fix: wrong pivot point used for feedback image scaling

Author: lzls

gallery-viewer/src/main/java/com/liuzhenlin/galleryviewer/GestureImageView.java

@@ -654,8 +654,8 @@ public boolean onDoubleTap(MotionEvent e) {
             else // else make it zoomed in
                 toScaleX = toScaleY = mDoubleTapMagnifiedImageScale;
 
-            final float pivotX = e.getX();
-            final float pivotY = e.getY();
+            final float pivotX = e.getX() - getPaddingLeft();
+            final float pivotY = e.getY() - getPaddingTop();
 
             mTmpMatrix.set(mImageMatrix);
             mTmpMatrix.postScale(toScaleX / scaleX, toScaleY / scaleY, pivotX, pivotY);
@@ -709,7 +709,8 @@ public boolean onScale(ScaleGestureDetector detector) {
             else if (scale * scaleY < mImageMinScale) toScaleY = mImageMinScale / scaleY;
             else toScaleY = scale;
 
-            mImageMatrix.postScale(toScaleX, toScaleY, detector.getFocusX(), detector.getFocusY());
+            mImageMatrix.postScale(toScaleX, toScaleY, detector.getFocusX() - getPaddingLeft(),
+                    detector.getFocusY() - getPaddingTop());
             setImageMatrix(mImageMatrix);
             return true;
         }