Cleaning some page animations

-> Fix jump when last page gets delted (issue 10908427)
-> Fade out empty screen
-> If the final page is empty, and that is the current page when
   spring loaded mode ends, animate back to the previous page
   and then fade out the final page. Examples: cancel widget
   or shortcut drop on the final page, scroll to final page and
   drop an icon into a the hotseat, etc.

Change-Id: I13438fb0af6555b6f0b511b7aff51b3972431438

3 files changed, 183 insertions, 53 deletions

diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index af58f79df..f35daaade 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -197,8 +197,8 @@ public class Launcher extends Activity
     private AnimatorSet mStateAnimation;
 
     static final int APPWIDGET_HOST_ID = 1024;
-    private static final int EXIT_SPRINGLOADED_MODE_SHORT_TIMEOUT = 300;
-    private static final int EXIT_SPRINGLOADED_MODE_LONG_TIMEOUT = 600;
+    public static final int EXIT_SPRINGLOADED_MODE_SHORT_TIMEOUT = 300;
+    private static final int ON_ACTIVITY_RESULT_ANIMATION_DELAY = 500;
     private static final int SHOW_CLING_DURATION = 250;
     private static final int DISMISS_CLING_DURATION = 200;
 
@@ -709,13 +709,24 @@ public class Launcher extends Activity
         // Reset the startActivity waiting flag
         mWaitingForResult = false;
 
+        Runnable exitSpringLoaded = new Runnable() {
+            @Override
+            public void run() {
+                exitSpringLoadedDragModeDelayed((resultCode != RESULT_CANCELED),
+                        EXIT_SPRINGLOADED_MODE_SHORT_TIMEOUT, null);
+            }
+        };
+
         if (requestCode == REQUEST_BIND_APPWIDGET) {
-            int appWidgetId = data != null ?
+            final int appWidgetId = data != null ?
                     data.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, -1) : -1;
             if (resultCode == RESULT_CANCELED) {
                 completeTwoStageWidgetDrop(RESULT_CANCELED, appWidgetId);
+                mWorkspace.removeExtraEmptyScreen(true, exitSpringLoaded,
+                        ON_ACTIVITY_RESULT_ANIMATION_DELAY, false);
             } else if (resultCode == RESULT_OK) {
-                addAppWidgetImpl(appWidgetId, mPendingAddInfo, null, mPendingAddWidgetInfo);
+                addAppWidgetImpl(appWidgetId, mPendingAddInfo, null,
+                        mPendingAddWidgetInfo, ON_ACTIVITY_RESULT_ANIMATION_DELAY);
             }
             return;
         } else if (requestCode == REQUEST_PICK_WALLPAPER) {
@@ -725,22 +736,37 @@ public class Launcher extends Activity
             return;
         }
 
-        boolean delayExitSpringLoadedMode = false;
         boolean isWidgetDrop = (requestCode == REQUEST_PICK_APPWIDGET ||
                 requestCode == REQUEST_CREATE_APPWIDGET);
 
         // We have special handling for widgets
         if (isWidgetDrop) {
-            int appWidgetId = data != null ?
+            final int appWidgetId = data != null ?
                     data.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, -1) : -1;
+            final int result;
+            final Runnable onComplete;
             if (appWidgetId < 0) {
                 Log.e(TAG, "Error: appWidgetId (EXTRA_APPWIDGET_ID) was not returned from the \\" +
                         "widget configuration activity.");
-                completeTwoStageWidgetDrop(RESULT_CANCELED, appWidgetId);
-                mWorkspace.stripEmptyScreens();
+                result = RESULT_CANCELED;
+                completeTwoStageWidgetDrop(result, appWidgetId);
+                onComplete = new Runnable() {
+                    @Override
+                    public void run() {
+                        exitSpringLoadedDragModeDelayed(false, 0, null);
+                    }
+                };
             } else {
-                completeTwoStageWidgetDrop(resultCode, appWidgetId);
+                result = resultCode;
+                onComplete = new Runnable() {
+                    @Override
+                    public void run() {
+                        completeTwoStageWidgetDrop(result, appWidgetId);
+                    }
+                };
             }
+            mWorkspace.removeExtraEmptyScreen(true, onComplete, ON_ACTIVITY_RESULT_ANIMATION_DELAY,
+                    false);
             return;
         }
 
@@ -760,15 +786,15 @@ public class Launcher extends Activity
             if (isWorkspaceLocked()) {
                 sPendingAddList.add(args);
             } else {
-                delayExitSpringLoadedMode = completeAdd(args);
+                completeAdd(args);
             }
+            mWorkspace.removeExtraEmptyScreen(true, exitSpringLoaded,
+                    ON_ACTIVITY_RESULT_ANIMATION_DELAY, false);
         } else if (resultCode == RESULT_CANCELED) {
-            mWorkspace.stripEmptyScreens();
+            mWorkspace.removeExtraEmptyScreen(true, exitSpringLoaded,
+                    ON_ACTIVITY_RESULT_ANIMATION_DELAY, false);
         }
         mDragLayer.clearAnimatedView();
-        // Exit spring loaded mode if necessary after cancelling the configuration of a widget
-        exitSpringLoadedDragModeDelayed((resultCode != RESULT_CANCELED), delayExitSpringLoadedMode,
-                null);
     }
 
     private void completeTwoStageWidgetDrop(final int resultCode, final int appWidgetId) {
@@ -788,25 +814,18 @@ public class Launcher extends Activity
                 public void run() {
                     completeAddAppWidget(appWidgetId, mPendingAddInfo.container,
                             mPendingAddInfo.screenId, layout, null);
-                    exitSpringLoadedDragModeDelayed((resultCode != RESULT_CANCELED), false,
-                            null);
+                    exitSpringLoadedDragModeDelayed((resultCode != RESULT_CANCELED),
+                            EXIT_SPRINGLOADED_MODE_SHORT_TIMEOUT, null);
                 }
             };
         } else if (resultCode == RESULT_CANCELED) {
             animationType = Workspace.CANCEL_TWO_STAGE_WIDGET_DROP_ANIMATION;
-            onCompleteRunnable = new Runnable() {
-                @Override
-                public void run() {
-                    exitSpringLoadedDragModeDelayed((resultCode != RESULT_CANCELED), false,
-                            null);
-                }
-            };
         }
         if (mDragLayer.getAnimatedView() != null) {
             mWorkspace.animateWidgetDrop(mPendingAddInfo, cellLayout,
                     (DragView) mDragLayer.getAnimatedView(), onCompleteRunnable,
                     animationType, boundWidget, true);
-        } else {
+        } else if (onCompleteRunnable != null) {
             // The animated view may be null in the case of a rotation during widget configuration
             onCompleteRunnable.run();
         }
@@ -1900,8 +1919,14 @@ public class Launcher extends Activity
         mPendingAddInfo.dropPos = null;
     }
 
-    void addAppWidgetImpl(final int appWidgetId, ItemInfo info, AppWidgetHostView boundWidget,
-            AppWidgetProviderInfo appWidgetInfo) {
+    void addAppWidgetImpl(final int appWidgetId, final ItemInfo info,
+            final AppWidgetHostView boundWidget, final AppWidgetProviderInfo appWidgetInfo) {
+        addAppWidgetImpl(appWidgetId, info, boundWidget, appWidgetInfo, 0);
+    }
+
+    void addAppWidgetImpl(final int appWidgetId, final ItemInfo info,
+            final AppWidgetHostView boundWidget, final AppWidgetProviderInfo appWidgetInfo, int
+            delay) {
         if (appWidgetInfo.configure != null) {
             mPendingAddWidgetInfo = appWidgetInfo;
 
@@ -1912,10 +1937,17 @@ public class Launcher extends Activity
             Utilities.startActivityForResultSafely(this, intent, REQUEST_CREATE_APPWIDGET);
         } else {
             // Otherwise just add it
+            Runnable onComplete = new Runnable() {
+                @Override
+                public void run() {
+                    // Exit spring loaded mode if necessary after adding the widget
+                    exitSpringLoadedDragModeDelayed(true, EXIT_SPRINGLOADED_MODE_SHORT_TIMEOUT,
+                            null);
+                }
+            };
             completeAddAppWidget(appWidgetId, info.container, info.screenId, boundWidget,
                     appWidgetInfo);
-            // Exit spring loaded mode if necessary after adding the widget
-            exitSpringLoadedDragModeDelayed(true, false, null);
+            mWorkspace.removeExtraEmptyScreen(true, onComplete, delay, false);
         }
     }
 
@@ -3104,7 +3136,7 @@ public class Launcher extends Activity
         }
     }
 
-    void exitSpringLoadedDragModeDelayed(final boolean successfulDrop, boolean extendedDelay,
+    void exitSpringLoadedDragModeDelayed(final boolean successfulDrop, int delay,
             final Runnable onCompleteRunnable) {
         if (mState != State.APPS_CUSTOMIZE_SPRING_LOADED) return;
 
@@ -3121,9 +3153,8 @@ public class Launcher extends Activity
                     exitSpringLoadedDragMode();
                 }
             }
-        }, (extendedDelay ?
-                EXIT_SPRINGLOADED_MODE_LONG_TIMEOUT :
-                EXIT_SPRINGLOADED_MODE_SHORT_TIMEOUT));
+        }, delay);
+
     }
 
     void exitSpringLoadedDragMode() {
@@ -3662,7 +3693,7 @@ public class Launcher extends Activity
         }
 
         // Remove the extra empty screen
-        mWorkspace.removeExtraEmptyScreen();
+        mWorkspace.removeExtraEmptyScreen(false, null);
 
         if (!AppsCustomizePagedView.DISABLE_ALL_APPS &&
                 addedApps != null && mAppsCustomizeContent != null) {
diff --git a/src/com/android/launcher3/SmoothPagedView.java b/src/com/android/launcher3/SmoothPagedView.java
index a45dbbf6e..64dcb34ca 100644
--- a/src/com/android/launcher3/SmoothPagedView.java
+++ b/src/com/android/launcher3/SmoothPagedView.java
@@ -52,8 +52,6 @@ public abstract class SmoothPagedView extends PagedView {
         }
 
         public float getInterpolation(float t) {
-            // _o(t) = t * t * ((tension + 1) * t + tension)
-            // o(t) = _o(t - 1) + 1
             t -= 1.0f;
             return t * t * ((mTension + 1) * t + mTension) + 1.0f;
         }
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index e9d41d521..d742d429a 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -22,6 +22,7 @@ import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
 import android.animation.LayoutTransition;
 import android.animation.ObjectAnimator;
+import android.animation.PropertyValuesHolder;
 import android.animation.TimeInterpolator;
 import android.animation.ValueAnimator;
 import android.animation.ValueAnimator.AnimatorUpdateListener;
@@ -89,6 +90,9 @@ public class Workspace extends SmoothPagedView
     private static final int CHILDREN_OUTLINE_FADE_OUT_DURATION = 375;
     private static final int CHILDREN_OUTLINE_FADE_IN_DURATION = 100;
 
+    protected static final int SNAP_OFF_EMPTY_SCREEN_DURATION = 400;
+    protected static final int FADE_EMPTY_SCREEN_DURATION = 150;
+
     private static final int BACKGROUND_FADE_OUT_DURATION = 350;
     private static final int ADJACENT_SCREEN_DROP_DURATION = 300;
     private static final int FLING_THRESHOLD_VELOCITY = 500;
@@ -128,6 +132,8 @@ public class Workspace extends SmoothPagedView
     private HashMap<Long, CellLayout> mWorkspaceScreens = new HashMap<Long, CellLayout>();
     private ArrayList<Long> mScreenOrder = new ArrayList<Long>();
 
+    private Runnable mRemoveEmptyScreenRunnable;
+
     /**
      * CellInfo for the cell that is currently being dragged
      */
@@ -392,7 +398,6 @@ public class Workspace extends SmoothPagedView
         InstallShortcutReceiver.disableAndFlushInstallQueue(getContext());
         UninstallShortcutReceiver.disableAndFlushUninstallQueue(getContext());
 
-        removeExtraEmptyScreen();
         mDragSourceInternal = null;
         mLauncher.onInteractionEnd();
     }
@@ -627,6 +632,9 @@ public class Workspace extends SmoothPagedView
         boolean lastChildOnScreen = false;
         boolean childOnFinalScreen = false;
 
+        // Cancel any pending removal of empty screen
+        mRemoveEmptyScreenRunnable = null;
+
         if (mDragSourceInternal != null) {
             if (mDragSourceInternal.getChildCount() == 1) {
                 lastChildOnScreen = true;
@@ -654,13 +662,95 @@ public class Workspace extends SmoothPagedView
         return false;
     }
 
-    public void removeExtraEmptyScreen() {
+    private void convertFinalScreenToEmptyScreenIfNecessary() {
+        if (hasExtraEmptyScreen() || mScreenOrder.size() == 0) return;
+        long finalScreenId = mScreenOrder.get(mScreenOrder.size() - 1);
+
+        if (finalScreenId == CUSTOM_CONTENT_SCREEN_ID) return;
+        CellLayout finalScreen = mWorkspaceScreens.get(finalScreenId);
+
+        // If the final screen is empty, convert it to the extra empty screen
+        if (finalScreen.getShortcutsAndWidgets().getChildCount() == 0) {
+            mWorkspaceScreens.remove(finalScreenId);
+            mScreenOrder.remove(finalScreenId);
+
+            // if this is the last non-custom content screen, convert it to the empty screen
+            mWorkspaceScreens.put(EXTRA_EMPTY_SCREEN_ID, finalScreen);
+            mScreenOrder.add(EXTRA_EMPTY_SCREEN_ID);
+        }
+    }
+
+    public void removeExtraEmptyScreen(final boolean animate, final Runnable onComplete) {
+        removeExtraEmptyScreen(animate, onComplete, 0, false);
+    }
+
+    public void removeExtraEmptyScreen(final boolean animate, final Runnable onComplete,
+            final int delay, final boolean stripEmptyScreens) {
+        if (delay > 0) {
+            postDelayed(new Runnable() {
+                @Override
+                public void run() {
+                    removeExtraEmptyScreen(animate, onComplete, 0, stripEmptyScreens);
+                }
+
+            }, delay);
+            return;
+        }
+
+        convertFinalScreenToEmptyScreenIfNecessary();
         if (hasExtraEmptyScreen()) {
-            CellLayout cl = mWorkspaceScreens.get(EXTRA_EMPTY_SCREEN_ID);
-            mWorkspaceScreens.remove(EXTRA_EMPTY_SCREEN_ID);
-            mScreenOrder.remove(EXTRA_EMPTY_SCREEN_ID);
-            removeView(cl);
+            int emptyIndex = mScreenOrder.indexOf(EXTRA_EMPTY_SCREEN_ID);
+            if (getNextPage() == emptyIndex) {
+                snapToPage(getNextPage() - 1, SNAP_OFF_EMPTY_SCREEN_DURATION);
+                fadeAndRemoveEmptyScreen(SNAP_OFF_EMPTY_SCREEN_DURATION, FADE_EMPTY_SCREEN_DURATION,
+                        onComplete, stripEmptyScreens);
+            } else {
+                fadeAndRemoveEmptyScreen(0, FADE_EMPTY_SCREEN_DURATION,
+                        onComplete, stripEmptyScreens);
+            }
+            return;
         }
+        if (onComplete != null) {
+            onComplete.run();
+        }
+    }
+
+    private void fadeAndRemoveEmptyScreen(int delay, int duration, final Runnable onComplete,
+            final boolean stripEmptyScreens) {
+        PropertyValuesHolder alpha = PropertyValuesHolder.ofFloat("alpha", 0f);
+        PropertyValuesHolder bgAlpha = PropertyValuesHolder.ofFloat("backgroundAlpha", 0f);
+
+        final CellLayout cl = mWorkspaceScreens.get(EXTRA_EMPTY_SCREEN_ID);
+
+        mRemoveEmptyScreenRunnable = new Runnable() {
+            @Override
+            public void run() {
+                if (hasExtraEmptyScreen()) {
+                    mWorkspaceScreens.remove(EXTRA_EMPTY_SCREEN_ID);
+                    mScreenOrder.remove(EXTRA_EMPTY_SCREEN_ID);
+                    removeView(cl);
+                    if (stripEmptyScreens) {
+                        stripEmptyScreens();
+                    }
+                }
+            }
+        };
+
+        ObjectAnimator oa = ObjectAnimator.ofPropertyValuesHolder(cl, alpha, bgAlpha);
+        oa.setDuration(duration);
+        oa.setStartDelay(delay);
+        oa.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                if (mRemoveEmptyScreenRunnable != null) {
+                    mRemoveEmptyScreenRunnable.run();
+                }
+                if (onComplete != null) {
+                    onComplete.run();
+                }
+            }
+        });
+        oa.start();
     }
 
     public boolean hasExtraEmptyScreen() {
@@ -753,6 +843,7 @@ public class Workspace extends SmoothPagedView
                 removeView(cl);
             } else {
                 // if this is the last non-custom content screen, convert it to the empty screen
+                mRemoveEmptyScreenRunnable = null;
                 mWorkspaceScreens.put(EXTRA_EMPTY_SCREEN_ID, cl);
                 mScreenOrder.add(EXTRA_EMPTY_SCREEN_ID);
             }
@@ -1103,11 +1194,15 @@ public class Workspace extends SmoothPagedView
     }
 
     protected void snapToPage(int whichPage, Runnable r) {
+        snapToPage(whichPage, SLOW_PAGE_SNAP_ANIMATION_DURATION, r);
+    }
+
+    protected void snapToPage(int whichPage, int duration, Runnable r) {
         if (mDelayedSnapToPageRunnable != null) {
             mDelayedSnapToPageRunnable.run();
         }
         mDelayedSnapToPageRunnable = r;
-        snapToPage(whichPage, SLOW_PAGE_SNAP_ANIMATION_DURATION);
+        snapToPage(whichPage, duration);
     }
 
     protected void snapToScreenId(long screenId, Runnable r) {
@@ -2726,13 +2821,13 @@ public class Workspace extends SmoothPagedView
                 // cell also contains a shortcut, then create a folder with the two shortcuts.
                 if (!mInScrollArea && createUserFolderIfNecessary(cell, container,
                         dropTargetLayout, mTargetCell, distance, false, d.dragView, null)) {
-                    stripEmptyScreens();
+                    removeExtraEmptyScreen(true, null, 0, true);
                     return;
                 }
 
                 if (addToExistingFolderIfNecessary(cell, dropTargetLayout, mTargetCell,
                         distance, d, false)) {
-                    stripEmptyScreens();
+                    removeExtraEmptyScreen(true, null, 0, true);
                     return;
                 }
 
@@ -2840,7 +2935,7 @@ public class Workspace extends SmoothPagedView
                     if (finalResizeRunnable != null) {
                         finalResizeRunnable.run();
                     }
-                    stripEmptyScreens();
+                    removeExtraEmptyScreen(true, null, 0, true);
                 }
             };
             mAnimatingViewIntoPlace = true;
@@ -3491,7 +3586,13 @@ public class Workspace extends SmoothPagedView
         final Runnable exitSpringLoadedRunnable = new Runnable() {
             @Override
             public void run() {
-                mLauncher.exitSpringLoadedDragModeDelayed(true, false, null);
+                removeExtraEmptyScreen(false, new Runnable() {
+                    @Override
+                    public void run() {
+                        mLauncher.exitSpringLoadedDragModeDelayed(true,
+                                Launcher.EXIT_SPRINGLOADED_MODE_SHORT_TIMEOUT, null);
+                    }
+                });
             }
         };
 
@@ -3727,7 +3828,7 @@ public class Workspace extends SmoothPagedView
                 external, scalePreview);
 
         Resources res = mLauncher.getResources();
-        int duration = res.getInteger(R.integer.config_dropAnimMaxDuration) - 200;
+        final int duration = res.getInteger(R.integer.config_dropAnimMaxDuration) - 200;
 
         // In the case where we've prebound the widget, we remove it from the DragLayer
         if (finalView instanceof AppWidgetHostView && external) {
@@ -3835,11 +3936,11 @@ public class Workspace extends SmoothPagedView
             final boolean isFlingToDelete, final boolean success) {
         if (mDeferDropAfterUninstall) {
             mDeferredAction = new Runnable() {
-                    public void run() {
-                        onDropCompleted(target, d, isFlingToDelete, success);
-                        mDeferredAction = null;
-                    }
-                };
+                public void run() {
+                    onDropCompleted(target, d, isFlingToDelete, success);
+                    mDeferredAction = null;
+                }
+            };
             return;
         }
 
@@ -3857,7 +3958,7 @@ public class Workspace extends SmoothPagedView
                 // If we move the item to anything not on the Workspace, check if any empty
                 // screens need to be removed. If we dropped back on the workspace, this will
                 // be done post drop animation.
-                stripEmptyScreens();
+                removeExtraEmptyScreen(true, null, 0, true);
             }
         } else if (mDragInfo != null) {
             CellLayout cellLayout;