG;
}
} else if (mode == DRAG) {
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x,
event.getY() - start.y);
} else if (mode == ZOOM) {
newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
finalscale = scale;
}
}
} else {
view.onTouchEvent(event);
}
break;
}
limitZoom(matrix);
view.setImageMatrix(matrix);
matrixTurning(matrix, view);
RectF r = new RectF();
matrix.mapRect(r);
scaledImageOffsetX = r.left;
scaledImageOffsetY = r.top;
return true;
}
});
}
private void limitZoom(Matrix m) {
float[] values = new float[9];
m.getValues(values);
float scaleX = values[Matrix.MSCALE_X];
float scaleY = values[Matrix.MSCALE_Y];
if(scaleX > MAX_ZOOM) {
scaleX = MAX_ZOOM;
} else if(scaleX < MIN_ZOOM) {
scaleX = MIN_ZOOM;
}
if(scaleY > MAX_ZOOM) {
scaleY = MAX_ZOOM;
} else if(scaleY < MIN_ZOOM) {
scaleY = MIN_ZOOM;
}
values[Matrix.MSCALE_X] = scaleX;
values[Matrix.MSCALE_Y] = scaleY;
m.setValues(values);
}
public boolean getFlag(boolean b) {
return falg = b;
}
/** Determine the space between the first two fingers */
private static float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
/** Calculate the mid point of the first two fingers */
private static void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
private void matrixTurning(Matrix matrix, ImageView view) {
float[] value = new float[9];
matrix.getValues(value);
float[] savedValue = new float[9];
savedMatrix2.getValues(savedValue);
// view size
int width = view.getWidth();
int height = view.getHeight();
// image size
Drawable d = view.getDrawable();
if (d == null)
return;
int imageWidth = d.getIntrinsicWidth();
int imageHeight = d.getIntrinsicHeight();
int scaleWidth = (int) (imageWidth * value[0]);
int scaleHeight = (int) (imageHeight * value[0]);
if (value[2] < width - scaleWidth)
value[2] = width - scaleWidth;
if (value[5] < height - scaleHeight)
value[5] = height - scaleHeight;
if (value[2] > 0)
value[2] = 0;
if (value[5] > 0)
value[5] = 0;
if (value[0] > 10 || value[4] > 10) {
value[0] = savedValue[0];
value[4] = savedValue[4];
value[2] = savedValue[2];
value[5] = savedValue[5];
}
if (imageWidth > width || imageHeight > height) {
if (scaleWidth < width && scaleHeight < height) {
int target = WIDTH;
if (imageWidth < imageHeight)
target = HEIGHT;
if (target == WIDTH)
value[0] = value[4] = (float) width / imageWidth;
if (target == HEIGHT)
value[0] = value[4] = (float) height / imageHeight;
scaleWidth = (int) (imageWidth * value[0]);
scaleHeight = (int) (imageHeight * value[4]);
if (scaleWidth == width)
value[0] = value[4] = (float) width / imageWidth;
if (scaleHeight == height)
value[0] = value[4] = (float) height / imageHeight;
}
} else {
if (value[0] < 1)
value[0] = 1;
if (value[4] < 1)
value[4] = 1;
}
scaleWidth = (int) (imageWidth * value[0]);
scaleHeight = (int) (imageHeight * value[4]);
if (scaleWidth < width) {
value[2] = (float) width / 2 - (float) scaleWidth / 2;
}
if (scaleHeight < height) {
value[5] = (float) height / 2 - (float) scaleHeight / 2;
}
matrix.setValues(value);
savedMatrix2.set(matrix);
}
public void PaintSet() {
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFFFF0000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(10);
// getWindowManager().getDefaultDisplay().getMetrics(mDisplayMetrics);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 }, 0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(24, BlurMaskFilter.Blur.NORMAL);
}
public void colorChanged(int color) {
mPaint.setColor(color);
}
}
class PaintView extends ImageView {
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
// onDraw
private Paint mPaint;
// onTouch
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
public PaintView(Context context) {
this(context, null);
}
public PaintView(Context context, AttributeSet attrs) {
super(context, attrs);
mBitmap = Bitmap.createBitmap(1024, 1024, Bitmap.Config.ARGB_8888);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
#Override
protected void onDraw(Canvas canvas) {
// canvas.drawColor(0xFFAAAAAA);
super.onDraw(canvas);
mCanvas = canvas;
// canvas = mCanvas;
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
// canvas.drawBitmap(mBitmap, PaintScreen.matrix, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
public void clear() {
mPaint.reset();
// invalidate();
}
public void setMPaint(Paint paint) {
mPaint = paint;
}
private void touchStart(float x, float y) {
// mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touchMove(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touchUp() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
Log.d("PaintView", "ev ->" + event.getAction());
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touchStart(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touchMove(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touchUp();
invalidate();
break;
}
return true;
}
public void cMatrix(Matrix matrix) {
mCanvas.setMatrix(matrix);
}
}