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-rw-r--r--src/com/android/camera/ui/ZoomView.java551
1 files changed, 551 insertions, 0 deletions
diff --git a/src/com/android/camera/ui/ZoomView.java b/src/com/android/camera/ui/ZoomView.java
new file mode 100644
index 000000000..edf151367
--- /dev/null
+++ b/src/com/android/camera/ui/ZoomView.java
@@ -0,0 +1,551 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * 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.android.camera.ui;
+
+import android.animation.Animator;
+import android.animation.ObjectAnimator;
+import android.animation.TypeEvaluator;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.BitmapRegionDecoder;
+import android.graphics.Matrix;
+import android.graphics.Rect;
+import android.graphics.RectF;
+import android.net.Uri;
+import android.os.AsyncTask;
+import android.util.Log;
+import android.view.GestureDetector;
+import android.view.MotionEvent;
+import android.view.ScaleGestureDetector;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.ImageView;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+
+public class ZoomView extends FrameLayout {
+
+ private static final String TAG = "ZoomView";
+
+ // Gesture statuses
+ private static final int IDLE = 0;
+ private static final int SCALE = 1;
+ private static final int SCROLL = 2;
+
+ // When the image is zoomed in to within TOLERANCE pixels of its original size,
+ // we consider it all the way zoomed in
+ private static final int TOLERANCE = 10;
+
+ private static final int ANIMATION_DURATION_MS = 200;
+
+ private int mViewportWidth = 0;
+ private int mViewportHeight = 0;
+
+ private ScaleGestureDetector mScaleDetector;
+ private GestureDetector mGesturesDetector;
+ private int mGestureState = IDLE;
+
+ private ImageView mPartialImage;
+ private ImageView mFullImage;
+
+ private RectF mInitialRect;
+ private int mFullResImageWidth;
+ private int mFullResImageHeight;
+
+ private BitmapRegionDecoder mRegionDecoder;
+ private DecodePartialBitmap mPartialDecodingTask;
+ private LoadBitmapTask mFullImageDecodingTask;
+ private RectF mBitmapRect;
+
+ private float mLastScalePivotX;
+ private float mLastScalePivotY;
+
+ private ObjectAnimator mAnimator;
+ private Uri mUri;
+
+ private TypeEvaluator<Matrix> mEvaluator = new TypeEvaluator<Matrix>() {
+ @Override
+ public Matrix evaluate(float fraction, Matrix startValue, Matrix endValue) {
+
+ RectF startRect = new RectF();
+ startValue.mapRect(startRect, mBitmapRect);
+ RectF endRect = new RectF();
+ endValue.mapRect(endRect, mBitmapRect);
+
+ float top = startRect.top + (endRect.top - startRect.top) * fraction;
+ float left = startRect.left + (endRect.left - startRect.left) * fraction;
+ float right = startRect.right + (endRect.right - startRect.right) * fraction;
+ float bottom = startRect.bottom + (endRect.bottom - startRect.bottom) * fraction;
+ RectF currentRect = new RectF(left, top, right, bottom);
+
+ Matrix m = new Matrix();
+ m.setRectToRect(mBitmapRect, currentRect, Matrix.ScaleToFit.CENTER);
+ return m;
+ }
+ };
+
+ private GestureDetector.SimpleOnGestureListener mGestureListener
+ = new GestureDetector.SimpleOnGestureListener(){
+ @Override
+ public boolean onDoubleTap(MotionEvent e) {
+ zoomAt(e.getX(), e.getY());
+ return true;
+ }
+
+ @Override
+ public boolean onScroll(MotionEvent e1, MotionEvent e2,
+ float distanceX, float distanceY) {
+ if (mGestureState == SCALE) {
+ return false;
+ }
+ mGestureState = SCROLL;
+
+ // Translate image matrix
+ Matrix m = new Matrix(mFullImage.getImageMatrix());
+ m.postTranslate(-distanceX, -distanceY);
+ mFullImage.setImageMatrix(m);
+ return true;
+ }
+
+ @Override
+ public boolean onSingleTapUp(MotionEvent ev) {
+ showPartiallyDecodedImage(true);
+ return true;
+ }
+ };
+
+ private ScaleGestureDetector.OnScaleGestureListener mScaleListener
+ = new ScaleGestureDetector.OnScaleGestureListener() {
+ @Override
+ public boolean onScale(ScaleGestureDetector detector) {
+ float scaleFactor = detector.getScaleFactor();
+ mLastScalePivotX = detector.getFocusX();
+ mLastScalePivotY = detector.getFocusY();
+
+ // Scale image matrix
+ Matrix m = new Matrix(mFullImage.getImageMatrix());
+ m.postScale(scaleFactor, scaleFactor, mLastScalePivotX, mLastScalePivotY);
+ mFullImage.setImageMatrix(m);
+ return true;
+ }
+
+ @Override
+ public boolean onScaleBegin(ScaleGestureDetector detector) {
+ mGestureState = SCALE;
+ cancelPartialDecodingTask();
+ return true;
+ }
+
+ @Override
+ public void onScaleEnd(ScaleGestureDetector detector) {
+ mGestureState = IDLE;
+ snapBack();
+ }
+ };
+
+ private void cancelPartialDecodingTask() {
+ if (mPartialDecodingTask != null) {
+ mPartialDecodingTask.cancel(true);
+ }
+ }
+
+ private class LoadBitmapTask extends AsyncTask<Object, Void, Bitmap> {
+ @Override
+ protected Bitmap doInBackground(Object... params) {
+ // Params[0]: BitmapFactory.options
+ if (params.length < 1) {
+ return null;
+ }
+ InputStream is = getInputStream();
+ if (isCancelled()) {
+ return null;
+ }
+ BitmapFactory.Options options = (BitmapFactory.Options) params[0];
+ return BitmapFactory.decodeStream(is, null, options);
+ }
+
+ @Override
+ protected void onPostExecute(Bitmap bitmap) {
+ if (bitmap == null) {
+ Log.e(TAG, "Failed to load bitmap");
+ return;
+ }
+ initFullImageView(bitmap);
+ mFullImageDecodingTask = null;
+ }
+ }
+
+ private class DecodePartialBitmap extends AsyncTask<RectF, Void, Bitmap> {
+
+ @Override
+ protected Bitmap doInBackground(RectF... params) {
+ RectF endRect = params[0];
+ // Find intersection with the screen
+ RectF visibleRect = new RectF(endRect);
+ visibleRect.intersect(0, 0, mViewportWidth, mViewportHeight);
+
+ Matrix m2 = new Matrix();
+ m2.setRectToRect(endRect, new RectF(0, 0, mFullResImageWidth, mFullResImageHeight),
+ Matrix.ScaleToFit.CENTER);
+ RectF visibleInImage = new RectF();
+ m2.mapRect(visibleInImage, visibleRect);
+
+ // Decode region
+ Rect v = new Rect();
+ visibleInImage.round(v);
+ if (isCancelled()) {
+ return null;
+ }
+
+ BitmapFactory.Options options = new BitmapFactory.Options();
+ options.inSampleSize = getSampleFactor(v.width(), v.height());
+ Bitmap b = mRegionDecoder.decodeRegion(v, options);
+ return b;
+ }
+
+ @Override
+ protected void onPostExecute(Bitmap b) {
+ if (b == null) {
+ return;
+ }
+ mPartialImage.setImageBitmap(b);
+ showPartiallyDecodedImage(true);
+ mPartialDecodingTask = null;
+ }
+ }
+
+ public ZoomView(Context context, Uri uri) {
+ super(context);
+ mUri = uri;
+ mPartialImage = new ImageView(context);
+ mFullImage = new ImageView(context);
+ LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT,
+ ViewGroup.LayoutParams.MATCH_PARENT);
+ addView(mPartialImage, lp);
+ addView(mFullImage, lp);
+ mFullImage.setScaleType(ImageView.ScaleType.MATRIX);
+ InputStream is = getInputStream();
+ try {
+ mRegionDecoder = BitmapRegionDecoder.newInstance(is, false);
+ is.close();
+ } catch (IOException e) {
+ Log.e(TAG, "Fail to instantiate region decoder");
+ }
+
+ addOnLayoutChangeListener(new OnLayoutChangeListener() {
+ @Override
+ public void onLayoutChange(View v, int left, int top, int right, int bottom,
+ int oldLeft, int oldTop, int oldRight, int oldBottom) {
+ int w = right - left;
+ int h = bottom - top;
+ if (mViewportHeight != h || mViewportWidth != w) {
+ mViewportWidth = w;
+ mViewportHeight = h;
+ loadBitmap();
+ }
+ }
+ });
+ mGesturesDetector = new GestureDetector(getContext(), mGestureListener);
+ mScaleDetector = new ScaleGestureDetector(getContext(), mScaleListener);
+ }
+
+ private void initFullImageView(Bitmap bitmap) {
+ mFullImage.setImageBitmap(bitmap);
+ int w = bitmap.getWidth();
+ int h = bitmap.getHeight();
+ mBitmapRect = new RectF(0, 0, w, h);
+ Matrix initialMatrix = new Matrix();
+ initialMatrix.setRectToRect(mBitmapRect, mInitialRect, Matrix.ScaleToFit.CENTER);
+ mFullImage.setImageMatrix(initialMatrix);
+ }
+
+ @Override
+ public boolean onTouchEvent(MotionEvent ev) {
+ // TODO: The touch event handling could use some refinement
+ if (ev.getActionMasked() == MotionEvent.ACTION_DOWN) {
+ endAnimation();
+ cancelPartialDecodingTask();
+ // Show down-sampled full image when there is touch interaction
+ showPartiallyDecodedImage(false);
+ mGestureState = IDLE;
+ } else if (ev.getActionMasked() == MotionEvent.ACTION_UP
+ && mGestureState == SCROLL) {
+ snapBack();
+ mGestureState = IDLE;
+ } else if (ev.getActionMasked() == MotionEvent.ACTION_POINTER_DOWN) {
+ mGestureState = SCALE;
+ }
+ boolean ret = mGesturesDetector.onTouchEvent(ev);
+ return mScaleDetector.onTouchEvent(ev) || ret;
+ }
+
+ private void showPartiallyDecodedImage(boolean show) {
+ if (show) {
+ mPartialImage.setVisibility(View.VISIBLE);
+ mFullImage.setVisibility(View.GONE);
+ } else {
+ mFullImage.setVisibility(View.VISIBLE);
+ mPartialImage.setVisibility(View.GONE);
+ }
+ }
+
+ /**
+ * Snap back to the screen bounds from current position
+ */
+ private void snapBack() {
+ RectF endRect = new RectF();
+ mFullImage.getImageMatrix().mapRect(endRect, mBitmapRect);
+ snapBack(endRect);
+ }
+
+ /**
+ * Snap back to the screen bounds from given position
+ */
+ private void snapBack(RectF endRect) {
+
+ if (endRect.width() < mViewportWidth && endRect.height() < mViewportHeight) {
+ snapToInitialRect(true);
+ return;
+ }
+
+ float dx = 0, dy = 0;
+ Matrix startMatrix = mFullImage.getImageMatrix();
+ Matrix endMatrix = new Matrix(startMatrix);
+ boolean needsSnapping = false;
+
+ if (endRect.width() > mFullResImageWidth) {
+ needsSnapping = true;
+ float x = mScaleDetector.getFocusX();
+ float y = mScaleDetector.getFocusY();
+ float scale = mFullResImageWidth / endRect.width();
+ endMatrix.postScale(scale, scale, x, y);
+ endMatrix.mapRect(endRect, mBitmapRect);
+ }
+
+ if (endRect.width() < mViewportWidth) {
+ // Center it
+ dx = mViewportWidth / 2 - (endRect.left + endRect.right) / 2;
+ } else {
+ if (endRect.left > 0) {
+ dx = -endRect.left;
+ } else if (endRect.right < mViewportWidth) {
+ dx = mViewportWidth - endRect.right;
+ }
+ }
+
+ if (endRect.height() < mViewportHeight) {
+ dy = mViewportHeight / 2 - (endRect.top + endRect.bottom) / 2;
+ } else {
+ if (endRect.top > 0) {
+ dy = -endRect.top;
+ } else if (endRect.bottom < mViewportHeight) {
+ dy = mViewportHeight - endRect.bottom;
+ }
+ }
+
+ if (dx != 0 || dy != 0 || needsSnapping) {
+ endRect.offset(dx, dy);
+ endMatrix.postTranslate(dx, dy);
+ startAnimation(startMatrix, endMatrix);
+ }
+
+ startPartialDecodingTask(endRect);
+ }
+
+ private void snapToInitialRect(boolean withAnimation) {
+ // Restore to initial rect
+ Matrix endMatrix = new Matrix();
+ endMatrix.setRectToRect(mBitmapRect, mInitialRect, Matrix.ScaleToFit.CENTER);
+ if (withAnimation) {
+ startAnimation(mFullImage.getImageMatrix(), endMatrix);
+ } else {
+ mFullImage.setImageMatrix(endMatrix);
+ }
+ }
+
+ private void zoomAt(float x, float y) {
+ Matrix startMatrix = mFullImage.getImageMatrix();
+ Matrix endMatrix = new Matrix();
+ RectF currentImageRect = new RectF();
+ startMatrix.mapRect(currentImageRect, mBitmapRect);
+
+ if (currentImageRect.width() < mFullResImageWidth - TOLERANCE) {
+ // Zoom in
+ float scale = ((float) mFullResImageWidth) / currentImageRect.width();
+ endMatrix.set(startMatrix);
+ endMatrix.postScale(scale, scale, x, y);
+ // Start animation
+ startAnimation(startMatrix, endMatrix);
+
+ RectF endRect = new RectF();
+ endMatrix.mapRect(endRect, mBitmapRect);
+ startPartialDecodingTask(endRect);
+ } else {
+ // Zoom out
+ endMatrix.setRectToRect(mBitmapRect, mInitialRect, Matrix.ScaleToFit.CENTER);
+ // Start animation
+ startAnimation(startMatrix, endMatrix);
+ }
+
+ }
+
+ private void startAnimation(Matrix startMatrix, final Matrix endMatrix) {
+ endAnimation();
+ showPartiallyDecodedImage(false);
+ mAnimator = ObjectAnimator.ofObject(mFullImage, "imageMatrix", mEvaluator,
+ startMatrix, endMatrix)
+ .setDuration(ANIMATION_DURATION_MS);
+ mAnimator.addListener(new Animator.AnimatorListener() {
+ @Override
+ public void onAnimationStart(Animator animation) {
+
+ }
+
+ @Override
+ public void onAnimationEnd(Animator animation) {
+ // Set end value
+ mFullImage.setImageMatrix(endMatrix);
+ mAnimator.removeAllListeners();
+ mAnimator = null;
+ }
+
+ @Override
+ public void onAnimationCancel(Animator animation) {
+
+ }
+
+ @Override
+ public void onAnimationRepeat(Animator animation) {
+
+ }
+ });
+ mAnimator.start();
+ }
+
+ private void endAnimation() {
+ if (mAnimator == null) {
+ return;
+ }
+ if (mAnimator.isRunning()) {
+ mAnimator.end();
+ }
+ }
+
+ private void startPartialDecodingTask(RectF endRect) {
+ // Cancel on-going partial decoding tasks
+ cancelPartialDecodingTask();
+ mPartialDecodingTask = new DecodePartialBitmap();
+ mPartialDecodingTask.execute(endRect);
+ }
+
+ private void loadBitmap() {
+ if (mFullResImageHeight == 0 || mFullResImageWidth == 0) {
+ decodeImageSize();
+ }
+
+ if (mViewportHeight != 0 && mViewportWidth != 0) {
+ // Calculate where the bitmap rect should be positioned based on viewport size
+ calculateInitialRect();
+ if (mBitmapRect != null && mBitmapRect.width() > mInitialRect.width()
+ && mBitmapRect.height() > mInitialRect.height()) {
+ // No need to reload bitmap
+ snapToInitialRect(false);
+ } else {
+ BitmapFactory.Options option = new BitmapFactory.Options();
+ // Down-sample the bitmap whenever possible to be efficient
+ int sampleFactor = getSampleFactor(mFullResImageWidth, mFullResImageHeight);
+ option.inSampleSize = sampleFactor;
+ if (mFullImageDecodingTask != null) {
+ mFullImageDecodingTask.cancel(true);
+ }
+ mFullImageDecodingTask = new LoadBitmapTask();
+ mFullImageDecodingTask.execute(option);
+ }
+ }
+ }
+
+ private void calculateInitialRect() {
+ float fitWidthScale = ((float) mViewportWidth) / ((float) mFullResImageWidth);
+ float fitHeightScale = ((float) mViewportHeight) / ((float) mFullResImageHeight);
+ float scale = Math.min(fitHeightScale, fitWidthScale);
+
+ int centerX = mViewportWidth / 2;
+ int centerY = mViewportHeight / 2;
+ int width = (int) (scale * mFullResImageWidth);
+ int height = (int) (scale * mFullResImageHeight);
+
+ mInitialRect = new RectF(centerX - width / 2, centerY - height / 2,
+ centerX + width / 2, centerY + height / 2);
+ }
+
+ private void decodeImageSize() {
+ BitmapFactory.Options option = new BitmapFactory.Options();
+ option.inJustDecodeBounds = true;
+ InputStream is = getInputStream();
+ BitmapFactory.decodeStream(is, null, option);
+ try {
+ is.close();
+ } catch (IOException e) {
+ Log.e(TAG, "Failed to close input stream");
+ }
+ mFullResImageWidth = option.outWidth;
+ mFullResImageHeight = option.outHeight;
+ }
+
+ // TODO: Cache the inputstream
+ private InputStream getInputStream() {
+ InputStream is = null;
+ try {
+ is = getContext().getContentResolver().openInputStream(mUri);
+ } catch (FileNotFoundException e) {
+ Log.e(TAG, "File not found at: " + mUri);
+ }
+ return is;
+ }
+
+ /**
+ * Find closest sample factor that is power of 2, based on the given width and height
+ *
+ * @param width width of the partial region to decode
+ * @param height height of the partial region to decode
+ * @return sample factor
+ */
+ private int getSampleFactor(int width, int height) {
+
+ float fitWidthScale = ((float) mViewportWidth) / ((float) width);
+ float fitHeightScale = ((float) mViewportHeight) / ((float) height);
+
+ float scale = Math.min(fitHeightScale, fitWidthScale);
+
+ // Find the closest sample factor that is power of 2
+ int sampleFactor = (int) (1f / scale);
+ if (sampleFactor <=1) {
+ return 1;
+ }
+ for (int i = 0; i < 32; i++) {
+ if ((1 << (i + 1)) > sampleFactor) {
+ sampleFactor = (1 << i);
+ break;
+ }
+ }
+ return sampleFactor;
+ }
+}