Tint task bar based on sampling of colors in the area

TODO: Add transition animation

Bug: 193938970
Test: manual
Change-Id: I0ffb94e0f11d47685a268ee8d057b6997f3a2ff6

quickstep/src/com/android/launcher3/taskbar/StashedHandleView.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.taskbar;
+
+import android.content.Context;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+import android.view.View;
+
+import androidx.annotation.ColorInt;
+import androidx.core.content.ContextCompat;
+
+import com.android.launcher3.R;
+
+public class StashedHandleView extends View {
+
+    private final @ColorInt int mStashedHandleLightColor;
+    private final @ColorInt int mStashedHandleDarkColor;
+    private final Rect mSampledRegion = new Rect();
+    private final int[] mTmpArr = new int[2];
+
+    public StashedHandleView(Context context) {
+        this(context, null);
+    }
+
+    public StashedHandleView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public StashedHandleView(Context context, AttributeSet attrs, int defStyleAttr) {
+        this(context, attrs, defStyleAttr, 0);
+    }
+
+    public StashedHandleView(Context context, AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+
+        mStashedHandleLightColor = ContextCompat.getColor(context,
+                R.color.taskbar_stashed_handle_light_color);
+        mStashedHandleDarkColor = ContextCompat.getColor(context,
+                R.color.taskbar_stashed_handle_dark_color);
+    }
+
+    public void updateSampledRegion() {
+        getLocationOnScreen(mTmpArr);
+        mSampledRegion.set(mTmpArr[0], mTmpArr[1], mTmpArr[0] + getWidth(),
+                mTmpArr[1] + getHeight());
+    }
+
+    public Rect getSampledRegion() {
+        return mSampledRegion;
+    }
+
+    public void updateHandleColor(boolean isRegionDark) {
+        setBackgroundColor(isRegionDark ? mStashedHandleLightColor : mStashedHandleDarkColor);
+    }
+}