i have this code for rotation/magnification and move image view,now i need to apply these functions for text view,but i was not successful in this mission,can any one help me to do that whit editing this code or another code?thanks
public class MainActivity extends Activity implements OnTouchListener {
private EditText ed_text;
private ImageView view;
private LinearLayout toolbar_lay;
private FrameLayout frame1;
private Matrix mMatrix = new Matrix();
private float mScaleFactor = .4f;
private float mRotationDegrees = 0.f;
private float mFocusX = 0.f;
private float mFocusY = 0.f;
private int mAlpha = 255;
private int mImageHeight, mImageWidth;
private ImageView background;
private ScaleGestureDetector mScaleDetector;
private RotateGestureDetector mRotateDetector;
private MoveGestureDetector mMoveDetector;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.frame3);
background=(ImageView) findViewById(R.id.frame_back);
Display display = getWindowManager().getDefaultDisplay();
mFocusX = display.getWidth()/2f;
mFocusY = display.getHeight()/2f;
// Set this class as touchListener to the ImageView
view = (ImageView) findViewById(R.id.id1);
Intent intent=getIntent();
String path=intent.getStringExtra("mybm");
Bitmap bm=BitmapFactory.decodeFile(path);
view.setImageBitmap(bm);
view.setOnTouchListener(this);
// Determine dimensions of 'earth' image
Drawable d = this.getResources().getDrawable(R.drawable.icon3);
mImageHeight = d.getIntrinsicHeight();
mImageWidth = d.getIntrinsicWidth();
float scaledImageCenterX = (mImageWidth*mScaleFactor)/2;
float scaledImageCenterY = (mImageHeight*mScaleFactor)/2;
mMatrix.postScale(mScaleFactor, mScaleFactor);
mMatrix.postTranslate(mFocusX - scaledImageCenterX,
mFocusY - scaledImageCenterY);
view.setImageMatrix(mMatrix);
// Setup Gesture Detectors
mScaleDetector = new ScaleGestureDetector(getApplicationContext(),
new ScaleListener());
mRotateDetector = new RotateGestureDetector(getApplicationContext(),
new RotateListener());
mMoveDetector = new MoveGestureDetector(getApplicationContext(),
new MoveListener());
//mShoveDetector =
new ShoveGestureDetector(getApplicationContext(),
new ShoveListener());
}
#SuppressWarnings("deprecation")
public boolean onTouch(View v, MotionEvent event) {
mScaleDetector.onTouchEvent(event);
mRotateDetector.onTouchEvent(event);
mMoveDetector.onTouchEvent(event);
// mShoveDetector.onTouchEvent(event);
float scaledImageCenterX = (mImageWidth*mScaleFactor)/2;
float scaledImageCenterY = (mImageHeight*mScaleFactor)/2;
mMatrix.reset();
mMatrix.postScale(mScaleFactor, mScaleFactor);
mMatrix.postRotate(mRotationDegrees,
scaledImageCenterX, scaledImageCenterY);
mMatrix.postTranslate(mFocusX - scaledImageCenterX,
mFocusY - scaledImageCenterY);
ImageView view = (ImageView) v;
view.setImageMatrix(mMatrix);
view.setAlpha(mAlpha);
return true; // indicate event was handled
}
private class ScaleListener
extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 10.0f));
return true;
}
}
private class RotateListener
extends RotateGestureDetector.SimpleOnRotateGestureListener
{
#Override
public boolean onRotate(RotateGestureDetector detector) {
mRotationDegrees -= detector.getRotationDegreesDelta();
return true;
}
}
private class MoveListener
extends MoveGestureDetector.SimpleOnMoveGestureListener {
#Override
public boolean onMove(MoveGestureDetector detector) {
PointF d = detector.getFocusDelta();
mFocusX += d.x;
mFocusY += d.y;
// mFocusX = detector.getFocusX();
// mFocusY = detector.getFocusY();
return true;
}
}
}
I think you have right idea going with treating the text as an
ImageView. But drop the conversion from a TextView. Instead treat the text image all along as an ImageView. Create a blank Canvas and a Paint, use Canvas.drawText to draw your text in the appropriate place in the Canvas's bitmap, and then use the image manipulation code above to expand/shrink/rotate your text.
Related
I want to rotate & scale in same time, but it's flickering while rotating and scaling the layout. This is my code
public class CustomRelaytivelayout extends RelativeLayout implements RotationGestureDetector.OnRotationGestureListener {
private float scale = 1.0f;
private float touchX = 0.0f;
private float touchY = 0.0f;
public ScaleGestureDetector mScaleDetector;
public RotationGestureDetector mRotationDetector;
private CustomRelaytivelayout customRelaytivelayout_;
float mScaleFactor = 1;
float mPivotX;
float mPivotY;
public CustomRelaytivelayout(Context context) {
super(context);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener(this));
mRotationDetector = new RotationGestureDetector(this);
customRelaytivelayout_ = this;
}
public CustomRelaytivelayout(Context context, AttributeSet attrs) {
super(context, attrs);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener(this));
mRotationDetector = new RotationGestureDetector(this);
customRelaytivelayout_ = this;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
private CustomRelaytivelayout customRelaytivelayout;
float startingSpan;
float endSpan;
float startFocusX;
float startFocusY;
public ScaleListener(CustomRelaytivelayout customRelaytivelayout_) {
customRelaytivelayout = customRelaytivelayout_;
}
#Override
public boolean onScale(ScaleGestureDetector detector) {
// Multiply scale factor
scale *= detector.getScaleFactor();
ViewHelper.setScaleX(customRelaytivelayout, scale);
ViewHelper.setScaleY(customRelaytivelayout, scale);
invalidate();
return true;
}
#Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
return true;
}
#Override
public void onScaleEnd(ScaleGestureDetector detector) {
}
}
private float angle = 0;
#Override
public void OnRotation(RotationGestureDetector rotationDetector) {
angle = angle + rotationDetector.getAngle();
Log.d("TAG_Angle", "" + angle);
customRelaytivelayout_.setRotation(-angle);
}
protected void dispatchDraw(Canvas canvas) {
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(mScaleFactor, mScaleFactor, mPivotX, mPivotY);
super.dispatchDraw(canvas);
canvas.restore();
}
public void scale(float scaleFactor, float pivotX, float pivotY) {
mScaleFactor = scaleFactor;
mPivotX = pivotX;
mPivotY = pivotY;
this.invalidate();
}
public void restore() {
mScaleFactor = 1;
this.invalidate();
}
}
Its flickering while rotating and scaling the layout.If any one have solution please share
Thanks in advance
Hi i am erasing bitmap that is draw at canvas with touch (fingers) that is working fine the problem i am facing is after rotate bitmap at canvas paths draw in opposition direction mean bitmap erase in opposition direction of my finger touch .
DrawingPane.class
public class DrawingPanel extends ImageView implements OnTouchListener {
private Matrix mMatrix = new Matrix();
private float mScaleFactor = 1f;
private float mRotationDegrees = 0.f;
private float mFocusX = 0.f;
private float mFocusY = 0.f;
private int mAlpha = 255;
private int mImageHeight, mImageWidth;
private ScaleGestureDetector mScaleDetector;
private RotateGestureDetector mRotateDetector;
private MoveGestureDetector mMoveDetector;
private ShoveGestureDetector mShoveDetector;
private boolean isMoving=false;
EditPhotoActivity editActivity;
Bitmap overlayDefault;
Bitmap overlay;
Bitmap bmp,bmp2;
Paint pTouch;
int whichTabSelected=0;
private Path mPath;
Display display ;
private ArrayList<Path> paths = new ArrayList<Path>();
private ArrayList<Float> xlist = new ArrayList<Float>();
private ArrayList<Float> ylist = new ArrayList<Float>();
#SuppressLint("NewApi")
public DrawingPanel(Context context, int colorPaint,Bitmap bmp) {
super(context);
if (Build.VERSION.SDK_INT >= 11) {
setLayerType(View.LAYER_TYPE_HARDWARE, null);
}
display = ((Activity)context).getWindowManager().getDefaultDisplay();
mFocusX = display.getWidth()/2f;
mFocusY = display.getHeight()/2f;
try {
overlayDefault=bmp;
overlay=bmp;
overlay=overlay.copy(Config.ARGB_8888, true);
overlay.setHasAlpha(true);
} catch (Exception e) {
e.printStackTrace();
}
mImageHeight = getHeight();
mImageWidth = getWidth();
// Setup Gesture Detectors
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
mRotateDetector = new RotateGestureDetector(context, new RotateListener());
mMoveDetector = new MoveGestureDetector(context, new MoveListener());
mShoveDetector = new ShoveGestureDetector(context, new ShoveListener());
pTouch = new Paint(Paint.ANTI_ALIAS_FLAG);
pTouch.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
pTouch.setColor(Color.TRANSPARENT);
//pTouch.setMaskFilter(new BlurMaskFilter(30, Blur.SOLID));
pTouch.setStyle(Paint.Style.STROKE);
pTouch.setStrokeJoin(Paint.Join.ROUND);
pTouch.setStrokeCap(Paint.Cap.ROUND);
pTouch.setStrokeWidth(50);
pTouch.setAntiAlias(true);
setFocusable(true);
setFocusableInTouchMode(true);
mPath = new Path();
paths.add(mPath);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mImageHeight=getHeight();
mImageWidth=getWidth();
bmp = Bitmap.createScaledBitmap(overlay, w, h, false);
bmp2 = Bitmap.createScaledBitmap(overlayDefault, w, h, false);
overlay = bmp.copy(Config.ARGB_8888, true);
overlayDefault = bmp2.copy(Config.ARGB_8888, true);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
}
#Override
protected void onDraw(Canvas canvas) {
// mCanvas.drawBitmap(overlayDefault,0, 0, null); //exclude this line to show all as you draw
// mCanvas.drawCircle(X, Y, 80, pTouch);
//draw the overlay over the background
float scaledImageCenterX = (mImageWidth*mScaleFactor)/2;
float scaledImageCenterY = (mImageHeight*mScaleFactor)/2;
mMatrix.reset();
mMatrix.postScale(mScaleFactor, mScaleFactor);
mMatrix.postRotate(mRotationDegrees, scaledImageCenterX, scaledImageCenterY);
if(isMoving)
{
mMatrix.postTranslate(mFocusX - scaledImageCenterX, mFocusY - scaledImageCenterY);
}
else
{
mMatrix.postTranslate(0,0);
}
canvas.setMatrix(mMatrix);
canvas.drawBitmap(overlay,0,0, null);
for (Path p : paths) {
canvas.drawPath(p, pTouch);
}
super.onDraw(canvas);
}
public Bitmap getBitmap(){
Bitmap b = Bitmap.createScaledBitmap(overlay,display.getWidth() ,display.getWidth(), false);
overlay = b.copy(Config.ARGB_8888, true);
return overlay;
}
public void setBitmap(Bitmap bmp1){
overlay = bmp1;
invalidate();
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 0;
public void touch_start(float x, float y) {
if(xlist.size()>0 && ylist.size()>0){
xlist.clear();
ylist.clear();
}
xlist.add(x);
ylist.add(y);
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
mPath.transform(mMatrix, mPath);
invalidate();
}
public void touch_move(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;
mPath.transform(mMatrix, mPath);
}
xlist.add(x);
ylist.add(y);
invalidate();
}
public void touch_up() {
mPath.lineTo(mX, mY);
mPath = new Path();
mPath.transform(mMatrix, mPath);
paths.add(mPath);
invalidate();
}
public void OnTouchParent(MotionEvent event){
mScaleDetector.onTouchEvent(event);
mRotateDetector.onTouchEvent(event);
mMoveDetector.onTouchEvent(event);
mShoveDetector.onTouchEvent(event);
float scaledImageCenterX = (mImageWidth*mScaleFactor)/2;
float scaledImageCenterY = (mImageHeight*mScaleFactor)/2;
mMatrix.reset();
mMatrix.postScale(mScaleFactor, mScaleFactor);
mMatrix.postRotate(mRotationDegrees, scaledImageCenterX, scaledImageCenterY);
mMatrix.postTranslate(mFocusX - scaledImageCenterX, mFocusY - scaledImageCenterY);
float x = event.getX();
float y = event.getY();
/*switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if(whichTabSelected==Constant.ERASE)
{
touch_start(x, y);
invalidate();
}
break;
case MotionEvent.ACTION_MOVE:
if(whichTabSelected==Constant.ERASE)
{
touch_move(x, y);
invalidate();
}
break;
case MotionEvent.ACTION_UP:
if(whichTabSelected==Constant.ERASE)
{
touch_up();
invalidate();
}
break;
}
if(whichTabSelected==Constant.ERASE)
{
return true;
}
else
{
return false;
}*/
invalidate();
}
#Override
public boolean onTouch(View arg0, MotionEvent event) {
if(getTabMode()==Constant.PANZOOM)
{
mScaleDetector.onTouchEvent(event);
mRotateDetector.onTouchEvent(event);
mMoveDetector.onTouchEvent(event);
mShoveDetector.onTouchEvent(event);
float scaledImageCenterX = (mImageWidth*mScaleFactor)/2;
float scaledImageCenterY = (mImageHeight*mScaleFactor)/2;
}
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if(getTabMode()==Constant.ERASE)
{
touch_start(x, y);
invalidate();
}
break;
case MotionEvent.ACTION_MOVE:
if(getTabMode()==Constant.ERASE)
{
touch_move(x, y);
invalidate();
}
break;
case MotionEvent.ACTION_UP:
if(getTabMode()==Constant.ERASE)
{
touch_up();
invalidate();
}
break;
}
invalidate();
return true;
}
public void setBottomTabMode(int mode)
{
whichTabSelected=mode;
}
public int getTabMode()
{
return whichTabSelected;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor(); // scale change since previous event
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 10.0f));
return true;
}
}
private class RotateListener extends RotateGestureDetector.SimpleOnRotateGestureListener {
#Override
public boolean onRotate(RotateGestureDetector detector) {
mRotationDegrees -= detector.getRotationDegreesDelta();
return true;
}
}
private class MoveListener extends MoveGestureDetector.SimpleOnMoveGestureListener {
#Override
public boolean onMove(MoveGestureDetector detector) {
PointF d = detector.getFocusDelta();
mFocusX += d.x;
mFocusY += d.y;
isMoving=true;
// mFocusX = detector.getFocusX();
// mFocusY = detector.getFocusY();
return true;
}
}
private class ShoveListener extends ShoveGestureDetector.SimpleOnShoveGestureListener {
#Override
public boolean onShove(ShoveGestureDetector detector) {
mAlpha += detector.getShovePixelsDelta();
if (mAlpha > 255)
mAlpha = 255;
else if (mAlpha < 0)
mAlpha = 0;
return true;
}
}
}
I fixed my problem. Actually when i rotate canvas the event.getX() and event.getY() were not map to current rotation of matrix so by adding this line in mMatrix.invert(tempMatrix); in OnDraw() and also map current x,y in OnTouch() by adding this in OnTouch() method .
float[] coords = new float[] { event.getX(), event.getY() };
tempMatrix.mapPoints(coords);
float x = coords[0];//event.getX();
float y = coords[1];//event.getY();
its working fine .
This effect is happening because you are applying the matrix twice to paths.
Once at touch_start/touch_move by doing mPath.transform(mMatrix, mPath);.
And then again at onDraw(Canvas canvas) by canvas.setMatrix(mMatrix); and then canvas.drawPath(p, pTouch);.
To fix, try to remove the mPath.transform(mMatrix, mPath); from touch_start/touch_move.
Also, I do not know if it is a good practice to set the matrix directly to the canvas. Instead of canvas.setMatrix(mMatrix);, I would prefer to do the following:
canvas.save();
canvas.concat(mMatrix);
//write the code....
canvas.restore();
I have 2 images in different framelayouts both images have touch listener attached.
And both are in one screen.First image is rotating successfully but the second image is not.
I am trying to rotate ,scale and move images using touchlistener.
Here is my code:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_crop);
image1 = (ImageView) findViewById(R.id.image1);
image1.setOnTouchListener(this);
image2 = (ImageView) findViewById(R.id.image2);
image2.setOnTouchListener(this);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.image1);
image1.setImageBitmap(bitmap);
mImageHeight = bitmap.getHeight();
mImageWidth = bitmap.getWidth();
mMatrix.postScale(mScaleFactor, mScaleFactor);
image1.setImageMatrix(mMatrix);
image2.setImageMatrix(mMatrix);
mScaleDetector = new ScaleGestureDetector(getApplicationContext(), new ScaleListener());
mRotateDetector = new RotateGestureDetector(getApplicationContext(), new RotateListener());
mMoveDetector = new MoveGestureDetector(getApplicationContext(), new MoveListener());
}
public boolean onTouch(View v, MotionEvent event) {
mScaleDetector.onTouchEvent(event);
mRotateDetector.onTouchEvent(event);
mMoveDetector.onTouchEvent(event);
float scaledImageCenterX = (mImageWidth * mScaleFactor) / 2;
float scaledImageCenterY = (mImageHeight * mScaleFactor) / 2;
mMatrix.reset();
mMatrix.postScale(mScaleFactor, mScaleFactor); // 12-march
mMatrix.postRotate(mRotationDegrees, scaledImageCenterX, scaledImageCenterY);
mMatrix.postTranslate(mFocusX - scaledImageCenterX, mFocusY - scaledImageCenterY);// 12-march
ImageView view = (ImageView) v;
view.setImageMatrix(mMatrix);
return true;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 10.0f));
return true;
}
}
private class RotateListener extends RotateGestureDetector.SimpleOnRotateGestureListener {
#Override
public boolean onRotate(RotateGestureDetector detector) {
mRotationDegrees -= detector.getRotationDegreesDelta();
return true;
}
}
private class MoveListener extends MoveGestureDetector.SimpleOnMoveGestureListener {
#Override
public boolean onMove(MoveGestureDetector detector) {
PointF d = detector.getFocusDelta();
mFocusX += d.x;
mFocusY += d.y;
return true;
}
}
I am trying to implement pinch zoom and drag using Android's gesture listener and scale listener. The problem is that when I perform pinch zoom, the image (which I am trying to zoom) bounces to a particular location. Also the zoom position is not centered.
The following code demonstrates what I am trying to achieve. Any idea why the image is jumping (and how to correct it) ?
public class CustomView extends View {
Bitmap image;
int screenHeight;
int screenWidth;
Paint paint;
GestureDetector gestures;
ScaleGestureDetector scaleGesture;
float scale = 1.0f;
float horizontalOffset, verticalOffset;
int NORMAL = 0;
int ZOOM = 1;
int DRAG = 2;
boolean isScaling = false;
float touchX, touchY;
int mode = NORMAL;
public CustomView(Context context) {
super(context);
//initializing variables
image = BitmapFactory.decodeResource(getResources(),
R.drawable.image_name);
//This is a full screen view
screenWidth = getResources().getDisplayMetrics().widthPixels;
screenHeight = getResources().getDisplayMetrics().heightPixels;
paint = new Paint();
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
paint.setColor(Color.WHITE);
scaleGesture = new ScaleGestureDetector(getContext(),
new ScaleListener());
gestures = new GestureDetector(getContext(), new GestureListener());
mode = NORMAL;
initialize();
}
//Best fit image display on canvas
private void initialize() {
float imgPartRatio = image.getWidth() / (float) image.getHeight();
float screenRatio = (float) screenWidth / (float) screenHeight;
if (screenRatio > imgPartRatio) {
scale = ((float) screenHeight) / (float) (image.getHeight()); // fit height
horizontalOffset = ((float) screenWidth - scale
* (float) (image.getWidth())) / 2.0f;
verticalOffset = 0;
} else {
scale = ((float) screenWidth) / (float) (image.getWidth()); // fit width
horizontalOffset = 0;
verticalOffset = ((float) screenHeight - scale
* (float) (image.getHeight())) / 2.0f;
}
invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
canvas.save();
canvas.drawColor(0, Mode.CLEAR);
canvas.drawColor(Color.WHITE);
if(mode == DRAG || mode == NORMAL) {
//This works perfectly as expected
canvas.translate(horizontalOffset, verticalOffset);
canvas.scale(scale, scale);
canvas.drawBitmap(image, getMatrix(), paint);
}
else if (mode == ZOOM) {
//PROBLEM AREA - when applying pinch zoom,
//the image jumps to a position abruptly
canvas.scale(scale, scale, touchX, touchY);
canvas.drawBitmap(image, getMatrix(), paint);
}
canvas.restore();
}
public class ScaleListener implements OnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
float scaleFactorNew = detector.getScaleFactor();
if (detector.isInProgress()) {
touchX = detector.getFocusX();
touchY = detector.getFocusY();
scale *= scaleFactorNew;
invalidate(0, 0, screenWidth, screenHeight);
}
return true;
}
#Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
isScaling = true;
mode=ZOOM;
return true;
}
#Override
public void onScaleEnd(ScaleGestureDetector detector) {
mode = NORMAL;
isScaling = false;
}
}
public class GestureListener implements GestureDetector.OnGestureListener,
GestureDetector.OnDoubleTapListener {
#Override
public boolean onDown(MotionEvent e) {
isScaling = false;
return true;
}
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
if (!isScaling) {
mode = DRAG;
isScaling = false;
horizontalOffset -= distanceX;
verticalOffset -= distanceY;
invalidate(0, 0, screenWidth, screenHeight);
} else {
mode = ZOOM;
isScaling = true;
}
return true;
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
scaleGesture.onTouchEvent(event);
gestures.onTouchEvent(event);
return true;
}
}
Thanks in advance.
I have implemented this behaviour, and I used a matrix to handle all the zooming and scrolling (and rotation, in my case). It makes for neat code and works like clockwork.
Store a Matrix as a class member:
Matrix drawMatrix;
Edit: Store old focus point, used to get the focus shift during scaling.
float lastFocusX;
float lastFocusY;
Edit: Set lastFocus variables in onScaleBegin
#Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
lastFocusX = detector.getFocusX();
lastFocusY = detector.getFocusY();
return true;
}
Replace your onScale:
#Override
public boolean onScale(ScaleGestureDetector detector) {
Matrix transformationMatrix = new Matrix();
float focusX = detector.getFocusX();
float focusY = detector.getFocusY();
//Zoom focus is where the fingers are centered,
transformationMatrix.postTranslate(-focusX, -focusY);
transformationMatrix.postScale(detector.getScaleFactor(), detector.getScaleFactor());
/* Adding focus shift to allow for scrolling with two pointers down. Remove it to skip this functionality. This could be done in fewer lines, but for clarity I do it this way here */
//Edited after comment by chochim
float focusShiftX = focusX - lastFocusX;
float focusShiftY = focusY - lastFocusY;
transformationMatrix.postTranslate(focusX + focusShiftX, focusY + focusShiftY);
drawMatrix.postConcat(transformationMatrix);
lastFocusX = focusX;
lastFocusY = focusY;
invalidate();
return true;
}
Similarly in onScroll:
#Override
public boolean onScroll(MotionEvent downEvent, MotionEvent currentEvent,
float distanceX, float distanceY) {
drawMatrix.postTranslate(-distanceX, -distanceY);
invalidate();
return true;
}
in onDraw; Draw with your drawMatrix:
canvas.drawBitmap(image, drawMatrix, paint);
Happy coding!
I want to pinch zoom an image but problem is when I zoom it does not zoom in and out from where my fingers are. It goes to point 0, 0.
Here is my code:
#Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor = detector.getScaleFactor();
Log.e("ScaleFactor", "" + mScaleFactor);
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.4f, Math.min(mScaleFactor, 5.0f));
if(mScaleFactor>=1)
mScaleFactor=1f;
invalidate();
return true;
}
I tried a lot but could get any way to fix this.
it is useful
private float[] matrixValues = new float[9];
private float maxZoom;
private float minZoom;
private float height;
private float width;
private RectF viewRect;
private void init() {
maxZoom = 4;
minZoom = 0.25f;
height = myimage.getDrawable().getIntrinsicHeight()+20;
width = myimage.getDrawable().getIntrinsicWidth()+20;
viewRect = new RectF(0, 0, myimage.getWidth()+20, myimage.getHeight()+20);
}