tests/HwAccelerationTest/src/com/android/test/hwui/RenderEffectShaderActivity.java

/*
 * Copyright (C) 2020 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.test.hwui;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.RenderEffect;
import android.graphics.RenderNode;
import android.graphics.Shader;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.LinearLayout;

@SuppressWarnings({"UnusedDeclaration"})
public class RenderEffectShaderActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        LinearLayout layout = new LinearLayout(this);
        layout.setClipChildren(false);
        layout.setGravity(Gravity.CENTER);
        layout.setOrientation(LinearLayout.VERTICAL);


        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(500, 500);
        params.bottomMargin = 100;

        layout.addView(new ShaderRenderEffectView(this), params);

        setContentView(layout);
    }

    public static class ShaderRenderEffectView extends View {

        private final Paint mPaint;
        private final RenderNode mRenderNode;

        public ShaderRenderEffectView(Context c) {
            super(c);

            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            mRenderNode = new RenderNode("blurNode");

        }

        @Override
        protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
            if (changed) {
                LinearGradient gradient = new LinearGradient(
                        0f, 0f,
                        0f, bottom - top,
                        new int[]{Color.CYAN, Color.MAGENTA},
                        null,
                        Shader.TileMode.CLAMP
                );
                mRenderNode.setRenderEffect(
                        RenderEffect.createShaderEffect(gradient)
                );

                int width = right - left;
                int height = bottom - top;
                mRenderNode.setPosition(0, 0, width, height);
                Canvas canvas = mRenderNode.beginRecording(width, height);
                mPaint.setColor(Color.BLUE);

                canvas.drawRect(
                        0,
                        0,
                        width,
                        height,
                        mPaint
                );

                mPaint.setColor(Color.RED);
                canvas.drawCircle((right - left) / 2f, (bottom - top) / 2f, 50f, mPaint);

                mRenderNode.endRecording();
            }
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            canvas.drawRenderNode(mRenderNode);
        }
    }
}