Develop Reference

Moving image with it's touch event in android?

I am trying to make that one image is moving automatically in whole screen as per resolution of mobile device. Now, i want its click or touch event. I have refereed many things but couldn't find any relevant answer. Is there any example related it so i can refer in android.

Use following code to move image.I am using it and it is working fine for me.
import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.FloatMath;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
public class Touch implements OnTouchListener {
// 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;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
#Override
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
// Dump touch event to log
dumpEvent(event);
// 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;
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;
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);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
/** 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_INDEX_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("]");
}
/** Determine the space between the first two fingers */
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);
}
/** Calculate the mid point of the first 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);
}
}
note->
from your activity attach this listener by doing
imageview.setOnTouchListener(new Touch());

public class MainActivity extends Activity implements View.OnTouchListener {
// these matrices will be used to move and zoom image
private Matrix matrix = new Matrix();
private Matrix savedMatrix = new Matrix();
// 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;
// remember some things for zooming
private PointF start = new PointF();
private PointF mid = new PointF();
private float oldDist = 1f;
private float d = 0f;
private float newRot = 0f;
private float[] lastEvent = null;
private ImageView view, fin;
private Bitmap bmap;
FrameLayout frm;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
view = (ImageView) findViewById(R.id.imageView);
fin = (ImageView) findViewById(R.id.imageView1);
view.setOnTouchListener(this);
frm=(FrameLayout)findViewById(R.id.frm);
}
public boolean onTouch(View v, MotionEvent event) {
// handle touch events here
view = (ImageView) v;
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) {
savedMatrix.set(matrix);
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:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
matrix.set(savedMatrix);
float dx = event.getX() - start.x;
float dy = event.getY() - start.y;
matrix.postTranslate(dx, dy);
} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = (newDist / oldDist);
matrix.postScale(scale, scale, mid.x, mid.y);
}
if (lastEvent != null && event.getPointerCount() == 2 || event.getPointerCount() == 3) {
newRot = rotation(event);
float r = newRot - d;
float[] values = new float[9];
matrix.getValues(values);
float tx = values[2];
float ty = values[5];
float sx = values[0];
float xc = (view.getWidth() / 2) * sx;
float yc = (view.getHeight() / 2) * sx;
matrix.postRotate(r, tx + xc, ty + yc);
}
}
break;
}
view.setBackgroundResource(R.mipmap.ic_launcher);
view.setImageMatrix(matrix);
bmap= Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bmap);
view.draw(canvas);
//fin.setImageBitmap(bmap);
return true;
}
public void ButtonClick(View v){
fin.setImageBitmap(bmap);
}
/**
* Determine the space between the first two fingers
*/
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
float s=x * x + y * y;
return (float)Math.sqrt(s);
}
/**
* Calculate the mid point of the first 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);
}
/**
* Calculate the degree to be rotated by.
*
* #param event
* #return Degrees
*/
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);
}
}
-> Try this.

Android Multitouch Dynamic Imageview Drag only recently added Imageview

This is My Touch Listener Class:
public class Touch_Listner implements OnTouchListener{
// these matrices will be used to move and zoom image
private Matrix matrix = new Matrix();
private Matrix savedMatrix = new Matrix();
// 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;
// remember some things for zooming
private PointF start = new PointF();
private PointF mid = new PointF();
private float oldDist = 1f;
private float d = 0f;
private float newRot = 0f;
private float[] lastEvent = null;
public boolean onTouch(View v, MotionEvent event) {
// handle touch events here
ImageView view = (ImageView) v;
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) {
savedMatrix.set(matrix);
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:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
matrix.set(savedMatrix);
float dx = event.getX() - start.x;
float dy = event.getY() - start.y;
matrix.postTranslate(dx, dy);
} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = (newDist / oldDist);
matrix.postScale(scale, scale, mid.x, mid.y);
}
if (lastEvent != null && event.getPointerCount() == 3) {
newRot = rotation(event);
float r = newRot - d;
float[] values = new float[9];
matrix.getValues(values);
float tx = values[2];
float ty = values[5];
float sx = values[0];
float xc = (view.getWidth() / 2) * sx;
float yc = (view.getHeight() / 2) * sx;
matrix.postRotate(r, tx + xc, ty + yc);
}
}
break;
}
view.setImageMatrix(matrix);
return true;
}
/**
* Determine the space between the first two fingers
*/
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);
}
/**
* Calculate the mid point of the first 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);
}
/**
* Calculate the degree to be rotated by.
*
* #param event
* #return Degrees
*/
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);
}
}
}
Create Dynamic Imageview using following method:
private void Add_Imageview(final String btn_id,Bitmap resource) {
ImageView image = new ImageView(this);
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(
FrameLayout.LayoutParams.FILL_PARENT,
FrameLayout.LayoutParams.FILL_PARENT);
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth(); // deprecated
int height = display.getHeight(); // deprecated
image.setScaleType(ImageView.ScaleType.MATRIX);
image.setImageBitmap(resource);
image.setTag(btn_id);
image.setId(imgview_index);
rel_image.addView(image);
image.getLayoutParams().height = rel_image.getHeight();
image.getLayoutParams().width = rel_image.getWidth();
int[] values = new int[2];
image.getLocationOnScreen(values);
System.out.println("x location::"+values[0]);
System.out.println(" y location::"+values[1]);
image.setOnTouchListener(new Touch_Listner());
}
when I call this method more than once it Drag only recently added Imageview i want to move rotate zoom any imageview any time

you can try this code https://github.com/siddhpuraamitr/MultitouchWithDynamicAddandRemove for your project...

Move a view with OnTouchEvent

I Have this code to put a View where I touch in a Screen.
But the View doesn't follow exactly the point where my finger touch.
Can I improve this behavior?
To works like Drag and Drop API but using onTouchEvent?
Thanks for all!
#Override
public boolean onTouchEvent(final MotionEvent event) {
final float x = event.getX();
final float y = event.getY();
moveView(x, y);
return super.onTouchEvent(event);
}
private void moveView(float x, float y) {
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
params.leftMargin = Math.round(x);
params.topMargin = Math.round(y);
selectedView.setLayoutParams(params);
}

try playing around with some offsets to your x and y coordinates.
//should be on the order of magnitude of the size of the view
float x_offset= 10; //Play with this.
float y_offset= 10; //Play with this.
final float x = event.getX() + x_offset;
final float y = event.getY() + y_offset;
moveView(x, y);

// 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;
//private static final float MAX_ZOOM = 5f;
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;
float[] lastEvent = null;
float degrees = 0f;
float newRot = 0f;
OnTouchListener touchAction = new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
//perfrom zoom & drag & rotate operations on touch of imageview
dragZoomRotate((ImageView)v, event);
return true;
}
};
private void dragZoomRotate(ImageView view, MotionEvent event){
view.setScaleType(ImageView.ScaleType.MATRIX);
// 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: // first and second finger down
oldDist = spacing(event);
savedMatrix.set(matrix);
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);
degrees = rotation(event);
break;
case MotionEvent.ACTION_UP: // first finger lifted
case MotionEvent.ACTION_POINTER_UP: // second finger lifted
mode = NONE;
lastEvent = null;
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 && event.getPointerCount()==2) {
float newDist = spacing(event);
matrix.set(savedMatrix);
if (newDist > 10f) {
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
if (lastEvent!=null){
newRot = rotation(event);
float r = newRot-degrees;
matrix.postRotate(r, view.getMeasuredWidth()/2, view.getMeasuredHeight()/2);
}
}
//
break;
}
view.setImageMatrix(matrix);
}
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);
}
/*
* --------------------------------------------------------------------------
* 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);
}
Now add the touchAction listener to the view which you want to move...
myImageView.setOnTouchListener(touchAction);

try change your layout from RelativeLayout to AbsoluteLayout

Android finger rotate , zoom and move image together?

i would like to ask can the three functions rotate, zoom and move the image with user's finger happen together in one application?
I found the source code to drag an image plus the zoom feature. However, i cannot find the way to add the rotation function to the code.
Can any one teach how to build these three functions together?

Try with below code its working for me.
float[] lastEvent = null;
float d = 0f;
float newRot = 0f;
private Matrix matrix = new Matrix();
private Matrix savedMatrix = new Matrix();
public static String fileNAME;
public static int framePos = 0;
private float scale = 0;
private float newDist = 0;
// Fields
private String TAG = this.getClass().getSimpleName();
// 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;
// Remember some things for zooming
private PointF start = new PointF();
private PointF mid = new PointF();
float oldDist = 1f;
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
// 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) {
savedMatrix.set(matrix);
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:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
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 && event.getPointerCount() == 2) {
float newDist = spacing(event);
matrix.set(savedMatrix);
if (newDist > 10f) {
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
if (lastEvent != null) {
newRot = rotation(event);
float r = newRot - d;
matrix.postRotate(r, view.getMeasuredWidth() / 2,
view.getMeasuredHeight() / 2);
}
}
break;
}
view.setImageMatrix(matrix);
return true;
}
//For rotate image on multi-touch.
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);
}

I would recommend using the android-multitouch-controller. It has worked great for me, and it offers multi-touch zoom, pan, and rotate just like you want. It's licensed under Apache v2. Be careful with the rotation. Multi-touch rotation only works well with certain devices.
NOTE: rotation is quirky on older touchscreen devices that use a
Synaptics or Synaptics-like "2x1D" sensor (G1, MyTouch, Droid, Nexus
One) and not a true 2D sensor like the HTC Incredible or HTC EVO 4G.

Get Canvas coordinates after scaling up/down or dragging in android

I'm developing an application in which I'm pasting images, doing drawing and painting on canvas. This app can also Scale up/down the canvas or drag it to different location.
My problem is: I can't get the correct canvas coordinates after scaling or dragging the canvas. I want to draw finger paint after the canvas is scaled or dragged but unable to retrieve the right place where i've touched..:(
Also I'm new bee. Here is the code.
#Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.save();
//canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor, super.getWidth() * 0.5f,
super.getHeight() * 0.5f);
mIcon.draw(canvas);
for (Path path : listPath) {
canvas.drawPath(path, paint);
}
canvas.restore();
}
public TouchExampleView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
// Let the ScaleGestureDetector inspect all events.
mScaleDetector.onTouchEvent(ev);
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
mLastTouchX = x;
mLastTouchY = y;
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE: {
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
// Only move if the ScaleGestureDetector isn't processing a gesture.
if (!mScaleDetector.isInProgress()) {
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
invalidate();
}
mLastTouchX = x;
mLastTouchY = y;
break;
}
case MotionEvent.ACTION_UP: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_POINTER_UP: {
final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.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 = ev.getX(newPointerIndex);
mLastTouchY = ev.getY(newPointerIndex);
mActivePointerId = ev.getPointerId(newPointerIndex);
}
break;
}
}
float objectNewX,objectNewY;
if (mScaleFactor >= 1) {
objectNewX = ev.getX() + (ev.getX() - super.getWidth() * 0.5f) * (mScaleFactor - 1);
objectNewY = ev.getY() + (ev.getY() - super.getHeight() * 0.5f) * (mScaleFactor - 1);
} else {
objectNewX = ev.getX() - (ev.getX() - super.getWidth() * 0.5f) * (1 - mScaleFactor);
objectNewY = ev.getY() - (ev.getY() - super.getHeight() * 0.5f) * (1 - mScaleFactor);
}
if (ev.getAction() == MotionEvent.ACTION_DOWN) {
path = new Path();
path.moveTo(objectNewX,objectNewY);
path.lineTo(objectNewX,objectNewY);
} else if (ev.getAction() == MotionEvent.ACTION_MOVE) {
path.lineTo(objectNewX,objectNewY);
listPath.add(path);
} else if (ev.getAction() == MotionEvent.ACTION_UP) {
path.lineTo(objectNewX,objectNewY);
listPath.add(path);
}
return true;
}
private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f));
invalidate();
return true;
}
}

Done it finally by myself.
Draw everything by applying this formula to (px,py) coordinates:
float px = ev.getX() / mScaleFactor + rect.left;
float py = ev.getY() / mScaleFactor + rect.top;
rect = canvas.getClipBounds();
//Get them in on Draw function and apply above formula before drawing

#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
clipBounds_canvas = canvas.getClipBounds();
/////Do whatever you want to do..!!!
};
#Override
public boolean onTouchEvent(MotionEvent ev) {
int x = ev.getX() / zoomFactor + clipBounds_canvas.left;
int y = ev.getY() / zoomFactor + clipBounds_canvas.top;
//Use the above two values insted of ev.getX() and ev.getY();
}
Hope this will help.