Api Demo - .graphics(11)

//关键字：Shader ，ShapeDrawable
package com.example.android.apis.graphics;

import com.example.android.apis.R;

import android.app.Activity;
import android.content.Context;
import android.graphics.*;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.*;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.*;

public class ShapeDrawable1 extends GraphicsActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new SampleView(this));
    }
    
    private static class SampleView extends View {
        private ShapeDrawable[] mDrawables;
        
        private static Shader makeSweep() {
            return new SweepGradient(150, 25,
                new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF, 0xFFFF0000 },
                null);
        }
        
        private static Shader makeLinear() {
            return new LinearGradient(0, 0, 50, 50,
                              new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF },
                              null, Shader.TileMode.MIRROR);
        }
        
        private static Shader makeTiling() {
            int[] pixels = new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF, 0};
            Bitmap bm = Bitmap.createBitmap(pixels, 2, 2,
                                            Bitmap.Config.ARGB_8888);
            
            return new BitmapShader(bm, Shader.TileMode.REPEAT,
                                        Shader.TileMode.REPEAT);
        }
        
        private static class MyShapeDrawable extends ShapeDrawable {
            private Paint mStrokePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            
            public MyShapeDrawable(Shape s) {
                super(s);
                mStrokePaint.setStyle(Paint.Style.STROKE);
            }
            
            public Paint getStrokePaint() {
                return mStrokePaint;
            }
            
            @Override protected void onDraw(Shape s, Canvas c, Paint p) {
                s.draw(c, p);
                s.draw(c, mStrokePaint);//另取一支画笔抗锯齿
            }
        }
        
        public SampleView(Context context) {
            super(context);
            setFocusable(true);

            float[] outerR = new float[] { 12, 12, 12, 12, 0, 0, 0, 0 };//外边框，分别对应顺时针四个角的度数
            RectF   inset = new RectF(6, 6, 6, 6);//内外边框距离
            float[] innerR = new float[] { 12, 12, 0, 0, 12, 12, 0, 0 };//内边框角度数。
            
            Path path = new Path();
            path.moveTo(50, 0);
            path.lineTo(0, 50);
            path.lineTo(50, 100);
            path.lineTo(100, 50);
            path.close();//用路径围城菱形
            
            mDrawables = new ShapeDrawable[7];
            mDrawables[0] = new ShapeDrawable(new RectShape());//矩形
            mDrawables[1] = new ShapeDrawable(new OvalShape());//椭圆
            mDrawables[2] = new ShapeDrawable(new RoundRectShape(outerR, null,
                                                                 null));//外边框为圆角
            mDrawables[3] = new ShapeDrawable(new RoundRectShape(outerR, inset,
                                                                 null));//为边框为圆角，内外边框形状一样
            mDrawables[4] = new ShapeDrawable(new RoundRectShape(outerR, inset,
                                                                 innerR));//内外都是圆角
            mDrawables[5] = new ShapeDrawable(new PathShape(path, 100, 100));//菱形，后两个参数分别对应标准宽高，缩放时以他们为标准等比缩放。
            mDrawables[6] = new MyShapeDrawable(new ArcShape(45, -270));//扇形
            
            mDrawables[0].getPaint().setColor(0xFFFF0000);
            mDrawables[1].getPaint().setColor(0xFF00FF00);
            mDrawables[2].getPaint().setColor(0xFF0000FF);
            mDrawables[3].getPaint().setShader(makeSweep());//扫描状阴影
            mDrawables[4].getPaint().setShader(makeLinear());//线性阴影
            mDrawables[5].getPaint().setShader(makeTiling());//平铺状阴影
            mDrawables[6].getPaint().setColor(0x88FF8844);
            
            PathEffect pe = new DiscretePathEffect(10, 4);//路径特效
            PathEffect pe2 = new CornerPathEffect(4);
            mDrawables[3].getPaint().setPathEffect(
                                                new ComposePathEffect(pe2, pe));//组合路径特效
        
            MyShapeDrawable msd = (MyShapeDrawable)mDrawables[6];
            msd.getStrokePaint().setStrokeWidth(4);
        }
        
        @Override protected void onDraw(Canvas canvas) {
            
            int x = 10;
            int y = 10;
            int width = 300;
            int height = 50;
            
            for (Drawable dr : mDrawables) {
                dr.setBounds(x, y, x + width, y + height);
                dr.draw(canvas);                
                y += height + 5;
            }
        }
    }
}