Develop Reference

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...

ImageView limit drag and drop and zoom out of screen

I want to limit drag and drop of imageView to not goes out of screen, i don't know how do that, specially when imageView is zoomed, how can i keep imageView in the screen when it's zoomed or not?
here is my code:
/**
* Apply drag zoom to image
*
* #param imageToEdit
* #param mActivity
*/
public static void setOntoucheListner(ImageView imageToEdit, Activity mActivity, final ImageView imageMask) {
// Calcul pourcentage du min image
float ratio1 = imageToEdit.getWidth() / imageMask.getWidth();
float ratio2 = imageToEdit.getHeight() / imageMask.getHeight();
if (ratio1 < 1 && ratio2 < 1)
ZOOM_MIN = 1;
else
ZOOM_MIN = Math.min(ratio1, ratio2);
Display display = mActivity.getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
screenWidth = size.x;
screenHeight = size.y;
matrix = new Matrix();
savedMatrix = new Matrix();
startPoint = new PointF();
midPoint = new PointF();
// imageToEdit.setImageMatrix(new Matrix());
/** * set on touch listner on image */
imageToEdit.setOnTouchListener(new View.OnTouchListener() {
private float savedTranslateX = 0;
private float savedTranslateY = 0;
#Override
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
System.out.println("matrix=" + savedMatrix.toString());
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
startPoint.set(event.getX(), event.getY());
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(midPoint, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
imageMask.getTop();
imageMask.getTop();
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - startPoint.x, event.getY() - startPoint.y);
mode = DRAG;
} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, midPoint.x, midPoint.y);
}
}
break;
}
float[] f = new float[9];
matrix.getValues(f);
float scaleX = f[Matrix.MSCALE_X];
float scaleY = f[Matrix.MSCALE_Y];
if (mode == ZOOM) {
if (scaleX <= ZOOM_MIN)
matrix.postScale((ZOOM_MIN) / scaleX, (ZOOM_MIN) / scaleY, midPoint.x, midPoint.y);
else if (scaleX >= ZOOM_MAX)
matrix.postScale((ZOOM_MAX) / scaleX, (ZOOM_MAX) / scaleY, midPoint.x, midPoint.y);
else {
view.setImageMatrix(matrix);
}
} else {
view.setImageMatrix(matrix);
}
return true;
}
#SuppressLint("FloatMath")
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);
}
});
}
}
Thank's a lot for your responses

I solved my problem, when user drap imageView out of bounds and release his fingers, i replace imageView on the last valid places so i complete case MotionEvent.ACTION_POINTER_UP like this: My limit here is not the screen but another ImageView,
case MotionEvent.ACTION_POINTER_UP:
matrix.getValues(values);
translateX = values[Matrix.MTRANS_X];
translateY = values[Matrix.MTRANS_Y];
Log.d("####### actualWidthImageToEdit"
+ actualWidthImageToEdit);
Log.d("####### translateX" + translateX);
Log.d("####### imageMask.getRight()" + imageMask.getRight());
// After User release fingers from screen we test if image
// is on a valid position if not we replace it in the last
// valid position
if (mode == DRAG || mode == DEZOOM) {
if (
// Limit Left, Move left to right
translateX > imageMask.getLeft()
// Limit Button, from top to buttom
|| translateY > imageMask.getTop()
// left to right
|| actualWidthImageToEdit
- imageMask.getRight() + translateX < 0
// Limit Top, from buttom to top
|| actualHeightImageToEdit
- imageMask.getBottom() + translateY < 0
) {
matrix = new Matrix(savedMatrix);
view.setImageMatrix(matrix);
view.invalidate();
}
}

Get width and height of the imageView after resizing using matrix

I want to get the width and height of the scaled imageView using this code that I got from the internet:
public class MultiTouch extends Activity 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;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageView view = (ImageView) findViewById(R.id.imageView);
view.setOnTouchListener(this);
}
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);
}
}
My problem is if my original imageview is smaller than the scaled image, the image is showing but with the original size of my imageview. This is the part where the image is zooming:
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = (newDist / oldDist);
matrix.postScale(scale, scale, mid.x, mid.y);
}
I want also to resize the container of my imageview.
This is the actual what is happening. the left image is the original, and the right side image is the actual result. I want the imageview container will be the same size of the scaled image.

you can get scaleFactor from your matrix by calling
float[] matrixValues = new float[9];
yourMatrix.getValues(matrixValues);
float scaleX = matrixValues[Matrix.MSCALE_X];
float scaleY = matrixValues[Matrix.MSCALE_Y];
and then multiplying your main width and height by appropriate values

Use WrapContent for both Height and Width of your ImageView

Android pinch zoom, ZoomOut and ZoomIn, in limit

I have already searched alot around here but haven't found a solution yet. So the thing is , I have a image 3000*3000 px, I set it to scale type matrix. Now I have only the left corner showing of the image. Now I don't want people to zoom in at this stage, only zoom out to a maximum of 'x' (Still have to see how much).
It's the imageview "kaart" that has to be zoomed.
question : How to let people only zoom out in the beginning and don't let them pass x ?and afterwards, don't let them zoom in more than the original size
i've tried with negative values , but that didn't work
Here is my code:
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// max and min zoom
//private static final float MIN_ZOOM = 1.0f;
//private static final float MAX_ZOOM = 5.0f;
//scale = Math.max(MIN_ZOOM, Math.min(scale, MAX_ZOOM));
// 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;
String savedItemClicked;
ImageView view;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.kaart);
view = (ImageView) findViewById(R.id.kaart);
view.setOnTouchListener(this);
}
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
ImageView view = (ImageView) v;
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());
//Log.d(TAG, "mode=DRAG");
mode = DRAG;
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;
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;
}
limitZoom(matrix);
limitDrag(matrix);
view.setImageMatrix(matrix);
return true;
}
#SuppressWarnings("deprecation")
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());
}
/** 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);
}
}
Hope someone can help me. I would really apreciate it.
EDIT
I have added 2 functions i found somewhere.
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);
}
and
private void limitDrag(Matrix m) {
float[] values = new float[9];
m.getValues(values);
float transX = values[Matrix.MTRANS_X];
float transY = values[Matrix.MTRANS_Y];
float scaleX = values[Matrix.MSCALE_X];
float scaleY = values[Matrix.MSCALE_Y];
ImageView iv = (ImageView)findViewById(R.id.kaart);
Rect bounds = iv.getDrawable().getBounds();
int viewWidth = getResources().getDisplayMetrics().widthPixels;
int viewHeight = getResources().getDisplayMetrics().heightPixels;
int width = bounds.right - bounds.left;
int height = bounds.bottom - bounds.top;
float minX = (-width + 20) * scaleX;
float minY = (-height + 20) * scaleY;
if(transX > (viewWidth - 20)) {
transX = viewWidth - 20;
} else if(transX < minX) {
transX = minX;
}
if(transY > (viewHeight - 80)) {
transY = viewHeight - 80;
} else if(transY < minY) {
transY = minY;
}
values[Matrix.MTRANS_X] = transX;
values[Matrix.MTRANS_Y] = transY;
m.setValues(values);
}
I have to call these functions right after the switch case and just before is set the imagematrix on my view. (I have added this to my previous code here above)
maybe this isn't the best solution , but it works .

If I understand your code, you keep saving the matrix as a way to remember what was the state of the zoom and scroll (which could be done by one matrix alone, but maybe you're doing other manipulations).
This way, every action effects are relative to the last state, and it's difficult to set an absolute limit to the zoom (and scroll too): to get their absolute values, you'd have to call matrix.getValues() and pick the values from the array it returns.
Try instead saving the current x-scroll, y-scroll and zoom, and at every action check if their updated values (that now remain absolute) would be inside your limits; if so actually update them, then reset the matrix and set the new scroll/zoom values.
(also, consider the use of GestureDetector and ScaleGestureDetector)

Imageview issue with zoom in and out,drag with maximum and minimum levels

I had implemented an image view with the zoom and drag functionalities.I am using matrix for the zoom and drag functionality.But my problem is that I cant set my minimum and maximum zoom level and the drag space limit.can any on e tell me how I can do that.
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 float spacing(PointF start,PointF end)
{
float x = end.x- start.x;
float y = end.y -start.y;
return FloatMath.sqrt(x * x + y * y);
}
#Override
public boolean onTouch(View v, MotionEvent event)
{
ImageView view = (ImageView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
float scale;
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:
if(mode==DRAG)
{
PointF end=new PointF();
end.set(event.getX(), event.getY());
Log.d("Fling", "Inside the Action Key UP"+spacing(start, end));
float []x = new float[9],org=new float[9];
matrix.getValues(x);
orgMatrix.getValues(org);
Log.d("Fling", "matrixValue"+matrix);
Log.d("Fling", "OrgmatrixValue"+orgMatrix);
float matrixSizex=x[Matrix.MSCALE_X];
float matrixSizey=x[Matrix.MSCALE_Y];
float matrixOrgSizex=org[Matrix.MSCALE_X];
float matrixOrgSizey=org[Matrix.MSCALE_Y];
if(Math.abs(matrixOrgSizex-matrixSizex)<0.17f&&Math.abs(matrixOrgSizey-matrixSizey)<0.17f)
{
Log.d("Fling", "Current Size is equal");
if(spacing(start, end)>30.f)
{
if((start.x>end.x+30)&&(Math.abs(start.y-end.y)<50.0f))
{
Log.d("Fling", "Is From Right To left");
loadedimage.setImageMatrix(orgMatrix);
leftSwipe();
view.setScaleType(ImageView.ScaleType.FIT_XY);
}
else if((end.x>start.x+30)&&(Math.abs(end.y-start.y)<50.0f))
{
Log.d("Fling", "Is From Left To Right");
loadedimage.setImageMatrix(orgMatrix);
rightSwipe();
view.setScaleType(ImageView.ScaleType.FIT_XY);
}
}
}
}
case MotionEvent.ACTION_POINTER_UP: //second finger lifted
mode = NONE;
Log.d(TAG, "mode=NONE" );
break;
case MotionEvent.ACTION_POINTER_DOWN: //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) {
//movement of first finger
PointF end=new PointF();
end.set(event.getX(), event.getY());
Log.d("Fling", "Inside the Action Key UP"+spacing(start, end));
float []x = new float[9],org=new float[9];
matrix.getValues(x);
orgMatrix.getValues(org);
Log.d("Fling", "matrixValue"+matrix);
Log.d("Fling", "OrgmatrixValue"+orgMatrix);
float matrixSizex=x[Matrix.MSCALE_X];
float matrixSizey=x[Matrix.MSCALE_Y];
float matrixOrgSizex=org[Matrix.MSCALE_X];
float matrixOrgSizey=org[Matrix.MSCALE_Y];
if(Math.abs(matrixOrgSizex-matrixSizex)>=0.17f&&Math.abs(matrixOrgSizey-matrixSizey)>=0.17f)
{
matrix.set(savedMatrix);
if (view.getLeft() >= 0)
{
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y);
}
}
}
else if (mode == ZOOM) { //pinch zooming
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 5f) {
matrix.set(savedMatrix);
scale = newDist / oldDist; //thinking i need to play around with this value to limit it**
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
// Perform the transformation
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
My Sample code is here can any one help me in setting minimum and maximum zoom and drag level.I also have problem when I touch in the image view it automatically get zoomed when converted to the matrix I cant make it stay fit in the device screen.I am totally stuck here........

To restrict zooming I compare the zoomed matrix with the identity matrix and don't assign it to my ImageView if it's smaller than the identity matrix, in which case I reset the scaled matrix back to the identity matrix. I'm using Mono for Android but I guess it will be almost the same in Java:
//check that zoom is not too small
if (Utils.SmallerThanIdentity(matrix))
{
ResetView(v);
}
Where SmallerThanIdentity is implemented:
public static bool SmallerThanIdentity(Android.Graphics.Matrix m)
{
float[] values = new float[9];
m.GetValues(values);
return ((values[0] < 1.0) || (values[4] < 1.0) || (values[8] < 1.0));
}
And here's ResetView. I have Java code for that:
public void resetView(View v)
{
ImageView view = (ImageView)v;
matrix = new Matrix();
view.setScaleType(ImageView.ScaleType.MATRIX);
view.setImageMatrix(matrix);
}
Regarding scroll, I use the ShouldScroll method below before translating the matrix to the area where I want to restrict the scrolling.
private bool ShouldScroll(Android.Graphics.Matrix matrix)
{
float[] values = new float[9];
matrix.GetValues(values);
float[] oldValues = new float[9];
oldMatrix.GetValues(oldValues);
float zoomPercentX = values[0] / oldValues[0];
float zoomPercentY = values[4] / oldValues[4];
float tmpW = -(this.Drawable.IntrinsicWidth / 2) * zoomPercentX;
float tmpH = -(this.Drawable.IntrinsicHeight / 2) * zoomPercentY;
return (values[2] < 0.0f) && (values[2] > tmpW) && //horizontal coordinates
(values[5] < 0.0f) && (values[5] > tmpH); //vertical coordinates
}