Fade theme color in tab switcher

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java
index e03bb150ecec617e61bb2a80060499997405c394..f541c80a93901d1154071525d637769b8df5a2dd 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java
@@ -4,6 +4,8 @@
 
 package org.chromium.chrome.browser.compositor.layouts.components;
 
+import static org.chromium.chrome.browser.compositor.layouts.ChromeAnimation.AnimatableAnimation.createAnimation;
+
 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Color;
@@ -12,7 +14,10 @@ import android.graphics.RectF;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.compositor.layouts.ChromeAnimation;
 import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.toolbar.ToolbarPhone;
+import org.chromium.chrome.browser.util.ColorUtils;
 import org.chromium.chrome.browser.util.MathUtils;
+import org.chromium.ui.interpolators.BakedBezierInterpolator;
 
 /**
  * {@link LayoutTab} is used to keep track of a thumbnail's bitmap and position and to
@@ -40,6 +45,7 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
         DECORATION_ALPHA,
         TOOLBAR_Y_OFFSET,
         SIDE_BORDER_SCALE,
+        TOOLBAR_COLOR,
     }
 
     public static final float ALPHA_THRESHOLD = 1.0f / 255.0f;
@@ -115,6 +121,11 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
      */
     private boolean mInitFromHostCalled = false;
 
+    /** The animation set specific to this LayoutTab. */
+    private ChromeAnimation<ChromeAnimation.Animatable<?>> mCurrentAnimations;
+    private int mInitialThemeColor;
+    private int mFinalThemeColor;
+
     // All the members bellow are initialized from the delayed initialization.
     //
     // Begin section --------------
@@ -208,16 +219,53 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
      * @param shouldStall           Whether the tab should display a desaturated thumbnail and
      *                              wait for the content layer to load.
      * @param canUseLiveTexture     Whether the tab can use a live texture when being displayed.
+     * @return True if the init requires the compositor to update.
      */
-    public void initFromHost(int backgroundColor, boolean shouldStall, boolean canUseLiveTexture,
+    public boolean initFromHost(int backgroundColor, boolean shouldStall, boolean canUseLiveTexture,
             int toolbarBackgroundColor, int textBoxBackgroundColor, float textBoxAlpha) {
         mBackgroundColor = backgroundColor;
-        mToolbarBackgroundColor = toolbarBackgroundColor;
+
+        boolean needsUpdate = false;
+
+        // If the toolbar color changed, animate between the old and new colors.
+        if (mToolbarBackgroundColor != toolbarBackgroundColor && isVisible()) {
+            ChromeAnimation.Animation<ChromeAnimation.Animatable<?>>  themeColorAnimation =
+                    createAnimation(this, Property.TOOLBAR_COLOR, 0.0f, 1.0f,
+                    ToolbarPhone.THEME_COLOR_TRANSITION_DURATION, 0, false,
+                    BakedBezierInterpolator.TRANSFORM_CURVE);
+
+            mInitialThemeColor = mToolbarBackgroundColor;
+            mFinalThemeColor = toolbarBackgroundColor;
+
+            if (mCurrentAnimations != null) {
+                mCurrentAnimations.updateAndFinish();
+            }
+
+            mCurrentAnimations = new ChromeAnimation<ChromeAnimation.Animatable<?>>();
+            mCurrentAnimations.add(themeColorAnimation);
+            mCurrentAnimations.start();
+            needsUpdate = true;
+        } else {
+            // If the layout tab isn't visible, just set the toolbar color without animating.
+            mToolbarBackgroundColor = toolbarBackgroundColor;
+        }
+
         mTextBoxBackgroundColor = textBoxBackgroundColor;
         mTextBoxAlpha = textBoxAlpha;
         mShouldStall = shouldStall;
         mCanUseLiveTexture = canUseLiveTexture;
         mInitFromHostCalled = true;
+
+        return needsUpdate;
+    }
+
+    /**
+     * Update any animation controlled by this object.
+     * @param time The current app time in ms.
+     * @return Whether the animations controlled by this LayoutTab are finished.
+     */
+    public boolean onUpdateAnimation(long time) {
+        return mCurrentAnimations == null ? true : mCurrentAnimations.update(time);
     }
 
     /**
@@ -774,6 +822,7 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
      * @param visible True if the {@link LayoutTab} is visible and need to be drawn.
      */
     public void setVisible(boolean visible) {
+        if (!visible && mCurrentAnimations != null) mCurrentAnimations.updateAndFinish();
         mVisible = visible;
     }
 
@@ -959,9 +1008,21 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
             case SIDE_BORDER_SCALE:
                 setSideBorderScale(val);
                 break;
+            case TOOLBAR_COLOR:
+                if (!isVisible()) {
+                    mCurrentAnimations.updateAndFinish();
+                } else {
+                    mToolbarBackgroundColor = ColorUtils.getColorWithOverlay(mInitialThemeColor,
+                            mFinalThemeColor, val);
+                }
+                break;
         }
     }
 
     @Override
-    public void onPropertyAnimationFinished(Property prop) {}
+    public void onPropertyAnimationFinished(Property prop) {
+        if (mCurrentAnimations != null && mCurrentAnimations.finished()) {
+            mCurrentAnimations = null;
+        }
+    }
 }