check below code will help you.
//CUSTOM IMAGEVIEW
import java.io.ByteArrayOutputStream;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.FloatMath;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
public class ScaleImageView extends ImageView implements OnTouchListener {
static final float STROKE_WIDTH = 10f;
static final float HALF_STROKE_WIDTH = STROKE_WIDTH / 2;
float lastTouchX;
float lastTouchY;
final RectF dirtyRect = new RectF();
private Context mContext;
private float MAX_SCALE = 2f;
private static Matrix mMatrix;
private final float[] mMatrixValues = new float[9];
// display width height.
private int mWidth;
private int mHeight;
private int mIntrinsicWidth;
private int mIntrinsicHeight;
private float mScale;
private float mMinScale;
private float mPrevDistance;
private boolean isScaling;
private int mPrevMoveX;
private int mPrevMoveY;
private GestureDetector mDetector;
Paint paint = new Paint();
public static Path path = new Path();
public static int imageheight, imagewidth;
String TAG = "ScaleImageView";
public ScaleImageView(Context context, AttributeSet attr) {
super(context, attr);
this.mContext = context;
initialize();
}
public ScaleImageView(Context context) {
super(context);
this.mContext = context;
initialize();
}
private void resetDirtyRect(float eventX, float eventY) {
dirtyRect.left = Math.min(lastTouchX, eventX);
dirtyRect.right = Math.max(lastTouchX, eventX);
dirtyRect.top = Math.min(lastTouchY, eventY);
dirtyRect.bottom = Math.max(lastTouchY, eventY);
}
@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
this.initialize();
}
@Override
public void setImageResource(int resId) {
super.setImageResource(resId);
this.initialize();
}
private void initialize() {
this.setScaleType(ScaleType.MATRIX);
this.mMatrix = new Matrix();
Drawable d = getDrawable();
paint.setAntiAlias(true);
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
if (d != null) {
mIntrinsicWidth = d.getIntrinsicWidth();
mIntrinsicHeight = d.getIntrinsicHeight();
setOnTouchListener(this);
}
mDetector = new GestureDetector(mContext,
new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDoubleTap(MotionEvent e) {
maxZoomTo((int) e.getX(), (int) e.getY());
cutting();
return super.onDoubleTap(e);
}
});
}
@Override
protected boolean setFrame(int l, int t, int r, int b) {
mWidth = r - l;
mHeight = b - t;
mMatrix.reset();
int r_norm = r - l;
mScale = (float) r_norm / (float) mIntrinsicWidth;
int paddingHeight = 0;
int paddingWidth = 0;
// scaling vertical
if (mScale * mIntrinsicHeight > mHeight) {
mScale = (float) mHeight / (float) mIntrinsicHeight;
mMatrix.postScale(mScale, mScale);
paddingWidth = (r - mWidth) / 2;
paddingHeight = 0;
// scaling horizontal
} else {
mMatrix.postScale(mScale, mScale);
paddingHeight = (b - mHeight) / 2;
paddingWidth = 0;
}
mMatrix.postTranslate(paddingWidth, paddingHeight);
setImageMatrix(mMatrix);
mMinScale = mScale;
zoomTo(mScale, mWidth / 2, mHeight / 2);
cutting();
return super.setFrame(l, t, r, b);
}
protected float getValue(Matrix matrix, int whichValue) {
matrix.getValues(mMatrixValues);
return mMatrixValues[whichValue];
}
protected float getScale() {
return getValue(mMatrix, Matrix.MSCALE_X);
}
public float getTranslateX() {
return getValue(mMatrix, Matrix.MTRANS_X);
}
protected float getTranslateY() {
return getValue(mMatrix, Matrix.MTRANS_Y);
}
protected void maxZoomTo(int x, int y) {
if (mMinScale != getScale() && (getScale() - mMinScale) > 0.1f) {
// threshold 0.1f
float scale = mMinScale / getScale();
zoomTo(scale, x, y);
} else {
float scale = MAX_SCALE / getScale();
zoomTo(scale, x, y);
}
}
public void zoomTo(float scale, int x, int y) {
if (getScale() * scale < mMinScale) {
return;
}
if (scale >= 1 && getScale() * scale > MAX_SCALE) {
return;
}
mMatrix.postScale(scale, scale);
// move to center
mMatrix.postTranslate(-(mWidth * scale - mWidth) / 2,
-(mHeight * scale - mHeight) / 2);
// move x and y distance
mMatrix.postTranslate(-(x - (mWidth / 2)) * scale, 0);
mMatrix.postTranslate(0, -(y - (mHeight / 2)) * scale);
setImageMatrix(mMatrix);
}
public void cutting() {
int width = (int) (mIntrinsicWidth * getScale());
int height = (int) (mIntrinsicHeight * getScale());
imagewidth = width;
imageheight = height;
if (getTranslateX() < -(width - mWidth)) {
mMatrix.postTranslate(-(getTranslateX() + width - mWidth), 0);
}
if (getTranslateX() > 0) {
mMatrix.postTranslate(-getTranslateX(), 0);
}
if (getTranslateY() < -(height - mHeight)) {
mMatrix.postTranslate(0, -(getTranslateY() + height - mHeight));
}
if (getTranslateY() > 0) {
mMatrix.postTranslate(0, -getTranslateY());
}
if (width < mWidth) {
mMatrix.postTranslate((mWidth - width) / 2, 0);
}
if (height < mHeight) {
mMatrix.postTranslate(0, (mHeight - height) / 2);
}
setImageMatrix(mMatrix);
}
private float distance(float x0, float x1, float y0, float y1) {
float x = x0 - x1;
float y = y0 - y1;
return FloatMath.sqrt(x * x + y * y);
}
private float dispDistance() {
return FloatMath.sqrt(mWidth * mWidth + mHeight * mHeight);
}
public void clear() {
path.reset();
invalidate();
}
public static void save() {
Bitmap returnedBitmap = Bitmap.createBitmap(
ScaleImageViewActivity.imageview.getWidth(),
ScaleImageViewActivity.imageview.getHeight(),
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(returnedBitmap);
Drawable bgDrawable = ScaleImageViewActivity.imageview.getDrawable();
if (bgDrawable != null)
bgDrawable.draw(canvas);
else
canvas.drawColor(Color.WHITE);
ScaleImageViewActivity.imageview.draw(canvas);
ByteArrayOutputStream bs = new ByteArrayOutputStream();
returnedBitmap.compress(Bitmap.CompressFormat.PNG, 50, bs);
Bitmap FinalBitmap = BitmapFactory.decodeByteArray(bs.toByteArray(), 0,
bs.toByteArray().length);
ScaleImageViewActivity.imageview.setImageBitmap(FinalBitmap);
path.reset();
// ScaleImageViewActivity.imageview.setImageMatrix(mMatrix);
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
if (!ScaleImageViewActivity.flag) {
if (mDetector.onTouchEvent(event)) {
return true;
}
int touchCount = event.getPointerCount();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_1_DOWN:
case MotionEvent.ACTION_POINTER_2_DOWN:
if (touchCount >= 2) {
float distance = distance(event.getX(0), event.getX(1),
event.getY(0), event.getY(1));
mPrevDistance = distance;
isScaling = true;
} else {
mPrevMoveX = (int) event.getX();
mPrevMoveY = (int) event.getY();
}
case MotionEvent.ACTION_MOVE:
if (touchCount >= 2 && isScaling) {
float dist = distance(event.getX(0), event.getX(1),
event.getY(0), event.getY(1));
float scale = (dist - mPrevDistance) / dispDistance();
mPrevDistance = dist;
scale += 1;
scale = scale * scale;
zoomTo(scale, mWidth / 2, mHeight / 2);
cutting();
} else if (!isScaling) {
int distanceX = mPrevMoveX - (int) event.getX();
int distanceY = mPrevMoveY - (int) event.getY();
mPrevMoveX = (int) event.getX();
mPrevMoveY = (int) event.getY();
mMatrix.postTranslate(-distanceX, -distanceY);
cutting();
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_POINTER_2_UP:
if (event.getPointerCount() <= 1) {
isScaling = false;
}
break;
}
} else {
float eventX = event.getX();
float eventY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
path.moveTo(eventX, eventY);
lastTouchX = eventX;
lastTouchY = eventY;
return true;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
resetDirtyRect(eventX, eventY);
int historySize = event.getHistorySize();
for (int i = 0; i < historySize; i++) {
float historicalX = event.getHistoricalX(i);
float historicalY = event.getHistoricalY(i);
path.lineTo(historicalX, historicalY);
}
path.lineTo(eventX, eventY);
break;
}
invalidate((int) (dirtyRect.left - HALF_STROKE_WIDTH),
(int) (dirtyRect.top - HALF_STROKE_WIDTH),
(int) (dirtyRect.right + HALF_STROKE_WIDTH),
(int) (dirtyRect.bottom + HALF_STROKE_WIDTH));
lastTouchX = eventX;
lastTouchY = eventY;
}
return true;
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
if (ScaleImageViewActivity.flag)
canvas.drawPath(path, paint);
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouch(View v, MotionEvent event) {
return super.onTouchEvent(event);
}
}
//ACTIVITY
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class ScaleImageViewActivity extends Activity implements OnClickListener {
Button btndraw, btnzoom, btnsave;
public static ScaleImageView imageview;
public static boolean flag = true;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
initwidget();
}
private void initwidget() {
imageview = (ScaleImageView) findViewById(R.id.image);
btnsave = (Button) findViewById(R.id.activity_main_save);
btndraw = (Button) findViewById(R.id.activity_main_zoom_draw);
btnzoom = (Button) findViewById(R.id.activity_main_zoom_zoom);
btndraw.setOnClickListener(this);
btnzoom.setOnClickListener(this);
btnsave.setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if (btndraw.equals(arg0)) {
flag = true;
} else if (btnzoom.equals(arg0)) {
flag = false;
} else if (btnsave.equals(arg0)) {
ScaleImageView.save();
}
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/activity_main_zoom_zoom"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Zoom" />
<Button
android:id="@+id/activity_main_zoom_draw"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Draw" />
<Button
android:id="@+id/activity_main_save"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Save" />
</LinearLayout>
<com.matabii.dev.scaleimageview.ScaleImageView
android:id="@+id/image"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/sample" />
</LinearLayout>