Defer expensive UI updates in filmstrip

Bug: 7322925
When using the filmstrip, delay expensive updates to
the action bar and share menus, some of which may require
disk accesses, until the rate of change of photos slows
down, instead of doing this work for every single image
that flies by.

Change-Id: Ie82adb4d54c96fec837d5954a91e1d4a17f548dd

1 files changed, 38 insertions, 7 deletions

diff --git a/src/com/android/gallery3d/app/PhotoPage.java b/src/com/android/gallery3d/app/PhotoPage.java
index 2e19a2ba8..f6e3fb745 100644
--- a/src/com/android/gallery3d/app/PhotoPage.java
+++ b/src/com/android/gallery3d/app/PhotoPage.java
@@ -93,6 +93,7 @@ public class PhotoPage extends ActivityState implements
     private static final int MSG_ON_CAMERA_CENTER = 9;
     private static final int MSG_ON_PICTURE_CENTER = 10;
     private static final int MSG_REFRESH_IMAGE = 11;
+    private static final int MSG_UPDATE_DEFERRED = 12;
 
     private static final int HIDE_BARS_TIMEOUT = 3500;
     private static final int UNFREEZE_GLROOT_TIMEOUT = 250;
@@ -169,6 +170,10 @@ public class PhotoPage extends ActivityState implements
     private boolean mSkipUpdateCurrentPhoto = false;
     private static final long CAMERA_SWITCH_CUTOFF_THRESHOLD_MS = 300;
 
+    private static final long DEFERRED_UPDATE_MS = 150;
+    private boolean mDeferredUpdateWaiting = false;
+    private long mDeferUpdateUntil = Long.MAX_VALUE;
+
     private RawTexture mFadeOutTexture;
     private Rect mOpenAnimationRect;
     public static final int ANIM_TIME_OPENING = 300;
@@ -314,6 +319,16 @@ public class PhotoPage extends ActivityState implements
                         mActivity.getGLRoot().unfreeze();
                         break;
                     }
+                    case MSG_UPDATE_DEFERRED: {
+                        long nextUpdate = mDeferUpdateUntil - SystemClock.uptimeMillis();
+                        if (nextUpdate <= 0) {
+                            mDeferredUpdateWaiting = false;
+                            updateUIForCurrentPhoto();
+                        } else {
+                            mHandler.sendEmptyMessageDelayed(MSG_UPDATE_DEFERRED, nextUpdate);
+                        }
+                        break;
+                    }
                     case MSG_ON_CAMERA_CENTER: {
                         mSkipUpdateCurrentPhoto = false;
                         boolean stayedOnCamera = false;
@@ -334,7 +349,7 @@ public class PhotoPage extends ActivityState implements
                         break;
                     }
                     case MSG_ON_PICTURE_CENTER: {
-                        if (mCurrentPhoto != null
+                        if (!mPhotoView.getFilmMode() && mCurrentPhoto != null
                                 && (mCurrentPhoto.getSupportedOperations() & MediaObject.SUPPORT_ACTION) != 0) {
                             mPhotoView.setFilmMode(true);
                         }
@@ -639,15 +654,21 @@ public class PhotoPage extends ActivityState implements
         setNfcBeamPushUri(uri);
     }
 
-    private void updateCurrentPhoto(MediaItem photo) {
-        if (mCurrentPhoto == photo) return;
-        mCurrentPhoto = photo;
+    private void requestDeferredUpdate() {
+        mDeferUpdateUntil = SystemClock.uptimeMillis() + DEFERRED_UPDATE_MS;
+        if (!mDeferredUpdateWaiting) {
+            mDeferredUpdateWaiting = true;
+            mHandler.sendEmptyMessageDelayed(MSG_UPDATE_DEFERRED, DEFERRED_UPDATE_MS);
+        }
+    }
+
+    private void updateUIForCurrentPhoto() {
         if (mCurrentPhoto == null) return;
 
         // If by swiping or deletion the user ends up on an action item
         // and zoomed in, zoom out so that the context of the action is
         // more clear
-        if ((photo.getSupportedOperations() & MediaObject.SUPPORT_ACTION) != 0
+        if ((mCurrentPhoto.getSupportedOperations() & MediaObject.SUPPORT_ACTION) != 0
                 && !mPhotoView.getFilmMode()) {
             mPhotoView.setWantPictureCenterCallbacks(true);
         }
@@ -658,8 +679,18 @@ public class PhotoPage extends ActivityState implements
             mDetailsHelper.reloadDetails();
         }
         if ((mSecureAlbum == null)
-                && (photo.getSupportedOperations() & MediaItem.SUPPORT_SHARE) != 0) {
-            updateShareURI(photo.getPath());
+                && (mCurrentPhoto.getSupportedOperations() & MediaItem.SUPPORT_SHARE) != 0) {
+            updateShareURI(mCurrentPhoto.getPath());
+        }
+    }
+
+    private void updateCurrentPhoto(MediaItem photo) {
+        if (mCurrentPhoto == photo) return;
+        mCurrentPhoto = photo;
+        if (mPhotoView.getFilmMode()) {
+            requestDeferredUpdate();
+        } else {
+            updateUIForCurrentPhoto();
         }
         if (mProgressBar != null) {
             mProgressBar.hideProgress();