Suppress header flash when collapsing notifications panel.

LayoutTransition is poking through and it shouldn't be.

This change also fixes a few related animation glitches
around the carrier label and fling velocity.

Bug: 6628429
Change-Id: I6655c9f9a8c95c7abd9c6d7099957cb229b86d5a

Author: dsandler

packages/SystemUI/res/values/dimens.xml

@@ -87,6 +87,8 @@
     <dimen name="fling_collapse_min_velocity">200dp</dimen>
     <!-- Cap on contribution of x dimension of gesture to overall velocity -->
     <dimen name="fling_gesture_max_x_velocity">200dp</dimen>
+    <!-- Cap on overall resulting fling speed (s^-1) -->
+    <dimen name="fling_gesture_max_output_velocity">3000dp</dimen>
 
     <!-- Minimum fraction of the display a gesture must travel, at any velocity, to qualify as a
          collapse request -->

packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java

@@ -134,6 +134,9 @@ public class PhoneStatusBar extends BaseStatusBar {
     private float mExpandAccelPx; // classic value: 2000px/s/s
     private float mCollapseAccelPx; // classic value: 2000px/s/s (will be negated to collapse "up")
 
+    private float mFlingGestureMaxOutputVelocityPx; // how fast can it really go? (should be a little 
+                                                    // faster than mSelfCollapseVelocityPx)
+
     PhoneStatusBarPolicy mIconPolicy;
 
     // These are no longer handled by the policy, because we need custom strategies for them
@@ -392,12 +395,13 @@ public boolean onTouch(View v, MotionEvent event) {
         mTickerView = mStatusBarView.findViewById(R.id.ticker);
 
         mPile = (NotificationRowLayout)mStatusBarWindow.findViewById(R.id.latestItems);
+        mPile.setLayoutTransitionsEnabled(false);
         mPile.setLongPressListener(getNotificationLongClicker());
         if (SHOW_CARRIER_LABEL) {
             mPile.setOnSizeChangedListener(new OnSizeChangedListener() {
                 @Override
                 public void onSizeChanged(View view, int w, int h, int oldw, int oldh) {
-                    updateCarrierLabelVisibility();
+                    updateCarrierLabelVisibility(false);
                 }
             });
         }
@@ -889,7 +893,7 @@ protected void updateNotificationIcons() {
         }
     }
 
-    protected void updateCarrierLabelVisibility() {
+    protected void updateCarrierLabelVisibility(boolean force) {
         if (!SHOW_CARRIER_LABEL) return;
         // The idea here is to only show the carrier label when there is enough room to see it, 
         // i.e. when there aren't enough notifications to fill the panel.
@@ -901,7 +905,7 @@ protected void updateCarrierLabelVisibility() {
         final boolean makeVisible = 
             mPile.getHeight() < (mScrollView.getHeight() - mCarrierLabelHeight);
 
-        if (mCarrierLabelVisible != makeVisible) {
+        if (force || mCarrierLabelVisible != makeVisible) {
             mCarrierLabelVisible = makeVisible;
             if (DEBUG) {
                 Slog.d(TAG, "making carrier label " + (makeVisible?"visible":"invisible"));
@@ -986,7 +990,7 @@ public void onAnimationEnd(Animator _a) {
                 .start();
         }
 
-        updateCarrierLabelVisibility();
+        updateCarrierLabelVisibility(false);
     }
 
     public void showClock(boolean show) {
@@ -1159,9 +1163,10 @@ private void makeExpandedVisible(boolean revealAfterDraw) {
         }
 
         mExpandedVisible = true;
+        mPile.setLayoutTransitionsEnabled(true);
         makeSlippery(mNavigationBarView, true);
 
-        updateCarrierLabelVisibility();
+        updateCarrierLabelVisibility(true);
 
         updateExpandedViewPos(EXPANDED_LEAVE_ALONE);
 
@@ -1279,6 +1284,7 @@ void performCollapse() {
             return;
         }
         mExpandedVisible = false;
+        mPile.setLayoutTransitionsEnabled(false);
         visibilityChanged(false);
         makeSlippery(mNavigationBarView, false);
 
@@ -1562,6 +1568,9 @@ boolean interceptTouchEvent(MotionEvent event) {
                 }
 
                 float vel = (float)Math.hypot(yVel, xVel);
+                if (vel > mFlingGestureMaxOutputVelocityPx) {
+                    vel = mFlingGestureMaxOutputVelocityPx;
+                }
                 if (negative) {
                     vel = -vel;
                 }
@@ -2041,7 +2050,7 @@ else if (expandedPosition == EXPANDED_LEAVE_ALONE) {
             mStatusBarWindow.setBackgroundColor(color);
         }
 
-        updateCarrierLabelVisibility();
+        updateCarrierLabelVisibility(false);
     }
 
     void updateDisplaySize() {
@@ -2268,6 +2277,8 @@ protected void loadDimens() {
 
         mFlingGestureMaxXVelocityPx = res.getDimension(R.dimen.fling_gesture_max_x_velocity);
 
+        mFlingGestureMaxOutputVelocityPx = res.getDimension(R.dimen.fling_gesture_max_output_velocity);
+
         mNotificationPanelMarginBottomPx
             = (int) res.getDimension(R.dimen.notification_panel_margin_bottom);
         mNotificationPanelMarginLeftPx

packages/SystemUI/src/com/android/systemui/statusbar/policy/NotificationRowLayout.java

@@ -68,14 +68,17 @@ public class NotificationRowLayout
     // animation is done
     boolean mRemoveViews = true;
 
+    private LayoutTransition mRealLayoutTransition;
+
     public NotificationRowLayout(Context context, AttributeSet attrs) {
         this(context, attrs, 0);
     }
 
     public NotificationRowLayout(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
 
-        setLayoutTransition(new LayoutTransition());
+        mRealLayoutTransition = new LayoutTransition();
+        setLayoutTransitionsEnabled(true);
 
         setOrientation(LinearLayout.VERTICAL);
 
@@ -121,9 +124,9 @@ public void setAnimateBounds(boolean anim) {
 
     private void logLayoutTransition() {
         Log.v(TAG, "layout " +
-              (getLayoutTransition().isChangingLayout() ? "is " : "is not ") +
+              (mRealLayoutTransition.isChangingLayout() ? "is " : "is not ") +
               "in transition and animations " +
-              (getLayoutTransition().isRunning() ? "are " : "are not ") +
+              (mRealLayoutTransition.isRunning() ? "are " : "are not ") +
               "running.");
     }
 
@@ -225,6 +228,18 @@ public void setViewRemoval(boolean removeViews) {
         mRemoveViews = removeViews;
     }
 
+    // Suppress layout transitions for a little while.
+    public void setLayoutTransitionsEnabled(boolean b) {
+        if (b) {
+            setLayoutTransition(mRealLayoutTransition);
+        } else {
+            if (mRealLayoutTransition.isRunning()) {
+                mRealLayoutTransition.cancel();
+            }
+            setLayoutTransition(null);
+        }
+    }
+
     public void dismissRowAnimated(View child) {
         dismissRowAnimated(child, 0);
     }