Develop Reference

Zoom In Zoom Out ImageView Android Studio

I'm trying to implement zoom in and zoom out in my imageView. This code works with no error, but I think the Image should not go less than 100% of its original size.
How to fix it? Anyone, please help me, thank you.
(the image too small)
This is my literature : (thank you for this answer)
public class ProfilePhotoActivity extends AppCompatActivity implements View.OnTouchListener {
private ImageView profilePhoto;
private String photoURL, name;
private static final String TAG = "Touch";
#SuppressWarnings("unused")
private static final float MIN_ZOOM = 1f,MAX_ZOOM = 1f;
// These matrices will be used to scale points of the image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// The 3 states (events) which the user is trying to perform
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// these PointF objects are used to record the point(s) the user is touching
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_profile_photo);
Intent intentGet =getIntent();
photoURL = intentGet.getStringExtra("PhotoURL");
name = intentGet.getStringExtra("Name");
setTitle(name);
getSupportActionBar().setBackgroundDrawable(new ColorDrawable(getResources().getColor(R.color.black)));
//load profile image
profilePhoto = (ImageView) findViewById(R.id.largeProfilePhoto);
Glide.with(getApplicationContext())
.load(photoURL)
.error(R.drawable.ic_person)
.into(profilePhoto);
profilePhoto.setOnTouchListener(this);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
super.onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public boolean onTouch(View v, MotionEvent event)
{
ImageView view = (ImageView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
float scale;
dumpEvent(event);
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_DOWN: // first finger down only
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG"); // write to LogCat
mode = DRAG;
break;
case MotionEvent.ACTION_UP: // first finger lifted
case MotionEvent.ACTION_POINTER_UP: // second finger lifted
mode = NONE;
Log.d(TAG, "mode=NONE");
break;
case MotionEvent.ACTION_POINTER_DOWN: // first and second finger down
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 5f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG)
{
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix of points
}
else if (mode == ZOOM)
{
// pinch zooming
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 5f)
{
matrix.set(savedMatrix);
scale = newDist / oldDist; // setting the scaling of the
// matrix...if scale > 1 means
// zoom in...if scale < 1 means
// zoom out
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix); // display the transformation on screen
return true; // indicate event was handled
}
/*
* --------------------------------------------------------------------------
* Method: spacing Parameters: MotionEvent Returns: float Description:
* checks the spacing between the two fingers on touch
* ----------------------------------------------------
*/
private float spacing(MotionEvent event)
{
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
/*
* --------------------------------------------------------------------------
* Method: midPoint Parameters: PointF object, MotionEvent Returns: void
* Description: calculates the midpoint between the two fingers
* ------------------------------------------------------------
*/
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);
}
/** 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("]");
Log.d("Touch Events ---------", sb.toString());
}
}

Android ImageView Scaling and translating issue

I’m developing an android application (API 19 4.4) and I encounter some issue with ImageViews.
I have a SurfaceView, in which I dynamically add ImageViews which I want to react to touch events.
On so far, I have managed to make the ImageView move and scale smoothly but I have an annoying behavior.
When I scale down the image to a certain limit (I would say half the original size) and I try to move it, the image flicker.
After a short analysis, it seems that it’s switching its position symmetrically around the finger point on the screen, cumulating distance, and finally gets out of sight (all that happens very fast ( < 1s).
I think I am missing something with the relative value of the touch event to the ImageView/SurfaceView, but I’m a quite a noob and I’m stucked…
Here is my code
public class MyImageView extends ImageView {
private ScaleGestureDetector mScaleDetector ;
private static final int MAX_SIZE = 1024;
private static final String TAG = "MyImageView";
PointF DownPT = new PointF(); // Record Mouse Position When Pressed Down
PointF StartPT = new PointF(); // Record Start Position of 'img'
public MyImageView(Context context) {
super(context);
mScaleDetector = new ScaleGestureDetector(context,new MySimpleOnScaleGestureListener());
setBackgroundColor(Color.RED);
setScaleType(ScaleType.MATRIX);
setAdjustViewBounds(true);
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
lp.setMargins(-MAX_SIZE, -MAX_SIZE, -MAX_SIZE, -MAX_SIZE);
this.setLayoutParams(lp);
this.setX(MAX_SIZE);
this.setY(MAX_SIZE);
}
int firstPointerID;
boolean inScaling=false;
#Override
public boolean onTouchEvent(MotionEvent event) {
// get pointer index from the event object
int pointerIndex = event.getActionIndex();
// get pointer ID
int pointerId = event.getPointerId(pointerIndex);
//First send event to scale detector to find out, if it's a scale
boolean res = mScaleDetector.onTouchEvent(event);
if (!mScaleDetector.isInProgress()) {
int eid = event.getAction();
switch (eid & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_MOVE :
if(pointerId == firstPointerID) {
PointF mv = new PointF( (int)(event.getX() - DownPT.x), (int)( event.getY() - DownPT.y));
this.setX((int)(StartPT.x+mv.x));
this.setY((int)(StartPT.y+mv.y));
StartPT = new PointF( this.getX(), this.getY() );
}
break;
case MotionEvent.ACTION_DOWN : {
firstPointerID = pointerId;
DownPT.x = (int) event.getX();
DownPT.y = (int) event.getY();
StartPT = new PointF( this.getX(), this.getY() );
break;
}
case MotionEvent.ACTION_POINTER_DOWN: {
break;
}
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_CANCEL: {
firstPointerID = -1;
break;
}
default :
break;
}
return true;
}
return true;
}
public boolean onScaling(ScaleGestureDetector detector) {
this.setScaleX(this.getScaleX()*detector.getScaleFactor());
this.setScaleY(this.getScaleY()*detector.getScaleFactor());
invalidate();
return true;
}
private class MySimpleOnScaleGestureListener extends SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
return onScaling(detector);
}
#Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
Log.d(TAG, "onScaleBegin");
return true;
}
#Override
public void onScaleEnd(ScaleGestureDetector arg0) {
Log.d(TAG, "onScaleEnd");
}
}
}
I have also another questions about rotations. How should I implement this?
Could I use the ScalegestureDetector in some way or have I to make this works in the view touch event? I would like to be able to scale and rotate in the same gesture (and move in another).
Thank for helping me, I would really appreciate!
Sorry for my english

this is a working example of two fingers move/scale/rotate (note: the code is quite short due to smart detector used - see MatrixGestureDetector):
class ViewPort extends View {
List<Layer> layers = new LinkedList<Layer>();
int[] ids = {R.drawable.layer0, R.drawable.layer1, R.drawable.layer2};
public ViewPort(Context context) {
super(context);
Resources res = getResources();
for (int i = 0; i < ids.length; i++) {
Layer l = new Layer(context, this, BitmapFactory.decodeResource(res, ids[i]));
layers.add(l);
}
}
#Override
protected void onDraw(Canvas canvas) {
for (Layer l : layers) {
l.draw(canvas);
}
}
private Layer target;
#Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
target = null;
for (int i = layers.size() - 1; i >= 0; i--) {
Layer l = layers.get(i);
if (l.contains(event)) {
target = l;
layers.remove(l);
layers.add(l);
invalidate();
break;
}
}
}
if (target == null) {
return false;
}
return target.onTouchEvent(event);
}
}
class Layer implements MatrixGestureDetector.OnMatrixChangeListener {
Matrix matrix = new Matrix();
Matrix inverse = new Matrix();
RectF bounds;
View parent;
Bitmap bitmap;
MatrixGestureDetector mgd = new MatrixGestureDetector(matrix, this);
public Layer(Context ctx, View p, Bitmap b) {
parent = p;
bitmap = b;
bounds = new RectF(0, 0, b.getWidth(), b.getHeight());
matrix.postTranslate(50 + (float) Math.random() * 50, 50 + (float) Math.random() * 50);
}
public boolean contains(MotionEvent event) {
matrix.invert(inverse);
float[] pts = {event.getX(), event.getY()};
inverse.mapPoints(pts);
if (!bounds.contains(pts[0], pts[1])) {
return false;
}
return Color.alpha(bitmap.getPixel((int) pts[0], (int) pts[1])) != 0;
}
public boolean onTouchEvent(MotionEvent event) {
mgd.onTouchEvent(event);
return true;
}
#Override
public void onChange(Matrix matrix) {
parent.invalidate();
}
public void draw(Canvas canvas) {
canvas.drawBitmap(bitmap, matrix, null);
}
}
class MatrixGestureDetector {
private static final String TAG = "MatrixGestureDetector";
private int ptpIdx = 0;
private Matrix mTempMatrix = new Matrix();
private Matrix mMatrix;
private OnMatrixChangeListener mListener;
private float[] mSrc = new float[4];
private float[] mDst = new float[4];
private int mCount;
interface OnMatrixChangeListener {
void onChange(Matrix matrix);
}
public MatrixGestureDetector(Matrix matrix, MatrixGestureDetector.OnMatrixChangeListener listener) {
this.mMatrix = matrix;
this.mListener = listener;
}
public void onTouchEvent(MotionEvent event) {
if (event.getPointerCount() > 2) {
return;
}
int action = event.getActionMasked();
int index = event.getActionIndex();
switch (action) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_DOWN:
int idx = index * 2;
mSrc[idx] = event.getX(index);
mSrc[idx + 1] = event.getY(index);
mCount++;
ptpIdx = 0;
break;
case MotionEvent.ACTION_MOVE:
for (int i = 0; i < mCount; i++) {
idx = ptpIdx + i * 2;
mDst[idx] = event.getX(i);
mDst[idx + 1] = event.getY(i);
}
mTempMatrix.setPolyToPoly(mSrc, ptpIdx, mDst, ptpIdx, mCount);
mMatrix.postConcat(mTempMatrix);
if(mListener != null) {
mListener.onChange(mMatrix);
}
System.arraycopy(mDst, 0, mSrc, 0, mDst.length);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
if (event.getPointerId(index) == 0) ptpIdx = 2;
mCount--;
break;
}
}
}

I tried to implementation of multiple touch on view not on bitmap using matrix, now i success. Now i think it will helpful to you for individual gesture for multiple image. Try it, it work best for me.
public class MultiTouchImageView extends ImageView implements OnTouchListener{
float[] lastEvent = null;
float d = 0f;
float newRot = 0f;
public static String fileNAME;
public static int framePos = 0;
//private ImageView view;
private boolean isZoomAndRotate;
private boolean isOutSide;
// We can be in one of these 3 states
private static final int NONE = 0;
private static final int DRAG = 1;
private static final int ZOOM = 2;
private int mode = NONE;
private PointF start = new PointF();
private PointF mid = new PointF();
float oldDist = 1f;
public MultiTouchImageView(Context context) {
super(context);
}
public MultiTouchImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public MultiTouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
#SuppressWarnings("deprecation")
#Override
public boolean onTouch(View v, MotionEvent event) {
//view = (ImageView) v;
bringToFront();
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
//savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
lastEvent = null;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
midPoint(mid, event);
mode = ZOOM;
}
lastEvent = new float[4];
lastEvent[0] = event.getX(0);
lastEvent[1] = event.getX(1);
lastEvent[2] = event.getY(0);
lastEvent[3] = event.getY(1);
d = rotation(event);
break;
case MotionEvent.ACTION_UP:
isZoomAndRotate = false;
case MotionEvent.ACTION_OUTSIDE:
isOutSide = true;
mode = NONE;
lastEvent = null;
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
break;
case MotionEvent.ACTION_MOVE:
if(!isOutSide){
if (mode == DRAG && !isZoomAndRotate) {
isZoomAndRotate = false;
setTranslationX((event.getX() - start.x) + getTranslationX());
setTranslationY((event.getY() - start.y) + getTranslationY());
} else if (mode == ZOOM && event.getPointerCount() == 2) {
isZoomAndRotate = true;
boolean isZoom = false;
if(!isRotate(event)){
float newDist = spacing(event);
if (newDist > 10f) {
float scale = newDist / oldDist * getScaleX();
setScaleX(scale);
setScaleY(scale);
isZoom = true;
}
}
else if(!isZoom){
newRot = rotation(event);
setRotation((float)(getRotation() + (newRot - d)));
}
}
}
break;
}
new GestureDetector(new MyGestureDectore());
Constants.currentSticker = this;
return true;
}
private class MyGestureDectore extends GestureDetector.SimpleOnGestureListener{
#Override
public boolean onDoubleTap(MotionEvent e) {
bringToFront();
return false;
}
#Override
public boolean onDoubleTapEvent(MotionEvent e) {
return false;
}
}
private float rotation(MotionEvent event) {
double delta_x = (event.getX(0) - event.getX(1));
double delta_y = (event.getY(0) - event.getY(1));
double radians = Math.atan2(delta_y, delta_x);
return (float) Math.toDegrees(radians);
}
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);
}
private boolean isRotate(MotionEvent event){
int dx1 = (int) (event.getX(0) - lastEvent[0]);
int dy1 = (int) (event.getY(0) - lastEvent[2]);
int dx2 = (int) (event.getX(1) - lastEvent[1]);
int dy2 = (int) (event.getY(1) - lastEvent[3]);
Log.d("dx1 ", ""+ dx1);
Log.d("dx2 ", "" + dx2);
Log.d("dy1 ", "" + dy1);
Log.d("dy2 ", "" + dy2);
//pointer 1
if(Math.abs(dx1) > Math.abs(dy1) && Math.abs(dx2) > Math.abs(dy2)) {
if(dx1 >= 2.0 && dx2 <= -2.0){
Log.d("first pointer ", "right");
return true;
}
else if(dx1 <= -2.0 && dx2 >= 2.0){
Log.d("first pointer ", "left");
return true;
}
}
else {
if(dy1 >= 2.0 && dy2 <= -2.0){
Log.d("seccond pointer ", "top");
return true;
}
else if(dy1 <= -2.0 && dy2 >= 2.0){
Log.d("second pointer ", "bottom");
return true;
}
}
return false;
}
}

I finally use this (spacing is used to calculated the distance between two fingers), I offset the imageview after scaling to keep it centered, works fine for now :
float newDist = spacing(event);
float scale = newDist / oldDist;
int oldH =getLayoutParams().height;
int oldW =getLayoutParams().width;
int newH =(int) (getLayoutParams().height*scale);
int newW =(int) (getLayoutParams().width*scale);
if(newH<MAX_SIZE && newW<MAX_SIZE){
//scale the height and width of the view
getLayoutParams().height = newH;
getLayoutParams().width = newW;
//calculate the X and Y offset to apply after scaling to keep the image centered
int xOffset = (int)(getLayoutParams().height - oldH)/2;
int yOffset = (int)(getLayoutParams().width - oldW)/2;
setX(getX()-xOffset);
setY(getY()-yOffset);
requestLayout();
setAdjustViewBounds(true);
oldDist=newDist;

All these examples had a glitchy gesture support because of scaleType was set to matrix. When I tried to zoom, I was not able to keep the image in center and control the amount of zoom. So I did some study and wrote a small, easy but very pleasing code for this: https://stackoverflow.com/a/65697376/13339685

Applying Zoom on Imageview and Sliding Imges

public class ShowImgsActivity extends Activity implements OnTouchListener{
int imagesArray[]={R.drawable.a1,R.drawable.a2,R.drawable.a3};
private ImageView img;
private List<String> sd;
float x1,x2;
float y1, y2;
private String[] files;
private AssetManager assetManager;
private int possition;
static int forwarInt=1;
private static final String TAG = "Touch";
#SuppressWarnings("unused")
private static final float MIN_ZOOM = 1f,MAX_ZOOM = 1f;
// These matrices will be used to scale points of the image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// The 3 states (events) which the user is trying to perform
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// these PointF objects are used to record the point(s) the user is touching
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.showimgsscreen);
init();
}
private void init() {
img=(ImageView) findViewById(R.id.img_prev);
assetManager =ShowImgsActivity.this.getAssets();
possition=getIntent().getIntExtra("Main_position",0);
try {
files = assetManager.list("Deaf/0"+possition);
getImage(getApplicationContext(), "Deaf/0"+possition, 0);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
forwarInt=0;
}
private void getImage(Context conetx,String folderName,int pos) throws IOException
{
if(pos<=files.length-1 && pos>=0)
{
Bitmap bmp;
bmp = BitmapFactory.decodeStream(assetManager.open(folderName+"/"
+ files[pos]));
img.setImageBitmap(bmp);
img.setOnTouchListener(this);
}else if (pos>files.length-1) {
forwarInt=files.length-1;
Toast.makeText(getApplicationContext(), "move backward", Toast.LENGTH_SHORT).show();
}
else if (pos<0) {
forwarInt=0;
Toast.makeText(getApplicationContext(), "move forward", Toast.LENGTH_SHORT).show();
}
else{
Log.e("_____________", "less greater");
}
}
#Override
public boolean onTouchEvent(MotionEvent touchevent) {
// touch=true;
switch (touchevent.getAction())
{
// when user first touches the screen we get x and y coordinate
case MotionEvent.ACTION_DOWN:
{
x1 = touchevent.getX();
y1 = touchevent.getY();
break;
}
case MotionEvent.ACTION_UP:
{
x2 = touchevent.getX();
y2 = touchevent.getY();
//if left to right sweep event on screen
if (x1 < x2)
{
forwarInt++;
Toast.makeText(this, "Left to Right Swap Performed", Toast.LENGTH_SHORT).show();
try {
getImage(getApplicationContext(), "Deaf/0"+possition, forwarInt);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// if right to left sweep event on screen
if (x1 > x2)
{
forwarInt--;
Toast.makeText(this, "Right to Left Swap Performed", Toast.LENGTH_SHORT).show();
try {
getImage(getApplicationContext(), "Deaf/0"+possition, forwarInt);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// if UP to Down sweep event on screen
if (y1 < y2)
{
// Toast.makeText(this, "UP to Down Swap Performed", Toast.LENGTH_LONG).show();
}
//if Down to UP sweep event on screen
if (y1 > y2)
{
// Toast.makeText(this, "Down to UP Swap Performed", Toast.LENGTH_LONG).show();
}
break;
}
}
return false;
}
#Override
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
float scale;
// dumpEvent(event);
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_DOWN: // first finger down only
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG"); // write to LogCat
mode = DRAG;
break;
case MotionEvent.ACTION_UP: // first finger lifted
case MotionEvent.ACTION_POINTER_UP: // second finger lifted
mode = NONE;
Log.d(TAG, "mode=NONE");
break;
case MotionEvent.ACTION_POINTER_DOWN: // first and second finger down
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 5f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG)
{
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix of points
}
else if (mode == ZOOM)
{
// pinch zooming
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 5f)
{
matrix.set(savedMatrix);
scale = newDist / oldDist; // setting the scaling of the
// matrix...if scale > 1 means
// zoom in...if scale < 1 means
// zoom out
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix); // display the transformation on screen
return true; // indicate event was handled
}
/*
* --------------------------------------------------------------------------
* Method: spacing Parameters: MotionEvent Returns: float Description:
* checks the spacing between the two fingers on touch
* ----------------------------------------------------
*/
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);
}
/*
* --------------------------------------------------------------------------
* Method: midPoint Parameters: PointF object, MotionEvent Returns: void
* Description: calculates the midpoint between the two fingers
* ------------------------------------------------------------
*/
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);
}
/** 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("]");
Log.d("Touch Events ---------", sb.toString());
}
}
i have images that are available in assets folder . I have Applied Sliding on Images now i want to apply zooming on each Image. But when i apply zooming functionality then Sliding functionality can't work.

Android pinch zoom not working when Image is set as background

I'm using this example to have pinch zoom property to my imageview. This example works perfectly when I set image as src to this imageview from xml. e.g.
<com.zoom.TouchImageView
android:id="#+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="matrix"
android:src="#drawable/idontcare" />
but then if image is not large enough it does not cover full screen. So instead of src if i use background
<com.zoom.TouchImageView
android:id="#+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="matrix"
android:background="#drawable/idontcare" />
it covers full screen but then pinch zoom does not work. Also instead of "matrix" if I use "fitXY" scale type pinchzoom does not work.
How do I achieve full screen image as well as pinchzoom? please help.
Thanks in advance.

TouchImageView only supports src not the background in ImageView. So what you can do is set your src with desired image and keep background in it as the bacground color of your image. something like that.
<com.zoom.TouchImageView
android:id="#+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="matrix"
android:src="#drawable/idontcare"
android:background="----- Background color of idontcare image--" />
try it.!

I passing the location of the image from sdcard to this activity and set to a imageview as a bitmap image ........
public class ZoomInZoomOut extends Activity implements OnTouchListener
{
private static final String TAG = "Touch";
#SuppressWarnings("unused")
private static final float MIN_ZOOM = 1f,MAX_ZOOM = 1f;
// These matrices will be used to scale points of the image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// The 3 states (events) which the user is trying to perform
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// these PointF objects are used to record the point(s) the user is touching
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
private String loc;
private ImageView view;
private Bitmap bmImg;
private ArrayList<String> array_loc;
private Button next;
private int total=0;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
try{
setContentView(R.layout.full_image);
Intent i = getIntent();
loc = i.getExtras().getString("loc").toString().trim();
int position = i.getExtras().getInt("id");
next = (Button)findViewById(R.id.next);
view = (ImageView) findViewById(R.id.full_image_view);
bmImg = BitmapFactory.decodeFile(loc);
view.setImageBitmap(bmImg);
view.setOnTouchListener(this);
System.out.println("..."+position);
array_loc = new ArrayList<String>();
String targetPath = "/mnt/sdcard/DCIM/Camera/";
File targetDirector = new File(targetPath);
File[] files = targetDirector.listFiles();
for (File file : files){
array_loc.add(file.getAbsolutePath());
total+=1;
}
System.out.println(array_loc);
System.out.println(array_loc.get(1));
next.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
}catch (Exception e) {
System.out.println(e);
}
}
public boolean onTouch(View v, MotionEvent event)
{
try{
ImageView view = (ImageView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
float scale;
dumpEvent(event);
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_DOWN: // first finger down only
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG"); // write to LogCat
mode = DRAG;
break;
case MotionEvent.ACTION_UP: // first finger lifted
case MotionEvent.ACTION_POINTER_UP: // second finger lifted
mode = NONE;
Log.d(TAG, "mode=NONE");
break;
case MotionEvent.ACTION_POINTER_DOWN: // first and second finger down
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 5f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG)
{
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix of points
}
else if (mode == ZOOM)
{
// pinch zooming
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 5f)
{
matrix.set(savedMatrix);
scale = newDist / oldDist; // setting the scaling of the
// matrix...if scale > 1 means
// zoom in...if scale < 1 means
// zoom out
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix); // display the transformation on screen
}catch (Exception e) {
System.out.println(e);
}
return true; // indicate event was handled
}
/*
* --------------------------------------------------------------------------
* Method: spacing Parameters: MotionEvent Returns: float Description:
* checks the spacing between the two fingers on touch
* ----------------------------------------------------
*/
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);
}
/*
* --------------------------------------------------------------------------
* Method: midPoint Parameters: PointF object, MotionEvent Returns: void
* Description: calculates the midpoint between the two fingers
* ------------------------------------------------------------
*/
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);
}
/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event)
{
try{
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("Touch Events ---------", sb.toString());
} catch (Exception e) {
System.out.println(e);
}
}
#Override
public void onBackPressed() {
// TODO Auto-generated method stub
Intent i = new Intent(getApplicationContext(),AndroidGridLayoutActivity.class);
startActivity(i);
ZoomInZoomOut.this.finish();
}
}

Drawing a rectangle over an image

In my application, there's an activity which gets image from the resource, i have incorporated panning and zooming functionality in the same.
What i want now is to draw a rectangle over it in such a way that the rectangle too shall zoom and pan with the image. I tried extending view and overriding the draw. Only the rectangle comes and not the image. Would be very helpful if someone could assist me.
public class XYZ extends Activity implements OnTouchListener {
private static final String TAG = "Touch" ;
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new 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;
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
private Bitmap mBitmap;
ImageView mapView;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.jubileemap);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inDither= false;
options.inInputShareable=true;
options.inTempStorage=new byte[8*1024];
mapView = (ImageView) findViewById(R.id.abc);
mBitmap =BitmapFactory.decodeResource(XYZ.this.getResources(),R.drawable.pqr, options);
mapView.setImageBitmap(mBitmap);
mapView.setOnTouchListener(JubileeMaps.this);
}
#Override
public void onLowMemory(){
Log.e("low memory", "low");
System.gc();
}
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);
}
#Override
public boolean onTouch(View v, MotionEvent event) {
mapView.setScaleType(ImageView.ScaleType.MATRIX);
// TODO Auto-generated method stub
ImageView view = (ImageView) v;
// Dump touch event to log
dumpEvent(event);
// Handle touch events here...
/*spacing(event);
midPoint(point,event);*/
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG" );
mode = DRAG;
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
Log.d(TAG, "mode=NONE" );
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x,
event.getY() - start.y);
} else if (mode == ZOOM) {
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM" );
}
break;
}
// Perform the transformation
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
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("]" );
Log.d(TAG, sb.toString());
}
#Override
public void onPause()
{
super.onPause();
System.gc();
}
#Override
protected void onResume()
{
super.onResume();
System.gc();
}
#Override
protected void onDestroy() {
super.onDestroy();
System.gc();
mapView.setImageBitmap(null);
mBitmap.recycle();
}
}
And the xml i'm using is:
<ImageZoomView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/zoomview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
This is the code i'm using..now on top of the image i wanna draw a recagle to mark an area which will zoom in and out as my image does.But have been unable to implements this.

You should override the onDraw method.
Be sure to leave the call to super.onDraw() and do your custom drawing below that line.
See this example:
http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/view/LabelView.html