webview点击进入activity，并缓存图片

package wst.webview; /* * Copyright 2012 Laurence Dawson * * 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. */ /* * This class is based upon the file ImageViewTouchBase.java which can be found at: * https://dl-ssl.google.com/dl/googlesource/git-repo/repo * * Copyright (C) 2009 The Android Open Source Project */ import android.annotation.SuppressLint; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Matrix; import android.graphics.Paint; import android.os.Build; import android.os.SystemClock; import android.util.AttributeSet; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.View; import android.view.animation.Animation; import android.view.animation.TranslateAnimation; @SuppressLint("NewApi") public class ZoomableImageView extends View { // Statics static final float sPanRate = 7; static final float sScaleRate = 1.25F; static final int sPaintDelay = 250; static final int sAnimationDelay = 500; // This is the base transformation which is used to show the image // initially. The current computation for this shows the image in // it's entirety, letterboxing as needed. One could chose to // show the image as cropped instead. // // This matrix is recomputed when we go from the thumbnail image to // the full size image. private Matrix mBaseMatrix = new Matrix(); // This is the supplementary transformation which reflects what // the user has done in terms of zooming and panning. // // This matrix remains the same when we go from the thumbnail image // to the full size image. private Matrix mSuppMatrix = new Matrix(); // This is the final matrix which is computed as the concatentation // of the base matrix and the supplementary matrix. private Matrix mDisplayMatrix = new Matrix(); // A replacement ImageView matrix private Matrix mMatrix = new Matrix(); // Used to filter the bitmaps when hardware acceleration is not enabled private Paint mPaint; // Temporary buffer used for getting the values out of a matrix. private float[] mMatrixValues = new float[9]; // The current bitmap being displayed. private Bitmap mBitmap; // Dimensions for the view private int mThisWidth = -1, mThisHeight = -1; // The max zoom for the view, determined programatically private float mMaxZoom; // If not null, calls setImageBitmap when onLayout is triggered private Runnable mOnLayoutRunnable = null; // Stacked to the internal queue to invalidate the view private Runnable mRefresh = null; // Stacked to the internal queue to scroll the view private Runnable mFling = null; // The time of the last draw operation private double mLastDraw = 0; // Scale and gesture listeners for the view private ScaleGestureDetector mScaleDetector; private GestureDetector mGestureDetector; // Single tap listener private OnImageTouchedListener mImageTouchedListener; // Programatic entry point public ZoomableImageView(Context context) { super(context); init( context ); } // Set the single tap listener public void setOnImageTouchedListener( OnImageTouchedListener listener ){ this.mImageTouchedListener = listener; } // XML entry point public ZoomableImageView(Context context, AttributeSet attrs) { super(context, attrs); init( context ); } // Setup the view private void init( Context context) { mPaint = new Paint(); mPaint.setDither(true); mPaint.setFilterBitmap(true); mPaint.setAntiAlias(true); // Setup the refresh runnable mRefresh = new Runnable() { @Override public void run() { postInvalidate(); } }; // Setup the gesture and scale listeners mScaleDetector = new ScaleGestureDetector( context, new ScaleListener() ); mGestureDetector = new GestureDetector(context, new MyGestureListener()); // Force hardware acceleration if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ) setLayerType(View.LAYER_TYPE_HARDWARE, null); } // Get the bitmap for the view public Bitmap getImageBitmap(){ return mBitmap; } // Free the bitmaps and matrices public void clear(){ if(mBitmap!=null) mBitmap = null; } // When the layout is calculated, set the @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); mThisWidth = right - left; mThisHeight = bottom - top; Runnable r = mOnLayoutRunnable; if (r != null) { mOnLayoutRunnable = null; r.run(); } if (mBitmap != null) { setBaseMatrix(mBitmap, mBaseMatrix); setImageMatrix(getImageViewMatrix()); } } // Translate a given point through a given matrix. static private void translatePoint(Matrix matrix, float [] xy) { matrix.mapPoints(xy); } // Identical to the setImageMatrix method in ImageView public void setImageMatrix(Matrix m){ if (m != null && m.isIdentity()) { m = null; } // don't invalidate unless we're actually changing our matrix if (m == null && !this.mMatrix.isIdentity() || m != null && !this.mMatrix.equals(m)) { this.mMatrix.set(m); invalidate(); } } // Sets the bitmap for the image and resets the base public void setImageBitmap(final Bitmap bitmap) { final int viewWidth = getWidth(); if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB && bitmap!=null && bitmap.getHeight()>1800 ) setLayerType(View.LAYER_TYPE_SOFTWARE, null); if (viewWidth <= 0) { mOnLayoutRunnable = new Runnable() { public void run() { setImageBitmap(bitmap); } }; return; } if (bitmap != null) { setBaseMatrix(bitmap, mBaseMatrix); this.mBitmap = bitmap; } else { mBaseMatrix.reset(); this.mBitmap = bitmap; } mSuppMatrix.reset(); setImageMatrix(getImageViewMatrix()); mMaxZoom = maxZoom(); // Set the image to fit the screen zoomTo(zoomDefault()); } // Unchanged from ImageViewTouchBase // Center as much as possible in one or both axis. Centering is // defined as follows: if the image is scaled down below the // view's dimensions then center it (literally). If the image // is scaled larger than the view and is translated out of view // then translate it back into view (i.e. eliminate black bars). protected void center(boolean vertical, boolean horizontal, boolean animate) { if (mBitmap == null) return; Matrix m = getImageViewMatrix(); float [] topLeft = new float[] { 0, 0 }; float [] botRight = new float[] { mBitmap.getWidth(), mBitmap.getHeight() }; translatePoint(m, topLeft); translatePoint(m, botRight); float height = botRight[1] - topLeft[1]; float width = botRight[0] - topLeft[0]; float deltaX = 0, deltaY = 0; if (vertical) { int viewHeight = getHeight(); if (height < viewHeight) { deltaY = (viewHeight - height)/2 - topLeft[1]; } else if (topLeft[1] > 0) { deltaY = -topLeft[1]; } else if (botRight[1] < viewHeight) { deltaY = getHeight() - botRight[1]; } } if (horizontal) { int viewWidth = getWidth(); if (width < viewWidth) { deltaX = (viewWidth - width)/2 - topLeft[0]; } else if (topLeft[0] > 0) { deltaX = -topLeft[0]; } else if (botRight[0] < viewWidth) { deltaX = viewWidth - botRight[0]; } } postTranslate(deltaX, deltaY); if (animate) { Animation a = new TranslateAnimation(-deltaX, 0, -deltaY, 0); a.setStartTime(SystemClock.elapsedRealtime());