/* * TouchImageView.java * By: Michael Ortiz * Updated By: Patrick Lackemacher * Updated By: Babay88 * Updated By: zfdang (add performLongClick) * ------------------- * Extends Android ImageView to include pinch zooming and panning. */ package com.athena.asm.view; import android.content.Context; import android.graphics.Matrix; import android.graphics.PointF; import android.graphics.drawable.Drawable; import android.os.Handler; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.View; import android.view.ViewConfiguration; import android.widget.ImageView; public class TouchImageView extends ImageView { Matrix matrix; // We can be in one of these 3 states static final int NONE = 0; static final int DRAG = 1; static final int ZOOM = 2; int mode = NONE; // Remember some things for zooming PointF last = new PointF(); PointF start = new PointF(); float minScale = 1f; float maxScale = 12f; float[] m; int viewWidth, viewHeight; static final int CLICK = 3; static final int LONG_CLICK = 10; float saveScale = 1f; protected float origWidth, origHeight; int oldMeasuredWidth, oldMeasuredHeight; ScaleGestureDetector mScaleDetector; Context context; /** * flag to wait long click event */ private boolean mWaitingForLongClick; private Handler mHandler = null; private PendingCheckForLongClick mPendingCheckForLongClick = null; class PendingCheckForLongClick implements Runnable { public void run() { if (mWaitingForLongClick) { mWaitingForLongClick = false; performLongClick(); } } } private void checkForLongClick(int delayOffset) { mWaitingForLongClick = true; if (mHandler == null) { mHandler = new Handler(); } if (mPendingCheckForLongClick != null) { mHandler.removeCallbacks(mPendingCheckForLongClick); } else { mPendingCheckForLongClick = new PendingCheckForLongClick(); } mHandler.postDelayed(mPendingCheckForLongClick, ViewConfiguration.getLongPressTimeout() - delayOffset); } private void clearCheckForLongClick() { mWaitingForLongClick = false; if (mHandler != null && mPendingCheckForLongClick!= null) { mHandler.removeCallbacks(mPendingCheckForLongClick); } } @Override public boolean canScrollHorizontally(int direction) { // clear longclick events clearCheckForLongClick(); if (mode == ZOOM) { // if mode is ZOOM, allow scroll return true; } if(direction > 0){ // scroll to the left // if the right board of the image is invisible then allow scroll; otherwise don't scroll float[] point = {getDrawable().getIntrinsicWidth(), 0}; matrix.mapPoints(point); // Log.d("canScrollHorizontally", String.format("direction = %d, point.x = %f, viewWidth = %d", direction, point[0], viewWidth)); // comparing float with integer, we can use strict equal. take 2 as threshold if(point[0] > viewWidth + 2) { return true; } else { return false; } } else { // scroll to the right // if the left board of the image is invisible then allow scroll; otherwise don't scroll float[] point = {0, 0}; matrix.mapPoints(point); // Log.d("canScrollHorizontally", String.format("direction = %d, point.x = %f, viewWidth = %d", direction, point[0], viewWidth)); // comparing float with integer, we can use strict equal. take 2 as threshold if(point[0] < -2 ) { return true; } else { return false; } } } public TouchImageView(Context context) { super(context); sharedConstructing(context); } public TouchImageView(Context context, AttributeSet attrs) { super(context, attrs); sharedConstructing(context); } private void sharedConstructing(Context context) { super.setClickable(true); this.context = context; mScaleDetector = new ScaleGestureDetector(context, new ScaleListener()); matrix = new Matrix(); m = new float[9]; setImageMatrix(matrix); setScaleType(ScaleType.MATRIX); setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { mScaleDetector.onTouchEvent(event); PointF curr = new PointF(event.getX(), event.getY()); int xDiff = (int) Math.abs(curr.x - start.x); int yDiff = (int) Math.abs(curr.y - start.y); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: last.set(curr); start.set(last); mode = DRAG; checkForLongClick(0); break; case MotionEvent.ACTION_MOVE: if (mode == DRAG) { float deltaX = curr.x - last.x; float deltaY = curr.y - last.y; float fixTransX = getFixDragTrans(deltaX, viewWidth, origWidth * saveScale); float fixTransY = getFixDragTrans(deltaY, viewHeight, origHeight * saveScale); matrix.postTranslate(fixTransX, fixTransY); fixTrans(); last.set(curr.x, curr.y); } if (xDiff > LONG_CLICK || yDiff > LONG_CLICK) { clearCheckForLongClick(); } break; case MotionEvent.ACTION_UP: mode = NONE; if (xDiff < CLICK && yDiff < CLICK) performClick(); clearCheckForLongClick(); break; case MotionEvent.ACTION_POINTER_UP: mode = NONE; break; } setImageMatrix(matrix); invalidate(); return true; // indicate event was handled } }); } public void setMaxZoom(float x) { maxScale = x; } private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener { @Override public boolean onScaleBegin(ScaleGestureDetector detector) { mode = ZOOM; return true; } @Override public boolean onScale(ScaleGestureDetector detector) { float mScaleFactor = detector.getScaleFactor(); float origScale = saveScale; saveScale *= mScaleFactor; if (saveScale > maxScale) { saveScale = maxScale; mScaleFactor = maxScale / origScale; } else if (saveScale < minScale) { saveScale = minScale; mScaleFactor = minScale / origScale; } if (origWidth * saveScale <= viewWidth || origHeight * saveScale <= viewHeight) matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2, viewHeight / 2); else matrix.postScale(mScaleFactor, mScaleFactor, detector.getFocusX(), detector.getFocusY()); fixTrans(); return true; } } void fixTrans() { matrix.getValues(m); float transX = m[Matrix.MTRANS_X]; float transY = m[Matrix.MTRANS_Y]; float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale); float fixTransY = getFixTrans(transY, viewHeight, origHeight * saveScale); if (fixTransX != 0 || fixTransY != 0) matrix.postTranslate(fixTransX, fixTransY); } 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; } float getFixDragTrans(float delta, float viewSize, float contentSize) { if (contentSize <= viewSize) { return 0; } return delta; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); viewWidth = MeasureSpec.getSize(widthMeasureSpec); viewHeight = MeasureSpec.getSize(heightMeasureSpec); // // Rescales image on rotation // if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight || viewWidth == 0 || viewHeight == 0) return; oldMeasuredHeight = viewHeight; oldMeasuredWidth = viewWidth; if (saveScale == 1) { //Fit to screen. float scale; Drawable drawable = getDrawable(); if (drawable == null || drawable.getIntrinsicWidth() == 0 || drawable.getIntrinsicHeight() == 0) return; int bmWidth = drawable.getIntrinsicWidth(); int bmHeight = drawable.getIntrinsicHeight(); // Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight); float scaleX = (float) viewWidth / (float) bmWidth; float scaleY = (float) viewHeight / (float) bmHeight; scale = Math.min(scaleX, scaleY); matrix.setScale(scale, scale); // Center the image float redundantYSpace = (float) viewHeight - (scale * (float) bmHeight); float redundantXSpace = (float) viewWidth - (scale * (float) bmWidth); redundantYSpace /= (float) 2; redundantXSpace /= (float) 2; matrix.postTranslate(redundantXSpace, redundantYSpace); origWidth = viewWidth - 2 * redundantXSpace; origHeight = viewHeight - 2 * redundantYSpace; setImageMatrix(matrix); } fixTrans(); } }