可以通过手势放大缩小图片的TouchImageView

package com.example.lianshou_test.view;import android.annotation.TargetApi;import android.content.Context;import android.content.res.Configuration;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Matrix;import android.graphics.PointF;import android.graphics.RectF;import android.graphics.drawable.Drawable;import android.net.Uri;import android.os.Build;import android.os.Build.VERSION;import android.os.Build.VERSION_CODES;import android.os.Bundle;import android.os.Parcelable;import android.util.AttributeSet;import android.util.Log;import android.view.GestureDetector;import android.view.MotionEvent;import android.view.ScaleGestureDetector;import android.view.View;import android.view.animation.AccelerateDecelerateInterpolator;import android.widget.ImageView;import android.widget.OverScroller;import android.widget.Scroller;//可以放大缩小的图片public class TouchImageView extends ImageView {private static final String DEBUG = "DEBUG";private static final float SUPER_MIN_MULTIPLIER = .75f;private static final float SUPER_MAX_MULTIPLIER = 1.25f;    private float normalizedScale;private Matrix matrix, prevMatrix;    private static enum State { NONE, DRAG, ZOOM, FLING, ANIMATE_ZOOM };    private State state;    private float minScale;    private float maxScale;    private float superMinScale;    private float superMaxScale;    private float[] m;        private Context context;    private Fling fling;        private ScaleType mScaleType;        private boolean imageRenderedAtLeastOnce;    private boolean onDrawReady;        private ZoomVariables delayedZoomVariables;    private int viewWidth, viewHeight, prevViewWidth, prevViewHeight;        private float matchViewWidth, matchViewHeight, prevMatchViewWidth, prevMatchViewHeight;        private ScaleGestureDetector mScaleDetector;    private GestureDetector mGestureDetector;    private GestureDetector.OnDoubleTapListener doubleTapListener = null;    private OnTouchListener userTouchListener = null;    private OnTouchImageViewListener touchImageViewListener = null;    public TouchImageView(Context context) {        super(context);        sharedConstructing(context);    }    public TouchImageView(Context context, AttributeSet attrs) {        super(context, attrs);        sharedConstructing(context);    }        public TouchImageView(Context context, AttributeSet attrs, int defStyle) {    super(context, attrs, defStyle);    sharedConstructing(context);    }        private void sharedConstructing(Context context) {        super.setClickable(true);        this.context = context;        mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());        mGestureDetector = new GestureDetector(context, new GestureListener());        matrix = new Matrix();        prevMatrix = new Matrix();        m = new float[9];        normalizedScale = 1;        if (mScaleType == null) {        mScaleType = ScaleType.FIT_CENTER;        }        minScale = 1;        maxScale = 3;        superMinScale = SUPER_MIN_MULTIPLIER * minScale;        superMaxScale = SUPER_MAX_MULTIPLIER * maxScale;        setImageMatrix(matrix);        setScaleType(ScaleType.MATRIX);        setState(State.NONE);        onDrawReady = false;        super.setOnTouchListener(new PrivateOnTouchListener());    }    @Override    public void setOnTouchListener(View.OnTouchListener l) {        userTouchListener = l;    }        public void setOnTouchImageViewListener(OnTouchImageViewListener l) {    touchImageViewListener = l;    }    public void setOnDoubleTapListener(GestureDetector.OnDoubleTapListener l) {        doubleTapListener = l;    }    @Override    public void setImageResource(int resId) {    super.setImageResource(resId);    savePreviousImageValues();    fitImageToView();    }        @Override    public void setImageBitmap(Bitmap bm) {    super.setImageBitmap(bm);    savePreviousImageValues();    fitImageToView();    }        @Override    public void setImageDrawable(Drawable drawable) {    super.setImageDrawable(drawable);    savePreviousImageValues();    fitImageToView();    }        @Override    public void setImageURI(Uri uri) {    super.setImageURI(uri);    savePreviousImageValues();    fitImageToView();    }        @Override    public void setScaleType(ScaleType type) {    if (type == ScaleType.FIT_START || type == ScaleType.FIT_END) {    throw new UnsupportedOperationException("TouchImageView does not support FIT_START or FIT_END");    }    if (type == ScaleType.MATRIX) {    super.setScaleType(ScaleType.MATRIX);        } else {    mScaleType = type;    if (onDrawReady) {    //    // If the image is already rendered, scaleType has been called programmatically    // and the TouchImageView should be updated with the new scaleType.    //    setZoom(this);    }    }    }        @Override    public ScaleType getScaleType() {    return mScaleType;    }        /**     * Returns false if image is in initial, unzoomed state. False, otherwise.     * @return true if image is zoomed     */    public boolean isZoomed() {    return normalizedScale != 1;    }        /**     * Return a Rect representing the zoomed image.     * @return rect representing zoomed image     */    public RectF getZoomedRect() {    if (mScaleType == ScaleType.FIT_XY) {    throw new UnsupportedOperationException("getZoomedRect() not supported with FIT_XY");    }    PointF topLeft = transformCoordTouchToBitmap(0, 0, true);    PointF bottomRight = transformCoordTouchToBitmap(viewWidth, viewHeight, true);        float w = getDrawable().getIntrinsicWidth();    float h = getDrawable().getIntrinsicHeight();    return new RectF(topLeft.x / w, topLeft.y / h, bottomRight.x / w, bottomRight.y / h);    }        /**     * Save the current matrix and view dimensions     * in the prevMatrix and prevView variables.     */    private void savePreviousImageValues() {    if (matrix != null && viewHeight != 0 && viewWidth != 0) {    matrix.getValues(m);    prevMatrix.setValues(m);    prevMatchViewHeight = matchViewHeight;        prevMatchViewWidth = matchViewWidth;        prevViewHeight = viewHeight;        prevViewWidth = viewWidth;    }    }        @Override    public Parcelable onSaveInstanceState() {    Bundle bundle = new Bundle();    bundle.putParcelable("instanceState", super.onSaveInstanceState());    bundle.putFloat("saveScale", normalizedScale);    bundle.putFloat("matchViewHeight", matchViewHeight);    bundle.putFloat("matchViewWidth", matchViewWidth);    bundle.putInt("viewWidth", viewWidth);    bundle.putInt("viewHeight", viewHeight);    matrix.getValues(m);    bundle.putFloatArray("matrix", m);    bundle.putBoolean("imageRendered", imageRenderedAtLeastOnce);    return bundle;    }        @Override    public void onRestoreInstanceState(Parcelable state) {      if (state instanceof Bundle) {        Bundle bundle = (Bundle) state;        normalizedScale = bundle.getFloat("saveScale");        m = bundle.getFloatArray("matrix");        prevMatrix.setValues(m);        prevMatchViewHeight = bundle.getFloat("matchViewHeight");        prevMatchViewWidth = bundle.getFloat("matchViewWidth");        prevViewHeight = bundle.getInt("viewHeight");        prevViewWidth = bundle.getInt("viewWidth");        imageRenderedAtLeastOnce = bundle.getBoolean("imageRendered");        super.onRestoreInstanceState(bundle.getParcelable("instanceState"));        return;      }      super.onRestoreInstanceState(state);    }        @Override    protected void onDraw(Canvas canvas) {    onDrawReady = true;    imageRenderedAtLeastOnce = true;    if (delayedZoomVariables != null) {    setZoom(delayedZoomVariables.scale, delayedZoomVariables.focusX, delayedZoomVariables.focusY, delayedZoomVariables.scaleType);    delayedZoomVariables = null;    }    super.onDraw(canvas);    }        @Override    public void onConfigurationChanged(Configuration newConfig) {    super.onConfigurationChanged(newConfig);    savePreviousImageValues();    }        /**     * Get the max zoom multiplier.     * @return max zoom multiplier.     */    public float getMaxZoom() {    return maxScale;    }    /**     * Set the max zoom multiplier. Default value: 3.     * @param max max zoom multiplier.     */    public void setMaxZoom(float max) {        maxScale = max;        superMaxScale = SUPER_MAX_MULTIPLIER * maxScale;    }        /**     * Get the min zoom multiplier.     * @return min zoom multiplier.     */    public float getMinZoom() {    return minScale;    }        /**     * Get the current zoom. This is the zoom relative to the initial     * scale, not the original resource.     * @return current zoom multiplier.     */    public float getCurrentZoom() {    return normalizedScale;    }        /**     * Set the min zoom multiplier. Default value: 1.     * @param min min zoom multiplier.     */    public void setMinZoom(float min) {    minScale = min;    superMinScale = SUPER_MIN_MULTIPLIER * minScale;    }        /**     * Reset zoom and translation to initial state.     */    public void resetZoom() {    normalizedScale = 1;    fitImageToView();    }        /**     * Set zoom to the specified scale. Image will be centered by default.     * @param scale     */    public void setZoom(float scale) {    setZoom(scale, 0.5f, 0.5f);    }        /**     * Set zoom to the specified scale. Image will be centered around the point     * (focusX, focusY). These floats range from 0 to 1 and denote the focus point     * as a fraction from the left and top of the view. For example, the top left      * corner of the image would be (0, 0). And the bottom right corner would be (1, 1).     * @param scale     * @param focusX     * @param focusY     */    public void setZoom(float scale, float focusX, float focusY) {    setZoom(scale, focusX, focusY, mScaleType);    }        /**     * Set zoom to the specified scale. Image will be centered around the point     * (focusX, focusY). These floats range from 0 to 1 and denote the focus point     * as a fraction from the left and top of the view. For example, the top left      * corner of the image would be (0, 0). And the bottom right corner would be (1, 1).     * @param scale     * @param focusX     * @param focusY     * @param scaleType     */    public void setZoom(float scale, float focusX, float focusY, ScaleType scaleType) {    //    // setZoom can be called before the image is on the screen, but at this point,     // image and view sizes have not yet been calculated in onMeasure. Thus, we should    // delay calling setZoom until the view has been measured.    //    if (!onDrawReady) {    delayedZoomVariables = new ZoomVariables(scale, focusX, focusY, scaleType);    return;    }        if (scaleType != mScaleType) {    setScaleType(scaleType);    }    resetZoom();    scaleImage(scale, viewWidth / 2, viewHeight / 2, true);    matrix.getValues(m);    m[Matrix.MTRANS_X] = -((focusX * getImageWidth()) - (viewWidth * 0.5f));    m[Matrix.MTRANS_Y] = -((focusY * getImageHeight()) - (viewHeight * 0.5f));    matrix.setValues(m);    fixTrans();    setImageMatrix(matrix);    }        /**     * Set zoom parameters equal to another TouchImageView. Including scale, position,     * and ScaleType.     * @param TouchImageView     */    public void setZoom(TouchImageView img) {    PointF center = img.getScrollPosition();    setZoom(img.getCurrentZoom(), center.x, center.y, img.getScaleType());    }        /**     * Return the point at the center of the zoomed image. The PointF coordinates range     * in value between 0 and 1 and the focus point is denoted as a fraction from the left      * and top of the view. For example, the top left corner of the image would be (0, 0).      * And the bottom right corner would be (1, 1).     * @return PointF representing the scroll position of the zoomed image.     */    public PointF getScrollPosition() {    Drawable drawable = getDrawable();    if (drawable == null) {    return null;    }    int drawableWidth = drawable.getIntrinsicWidth();        int drawableHeight = drawable.getIntrinsicHeight();                PointF point = transformCoordTouchToBitmap(viewWidth / 2, viewHeight / 2, true);        point.x /= drawableWidth;        point.y /= drawableHeight;        return point;    }        /**     * Set the focus point of the zoomed image. The focus points are denoted as a fraction from the     * left and top of the view. The focus points can range in value between 0 and 1.      * @param focusX     * @param focusY     */    public void setScrollPosition(float focusX, float focusY) {    setZoom(normalizedScale, focusX, focusY);    }        /**     * Performs boundary checking and fixes the image matrix if it      * is out of bounds.     */    private void fixTrans() {        matrix.getValues(m);        float transX = m[Matrix.MTRANS_X];        float transY = m[Matrix.MTRANS_Y];                float fixTransX = getFixTrans(transX, viewWidth, getImageWidth());        float fixTransY = getFixTrans(transY, viewHeight, getImageHeight());                if (fixTransX != 0 || fixTransY != 0) {            matrix.postTranslate(fixTransX, fixTransY);        }    }        /**     * When transitioning from zooming from focus to zoom from center (or vice versa)     * the image can become unaligned within the view. This is apparent when zooming     * quickly. When the content size is less than the view size, the content will often     * be centered incorrectly within the view. fixScaleTrans first calls fixTrans() and      * then makes sure the image is centered correctly within the view.     */    private void fixScaleTrans() {    fixTrans();    matrix.getValues(m);    if (getImageWidth() < viewWidth) {    m[Matrix.MTRANS_X] = (viewWidth - getImageWidth()) / 2;    }        if (getImageHeight() < viewHeight) {    m[Matrix.MTRANS_Y] = (viewHeight - getImageHeight()) / 2;    }    matrix.setValues(m);    }    private float getFixTrans(float trans, float viewSize, float contentSize) {        float minTrans, maxTrans;        if (contentSize <= viewSize) {            minTrans = 0;            maxTrans = viewSize - contentSize;                    } else {            minTrans = viewSize - contentSize;            maxTrans = 0;        }        if (trans < minTrans)            return -trans + minTrans;        if (trans > maxTrans)            return -trans + maxTrans;        return 0;    }        private float getFixDragTrans(float delta, float viewSize, float contentSize) {        if (contentSize <= viewSize) {            return 0;        }        return delta;    }        private float getImageWidth() {    return matchViewWidth * normalizedScale;    }        private float getImageHeight() {    return matchViewHeight * normalizedScale;    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        Drawable drawable = getDrawable();        if (drawable == null || drawable.getIntrinsicWidth() == 0 || drawable.getIntrinsicHeight() == 0) {        setMeasuredDimension(0, 0);        return;        }                int drawableWidth = drawable.getIntrinsicWidth();        int drawableHeight = drawable.getIntrinsicHeight();        int widthSize = MeasureSpec.getSize(widthMeasureSpec);        int widthMode = MeasureSpec.getMode(widthMeasureSpec);        int heightSize = MeasureSpec.getSize(heightMeasureSpec);        int heightMode = MeasureSpec.getMode(heightMeasureSpec);        viewWidth = setViewSize(widthMode, widthSize, drawableWidth);        viewHeight = setViewSize(heightMode, heightSize, drawableHeight);                //        // Set view dimensions        //        setMeasuredDimension(viewWidth, viewHeight);                //        // Fit content within view        //        fitImageToView();    }        /**     * If the normalizedScale is equal to 1, then the image is made to fit the screen. Otherwise,     * it is made to fit the screen according to the dimensions of the previous image matrix. This     * allows the image to maintain its zoom after rotation.     */    private void fitImageToView() {    Drawable drawable = getDrawable();        if (drawable == null || drawable.getIntrinsicWidth() == 0 || drawable.getIntrinsicHeight() == 0) {        return;        }        if (matrix == null || prevMatrix == null) {        return;        }                int drawableWidth = drawable.getIntrinsicWidth();        int drawableHeight = drawable.getIntrinsicHeight();        //    // Scale image for view    //        float scaleX = (float) viewWidth / drawableWidth;        float scaleY = (float) viewHeight / drawableHeight;                switch (mScaleType) {        case CENTER:        scaleX = scaleY = 1;        break;                case CENTER_CROP:        scaleX = scaleY = Math.max(scaleX, scaleY);        break;                case CENTER_INSIDE:        scaleX = scaleY = Math.min(1, Math.min(scaleX, scaleY));                case FIT_CENTER:        scaleX = scaleY = Math.min(scaleX, scaleY);        break;                case FIT_XY:        break;            default:    //    // FIT_START and FIT_END not supported    //    throw new UnsupportedOperationException("TouchImageView does not support FIT_START or FIT_END");                }        //        // Center the image        //        float redundantXSpace = viewWidth - (scaleX * drawableWidth);        float redundantYSpace = viewHeight - (scaleY * drawableHeight);        matchViewWidth = viewWidth - redundantXSpace;        matchViewHeight = viewHeight - redundantYSpace;        if (!isZoomed() && !imageRenderedAtLeastOnce) {        //        // Stretch and center image to fit view        //        matrix.setScale(scaleX, scaleY);        matrix.postTranslate(redundantXSpace / 2, redundantYSpace / 2);        normalizedScale = 1;                } else {        //        // These values should never be 0 or we will set viewWidth and viewHeight        // to NaN in translateMatrixAfterRotate. To avoid this, call savePreviousImageValues        // to set them equal to the current values.        //        if (prevMatchViewWidth == 0 || prevMatchViewHeight == 0) {        savePreviousImageValues();        }                prevMatrix.getValues(m);                //        // Rescale Matrix after rotation        //        m[Matrix.MSCALE_X] = matchViewWidth / drawableWidth * normalizedScale;        m[Matrix.MSCALE_Y] = matchViewHeight / drawableHeight * normalizedScale;                //        // TransX and TransY from previous matrix        //            float transX = m[Matrix.MTRANS_X];            float transY = m[Matrix.MTRANS_Y];                        //            // Width            //            float prevActualWidth = prevMatchViewWidth * normalizedScale;            float actualWidth = getImageWidth();            translateMatrixAfterRotate(Matrix.MTRANS_X, transX, prevActualWidth, actualWidth, prevViewWidth, viewWidth, drawableWidth);                        //            // Height            //            float prevActualHeight = prevMatchViewHeight * normalizedScale;            float actualHeight = getImageHeight();            translateMatrixAfterRotate(Matrix.MTRANS_Y, transY, prevActualHeight, actualHeight, prevViewHeight, viewHeight, drawableHeight);                        //            // Set the matrix to the adjusted scale and translate values.            //            matrix.setValues(m);        }        fixTrans();        setImageMatrix(matrix);    }        /**     * Set view dimensions based on layout params     *      * @param mode      * @param size     * @param drawableWidth     * @return     */    private int setViewSize(int mode, int size, int drawableWidth) {    int viewSize;    switch (mode) {case MeasureSpec.EXACTLY:viewSize = size;break;case MeasureSpec.AT_MOST:viewSize = Math.min(drawableWidth, size);break;case MeasureSpec.UNSPECIFIED:viewSize = drawableWidth;break;default:viewSize = size; break;}    return viewSize;    }        /**     * After rotating, the matrix needs to be translated. This function finds the area of image      * which was previously centered and adjusts translations so that is again the center, post-rotation.     *      * @param axis Matrix.MTRANS_X or Matrix.MTRANS_Y     * @param trans the value of trans in that axis before the rotation     * @param prevImageSize the width/height of the image before the rotation     * @param imageSize width/height of the image after rotation     * @param prevViewSize width/height of view before rotation     * @param viewSize width/height of view after rotation     * @param drawableSize width/height of drawable     */    private void translateMatrixAfterRotate(int axis, float trans, float prevImageSize, float imageSize, int prevViewSize, int viewSize, int drawableSize) {    if (imageSize < viewSize) {        //        // The width/height of image is less than the view's width/height. Center it.        //        m[axis] = (viewSize - (drawableSize * m[Matrix.MSCALE_X])) * 0.5f;                } else if (trans > 0) {        //        // The image is larger than the view, but was not before rotation. Center it.        //        m[axis] = -((imageSize - viewSize) * 0.5f);                } else {        //        // Find the area of the image which was previously centered in the view. Determine its distance        // from the left/top side of the view as a fraction of the entire image's width/height. Use that percentage        // to calculate the trans in the new view width/height.        //        float percentage = (Math.abs(trans) + (0.5f * prevViewSize)) / prevImageSize;        m[axis] = -((percentage * imageSize) - (viewSize * 0.5f));        }    }        private void setState(State state) {    this.state = state;    }        public boolean canScrollHorizontallyFroyo(int direction) {        return canScrollHorizontally(direction);    }        @Override    public boolean canScrollHorizontally(int direction) {    matrix.getValues(m);    float x = m[Matrix.MTRANS_X];        if (getImageWidth() < viewWidth) {    return false;        } else if (x >= -1 && direction < 0) {    return false;        } else if (Math.abs(x) + viewWidth + 1 >= getImageWidth() && direction > 0) {    return false;    }        return true;    }        /**     * Gesture Listener detects a single click or long click and passes that on     * to the view's listener.     * @author Ortiz     *     */    private class GestureListener extends GestureDetector.SimpleOnGestureListener {            @Override        public boolean onSingleTapConfirmed(MotionEvent e)        {            if(doubleTapListener != null) {            return doubleTapListener.onSingleTapConfirmed(e);            }        return performClick();        }                @Override        public void onLongPress(MotionEvent e)        {        performLongClick();        }                @Override        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)        {        if (fling != null) {        //        // If a previous fling is still active, it should be cancelled so that two flings        // are not run simultaenously.        //        fling.cancelFling();        }        fling = new Fling((int) velocityX, (int) velocityY);        compatPostOnAnimation(fling);        return super.onFling(e1, e2, velocityX, velocityY);        }                @Override        public boolean onDoubleTap(MotionEvent e) {        boolean consumed = false;            if(doubleTapListener != null) {            consumed = doubleTapListener.onDoubleTap(e);            }        if (state == State.NONE) {        float targetZoom = (normalizedScale == minScale) ? maxScale : minScale;        DoubleTapZoom doubleTap = new DoubleTapZoom(targetZoom, e.getX(), e.getY(), false);        compatPostOnAnimation(doubleTap);        consumed = true;        }        return consumed;        }        @Override        public boolean onDoubleTapEvent(MotionEvent e) {            if(doubleTapListener != null) {            return doubleTapListener.onDoubleTapEvent(e);            }            return false;        }    }        public interface OnTouchImageViewListener {    public void onMove();    }        /**     * Responsible for all touch events. Handles the heavy lifting of drag and also sends     * touch events to Scale Detector and Gesture Detector.     * @author Ortiz     *     */    private class PrivateOnTouchListener implements OnTouchListener {        //        // Remember last point position for dragging        //        private PointF last = new PointF();        @Override        public boolean onTouch(View v, MotionEvent event) {            mScaleDetector.onTouchEvent(event);            mGestureDetector.onTouchEvent(event);            PointF curr = new PointF(event.getX(), event.getY());                        if (state == State.NONE || state == State.DRAG || state == State.FLING) {            switch (event.getAction()) {                case MotionEvent.ACTION_DOWN:                last.set(curr);                    if (fling != null)                    fling.cancelFling();                    setState(State.DRAG);                    break;                                    case MotionEvent.ACTION_MOVE:                    if (state == State.DRAG) {                        float deltaX = curr.x - last.x;                        float deltaY = curr.y - last.y;                        float fixTransX = getFixDragTrans(deltaX, viewWidth, getImageWidth());                        float fixTransY = getFixDragTrans(deltaY, viewHeight, getImageHeight());                        matrix.postTranslate(fixTransX, fixTransY);                        fixTrans();                        last.set(curr.x, curr.y);                    }                    break;                case MotionEvent.ACTION_UP:                case MotionEvent.ACTION_POINTER_UP:                    setState(State.NONE);                    break;            }            }                        setImageMatrix(matrix);                        //    // User-defined OnTouchListener    //    if(userTouchListener != null) {    userTouchListener.onTouch(v, event);    }                //    // OnTouchImageViewListener is set: TouchImageView dragged by user.    //    if (touchImageViewListener != null) {    touchImageViewListener.onMove();    }                //            // indicate event was handled            //            return true;        }    }    /**     * ScaleListener detects user two finger scaling and scales image.     * @author Ortiz     *     */    private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {        @Override        public boolean onScaleBegin(ScaleGestureDetector detector) {            setState(State.ZOOM);            return true;        }        @Override        public boolean onScale(ScaleGestureDetector detector) {        scaleImage(detector.getScaleFactor(), detector.getFocusX(), detector.getFocusY(), true);                //        // OnTouchImageViewListener is set: TouchImageView pinch zoomed by user.        //        if (touchImageViewListener != null) {        touchImageViewListener.onMove();        }            return true;        }                @Override        public void onScaleEnd(ScaleGestureDetector detector) {        super.onScaleEnd(detector);        setState(State.NONE);        boolean animateToZoomBoundary = false;        float targetZoom = normalizedScale;        if (normalizedScale > maxScale) {        targetZoom = maxScale;        animateToZoomBoundary = true;                } else if (normalizedScale < minScale) {        targetZoom = minScale;        animateToZoomBoundary = true;        }                if (animateToZoomBoundary) {        DoubleTapZoom doubleTap = new DoubleTapZoom(targetZoom, viewWidth / 2, viewHeight / 2, true);        compatPostOnAnimation(doubleTap);        }        }    }        private void scaleImage(double deltaScale, float focusX, float focusY, boolean stretchImageToSuper) {        float lowerScale, upperScale;    if (stretchImageToSuper) {    lowerScale = superMinScale;    upperScale = superMaxScale;        } else {    lowerScale = minScale;    upperScale = maxScale;    }        float origScale = normalizedScale;        normalizedScale *= deltaScale;        if (normalizedScale > upperScale) {            normalizedScale = upperScale;            deltaScale = upperScale / origScale;        } else if (normalizedScale < lowerScale) {            normalizedScale = lowerScale;            deltaScale = lowerScale / origScale;        }                matrix.postScale((float) deltaScale, (float) deltaScale, focusX, focusY);        fixScaleTrans();    }        /**     * DoubleTapZoom calls a series of runnables which apply     * an animated zoom in/out graphic to the image.     * @author Ortiz     *     */    private class DoubleTapZoom implements Runnable {        private long startTime;    private static final float ZOOM_TIME = 500;    private float startZoom, targetZoom;    private float bitmapX, bitmapY;    private boolean stretchImageToSuper;    private AccelerateDecelerateInterpolator interpolator = new AccelerateDecelerateInterpolator();    private PointF startTouch;    private PointF endTouch;    DoubleTapZoom(float targetZoom, float focusX, float focusY, boolean stretchImageToSuper) {    setState(State.ANIMATE_ZOOM);    startTime = System.currentTimeMillis();    this.startZoom = normalizedScale;    this.targetZoom = targetZoom;    this.stretchImageToSuper = stretchImageToSuper;    PointF bitmapPoint = transformCoordTouchToBitmap(focusX, focusY, false);    this.bitmapX = bitmapPoint.x;    this.bitmapY = bitmapPoint.y;        //    // Used for translating image during scaling    //    startTouch = transformCoordBitmapToTouch(bitmapX, bitmapY);    endTouch = new PointF(viewWidth / 2, viewHeight / 2);    }@Overridepublic void run() {float t = interpolate();double deltaScale = calculateDeltaScale(t);scaleImage(deltaScale, bitmapX, bitmapY, stretchImageToSuper);translateImageToCenterTouchPosition(t);fixScaleTrans();setImageMatrix(matrix);//// OnTouchImageViewListener is set: double tap runnable updates listener// with every frame.//if (touchImageViewListener != null) {touchImageViewListener.onMove();}if (t < 1f) {//// We haven't finished zooming//compatPostOnAnimation(this);} else {//// Finished zooming//setState(State.NONE);}}/** * Interpolate between where the image should start and end in order to translate * the image so that the point that is touched is what ends up centered at the end * of the zoom. * @param t */private void translateImageToCenterTouchPosition(float t) {float targetX = startTouch.x + t * (endTouch.x - startTouch.x);float targetY = startTouch.y + t * (endTouch.y - startTouch.y);PointF curr = transformCoordBitmapToTouch(bitmapX, bitmapY);matrix.postTranslate(targetX - curr.x, targetY - curr.y);}/** * Use interpolator to get t * @return */private float interpolate() {long currTime = System.currentTimeMillis();float elapsed = (currTime - startTime) / ZOOM_TIME;elapsed = Math.min(1f, elapsed);return interpolator.getInterpolation(elapsed);}/** * Interpolate the current targeted zoom and get the delta * from the current zoom. * @param t * @return */private double calculateDeltaScale(float t) {double zoom = startZoom + t * (targetZoom - startZoom);return zoom / normalizedScale;}    }        /**     * This function will transform the coordinates in the touch event to the coordinate      * system of the drawable that the imageview contain     * @param x x-coordinate of touch event     * @param y y-coordinate of touch event     * @param clipToBitmap Touch event may occur within view, but outside image content. True, to clip return value     * to the bounds of the bitmap size.     * @return Coordinates of the point touched, in the coordinate system of the original drawable.     */    private PointF transformCoordTouchToBitmap(float x, float y, boolean clipToBitmap) {         matrix.getValues(m);         float origW = getDrawable().getIntrinsicWidth();         float origH = getDrawable().getIntrinsicHeight();         float transX = m[Matrix.MTRANS_X];         float transY = m[Matrix.MTRANS_Y];         float finalX = ((x - transX) * origW) / getImageWidth();         float finalY = ((y - transY) * origH) / getImageHeight();                  if (clipToBitmap) {         finalX = Math.min(Math.max(finalX, 0), origW);         finalY = Math.min(Math.max(finalY, 0), origH);         }                  return new PointF(finalX , finalY);    }        /**     * Inverse of transformCoordTouchToBitmap. This function will transform the coordinates in the     * drawable's coordinate system to the view's coordinate system.     * @param bx x-coordinate in original bitmap coordinate system     * @param by y-coordinate in original bitmap coordinate system     * @return Coordinates of the point in the view's coordinate system.     */    private PointF transformCoordBitmapToTouch(float bx, float by) {        matrix.getValues(m);                float origW = getDrawable().getIntrinsicWidth();        float origH = getDrawable().getIntrinsicHeight();        float px = bx / origW;        float py = by / origH;        float finalX = m[Matrix.MTRANS_X] + getImageWidth() * px;        float finalY = m[Matrix.MTRANS_Y] + getImageHeight() * py;        return new PointF(finalX , finalY);    }        /**     * Fling launches sequential runnables which apply     * the fling graphic to the image. The values for the translation     * are interpolated by the Scroller.     * @author Ortiz     *     */    private class Fling implements Runnable {            CompatScroller scroller;    int currX, currY;        Fling(int velocityX, int velocityY) {    setState(State.FLING);    scroller = new CompatScroller(context);    matrix.getValues(m);        int startX = (int) m[Matrix.MTRANS_X];    int startY = (int) m[Matrix.MTRANS_Y];    int minX, maxX, minY, maxY;        if (getImageWidth() > viewWidth) {    minX = viewWidth - (int) getImageWidth();    maxX = 0;        } else {    minX = maxX = startX;    }        if (getImageHeight() > viewHeight) {    minY = viewHeight - (int) getImageHeight();    maxY = 0;        } else {    minY = maxY = startY;    }        scroller.fling(startX, startY, (int) velocityX, (int) velocityY, minX,                    maxX, minY, maxY);    currX = startX;    currY = startY;    }        public void cancelFling() {    if (scroller != null) {    setState(State.NONE);    scroller.forceFinished(true);    }    }    @Overridepublic void run() {//// OnTouchImageViewListener is set: TouchImageView listener has been flung by user.// Listener runnable updated with each frame of fling animation.//if (touchImageViewListener != null) {touchImageViewListener.onMove();}if (scroller.isFinished()) {        scroller = null;        return;        }if (scroller.computeScrollOffset()) {        int newX = scroller.getCurrX();            int newY = scroller.getCurrY();            int transX = newX - currX;            int transY = newY - currY;            currX = newX;            currY = newY;            matrix.postTranslate(transX, transY);            fixTrans();            setImageMatrix(matrix);            compatPostOnAnimation(this);        }}    }        @TargetApi(Build.VERSION_CODES.GINGERBREAD)private class CompatScroller {    Scroller scroller;    OverScroller overScroller;    boolean isPreGingerbread;        public CompatScroller(Context context) {    if (VERSION.SDK_INT < VERSION_CODES.GINGERBREAD) {    isPreGingerbread = true;    scroller = new Scroller(context);        } else {    isPreGingerbread = false;    overScroller = new OverScroller(context);    }    }        public void fling(int startX, int startY, int velocityX, int velocityY, int minX, int maxX, int minY, int maxY) {    if (isPreGingerbread) {    scroller.fling(startX, startY, velocityX, velocityY, minX, maxX, minY, maxY);    } else {    overScroller.fling(startX, startY, velocityX, velocityY, minX, maxX, minY, maxY);    }    }        public void forceFinished(boolean finished) {    if (isPreGingerbread) {    scroller.forceFinished(finished);    } else {    overScroller.forceFinished(finished);    }    }        public boolean isFinished() {    if (isPreGingerbread) {    return scroller.isFinished();    } else {    return overScroller.isFinished();    }    }        public boolean computeScrollOffset() {    if (isPreGingerbread) {    return scroller.computeScrollOffset();    } else {    overScroller.computeScrollOffset();    return overScroller.computeScrollOffset();    }    }        public int getCurrX() {    if (isPreGingerbread) {    return scroller.getCurrX();    } else {    return overScroller.getCurrX();    }    }        public int getCurrY() {    if (isPreGingerbread) {    return scroller.getCurrY();    } else {    return overScroller.getCurrY();    }    }    }        @TargetApi(Build.VERSION_CODES.JELLY_BEAN)private void compatPostOnAnimation(Runnable runnable) {    if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN) {            postOnAnimation(runnable);                    } else {            postDelayed(runnable, 1000/60);        }    }        private class ZoomVariables {    public float scale;    public float focusX;    public float focusY;    public ScaleType scaleType;        public ZoomVariables(float scale, float focusX, float focusY, ScaleType scaleType) {    this.scale = scale;    this.focusX = focusX;    this.focusY = focusY;    this.scaleType = scaleType;    }    }        private void printMatrixInfo() {    float[] n = new float[9];    matrix.getValues(n);    Log.d(DEBUG, "Scale: " + n[Matrix.MSCALE_X] + " TransX: " + n[Matrix.MTRANS_X] + " TransY: " + n[Matrix.MTRANS_Y]);    }}