package com.github.h01d.chatapp.utils; /** * This is a part of ChatApp Project (https://github.com/h01d/ChatApp) * Licensed under Apache License 2.0 * * @author Raf (https://github.com/h01d) * @version 1.1 * @since 27/02/2018 */ import android.content.Context; import android.graphics.Matrix; import android.graphics.PointF; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.View; public class TouchImageView extends android.support.v7.widget.AppCompatImageView { Matrix matrix; static final int NONE = 0; static final int DRAG = 1; static final int ZOOM = 2; int mode = NONE; PointF last = new PointF(); PointF start = new PointF(); float minScale = 1f; float maxScale = 3f; float[] m; int viewWidth, viewHeight; static final int CLICK = 3; float saveScale = 1f; protected float origWidth, origHeight; int oldMeasuredWidth, oldMeasuredHeight; ScaleGestureDetector mScaleDetector; Context context; public TouchImageView(Context context) { super(context); sharedConstructing(context); } public TouchImageView(Context context, AttributeSet attrs) { super(context, attrs); sharedConstructing(context); } private void stopInterceptEvent() { getParent().requestDisallowInterceptTouchEvent(true); } private void startInterceptEvent() { getParent().requestDisallowInterceptTouchEvent(false); } 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()); switch(event.getAction()) { case MotionEvent.ACTION_DOWN: last.set(curr); start.set(last); mode = DRAG; stopInterceptEvent(); 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); float transX = m[Matrix.MTRANS_X]; if((int) (getFixTrans(transX, viewWidth, origWidth * saveScale) + fixTransX) == 0) { startInterceptEvent(); } else { stopInterceptEvent(); } } break; case MotionEvent.ACTION_UP: mode = NONE; int xDiff = (int) Math.abs(curr.x - start.x); int yDiff = (int) Math.abs(curr.y - start.y); if(xDiff < CLICK && yDiff < CLICK) { performClick(); } startInterceptEvent(); break; case MotionEvent.ACTION_POINTER_UP: mode = NONE; break; } setImageMatrix(matrix); invalidate(); return true; } }); } 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); if(oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight || viewWidth == 0 || viewHeight == 0) { return; } oldMeasuredHeight = viewHeight; oldMeasuredWidth = viewWidth; if(saveScale == 1) { float scale; Drawable drawable = getDrawable(); if(drawable == null || drawable.getIntrinsicWidth() == 0 || drawable.getIntrinsicHeight() == 0) { return; } int bmWidth = drawable.getIntrinsicWidth(); int bmHeight = drawable.getIntrinsicHeight(); float scaleX = (float) viewWidth / (float) bmWidth; float scaleY = (float) viewHeight / (float) bmHeight; scale = Math.min(scaleX, scaleY); matrix.setScale(scale, scale); 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(); } }