From 33f8567dd5003e4bb342683f3768ab7552648b02 Mon Sep 17 00:00:00 2001
From: Chih-Chung Chang <chihchung@google.com>
Date: Tue, 1 May 2012 15:35:02 +0800
Subject: [PATCH] Fix the Camera controls disappearing after zooming problem.

Bug: 6392682
Change-Id: I065c52b44c02f9314e58e82846cdf22e2d940eab
---
 src/com/android/gallery3d/app/PhotoPage.java |  2 +-
 src/com/android/gallery3d/ui/PhotoView.java  | 38 +++++++++++++++++++++++-----
 2 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/src/com/android/gallery3d/app/PhotoPage.java b/src/com/android/gallery3d/app/PhotoPage.java
index d7936e24f..1851b976c 100644
--- a/src/com/android/gallery3d/app/PhotoPage.java
+++ b/src/com/android/gallery3d/app/PhotoPage.java
@@ -712,7 +712,7 @@ public class PhotoPage extends ActivityState implements
         onUserInteraction();
         if (mAppBridge != null) {
             mAppBridge.setServer(this);
-            mModel.moveTo(0);  // move to the camera preview after resume
+            mPhotoView.resetToFirstPicture();
         }
     }
 
diff --git a/src/com/android/gallery3d/ui/PhotoView.java b/src/com/android/gallery3d/ui/PhotoView.java
index b54a685d4..c6b370d74 100644
--- a/src/com/android/gallery3d/ui/PhotoView.java
+++ b/src/com/android/gallery3d/ui/PhotoView.java
@@ -737,6 +737,8 @@ public class PhotoView extends GLView {
         private boolean mCanChangeMode;
         // If we have changed the film mode in this scaling gesture.
         private boolean mModeChanged;
+        // If this scaling gesture should be ignored.
+        private boolean mIgnoreScalingGesture;
 
         @Override
         public boolean onSingleTapUp(float x, float y) {
@@ -784,6 +786,11 @@ public class PhotoView extends GLView {
 
         @Override
         public boolean onScaleBegin(float focusX, float focusY) {
+            // We ignore the scaling gesture if it is a camera preview.
+            mIgnoreScalingGesture = mPictures.get(0).isCamera();
+            if (mIgnoreScalingGesture) {
+                return true;
+            }
             mPositionController.beginScale(focusX, focusY);
             // We can change mode if we are in film mode, or we are in page
             // mode and at minimal scale.
@@ -795,9 +802,17 @@ public class PhotoView extends GLView {
 
         @Override
         public boolean onScale(float focusX, float focusY, float scale) {
+            if (mIgnoreScalingGesture) {
+                return true;
+            }
             if (mModeChanged) return true;
             if (Float.isNaN(scale) || Float.isInfinite(scale)) return false;
+
+            // We wait for the scale change accumulated to a large enough change
+            // before reacting to it. Otherwise we may mistakenly treat a
+            // zoom-in gesture as zoom-out or vice versa.
             if (scale > 0.99f && scale < 1.01f) return false;
+
             int outOfRange = mPositionController.scaleBy(scale, focusX, focusY);
 
             // If mode changes, we treat this scaling gesture has ended.
@@ -807,7 +822,7 @@ public class PhotoView extends GLView {
                     stopExtraScalingIfNeeded();
 
                     // Removing the touch down flag allows snapback to happen
-                    // for file mode change.
+                    // for film mode change.
                     mHolding &= ~HOLD_TOUCH_DOWN;
                     setFilmMode(!mFilmMode);
 
@@ -827,6 +842,15 @@ public class PhotoView extends GLView {
             return true;
         }
 
+        @Override
+        public void onScaleEnd() {
+            if (mIgnoreScalingGesture) {
+                return;
+            }
+            if (mModeChanged) return;
+            mPositionController.endScale();
+        }
+
         private void startExtraScalingIfNeeded() {
             if (!mCancelExtraScalingPending) {
                 mHandler.sendEmptyMessageDelayed(
@@ -845,12 +869,6 @@ public class PhotoView extends GLView {
         }
 
         @Override
-        public void onScaleEnd() {
-            if (mModeChanged) return;
-            mPositionController.endScale();
-        }
-
-        @Override
         public void onDown() {
             mHolding |= HOLD_TOUCH_DOWN;
         }
@@ -905,6 +923,12 @@ public class PhotoView extends GLView {
         mTileView.prepareTextures();
     }
 
+    // move to the camera preview and show controls after resume
+    public void resetToFirstPicture() {
+        mModel.moveTo(0);
+        setFilmMode(false);
+    }
+
     ////////////////////////////////////////////////////////////////////////////
     //  Rendering
     ////////////////////////////////////////////////////////////////////////////
-- 
2.11.0