Enabling recents stack clipping

The taskviews now avoid overdraw by clipping invisible
parts. Also adapted some timings of the animation.

Bug: 17455301
Change-Id: Ifbf7bab363e530cb2ad842baed50fc16dcfcc4c4

1 files changed, 77 insertions, 0 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/recents/misc/Utilities.java b/packages/SystemUI/src/com/android/systemui/recents/misc/Utilities.java
index 4c6b389..f01d17c 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/misc/Utilities.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/misc/Utilities.java
@@ -18,11 +18,14 @@ package com.android.systemui.recents.misc;
 
 import android.content.Intent;
 import android.graphics.Color;
+import android.graphics.Matrix;
 import android.graphics.Rect;
+import android.view.View;
 import com.android.systemui.recents.RecentsConfiguration;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.ArrayList;
 
 /* Common code */
 public class Utilities {
@@ -68,6 +71,80 @@ public class Utilities {
         }
     }
 
+    /** Maps a coorindate in a descendant view into the parent. */
+    public static float mapCoordInDescendentToSelf(View descendant, View root,
+            float[] coord, boolean includeRootScroll) {
+        ArrayList<View> ancestorChain = new ArrayList<View>();
+
+        float[] pt = {coord[0], coord[1]};
+
+        View v = descendant;
+        while(v != root && v != null) {
+            ancestorChain.add(v);
+            v = (View) v.getParent();
+        }
+        ancestorChain.add(root);
+
+        float scale = 1.0f;
+        int count = ancestorChain.size();
+        for (int i = 0; i < count; i++) {
+            View v0 = ancestorChain.get(i);
+            // For TextViews, scroll has a meaning which relates to the text position
+            // which is very strange... ignore the scroll.
+            if (v0 != descendant || includeRootScroll) {
+                pt[0] -= v0.getScrollX();
+                pt[1] -= v0.getScrollY();
+            }
+
+            v0.getMatrix().mapPoints(pt);
+            pt[0] += v0.getLeft();
+            pt[1] += v0.getTop();
+            scale *= v0.getScaleX();
+        }
+
+        coord[0] = pt[0];
+        coord[1] = pt[1];
+        return scale;
+    }
+
+    /** Maps a coordinate in the root to a descendent. */
+    public static float mapCoordInSelfToDescendent(View descendant, View root,
+            float[] coord, Matrix tmpInverseMatrix) {
+        ArrayList<View> ancestorChain = new ArrayList<View>();
+
+        float[] pt = {coord[0], coord[1]};
+
+        View v = descendant;
+        while(v != root) {
+            ancestorChain.add(v);
+            v = (View) v.getParent();
+        }
+        ancestorChain.add(root);
+
+        float scale = 1.0f;
+        int count = ancestorChain.size();
+        tmpInverseMatrix.set(Matrix.IDENTITY_MATRIX);
+        for (int i = count - 1; i >= 0; i--) {
+            View ancestor = ancestorChain.get(i);
+            View next = i > 0 ? ancestorChain.get(i-1) : null;
+
+            pt[0] += ancestor.getScrollX();
+            pt[1] += ancestor.getScrollY();
+
+            if (next != null) {
+                pt[0] -= next.getLeft();
+                pt[1] -= next.getTop();
+                next.getMatrix().invert(tmpInverseMatrix);
+                tmpInverseMatrix.mapPoints(pt);
+                scale *= next.getScaleX();
+            }
+        }
+
+        coord[0] = pt[0];
+        coord[1] = pt[1];
+        return scale;
+    }
+
     /** Calculates the constrast between two colors, using the algorithm provided by the WCAG v2. */
     public static float computeContrastBetweenColors(int bg, int fg) {
         float bgR = Color.red(bg) / 255f;