Make group expanding nicer

The group expanding now follows the finger.

Bug: 19437552
Change-Id: If85557bb75ea2f2e560cb28d62a06c217187c9c3
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
index 36090a3..da125d8 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
@@ -869,6 +869,9 @@
     public void setUserLocked(boolean userLocked) {
         mUserLocked = userLocked;
         mPrivateLayout.setUserExpanding(userLocked);
+        if (mIsSummaryWithChildren) {
+            mChildrenContainer.setUserLocked(userLocked);
+        }
     }
 
     /**
@@ -1175,6 +1178,9 @@
         int contentHeight = Math.max(getMinHeight(), height);
         mPrivateLayout.setContentHeight(contentHeight);
         mPublicLayout.setContentHeight(contentHeight);
+        if (mIsSummaryWithChildren) {
+            mChildrenContainer.setActualHeight(height);
+        }
         if (mGuts != null) {
             mGuts.setActualHeight(height);
         }
@@ -1260,7 +1266,7 @@
         return mMaxExpandHeight != 0;
     }
 
-    private NotificationContentView getShowingLayout() {
+    public NotificationContentView getShowingLayout() {
         return mShowingPublic ? mPublicLayout : mPrivateLayout;
     }
 
@@ -1296,8 +1302,15 @@
     }
 
     @Override
-    public boolean needsIncreasedPadding() {
-        return mIsSummaryWithChildren && isGroupExpanded();
+    public float getIncreasedPaddingAmount() {
+        if (mIsSummaryWithChildren) {
+            if (isGroupExpanded()) {
+                return 1.0f;
+            } else if (isUserLocked()) {
+                return mChildrenContainer.getChildExpandFraction();
+            }
+        }
+        return 0.0f;
     }
 
     @Override
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableView.java b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableView.java
index c9e1cff..1ff87f5 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableView.java
@@ -391,8 +391,11 @@
     public void setShadowAlpha(float shadowAlpha) {
     }
 
-    public boolean needsIncreasedPadding() {
-        return false;
+    /**
+     * @return an amount between 0 and 1 of increased padding that this child needs
+     */
+    public float getIncreasedPaddingAmount() {
+        return 0.0f;
     }
 
     public boolean mustStayOnScreen() {
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java
index fa2608a..977b37e 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java
@@ -401,10 +401,14 @@
     }
 
     public int getMinHeight() {
-        if (mIsChildInGroup && !isGroupExpanded()) {
-            return mSingleLineView.getHeight();
-        } else {
+        return getMinHeight(false /* likeGroupExpanded */);
+    }
+
+    public int getMinHeight(boolean likeGroupExpanded) {
+        if (likeGroupExpanded || !mIsChildInGroup || isGroupExpanded()) {
             return mContractedChild.getHeight();
+        } else {
+            return mSingleLineView.getHeight();
         }
     }
 
@@ -535,8 +539,11 @@
      */
     private int calculateVisibleType() {
         if (mUserExpanding) {
-            int expandedVisualType = getVisualTypeForHeight(
-                    mContainingNotification.getMaxExpandHeight());
+            int height = !mIsChildInGroup || isGroupExpanded()
+                    || mContainingNotification.isExpanded()
+                    ? mContainingNotification.getMaxContentHeight()
+                    : mContainingNotification.getShowingLayout().getMinHeight();
+            int expandedVisualType = getVisualTypeForHeight(height);
             int collapsedVisualType = getVisualTypeForHeight(
                     mContainingNotification.getMinExpandHeight());
             return mTransformationStartVisibleType == collapsedVisualType
@@ -552,7 +559,7 @@
         if (!noExpandedChild && viewHeight == mExpandedChild.getHeight()) {
             return VISIBLE_TYPE_EXPANDED;
         }
-        if (mIsChildInGroup && !isGroupExpanded()) {
+        if (!mUserExpanding && mIsChildInGroup && !isGroupExpanded()) {
             return VISIBLE_TYPE_SINGLELINE;
         }
 
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationChildrenContainer.java b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationChildrenContainer.java
index 49aec42..030c8b7 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationChildrenContainer.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationChildrenContainer.java
@@ -29,6 +29,7 @@
 import com.android.systemui.statusbar.ExpandableNotificationRow;
 import com.android.systemui.statusbar.notification.HybridNotificationView;
 import com.android.systemui.statusbar.notification.HybridNotificationViewManager;
+import com.android.systemui.statusbar.notification.NotificationUtils;
 import com.android.systemui.statusbar.phone.NotificationPanelView;
 
 import java.util.ArrayList;
@@ -60,6 +61,8 @@
     private ViewState mGroupOverFlowState;
     private int mRealHeight;
     private int mLayoutDirection = LAYOUT_DIRECTION_UNDEFINED;
+    private boolean mUserLocked;
+    private int mActualHeight;
 
     public NotificationChildrenContainer(Context context) {
         this(context, null);
@@ -281,27 +284,45 @@
      */
     private int getIntrinsicHeight(float maxAllowedVisibleChildren) {
         int intrinsicHeight = mNotificationHeaderHeight;
-        if (mChildrenExpanded) {
-            intrinsicHeight += mNotificatonTopPadding;
-        }
         int visibleChildren = 0;
         int childCount = mChildren.size();
+        boolean firstChild = true;
+        float expandFactor = 0;
+        if (mUserLocked) {
+            expandFactor = getChildExpandFraction();
+        }
         for (int i = 0; i < childCount; i++) {
             if (visibleChildren >= maxAllowedVisibleChildren) {
                 break;
             }
+            if (!firstChild) {
+                if (mUserLocked) {
+                    intrinsicHeight += NotificationUtils.interpolate(mChildPadding, mDividerHeight,
+                            expandFactor);
+                } else {
+                    intrinsicHeight += mChildrenExpanded ? mDividerHeight : mChildPadding;
+                }
+            } else {
+                if (mUserLocked) {
+                    intrinsicHeight += NotificationUtils.interpolate(
+                            0,
+                            mNotificatonTopPadding + mDividerHeight,
+                            expandFactor);
+                } else {
+                    intrinsicHeight += mChildrenExpanded
+                            ? mNotificatonTopPadding + mDividerHeight
+                            : 0;
+                }
+                firstChild = false;
+            }
             ExpandableNotificationRow child = mChildren.get(i);
             intrinsicHeight += child.getIntrinsicHeight();
             visibleChildren++;
         }
-        if (visibleChildren > 0) {
-            if (mChildrenExpanded) {
-                intrinsicHeight += visibleChildren * mDividerHeight;
-            } else {
-                intrinsicHeight += (visibleChildren - 1) * mChildPadding;
-            }
-        }
-        if (!mChildrenExpanded) {
+        if (mUserLocked) {
+            intrinsicHeight += NotificationUtils.interpolate(mCollapsedBottompadding, 0.0f,
+                    expandFactor);
+        } else if (!mChildrenExpanded) {
             intrinsicHeight += mCollapsedBottompadding;
         }
         return intrinsicHeight;
@@ -323,12 +344,28 @@
         int lastVisibleIndex = hasOverflow
                 ? maxAllowedVisibleChildren - 2
                 : maxAllowedVisibleChildren - 1;
+        float expandFactor = 0;
+        if (mUserLocked) {
+            expandFactor = getChildExpandFraction();
+        }
         for (int i = 0; i < childCount; i++) {
             ExpandableNotificationRow child = mChildren.get(i);
             if (!firstChild) {
-                yPosition += mChildrenExpanded ? mDividerHeight : mChildPadding;
+                if (mUserLocked) {
+                     yPosition += NotificationUtils.interpolate(mChildPadding, mDividerHeight,
+                             expandFactor);
+                } else {
+                    yPosition += mChildrenExpanded ? mDividerHeight : mChildPadding;
+                }
             } else {
-                yPosition += mChildrenExpanded ? mNotificatonTopPadding + mDividerHeight : 0;
+                if (mUserLocked) {
+                    yPosition += NotificationUtils.interpolate(
+                            0,
+                            mNotificatonTopPadding + mDividerHeight,
+                            expandFactor);
+                } else {
+                    yPosition += mChildrenExpanded ? mNotificatonTopPadding + mDividerHeight : 0;
+                }
                 firstChild = false;
             }
             StackViewState childState = resultState.getViewStateForView(child);
@@ -375,6 +412,7 @@
     public void applyState(StackScrollState state) {
         int childCount = mChildren.size();
         ViewState tmpState = new ViewState();
+        float expandFraction = getChildExpandFraction();
         for (int i = 0; i < childCount; i++) {
             ExpandableNotificationRow child = mChildren.get(i);
             StackViewState viewState = state.getViewStateForView(child);
@@ -384,7 +422,11 @@
             View divider = mDividers.get(i);
             tmpState.initFrom(divider);
             tmpState.yTranslation = viewState.yTranslation - mDividerHeight;
-            tmpState.alpha = mChildrenExpanded && viewState.alpha != 0 ? 0.5f : 0;
+            float alpha = mChildrenExpanded && viewState.alpha != 0 ? 0.5f : 0;
+            if (mUserLocked && viewState.alpha != 0) {
+                alpha = NotificationUtils.interpolate(0, 0.5f, expandFraction);
+            }
+            tmpState.alpha = alpha;
             state.applyViewState(divider, tmpState);
         }
         if (mGroupOverflowContainer != null) {
@@ -407,6 +449,7 @@
             long baseDelay, long duration) {
         int childCount = mChildren.size();
         ViewState tmpState = new ViewState();
+        float expandFraction = getChildExpandFraction();
         for (int i = childCount - 1; i >= 0; i--) {
             ExpandableNotificationRow child = mChildren.get(i);
             StackViewState viewState = state.getViewStateForView(child);
@@ -416,7 +459,11 @@
             View divider = mDividers.get(i);
             tmpState.initFrom(divider);
             tmpState.yTranslation = viewState.yTranslation - mDividerHeight;
-            tmpState.alpha = mChildrenExpanded && viewState.alpha != 0 ? 0.5f : 0;
+            float alpha = mChildrenExpanded && viewState.alpha != 0 ? 0.5f : 0;
+            if (mUserLocked && viewState.alpha != 0) {
+                alpha = NotificationUtils.interpolate(0, 0.5f, expandFraction);
+            }
+            tmpState.alpha = alpha;
             stateAnimator.startViewAnimations(divider, tmpState, baseDelay, duration);
         }
         if (mGroupOverflowContainer != null) {
@@ -449,7 +496,70 @@
     }
 
     public int getMaxContentHeight() {
-        return getIntrinsicHeight(NUMBER_OF_CHILDREN_WHEN_CHILDREN_EXPANDED);
+        int maxContentHeight = mNotificationHeaderHeight + mNotificatonTopPadding;
+        int visibleChildren = 0;
+        int childCount = mChildren.size();
+        for (int i = 0; i < childCount; i++) {
+            if (visibleChildren >= NUMBER_OF_CHILDREN_WHEN_CHILDREN_EXPANDED) {
+                break;
+            }
+            ExpandableNotificationRow child = mChildren.get(i);
+            float childHeight = child.isExpanded()
+                    ? child.getMaxExpandHeight()
+                    : child.getShowingLayout().getMinHeight(true /* likeGroupExpanded */);
+            maxContentHeight += childHeight;
+            visibleChildren++;
+        }
+        if (visibleChildren > 0) {
+            maxContentHeight += visibleChildren * mDividerHeight;
+        }
+        return maxContentHeight;
+    }
+
+    public void setActualHeight(int actualHeight) {
+        if (!mUserLocked) {
+            return;
+        }
+        mActualHeight = actualHeight;
+        float fraction = getChildExpandFraction();
+        int childCount = mChildren.size();
+        for (int i = 0; i < childCount; i++) {
+            ExpandableNotificationRow child = mChildren.get(i);
+            float childHeight = child.isExpanded()
+                    ? child.getMaxExpandHeight()
+                    : child.getShowingLayout().getMinHeight(true /* likeGroupExpanded */);
+            float singleLineHeight = child.getShowingLayout().getMinHeight(
+                    false /* likeGroupExpanded */);
+            child.setActualHeight((int) NotificationUtils.interpolate(singleLineHeight, childHeight,
+                    fraction), false);
+        }
+    }
+
+    public float getChildExpandFraction() {
+        int allChildrenVisibleHeight = getChildrenExpandStartHeight();
+        int maxContentHeight = getMaxContentHeight();
+        float factor = (mActualHeight - allChildrenVisibleHeight)
+                / (float) (maxContentHeight - allChildrenVisibleHeight);
+        return Math.max(0.0f, Math.min(1.0f, factor));
+    }
+
+    private int getChildrenExpandStartHeight() {
+        int intrinsicHeight = mNotificationHeaderHeight;
+        int visibleChildren = 0;
+        int childCount = mChildren.size();
+        for (int i = 0; i < childCount; i++) {
+            if (visibleChildren >= NUMBER_OF_CHILDREN_WHEN_CHILDREN_EXPANDED) {
+                break;
+            }
+            ExpandableNotificationRow child = mChildren.get(i);
+            intrinsicHeight += child.getMinHeight();
+            visibleChildren++;
+        }
+        if (visibleChildren > 0) {
+            intrinsicHeight += (visibleChildren - 1) * mChildPadding;
+        }
+        intrinsicHeight += mCollapsedBottompadding;
+        return intrinsicHeight;
     }
 
     public int getMinHeight() {
@@ -477,4 +587,13 @@
             mDividers.set(i, divider);
         }
     }
+
+    public void setUserLocked(boolean userLocked) {
+        mUserLocked = userLocked;
+        int childCount = mChildren.size();
+        for (int i = 0; i < childCount; i++) {
+            ExpandableNotificationRow child = mChildren.get(i);
+            child.setUserLocked(userLocked);
+        }
+    }
 }
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
index fe06c3a..e1f9f3c 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
@@ -64,6 +64,7 @@
 import com.android.systemui.statusbar.StackScrollerDecorView;
 import com.android.systemui.statusbar.StatusBarState;
 import com.android.systemui.statusbar.notification.FakeShadowView;
+import com.android.systemui.statusbar.notification.NotificationUtils;
 import com.android.systemui.statusbar.phone.NotificationGroupManager;
 import com.android.systemui.statusbar.phone.PhoneStatusBar;
 import com.android.systemui.statusbar.phone.ScrimController;
@@ -538,7 +539,7 @@
             ExpandableView child = (ExpandableView) getChildAt(i);
             if (mChildrenToAddAnimated.contains(child)) {
                 int startingPosition = getPositionInLinearLayout(child);
-                int padding = child.needsIncreasedPadding()
+                int padding = child.getIncreasedPaddingAmount() == 1.0f
                         ? mIncreasedPaddingBetweenElements :
                         mPaddingBetweenElements;
                 int childHeight = getIntrinsicHeight(child) + padding;
@@ -1531,18 +1532,18 @@
 
     private void updateContentHeight() {
         int height = 0;
-        boolean previousNeedsIncreasedPaddings = false;
+        float previousIncreasedAmount = 0.0f;
         for (int i = 0; i < getChildCount(); i++) {
             ExpandableView expandableView = (ExpandableView) getChildAt(i);
             if (expandableView.getVisibility() != View.GONE) {
-                boolean needsIncreasedPaddings = expandableView.needsIncreasedPadding();
+                float increasedPaddingAmount = expandableView.getIncreasedPaddingAmount();
                 if (height != 0) {
-                    int padding = needsIncreasedPaddings || previousNeedsIncreasedPaddings
-                            ? mIncreasedPaddingBetweenElements
-                            : mPaddingBetweenElements;
-                    height += padding;
+                    height += (int) NotificationUtils.interpolate(
+                            mPaddingBetweenElements,
+                            mIncreasedPaddingBetweenElements,
+                            Math.max(previousIncreasedAmount, increasedPaddingAmount));
                 }
-                previousNeedsIncreasedPaddings = needsIncreasedPaddings;
+                previousIncreasedAmount = increasedPaddingAmount;
                 height += expandableView.getIntrinsicHeight();
             }
         }
@@ -2097,9 +2098,10 @@
      */
     private void updateScrollStateForRemovedChild(ExpandableView removedChild) {
         int startingPosition = getPositionInLinearLayout(removedChild);
-        int padding = removedChild.needsIncreasedPadding()
-                ? mIncreasedPaddingBetweenElements :
-                mPaddingBetweenElements;
+        int padding = (int) NotificationUtils.interpolate(
+                mPaddingBetweenElements,
+                mIncreasedPaddingBetweenElements,
+                removedChild.getIncreasedPaddingAmount());
         int childHeight = getIntrinsicHeight(removedChild) + padding;
         int endPosition = startingPosition + childHeight;
         if (endPosition <= mOwnScrollY) {
@@ -2123,19 +2125,19 @@
 
     private int getPositionInLinearLayout(View requestedChild) {
         int position = 0;
-        boolean previousNeedsIncreasedPaddings = false;
+        float previousIncreasedAmount = 0.0f;
         for (int i = 0; i < getChildCount(); i++) {
             ExpandableView child = (ExpandableView) getChildAt(i);
             boolean notGone = child.getVisibility() != View.GONE;
             if (notGone) {
-                boolean needsIncreasedPaddings = child.needsIncreasedPadding();
+                float increasedPaddingAmount = child.getIncreasedPaddingAmount();
                 if (position != 0) {
-                    int padding = needsIncreasedPaddings || previousNeedsIncreasedPaddings
-                            ? mIncreasedPaddingBetweenElements :
-                            mPaddingBetweenElements;
-                    position += padding;
+                    position += (int) NotificationUtils.interpolate(
+                            mPaddingBetweenElements,
+                            mIncreasedPaddingBetweenElements,
+                            Math.max(previousIncreasedAmount, increasedPaddingAmount));
                 }
-                previousNeedsIncreasedPaddings = needsIncreasedPaddings;
+                previousIncreasedAmount = increasedPaddingAmount;
             }
             if (child == requestedChild) {
                 return position;
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/stack/StackScrollAlgorithm.java b/packages/SystemUI/src/com/android/systemui/statusbar/stack/StackScrollAlgorithm.java
index d78d626..eea923f 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/stack/StackScrollAlgorithm.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/stack/StackScrollAlgorithm.java
@@ -25,9 +25,10 @@
 import com.android.systemui.statusbar.ExpandableNotificationRow;
 import com.android.systemui.statusbar.ExpandableView;
 import com.android.systemui.statusbar.notification.FakeShadowView;
+import com.android.systemui.statusbar.notification.NotificationUtils;
 
 import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.HashMap;
 import java.util.List;
 
 /**
@@ -297,18 +298,22 @@
         int childCount = hostView.getChildCount();
         state.visibleChildren.clear();
         state.visibleChildren.ensureCapacity(childCount);
-        state.increasedPaddingSet.clear();
+        state.increasedPaddingMap.clear();
         int notGoneIndex = 0;
         ExpandableView lastView = null;
         for (int i = 0; i < childCount; i++) {
             ExpandableView v = (ExpandableView) hostView.getChildAt(i);
             if (v.getVisibility() != View.GONE) {
                 notGoneIndex = updateNotGoneIndex(resultState, state, notGoneIndex, v);
-                boolean needsIncreasedPadding = v.needsIncreasedPadding();
-                if (needsIncreasedPadding) {
-                    state.increasedPaddingSet.add(v);
+                float increasedPadding = v.getIncreasedPaddingAmount();
+                if (increasedPadding != 0.0f) {
+                    state.increasedPaddingMap.put(v, increasedPadding);
                     if (lastView != null) {
-                        state.increasedPaddingSet.add(lastView);
+                        Float prevValue = state.increasedPaddingMap.get(lastView);
+                        float newValue = prevValue != null
+                                ? Math.max(prevValue, increasedPadding)
+                                : increasedPadding;
+                        state.increasedPaddingMap.put(lastView, newValue);
                     }
                 }
                 if (v instanceof ExpandableNotificationRow) {
@@ -423,9 +428,12 @@
 
     private int getPaddingAfterChild(StackScrollAlgorithmState algorithmState,
             ExpandableView child) {
-        return algorithmState.increasedPaddingSet.contains(child)
-                ? mIncreasedPaddingBetweenElements
-                : mPaddingBetweenElements;
+        Float paddingValue = algorithmState.increasedPaddingMap.get(child);
+        return paddingValue == null
+                ? mPaddingBetweenElements
+                : (int) NotificationUtils.interpolate(mPaddingBetweenElements,
+                        mIncreasedPaddingBetweenElements,
+                        paddingValue);
     }
 
     private void updateHeadsUpStates(StackScrollState resultState,
@@ -765,9 +773,10 @@
         public final ArrayList<ExpandableView> visibleChildren = new ArrayList<ExpandableView>();
 
         /**
-         * The children from the host that need an increased padding after them.
+         * The children from the host that need an increased padding after them. A value of 0 means
+         * no increased padding, a value of 1 means full padding.
          */
-        public final HashSet<ExpandableView> increasedPaddingSet = new HashSet<>();
+        public final HashMap<ExpandableView, Float> increasedPaddingMap = new HashMap<>();
     }
 
 }