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POHow to properly set fixTransX & fixTransY of TouchImageView to implement doubleTap to ZoomOut?
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copied!<p>I am using <code>TouchImageView</code> from <a href="https://github.com/MikeOrtiz/TouchImageView/blob/master/src/com/example/touch/TouchImageView.java" rel="nofollow">here</a>. </p> <p>I am trying to implement <code>ZoomOut</code> for double tap. I have done it partially. But, I am facing some issues when zoomed out. If I zoom the Image & if I give a double tap, then image is not getting rendered properly.</p> <p>Here is my modified version</p> <p>TouchImageView.java</p> <pre><code>package com.bharath.downloadissuedemo; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Matrix; import android.graphics.PointF; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; 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.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 = 3f; float[] m; int viewWidth, viewHeight; static final int CLICK = 3; float saveScale = 1f; protected float origWidth, origHeight; int oldMeasuredWidth, oldMeasuredHeight; GestureDetector gestureDetector; ScaleGestureDetector mScaleDetector; Context context; public TouchImageView(Context context) { super(context); sharedConstructing(context); gestureDetector = new GestureDetector(getContext(), new GestureListener(this)); } public TouchImageView(Context context, AttributeSet attrs) { super(context, attrs); sharedConstructing(context); gestureDetector = new GestureDetector(getContext(), new GestureListener(this)); } 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() & MotionEvent.ACTION_MASK) { case MotionEvent.ACTION_DOWN: last.set(curr); start.set(last); mode = DRAG; 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); } 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(); break; case MotionEvent.ACTION_POINTER_UP: mode = NONE; break; } setImageMatrix(matrix); invalidate(); return gestureDetector.onTouchEvent(event); // 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; System.out.println("Orig Scale = "+origScale); saveScale *= mScaleFactor; System.out.println("Sace Scale = "+saveScale); System.out.println("m Scale Factor = "+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); System.out.println("Translation X ="+fixTransX); System.out.println("Translation Y ="+fixTransY); ((ViewPagerInterface)getContext()).enable(); if (fixTransX != 0 || fixTransY != 0) { matrix.postTranslate(fixTransX, fixTransY); } else if (saveScale!=1.0) { ((ViewPagerInterface)getContext()).disable(); } } 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(); } private class GestureListener extends GestureDetector.SimpleOnGestureListener { public TouchImageView touchImageView=null; public GestureListener(TouchImageView tmv) { touchImageView=tmv; } @Override public boolean onDown(MotionEvent e) { return false; } // event when double tap occurs @Override public boolean onDoubleTap(MotionEvent e) { if (saveScale>1.0f) { Drawable d = getDrawable(); Bitmap bmp = ((BitmapDrawable)d).getBitmap(); System.out.println("bmp Width = "+bmp.getWidth()); System.out.println("bmp Height = "+bmp.getHeight()); System.out.println("Original Width = "+origWidth); System.out.println("Original Height = "+origHeight); System.out.println("View Width "+viewWidth); System.out.println("View height"+viewHeight); float scaleX= viewWidth/(origWidth*saveScale); float scaleY =viewHeight/(origHeight*saveScale); float finalScale = Math.min(scaleX, scaleY); matrix.postScale(finalScale, finalScale, viewWidth / 2, viewHeight / 2); saveScale=1.0f; // // float redundantYSpace = (float) viewHeight - (finalScale * (float) bmp.getHeight()); // float redundantXSpace = (float) viewWidth - (finalScale * (float) bmp); // redundantYSpace /= (float) 2; // redundantXSpace /= (float) 2; // matrix.postTranslate(redundantXSpace, redundantYSpace); matrix.getValues(m); float transX = m[Matrix.MTRANS_X]; float transY = m[Matrix.MTRANS_Y]; float fixTransX = getFixTrans(transX, viewWidth, origWidth * finalScale); float fixTransY = getFixTrans(transY, viewHeight, origHeight * finalScale); // System.out.println("Translation X ="+transX); System.out.println("Translation Y ="+transY); System.out.println("Fix X ="+fixTransX); System.out.println("Fix Y ="+fixTransY); ((ViewPagerInterface)getContext()).enable(); matrix.postTranslate(fixTransX, fixTransY); } // fixTrans(); // System.out.println("Intrinsic Width "+bmp.getWidth()); // System.out.println("Intrinsic Height "+bmp.getHeight()); // RectF drawableRect = new RectF(0, 0,bmp.getWidth(),bmp.getHeight()); // RectF viewRect = new RectF(0, 0,getWidth(), getHeight()); // m.setRectToRect(drawableRect, viewRect, Matrix.ScaleToFit.CENTER); // setScale(,); // setScaleX(getWidth()/bmp.getWidth()); // setScaleY( getHeight()/bmp.getHeight()); //setScaleX(scaleX)// saveScale=1.0f; // setImageMatrix(m); // invalidate(); return true; } @Override public boolean onSingleTapConfirmed(MotionEvent e) { // System.out.println("SIngle Tap Occurred"); // touchImageView.saveScale=1.0f; // touchImageView.invalidate(); return super.onSingleTapConfirmed(e); } } } </code></pre> <p>In the above code, please see the method</p> <pre><code> public boolean onDoubleTap(MotionEvent e) </code></pre> <p>What was the mistake I made in the above method?</p>

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