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      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.example.android.apis.graphics;
     18 
     19 import android.content.Context;
     20 import android.graphics.*;
     21 import android.os.Bundle;
     22 import android.view.MotionEvent;
     23 import android.view.*;
     24 
     25 public class Patterns extends GraphicsActivity {
     26 
     27     @Override
     28     protected void onCreate(Bundle savedInstanceState) {
     29         super.onCreate(savedInstanceState);
     30         setContentView(new SampleView(this));
     31     }
     32 
     33     private static Bitmap makeBitmap1() {
     34         Bitmap bm = Bitmap.createBitmap(40, 40, Bitmap.Config.RGB_565);
     35         Canvas c = new Canvas(bm);
     36         c.drawColor(Color.RED);
     37         Paint p = new Paint();
     38         p.setColor(Color.BLUE);
     39         c.drawRect(5, 5, 35, 35, p);
     40         return bm;
     41     }
     42 
     43     private static Bitmap makeBitmap2() {
     44         Bitmap bm = Bitmap.createBitmap(64, 64, Bitmap.Config.ARGB_8888);
     45         Canvas c = new Canvas(bm);
     46         Paint p = new Paint(Paint.ANTI_ALIAS_FLAG);
     47         p.setColor(Color.GREEN);
     48         p.setAlpha(0xCC);
     49         c.drawCircle(32, 32, 27, p);
     50         return bm;
     51     }
     52 
     53     private static class SampleView extends View {
     54         private final Shader mShader1;
     55         private final Shader mShader2;
     56         private final Paint mPaint;
     57         private final DrawFilter mFastDF;
     58 
     59         private float mTouchStartX;
     60         private float mTouchStartY;
     61         private float mTouchCurrX;
     62         private float mTouchCurrY;
     63         private DrawFilter mDF;
     64 
     65         public SampleView(Context context) {
     66             super(context);
     67             setFocusable(true);
     68             setFocusableInTouchMode(true);
     69 
     70             mFastDF = new PaintFlagsDrawFilter(Paint.FILTER_BITMAP_FLAG |
     71                                                Paint.DITHER_FLAG,
     72                                                0);
     73 
     74             mShader1 = new BitmapShader(makeBitmap1(), Shader.TileMode.REPEAT,
     75                                         Shader.TileMode.REPEAT);
     76             mShader2 = new BitmapShader(makeBitmap2(), Shader.TileMode.REPEAT,
     77                                         Shader.TileMode.REPEAT);
     78 
     79             Matrix m = new Matrix();
     80             m.setRotate(30);
     81             mShader2.setLocalMatrix(m);
     82 
     83             mPaint = new Paint(Paint.FILTER_BITMAP_FLAG);
     84         }
     85 
     86         @Override protected void onDraw(Canvas canvas) {
     87             canvas.setDrawFilter(mDF);
     88 
     89             mPaint.setShader(mShader1);
     90             canvas.drawPaint(mPaint);
     91 
     92             canvas.translate(mTouchCurrX - mTouchStartX,
     93                              mTouchCurrY - mTouchStartY);
     94 
     95             mPaint.setShader(mShader2);
     96             canvas.drawPaint(mPaint);
     97         }
     98 
     99         @Override
    100         public boolean onTouchEvent(MotionEvent event) {
    101             float x = event.getX();
    102             float y = event.getY();
    103 
    104             switch (event.getAction()) {
    105                 case MotionEvent.ACTION_DOWN:
    106                     mTouchStartX = mTouchCurrX = x;
    107                     mTouchStartY = mTouchCurrY = y;
    108                     mDF = mFastDF;
    109                     invalidate();
    110                     break;
    111                 case MotionEvent.ACTION_MOVE:
    112                     mTouchCurrX = x;
    113                     mTouchCurrY = y;
    114                     invalidate();
    115                     break;
    116                 case MotionEvent.ACTION_UP:
    117                     mDF = null;
    118                     invalidate();
    119                     break;
    120             }
    121             return true;
    122         }
    123     }
    124 }
    125 
    126