Add an experimental search widget

chrome/android/java/src/org/chromium/chrome/browser/searchwidget/BoxAnimatorScrim.java

Index: chrome/android/java/src/org/chromium/chrome/browser/searchwidget/BoxAnimatorScrim.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/searchwidget/BoxAnimatorScrim.java b/chrome/android/java/src/org/chromium/chrome/browser/searchwidget/BoxAnimatorScrim.java
new file mode 100644
index 0000000000000000000000000000000000000000..ae7a4d882582546679901f0258465cbfd96710d3
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/searchwidget/BoxAnimatorScrim.java
@@ -0,0 +1,87 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.searchwidget;
+
+import android.animation.ValueAnimator;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.util.AttributeSet;
+import android.view.View;
+
+import org.chromium.base.ApiCompatibilityUtils;
+import org.chromium.chrome.R;
+
+/** Draws a scrim and animates a search box moving into place. */
+class BoxAnimatorScrim extends View implements ValueAnimator.AnimatorUpdateListener {
+    /** Transparency used for the scrim. */
+    private static final int BACKGROUND_TRANSPARENCY = 154;
+
+    private final Drawable mCardDrawable;
+    private final Rect mAnimationRect = new Rect();
+    private final int mBackgroundColor;
+
+    private Rect mSourceRect;
+    private Rect mTargetRect;
+    private float mInterpolatedValue;
+
+    public BoxAnimatorScrim(Context context, AttributeSet attrs) {
+        super(context, attrs);
+
+        mBackgroundColor =
+                ApiCompatibilityUtils.getColor(getResources(), R.color.light_normal_color)
+                & 0x00ffffff;
+
+        // Mutate to prevent the animation from affecting other places the Drawable is used.
+        mCardDrawable = ApiCompatibilityUtils.getDrawable(getResources(), R.drawable.card_single);
+        mCardDrawable.mutate();
+    }
+
+    /** Sets where the box will animate from and where it will go. */
+    public void setAnimationRects(Rect source, Rect target) {
+        mSourceRect = source;
+        mTargetRect = target;
+    }
+
+    /** Returns the last known value of the animation. */
+    public float getInterpolatedValue() {
+        return mInterpolatedValue;
+    }
+
+    /** Set the current value of the animation. */
+    public void setInterpolatedValue(float value) {
+        mInterpolatedValue = Math.max(0.0f, Math.min(1.0f, value));
+        postInvalidateOnAnimation();
+    }
+
+    @Override
+    public void onDraw(Canvas canvas) {
+        // Draw the background.
+        int currentAlpha = (int) (BACKGROUND_TRANSPARENCY * mInterpolatedValue);
+        int color = (currentAlpha << 24) + mBackgroundColor;
+        canvas.drawColor(color);
+
+        // Draw the search box moving into place, if needed.
+        if (mSourceRect == null || mTargetRect == null) return;
+        if (mInterpolatedValue >= 1.0f) return;
+
+        mAnimationRect.left = (int) interpolate(mSourceRect.left, mTargetRect.left);
+        mAnimationRect.right = (int) interpolate(mSourceRect.right, mTargetRect.right);
+        mAnimationRect.top = (int) interpolate(mSourceRect.top, mTargetRect.top);
+        mAnimationRect.bottom = (int) interpolate(mSourceRect.bottom, mTargetRect.bottom);
+        mCardDrawable.setBounds(mAnimationRect);
+        mCardDrawable.draw(canvas);
+    }
+
+    @Override
+    public void onAnimationUpdate(ValueAnimator animation) {
+        setInterpolatedValue((Float) animation.getAnimatedValue());
+    }
+
+    private float interpolate(float start, float end) {
+        return ((1.0f - mInterpolatedValue) * start) + (mInterpolatedValue * end);
+    }
+}