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made good boundary detection, working both for zoom in and zoom out
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@Babay88
Babay88 committed Oct 24, 2012
1 parent ced91f9 commit ce66699
Showing 1 changed file with 57 additions and 83 deletions.
140 changes: 57 additions & 83 deletions src/com/example/touch/TouchImageView.java
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Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,7 @@ public class TouchImageView extends ImageView {
// Remember some things for zooming
PointF last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float minScale = 0.5f;
float maxScale = 3f;
float[] m;

Expand Down Expand Up @@ -84,34 +84,8 @@ public boolean onTouch(View v, MotionEvent event) {
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
float deltaX = curr.x - last.x;
float deltaY = curr.y - last.y;
float scaleWidth = Math.round(origWidth * saveScale);
float scaleHeight = Math.round(origHeight * saveScale);
if (scaleWidth < width) {
deltaX = 0;
if (y + deltaY > 0)
deltaY = -y;
else if (y + deltaY < -bottom)
deltaY = -(y + bottom);
} else if (scaleHeight < height) {
deltaY = 0;
if (x + deltaX > 0)
deltaX = -x;
else if (x + deltaX < -right)
deltaX = -(x + right);
} else {
if (x + deltaX > 0)
deltaX = -x;
else if (x + deltaX < -right)
deltaX = -(x + right);

if (y + deltaY > 0)
deltaY = -y;
else if (y + deltaY < -bottom)
deltaY = -(y + bottom);
}
matrix.postTranslate(deltaX, deltaY);
matrix.postTranslate(curr.x - last.x, curr.y - last.y);
fixTrans();
last.set(curr.x, curr.y);
}
break;
Expand Down Expand Up @@ -156,61 +130,61 @@ 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;
}
right = width * saveScale - width - (2 * redundantXSpace * saveScale);
bottom = height * saveScale - height - (2 * redundantYSpace * saveScale);
if (origWidth * saveScale <= width || origHeight * saveScale <= height) {
matrix.postScale(mScaleFactor, mScaleFactor, width / 2, height / 2);
if (mScaleFactor < 1) {
matrix.getValues(m);
float x = m[Matrix.MTRANS_X];
float y = m[Matrix.MTRANS_Y];
if (mScaleFactor < 1) {
if (Math.round(origWidth * saveScale) < width) {
if (y < -bottom)
matrix.postTranslate(0, -(y + bottom));
else if (y > 0)
matrix.postTranslate(0, -y);
} else {
if (x < -right)
matrix.postTranslate(-(x + right), 0);
else if (x > 0)
matrix.postTranslate(-x, 0);
}
}
}
} else {
matrix.postScale(mScaleFactor, mScaleFactor, detector.getFocusX(), detector.getFocusY());
matrix.getValues(m);
float x = m[Matrix.MTRANS_X];
float y = m[Matrix.MTRANS_Y];
if (mScaleFactor < 1) {
if (x < -right)
matrix.postTranslate(-(x + right), 0);
else if (x > 0)
matrix.postTranslate(-x, 0);
if (y < -bottom)
matrix.postTranslate(0, -(y + bottom));
else if (y > 0)
matrix.postTranslate(0, -y);
}
}
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;
}
//right = width * saveScale - width - (2 * redundantXSpace * saveScale);
//bottom = height * saveScale - height - (2 * redundantYSpace * saveScale);

if (origWidth * saveScale <= width || origHeight * saveScale <= height)
matrix.postScale(mScaleFactor, mScaleFactor, width / 2, height / 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, width, origWidth * saveScale);
float fixTransY = getFixTrans(transY, height, 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;
}

@Override
protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec)
Expand Down

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