Fixing regression with scrolling and launching an out-of-view task. (Bug 16875419)

Change-Id: Ib64e18f9a0f1de02de28a29251dd1d159d5d89ee

4 files changed, 25 insertions, 18 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/recents/AlternateRecentsComponent.java b/packages/SystemUI/src/com/android/systemui/recents/AlternateRecentsComponent.java
index a55c0f2..bb5fe54 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/AlternateRecentsComponent.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/AlternateRecentsComponent.java
@@ -328,7 +328,7 @@ public class AlternateRecentsComponent implements ActivityOptions.OnAnimationSta
         TaskStackViewLayoutAlgorithm algo = tsv.getStackAlgorithm();
         Rect taskStackBounds = new Rect(mTaskStackBounds);
         taskStackBounds.bottom -= mSystemInsets.bottom;
-        tsv.computeRects(mWindowRect.width(), mWindowRect.height(), taskStackBounds);
+        tsv.computeRects(mWindowRect.width(), mWindowRect.height(), taskStackBounds, mTriggeredFromAltTab);
         tsv.getScroller().setStackScrollToInitialState();
 
         // Find the running task in the TaskStack
diff --git a/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java b/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
index 58d5df7..34e8860 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/views/RecentsView.java
@@ -386,7 +386,7 @@ public class RecentsView extends FrameLayout implements TaskStackView.TaskStackV
             sourceView = stackView;
             transform = stackView.getStackAlgorithm().getStackTransform(task, stackScroll, transform, null);
             offsetX = transform.rect.left;
-            offsetY = Math.min(transform.rect.top, mConfig.displayRect.height());
+            offsetY = mConfig.displayRect.height();
         } else {
             transform = stackView.getStackAlgorithm().getStackTransform(task, stackScroll, transform, null);
         }
diff --git a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
index 9e7dbf4..46996bb 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
@@ -349,9 +349,9 @@ public class TaskStackView extends FrameLayout implements TaskStack.TaskStackCal
     }
 
     /** Updates the min and max virtual scroll bounds */
-    void updateMinMaxScroll(boolean boundScrollToNewMinMax) {
+    void updateMinMaxScroll(boolean boundScrollToNewMinMax, boolean launchedWithAltTab) {
         // Compute the min and max scroll values
-        mLayoutAlgorithm.computeMinMaxScroll(mStack.getTasks());
+        mLayoutAlgorithm.computeMinMaxScroll(mStack.getTasks(), launchedWithAltTab);
 
         // Debug logging
         if (boundScrollToNewMinMax) {
@@ -388,17 +388,17 @@ public class TaskStackView extends FrameLayout implements TaskStack.TaskStackCal
                 };
             }
 
+            // Scroll the view into position (just center it in the curve)
             if (scrollToNewPosition) {
-                // Scroll the view into position
-                // XXX: We probably want this to be centered in view instead of p = 0f
-                float newScroll = mStackScroller.getBoundedStackScroll(
-                        mLayoutAlgorithm.getStackScrollForTaskIndex(t));
+                float newScroll = mLayoutAlgorithm.getStackScrollForTaskIndex(t) - 0.5f;
+                newScroll = mStackScroller.getBoundedStackScroll(newScroll);
                 mStackScroller.animateScroll(mStackScroller.getStackScroll(), newScroll, postScrollRunnable);
             } else {
                 if (postScrollRunnable != null) {
                     postScrollRunnable.run();
                 }
             }
+
         }
     }
 
@@ -435,12 +435,13 @@ public class TaskStackView extends FrameLayout implements TaskStack.TaskStackCal
     }
 
     /** Computes the stack and task rects */
-    public void computeRects(int windowWidth, int windowHeight, Rect taskStackBounds) {
+    public void computeRects(int windowWidth, int windowHeight, Rect taskStackBounds,
+                             boolean launchedWithAltTab) {
         // Compute the rects in the stack algorithm
         mLayoutAlgorithm.computeRects(windowWidth, windowHeight, taskStackBounds);
 
         // Update the scroll bounds
-        updateMinMaxScroll(false);
+        updateMinMaxScroll(false, launchedWithAltTab);
     }
 
     /**
@@ -455,7 +456,7 @@ public class TaskStackView extends FrameLayout implements TaskStack.TaskStackCal
         // Compute our stack/task rects
         Rect taskStackBounds = new Rect(mTaskStackBounds);
         taskStackBounds.bottom -= mConfig.systemInsets.bottom;
-        computeRects(width, height, taskStackBounds);
+        computeRects(width, height, taskStackBounds, mConfig.launchedWithAltTab);
 
         // If this is the first layout, then scroll to the front of the stack and synchronize the
         // stack views immediately to load all the views
@@ -543,9 +544,8 @@ public class TaskStackView extends FrameLayout implements TaskStack.TaskStackCal
             mStartEnterAnimationContext = null;
         }
 
-        // Update the focused task index to be the next item to the top task
+        // When Alt-Tabbing, we scroll to and focus the previous task
         if (mConfig.launchedWithAltTab) {
-            // When alt-tabbing, we focus the next previous task
             focusTask(Math.max(0, mStack.getTaskCount() - 2), false);
         }
     }
@@ -661,7 +661,7 @@ public class TaskStackView extends FrameLayout implements TaskStack.TaskStackCal
         mCb.onTaskViewDismissed(removedTask);
 
         // Update the min/max scroll and animate other task views into their new positions
-        updateMinMaxScroll(true);
+        updateMinMaxScroll(true, mConfig.launchedWithAltTab);
         requestSynchronizeStackViewsWithModel(200);
 
         // Update the new front most task
diff --git a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackViewLayoutAlgorithm.java b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackViewLayoutAlgorithm.java
index b1482bb..633e6fa 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackViewLayoutAlgorithm.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackViewLayoutAlgorithm.java
@@ -18,7 +18,6 @@ package com.android.systemui.recents.views;
 
 import android.graphics.Rect;
 import com.android.systemui.recents.RecentsConfiguration;
-import com.android.systemui.recents.misc.Console;
 import com.android.systemui.recents.misc.Utilities;
 import com.android.systemui.recents.model.Task;
 
@@ -87,8 +86,9 @@ public class TaskStackViewLayoutAlgorithm {
                 left + size, mStackRect.top + size);
     }
 
-    /** Computes the minimum and maximum scroll progress values */
-    void computeMinMaxScroll(ArrayList<Task> tasks) {
+    /** Computes the minimum and maximum scroll progress values.  This method may be called before
+     * the RecentsConfiguration is set, so we need to pass in the alt-tab state. */
+    void computeMinMaxScroll(ArrayList<Task> tasks, boolean launchedWithAltTab) {
         // Clear the progress map
         mTaskProgressMap.clear();
 
@@ -130,7 +130,12 @@ public class TaskStackViewLayoutAlgorithm {
 
         mMinScrollP = 0f;
         mMaxScrollP = pAtFrontMostCardTop - ((1f - pTaskHeightOffset - pNavBarOffset));
-        mInitialScrollP = pAtSecondFrontMostCardTop - ((1f - pTaskHeightOffset - pNavBarOffset));
+        if (launchedWithAltTab) {
+            // Center the second most task, since that will be focused first
+            mInitialScrollP = pAtSecondFrontMostCardTop - 0.5f;
+        } else {
+            mInitialScrollP = pAtSecondFrontMostCardTop - ((1f - pTaskHeightOffset - pNavBarOffset));
+        }
     }
 
     /** Update/get the transform */
@@ -151,6 +156,7 @@ public class TaskStackViewLayoutAlgorithm {
         // If the task top is outside of the bounds below the screen, then immediately reset it
         if (pTaskRelative > 1f) {
             transformOut.reset();
+            transformOut.rect.set(mTaskRect);
             return transformOut;
         }
         // The check for the top is trickier, since we want to show the next task if it is at all
@@ -158,6 +164,7 @@ public class TaskStackViewLayoutAlgorithm {
         if (pTaskRelative < 0f) {
             if (prevTransform != null && Float.compare(prevTransform.p, 0f) <= 0) {
                 transformOut.reset();
+                transformOut.rect.set(mTaskRect);
                 return transformOut;
             }
         }