支持手势缩放的ImageView

/* * TouchImageView.java * By: Michael Ortiz * Updated By: Patrick Lackemacher * Updated By: Babay88 * Updated By: @ipsilondev * Updated By: hank-cp * Updated By: singpolyma * ------------------- * Extends Android ImageView to include pinch zooming, panning, fling and double tap zoom. */ package com.ortiz.touch; 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; public class TouchImageView extends ImageView { private static final String DEBUG = "DEBUG"; // // SuperMin and SuperMax multipliers. Determine how much the image can be // zoomed below or above the zoom boundaries, before animating back to the // min/max zoom boundary. // private static final float SUPER_MIN_MULTIPLIER = .75f; private static final float SUPER_MAX_MULTIPLIER = 1.25f; // // Scale of image ranges from minScale to maxScale, where minScale == 1 // when the image is stretched to fit view. // private float normalizedScale; // // Matrix applied to image. MSCALE_X and MSCALE_Y should always be equal. // MTRANS_X and MTRANS_Y are the other values used. prevMatrix is the matrix // saved prior to the screen rotating. // 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; // // Size of view and previous view size (ie before rotation) // private int viewWidth, viewHeight, prevViewWidth, prevViewHeight; // // Size of image when it is stretched to fit view. Before and After rotation. // 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.