/******************************************************************************* * Copyright 2011, 2012 Chris Banes. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. *******************************************************************************/ package com.todayinfo.ui.component.gesture; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Matrix; import android.graphics.Matrix.ScaleToFit; import android.graphics.RectF; import android.graphics.drawable.Drawable; import android.util.FloatMath; import android.util.Log; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.View.OnLongClickListener; import android.view.ViewParent; import android.view.ViewTreeObserver; import android.view.animation.AccelerateDecelerateInterpolator; import android.view.animation.Interpolator; import android.widget.ImageView; import android.widget.ImageView.ScaleType; import java.lang.ref.WeakReference; import static android.view.MotionEvent.ACTION_CANCEL; import static android.view.MotionEvent.ACTION_DOWN; import static android.view.MotionEvent.ACTION_UP; public class PhotoViewAttacher implements IPhotoView, View.OnTouchListener, OnGestureListener, ViewTreeObserver.OnGlobalLayoutListener { private static final String LOG_TAG = "PhotoViewAttacher"; // let debug flag be dynamic, but still Proguard can be used to remove from // release builds private static final boolean DEBUG = Log.isLoggable(LOG_TAG, Log.DEBUG); static final Interpolator sInterpolator = new AccelerateDecelerateInterpolator(); int ZOOM_DURATION = DEFAULT_ZOOM_DURATION; static final int EDGE_NONE = -1; static final int EDGE_LEFT = 0; static final int EDGE_RIGHT = 1; static final int EDGE_BOTH = 2; private float mMinScale = DEFAULT_MIN_SCALE; private float mMidScale = DEFAULT_MID_SCALE; private float mMaxScale = DEFAULT_MAX_SCALE; private boolean mAllowParentInterceptOnEdge = true; private static void checkZoomLevels(float minZoom, float midZoom, float maxZoom) { if (minZoom >= midZoom) { throw new IllegalArgumentException( "MinZoom has to be less than MidZoom"); } else if (midZoom >= maxZoom) { throw new IllegalArgumentException( "MidZoom has to be less than MaxZoom"); } } /** * @return true if the ImageView exists, and it's Drawable existss */ private static boolean hasDrawable(ImageView imageView) { return null != imageView && null != imageView.getDrawable(); } /** * @return true if the ScaleType is supported. */ private static boolean isSupportedScaleType(final ScaleType scaleType) { if (null == scaleType) { return false; } switch (scaleType) { case MATRIX: throw new IllegalArgumentException(scaleType.name() + " is not supported in PhotoView"); default: return true; } } /** * Set's the ImageView's ScaleType to Matrix. */ private static void setImageViewScaleTypeMatrix(ImageView imageView) { /** * PhotoView sets it's own ScaleType to Matrix, then diverts all calls * setScaleType to this.setScaleType automatically. */ if (null != imageView && !(imageView instanceof IPhotoView)) { if (!ScaleType.MATRIX.equals(imageView.getScaleType())) { imageView.setScaleType(ScaleType.MATRIX); } } } private WeakReference<ImageView> mImageView; // Gesture Detectors private GestureDetector mGestureDetector; private com.todayinfo.ui.component.gesture.GestureDetector mScaleDragDetector; // These are set so we don't keep allocating them on the heap private final Matrix mBaseMatrix = new Matrix(); private final Matrix mDrawMatrix = new Matrix(); private final Matrix mSuppMatrix = new Matrix(); private final RectF mDisplayRect = new RectF(); private final float[] mMatrixValues = new float[9]; // Listeners private OnMatrixChangedListener mMatrixChangeListener; private OnPhotoTapListener mPhotoTapListener; private OnViewTapListener mViewTapListener; private OnLongClickListener mLongClickListener; private int mIvTop, mIvRight, mIvBottom, mIvLeft; private FlingRunnable mCurrentFlingRunnable; private int mScrollEdge = EDGE_BOTH; private boolean mZoomEnabled; private ScaleType mScaleType = ScaleType.FIT_CENTER; public PhotoViewAttacher(ImageView imageView) { mImageView = new WeakReference<ImageView>(imageView); imageView.setDrawingCacheEnabled(true); imageView.setOnTouchListener(this); ViewTreeObserver observer = imageView.getViewTreeObserver(); if (null != observer) observer.addOnGlobalLayoutListener(this); // Make sure we using MATRIX Scale Type setImageViewScaleTypeMatrix(imageView); if (imageView.isInEditMode()) { return; } // Create Gesture Detectors... mScaleDragDetector = VersionedGestureDetector.newInstance( imageView.getContext(), this); mGestureDetector = new GestureDetector(imageView.getContext(), new GestureDetector.SimpleOnGestureListener() { // forward long click listener @Override public void onLongPress(MotionEvent e) { if (null != mLongClickListener) { mLongClickListener.onLongClick(getImageView()); } } }); mGestureDetector.setOnDoubleTapListener(new DefaultOnDoubleTapListener(this)); // Finally, update the UI so that we're zoomable setZoomable(true); } @Override public void setOnDoubleTapListener(GestureDetector.OnDoubleTapListener newOnDoubleTapListener) { if (newOnDoubleTapListener != null) this.mGestureDetector.setOnDoubleTapListener(newOnDoubleTapListener); else this.mGestureDetector.setOnDoubleTapListener(new DefaultOnDoubleTapListener(this)); } @Override public boolean canZoom() { return mZoomEnabled; } /** * Clean-up the resources attached to this object. This needs to be called when the ImageView is * no longer used. A good example is from {@link android.view.View#onDetachedFromWindow()} or * from {@link android.app.Activity#onDestroy()}. This is automatically called if you are using * {@link uk.co.senab.photoview.PhotoView}. */ @SuppressWarnings("deprecation") public void cleanup() { if (null == mImageView) { return; // cleanup already done } final ImageView imageView = mImageView.get(); if (null != imageView) { // Remove this as a global layout listener ViewTreeObserver observer = imageView.getViewTreeObserver(); if (null != observer && observer.isAlive()) { observer.removeGlobalOnLayoutListener(this); } // Remove the ImageView's reference to this imageView.setOnTouchListener(null); // make sure a pending fling runnable won't be run cancelFling(); } if (null != mGestureDetector) { mGestureDetector.setOnDoubleTapListener(null); } // Clear listeners too mMatrixChangeListener = null; mPhotoTapListener = null; mViewTapListener = null; // Finally, clear ImageView mImageView = null; } @Override public RectF getDisplayRect() { checkMatrixBounds(); return getDisplayRect(getDrawMatrix()); } @Override public boolean setDisplayMatrix(Matrix finalMatrix) { if (finalMatrix == null) throw new IllegalArgumentException("Matrix cannot be null"); ImageView imageView = getImageView(); if (null == imageView) return false; if (null == imageView.getDrawable()) return false; mSuppMatrix.set(finalMatrix); setImageViewMatrix(getDrawMatrix()); checkMatrixBounds(); return true; } /** * @deprecated use {@link #setRotationTo(float)} */ @Override public void setPhotoViewRotation(float degrees) { mSuppMatrix.setRotate(degrees % 360); checkAndDisplayMatrix(); } @Override public void setRotationTo(float degrees) { mSuppMatrix.setRotate(degrees % 360); checkAndDisplayMatrix(); } @Override public void setRotationBy(float degrees) { mSuppMatrix.postRotate(degrees % 360); checkAndDisplayMatrix(); } public ImageView getImageView() { ImageView imageView = null; if (null != mImageView) { imageView = mImageView.get(); } // If we don't have an ImageView, call cleanup() if (null == imageView) { cleanup(); Log.i(LOG_TAG, "ImageView no longer exists. You should not use this PhotoViewAttacher any more."); } return imageView; } @Override @Deprecated public float getMinScale() { return getMinimumScale(); } @Override public float getMinimumScale() { return mMinScale; } @Override @Deprecated public float getMidScale() { return getMediumScale(); } @Override public float getMediumScale() { return mMidScale; } @Override @Deprecated public float getMaxScale() { return getMaximumScale(); } @Override public float getMaximumScale() { return mMaxScale; } @Override public float getScale() { return FloatMath.sqrt((float) Math.pow(getValue(mSuppMatrix, Matrix.MSCALE_X), 2) + (float) Math.pow(getValue(mSuppMatrix, Matrix.MSKEW_Y), 2)); } @Override public ScaleType getScaleType() { return mScaleType; } @Override public void onDrag(float dx, float dy) { if (mScaleDragDetector.isScaling()) { return; // Do not drag if we are already scaling } if (DEBUG) { LogManager.getLogger().d(LOG_TAG, String.format("onDrag: dx: %.2f. dy: %.2f", dx, dy)); } ImageView imageView = getImageView(); mSuppMatrix.postTranslate(dx, dy); checkAndDisplayMatrix(); /** * Here we decide whether to let the ImageView's parent to start taking * over the touch event. * * First we check whether this function is enabled. We never want the * parent to take over if we're scaling. We then check the edge we're * on, and the direction of the scroll (i.e. if we're pulling against * the edge, aka 'overscrolling', let the parent take over). */ ViewParent parent = imageView.getParent(); if (mAllowParentInterceptOnEdge && !mScaleDragDetector.isScaling()) { if (mScrollEdge == EDGE_BOTH || (mScrollEdge == EDGE_LEFT && dx >= 1f) || (mScrollEdge == EDGE_RIGHT && dx <= -1f)) { if (null != parent) parent.requestDisallowInterceptTouchEvent(false); } } else { if (null != parent) { parent.requestDisallowInterceptTouchEvent(true); } } } @Override public void onFling(float startX, float startY, float velocityX, float velocityY) { if (DEBUG) { LogManager.getLogger().d( LOG_TAG, "onFling. sX: " + startX + " sY: " + startY + " Vx: " + velocityX + " Vy: " + velocityY); } ImageView imageView = getImageView(); mCurrentFlingRunnable = new FlingRunnable(imageView.getContext()); mCurrentFlingRunnable.fling(getImageViewWidth(imageView), getImageViewHeight(imageView), (int) velocityX, (int) velocityY); imageView.post(mCurrentFlingRunnable); } @Override public void onGlobalLayout() { ImageView imageView = getImageView(); if (null != imageView) { if (mZoomEnabled) { final int top = imageView.getTop(); final int right = imageView.getRight(); final int bottom = imageView.getBottom(); final int left = imageView.getLeft(); /** * We need to check whether the ImageView's bounds have changed. * This would be easier if we targeted API 11+ as we could just use * View.OnLayoutChangeListener. Instead we have to replicate the * work, keeping track of the ImageView's bounds and then checking * if the values change. */ if (top != mIvTop || bottom != mIvBottom || left != mIvLeft || right != mIvRight) { // Update our base matrix, as the bounds have changed updateBaseMatrix(imageView.getDrawable()); // Update values as something has changed mIvTop = top; mIvRight = right; mIvBottom = bottom; mIvLeft = left; } } else { updateBaseMatrix(imageView.getDrawable()); } } } @Override public void onScale(float scaleFactor, float focusX, float focusY) { if (DEBUG) { LogManager.getLogger().d( LOG_TAG, String.format("onScale: scale: %.2f. fX: %.2f. fY: %.2f", scaleFactor, focusX, focusY)); } if (getScale() < mMaxScale || scaleFactor < 1f) { mSuppMatrix.postScale(scaleFactor, scaleFactor, focusX, focusY); checkAndDisplayMatrix(); } } @Override public boolean onTouch(View v, MotionEvent ev) { boolean handled = false; if (mZoomEnabled && hasDrawable((ImageView) v)) { ViewParent parent = v.getParent(); switch (ev.getAction()) { case ACTION_DOWN: // First, disable the Parent from intercepting the touch // event if (null != parent) parent.requestDisallowInterceptTouchEvent(true); else Log.i(LOG_TAG, "onTouch getParent() returned null"); // If we're flinging, and the user presses down, cancel // fling cancelFling(); break; case ACTION_CANCEL: case ACTION_UP: // If the user has zoomed less than min scale, zoom back // to min scale if (getScale() < mMinScale) { RectF rect = getDisplayRect(); if (null != rect) { v.post(new AnimatedZoomRunnable(getScale(), mMinScale, rect.centerX(), rect.centerY())); handled = true; } } break; } // Try the Scale/Drag detector if (null != mScaleDragDetector && mScaleDragDetector.onTouchEvent(ev)) { handled = true; } // Check to see if the user double tapped if (null != mGestureDetector && mGestureDetector.onTouchEvent(ev)) { handled = true; } } return handled; } @Override public void setAllowParentInterceptOnEdge(boolean allow) { mAllowParentInterceptOnEdge = allow; } @Override @Deprecated public void setMinScale(float minScale) { setMinimumScale(minScale); } @Override public void setMinimumScale(float minimumScale) { checkZoomLevels(minimumScale, mMidScale, mMaxScale); mMinScale = minimumScale; } @Override @Deprecated public void setMidScale(float midScale) { setMediumScale(midScale); } @Override public void setMediumScale(float mediumScale) { checkZoomLevels(mMinScale, mediumScale, mMaxScale); mMidScale = mediumScale; } @Override @Deprecated public void setMaxScale(float maxScale) { setMaximumScale(maxScale); } @Override public void setMaximumScale(float maximumScale) { checkZoomLevels(mMinScale, mMidScale, maximumScale); mMaxScale = maximumScale; } @Override public void setOnLongClickListener(OnLongClickListener listener) { mLongClickListener = listener; } @Override public void setOnMatrixChangeListener(OnMatrixChangedListener listener) { mMatrixChangeListener = listener; } @Override public void setOnPhotoTapListener(OnPhotoTapListener listener) { mPhotoTapListener = listener; } @Override public OnPhotoTapListener getOnPhotoTapListener() { return mPhotoTapListener; } @Override public void setOnViewTapListener(OnViewTapListener listener) { mViewTapListener = listener; } @Override public OnViewTapListener getOnViewTapListener() { return mViewTapListener; } @Override public void setScale(float scale) { setScale(scale, false); } @Override public void setScale(float scale, boolean animate) { ImageView imageView = getImageView(); if (null != imageView) { setScale(scale, (imageView.getRight()) / 2, (imageView.getBottom()) / 2, animate); } } @Override public void setScale(float scale, float focalX, float focalY, boolean animate) { ImageView imageView = getImageView(); if (null != imageView) { // Check to see if the scale is within bounds if (scale < mMinScale || scale > mMaxScale) { LogManager .getLogger() .i(LOG_TAG, "Scale must be within the range of minScale and maxScale"); return; } if (animate) { imageView.post(new AnimatedZoomRunnable(getScale(), scale, focalX, focalY)); } else { mSuppMatrix.setScale(scale, scale, focalX, focalY); checkAndDisplayMatrix(); } } } @Override public void setScaleType(ScaleType scaleType) { if (isSupportedScaleType(scaleType) && scaleType != mScaleType) { mScaleType = scaleType; // Finally update update(); } } @Override public void setZoomable(boolean zoomable) { mZoomEnabled = zoomable; update(); } public void update() { ImageView imageView = getImageView(); if (null != imageView) { if (mZoomEnabled) { // Make sure we using MATRIX Scale Type setImageViewScaleTypeMatrix(imageView); // Update the base matrix using the current drawable updateBaseMatrix(imageView.getDrawable()); } else { // Reset the Matrix... resetMatrix(); } } } @Override public Matrix getDisplayMatrix() { return new Matrix(getDrawMatrix()); } public Matrix getDrawMatrix() { mDrawMatrix.set(mBaseMatrix); mDrawMatrix.postConcat(mSuppMatrix); return mDrawMatrix; } private void cancelFling() { if (null != mCurrentFlingRunnable) { mCurrentFlingRunnable.cancelFling(); mCurrentFlingRunnable = null; } } /** * Helper method that simply checks the Matrix, and then displays the result */ private void checkAndDisplayMatrix() { if (checkMatrixBounds()) { setImageViewMatrix(getDrawMatrix()); } } private void checkImageViewScaleType() { ImageView imageView = getImageView(); /** * PhotoView's getScaleType() will just divert to this.getScaleType() so * only call if we're not attached to a PhotoView. */ if (null != imageView && !(imageView instanceof IPhotoView)) { if (!ScaleType.MATRIX.equals(imageView.getScaleType())) { throw new IllegalStateException( "The ImageView's ScaleType has been changed since attaching a PhotoViewAttacher"); } } } private boolean checkMatrixBounds() { final ImageView imageView = getImageView(); if (null == imageView) { return false; } final RectF rect = getDisplayRect(getDrawMatrix()); if (null == rect) { return false; } final float height = rect.height(), width = rect.width(); float deltaX = 0, deltaY = 0; final int viewHeight = getImageViewHeight(imageView); if (height <= viewHeight) { switch (mScaleType) { case FIT_START: deltaY = -rect.top; break; case FIT_END: deltaY = viewHeight - height - rect.top; break; default: deltaY = (viewHeight - height) / 2 - rect.top; break; } } else if (rect.top > 0) { deltaY = -rect.top; } else if (rect.bottom < viewHeight) { deltaY = viewHeight - rect.bottom; } final int viewWidth = getImageViewWidth(imageView); if (width <= viewWidth) { switch (mScaleType) { case FIT_START: deltaX = -rect.left; break; case FIT_END: deltaX = viewWidth - width - rect.left; break; default: deltaX = (viewWidth - width) / 2 - rect.left; break; } mScrollEdge = EDGE_BOTH; } else if (rect.left > 0) { mScrollEdge = EDGE_LEFT; deltaX = -rect.left; } else if (rect.right < viewWidth) { deltaX = viewWidth - rect.right; mScrollEdge = EDGE_RIGHT; } else { mScrollEdge = EDGE_NONE; } // Finally actually translate the matrix mSuppMatrix.postTranslate(deltaX, deltaY); return true; } /** * Helper method that maps the supplied Matrix to the current Drawable * * @param matrix - Matrix to map Drawable against * @return RectF - Displayed Rectangle */ private RectF getDisplayRect(Matrix matrix) { ImageView imageView = getImageView(); if (null != imageView) { Drawable d = imageView.getDrawable(); if (null != d) { mDisplayRect.set(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight()); matrix.mapRect(mDisplayRect); return mDisplayRect; } } return null; } public Bitmap getVisibleRectangleBitmap() { ImageView imageView = getImageView(); return imageView == null ? null : imageView.getDrawingCache(); } @Override public void setZoomTransitionDuration(int milliseconds) { if (milliseconds < 0) milliseconds = DEFAULT_ZOOM_DURATION; this.ZOOM_DURATION = milliseconds; } @Override public IPhotoView getIPhotoViewImplementation() { return this; } /** * Helper method that 'unpacks' a Matrix and returns the required value * * @param matrix - Matrix to unpack * @param whichValue - Which value from Matrix.M* to return * @return float - returned value */ private float getValue(Matrix matrix, int whichValue) { matrix.getValues(mMatrixValues); return mMatrixValues[whichValue]; } /** * Resets the Matrix back to FIT_CENTER, and then displays it.s */ private void resetMatrix() { mSuppMatrix.reset(); setImageViewMatrix(getDrawMatrix()); checkMatrixBounds(); } private void setImageViewMatrix(Matrix matrix) { ImageView imageView = getImageView(); if (null != imageView) { checkImageViewScaleType(); imageView.setImageMatrix(matrix); // Call MatrixChangedListener if needed if (null != mMatrixChangeListener) { RectF displayRect = getDisplayRect(matrix); if (null != displayRect) { mMatrixChangeListener.onMatrixChanged(displayRect); } } } } /** * Calculate Matrix for FIT_CENTER * * @param d - Drawable being displayed */ private void updateBaseMatrix(Drawable d) { ImageView imageView = getImageView(); if (null == imageView || null == d) { return; } final float viewWidth = getImageViewWidth(imageView); final float viewHeight = getImageViewHeight(imageView); final int drawableWidth = d.getIntrinsicWidth(); final int drawableHeight = d.getIntrinsicHeight(); mBaseMatrix.reset(); final float widthScale = viewWidth / drawableWidth; final float heightScale = viewHeight / drawableHeight; if (mScaleType == ScaleType.CENTER) { mBaseMatrix.postTranslate((viewWidth - drawableWidth) / 2F, (viewHeight - drawableHeight) / 2F); } else if (mScaleType == ScaleType.CENTER_CROP) { float scale = Math.max(widthScale, heightScale); mBaseMatrix.postScale(scale, scale); mBaseMatrix.postTranslate((viewWidth - drawableWidth * scale) / 2F, (viewHeight - drawableHeight * scale) / 2F); } else if (mScaleType == ScaleType.CENTER_INSIDE) { float scale = Math.min(1.0f, Math.min(widthScale, heightScale)); mBaseMatrix.postScale(scale, scale); mBaseMatrix.postTranslate((viewWidth - drawableWidth * scale) / 2F, (viewHeight - drawableHeight * scale) / 2F); } else { RectF mTempSrc = new RectF(0, 0, drawableWidth, drawableHeight); RectF mTempDst = new RectF(0, 0, viewWidth, viewHeight); switch (mScaleType) { case FIT_CENTER: mBaseMatrix .setRectToRect(mTempSrc, mTempDst, ScaleToFit.CENTER); break; case FIT_START: mBaseMatrix.setRectToRect(mTempSrc, mTempDst, ScaleToFit.START); break; case FIT_END: mBaseMatrix.setRectToRect(mTempSrc, mTempDst, ScaleToFit.END); break; case FIT_XY: mBaseMatrix.setRectToRect(mTempSrc, mTempDst, ScaleToFit.FILL); break; default: break; } } resetMatrix(); } private int getImageViewWidth(ImageView imageView) { if (null == imageView) return 0; return imageView.getWidth() - imageView.getPaddingLeft() - imageView.getPaddingRight(); } private int getImageViewHeight(ImageView imageView) { if (null == imageView) return 0; return imageView.getHeight() - imageView.getPaddingTop() - imageView.getPaddingBottom(); } /** * Interface definition for a callback to be invoked when the internal Matrix has changed for * this View. * * @author Chris Banes */ public static interface OnMatrixChangedListener { /** * Callback for when the Matrix displaying the Drawable has changed. This could be because * the View's bounds have changed, or the user has zoomed. * * @param rect - Rectangle displaying the Drawable's new bounds. */ void onMatrixChanged(RectF rect); } /** * Interface definition for a callback to be invoked when the Photo is tapped with a single * tap. * * @author Chris Banes */ public static interface OnPhotoTapListener { /** * A callback to receive where the user taps on a photo. You will only receive a callback if * the user taps on the actual photo, tapping on 'whitespace' will be ignored. * * @param view - View the user tapped. * @param x - where the user tapped from the of the Drawable, as percentage of the * Drawable width. * @param y - where the user tapped from the top of the Drawable, as percentage of the * Drawable height. */ void onPhotoTap(View view, float x, float y); } /** * Interface definition for a callback to be invoked when the ImageView is tapped with a single * tap. * * @author Chris Banes */ public static interface OnViewTapListener { /** * A callback to receive where the user taps on a ImageView. You will receive a callback if * the user taps anywhere on the view, tapping on 'whitespace' will not be ignored. * * @param view - View the user tapped. * @param x - where the user tapped from the left of the View. * @param y - where the user tapped from the top of the View. */ void onViewTap(View view, float x, float y); } private class AnimatedZoomRunnable implements Runnable { private final float mFocalX, mFocalY; private final long mStartTime; private final float mZoomStart, mZoomEnd; public AnimatedZoomRunnable(final float currentZoom, final float targetZoom, final float focalX, final float focalY) { mFocalX = focalX; mFocalY = focalY; mStartTime = System.currentTimeMillis(); mZoomStart = currentZoom; mZoomEnd = targetZoom; } @Override public void run() { ImageView imageView = getImageView(); if (imageView == null) { return; } float t = interpolate(); float scale = mZoomStart + t * (mZoomEnd - mZoomStart); float deltaScale = scale / getScale(); mSuppMatrix.postScale(deltaScale, deltaScale, mFocalX, mFocalY); checkAndDisplayMatrix(); // We haven't hit our target scale yet, so post ourselves again if (t < 1f) { Compat.postOnAnimation(imageView, this); } } private float interpolate() { float t = 1f * (System.currentTimeMillis() - mStartTime) / ZOOM_DURATION; t = Math.min(1f, t); t = sInterpolator.getInterpolation(t); return t; } } private class FlingRunnable implements Runnable { private final ScrollerProxy mScroller; private int mCurrentX, mCurrentY; public FlingRunnable(Context context) { mScroller = ScrollerProxy.getScroller(context); } public void cancelFling() { if (DEBUG) { LogManager.getLogger().d(LOG_TAG, "Cancel Fling"); } mScroller.forceFinished(true); } public void fling(int viewWidth, int viewHeight, int velocityX, int velocityY) { final RectF rect = getDisplayRect(); if (null == rect) { return; } final int startX = Math.round(-rect.left); final int minX, maxX, minY, maxY; if (viewWidth < rect.width()) { minX = 0; maxX = Math.round(rect.width() - viewWidth); } else { minX = maxX = startX; } final int startY = Math.round(-rect.top); if (viewHeight < rect.height()) { minY = 0; maxY = Math.round(rect.height() - viewHeight); } else { minY = maxY = startY; } mCurrentX = startX; mCurrentY = startY; if (DEBUG) { LogManager.getLogger().d( LOG_TAG, "fling. StartX:" + startX + " StartY:" + startY + " MaxX:" + maxX + " MaxY:" + maxY); } // If we actually can move, fling the scroller if (startX != maxX || startY != maxY) { mScroller.fling(startX, startY, velocityX, velocityY, minX, maxX, minY, maxY, 0, 0); } } @Override public void run() { if (mScroller.isFinished()) { return; // remaining post that should not be handled } ImageView imageView = getImageView(); if (null != imageView && mScroller.computeScrollOffset()) { final int newX = mScroller.getCurrX(); final int newY = mScroller.getCurrY(); if (DEBUG) { LogManager.getLogger().d( LOG_TAG, "fling run(). CurrentX:" + mCurrentX + " CurrentY:" + mCurrentY + " NewX:" + newX + " NewY:" + newY); } mSuppMatrix.postTranslate(mCurrentX - newX, mCurrentY - newY); setImageViewMatrix(getDrawMatrix()); mCurrentX = newX; mCurrentY = newY; // Post On animation Compat.postOnAnimation(imageView, this); } } } }