1 files changed, 129 insertions, 0 deletions
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarScrimView.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarScrimView.java
new file mode 100644
index 0000000000..94a3307bc3
--- /dev/null
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarScrimView.java
@@ -0,0 +1,129 @@
+/*
+ * 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.Canvas;
+import android.graphics.Paint;
+import android.graphics.Path;
+import android.util.AttributeSet;
+import android.view.View;
+
+/**
+ * View that handles scrimming the taskbar and the inverted corners it draws. The scrim is used
+ * when bubbles is expanded.
+ */
+public class TaskbarScrimView extends View {
+    private final Paint mTaskbarScrimPaint;
+    private final Path mInvertedLeftCornerPath, mInvertedRightCornerPath;
+
+    private boolean mShowScrim;
+    private float mLeftCornerRadius, mRightCornerRadius;
+    private float mBackgroundHeight;
+
+    public TaskbarScrimView(Context context) {
+        this(context, null);
+    }
+
+    public TaskbarScrimView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public TaskbarScrimView(Context context, AttributeSet attrs, int defStyleAttr) {
+        this(context, attrs, defStyleAttr, 0);
+    }
+
+    public TaskbarScrimView(Context context, AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+
+        mTaskbarScrimPaint = new Paint();
+        mTaskbarScrimPaint.setColor(getResources().getColor(android.R.color.system_neutral1_1000));
+        mTaskbarScrimPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
+        mTaskbarScrimPaint.setStyle(Paint.Style.FILL);
+
+        mInvertedLeftCornerPath = new Path();
+        mInvertedRightCornerPath = new Path();
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        super.onDraw(canvas);
+
+        if (mShowScrim) {
+            canvas.save();
+            canvas.translate(0, canvas.getHeight() - mBackgroundHeight);
+
+            // Scrim the taskbar itself.
+            canvas.drawRect(0, 0, canvas.getWidth(), mBackgroundHeight, mTaskbarScrimPaint);
+
+            // Scrim the inverted rounded corners above the taskbar.
+            canvas.translate(0, -mLeftCornerRadius);
+            canvas.drawPath(mInvertedLeftCornerPath, mTaskbarScrimPaint);
+            canvas.translate(0, mLeftCornerRadius);
+            canvas.translate(canvas.getWidth() - mRightCornerRadius, -mRightCornerRadius);
+            canvas.drawPath(mInvertedRightCornerPath, mTaskbarScrimPaint);
+
+            canvas.restore();
+        }
+    }
+
+    /**
+     * Sets the height of the taskbar background.
+     * @param height the height of the background.
+     */
+    protected void setBackgroundHeight(float height) {
+        mBackgroundHeight = height;
+        if (mShowScrim) {
+            invalidate();
+        }
+    }
+
+    /**
+     * Sets the alpha of the taskbar scrim.
+     * @param alpha the alpha of the scrim.
+     */
+    protected void setScrimAlpha(float alpha) {
+        mShowScrim = alpha > 0f;
+        mTaskbarScrimPaint.setAlpha((int) (alpha * 255));
+        invalidate();
+    }
+
+    /**
+     * Sets the radius of the left and right corners above the taskbar.
+     * @param leftCornerRadius the radius of the left corner.
+     * @param rightCornerRadius the radius of the right corner.
+     */
+    protected void setCornerSizes(float leftCornerRadius, float rightCornerRadius) {
+        mLeftCornerRadius = leftCornerRadius;
+        mRightCornerRadius = rightCornerRadius;
+
+        Path square = new Path();
+        square.addRect(0, 0, mLeftCornerRadius, mLeftCornerRadius, Path.Direction.CW);
+        Path circle = new Path();
+        circle.addCircle(mLeftCornerRadius, 0, mLeftCornerRadius, Path.Direction.CW);
+        mInvertedLeftCornerPath.op(square, circle, Path.Op.DIFFERENCE);
+        square.reset();
+        square.addRect(0, 0, mRightCornerRadius, mRightCornerRadius, Path.Direction.CW);
+        circle.reset();
+        circle.addCircle(0, 0, mRightCornerRadius, Path.Direction.CW);
+        mInvertedRightCornerPath.op(square, circle, Path.Op.DIFFERENCE);
+
+        if (mShowScrim) {
+            invalidate();
+        }
+    }
+}