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      1 /*
      2  * Copyright (C) 2009 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 com.example.android.apis.R;
     20 
     21 import android.app.Activity;
     22 import android.content.Context;
     23 import android.graphics.*;
     24 import android.graphics.drawable.*;
     25 import android.os.Bundle;
     26 import android.view.KeyEvent;
     27 import android.view.*;
     28 
     29 public class ColorFilters extends GraphicsActivity {
     30 
     31     @Override
     32     protected void onCreate(Bundle savedInstanceState) {
     33         super.onCreate(savedInstanceState);
     34         setContentView(new SampleView(this));
     35 
     36     }
     37 
     38     private static class SampleView extends View {
     39         private Activity mActivity;
     40         private Drawable mDrawable;
     41         private Drawable[] mDrawables;
     42         private Paint mPaint;
     43         private Paint mPaint2;
     44         private float mPaintTextOffset;
     45         private int[] mColors;
     46         private PorterDuff.Mode[] mModes;
     47         private int mModeIndex;
     48 
     49         private static void addToTheRight(Drawable curr, Drawable prev) {
     50             Rect r = prev.getBounds();
     51             int x = r.right + 12;
     52             int center = (r.top + r.bottom) >> 1;
     53             int h = curr.getIntrinsicHeight();
     54             int y = center - (h >> 1);
     55 
     56             curr.setBounds(x, y, x + curr.getIntrinsicWidth(), y + h);
     57         }
     58 
     59         public SampleView(Activity activity) {
     60             super(activity);
     61             mActivity = activity;
     62             Context context = activity;
     63             setFocusable(true);
     64 
     65             mDrawable = context.getResources().getDrawable(R.drawable.btn_default_normal);
     66             mDrawable.setBounds(0, 0, 150, 48);
     67             mDrawable.setDither(true);
     68 
     69             int[] resIDs = new int[] {
     70                 R.drawable.btn_circle_normal,
     71                 R.drawable.btn_check_off,
     72                 R.drawable.btn_check_on
     73             };
     74             mDrawables = new Drawable[resIDs.length];
     75             Drawable prev = mDrawable;
     76             for (int i = 0; i < resIDs.length; i++) {
     77                 mDrawables[i] = context.getResources().getDrawable(resIDs[i]);
     78                 mDrawables[i].setDither(true);
     79                 addToTheRight(mDrawables[i], prev);
     80                 prev = mDrawables[i];
     81             }
     82 
     83             mPaint = new Paint();
     84             mPaint.setAntiAlias(true);
     85             mPaint.setTextSize(16);
     86             mPaint.setTextAlign(Paint.Align.CENTER);
     87 
     88             mPaint2 = new Paint(mPaint);
     89             mPaint2.setAlpha(64);
     90 
     91             Paint.FontMetrics fm = mPaint.getFontMetrics();
     92             mPaintTextOffset = (fm.descent + fm.ascent) * 0.5f;
     93 
     94             mColors = new int[] {
     95                 0,
     96                 0xCC0000FF,
     97                 0x880000FF,
     98                 0x440000FF,
     99                 0xFFCCCCFF,
    100                 0xFF8888FF,
    101                 0xFF4444FF,
    102             };
    103 
    104             mModes = new PorterDuff.Mode[] {
    105                 PorterDuff.Mode.SRC_ATOP,
    106                 PorterDuff.Mode.MULTIPLY,
    107             };
    108             mModeIndex = 0;
    109 
    110             updateTitle();
    111         }
    112 
    113         private void swapPaintColors() {
    114             if (mPaint.getColor() == 0xFF000000) {
    115                 mPaint.setColor(0xFFFFFFFF);
    116                 mPaint2.setColor(0xFF000000);
    117             } else {
    118                 mPaint.setColor(0xFF000000);
    119                 mPaint2.setColor(0xFFFFFFFF);
    120             }
    121             mPaint2.setAlpha(64);
    122         }
    123 
    124         private void updateTitle() {
    125             mActivity.setTitle(mModes[mModeIndex].toString());
    126         }
    127 
    128         private void drawSample(Canvas canvas, ColorFilter filter) {
    129             Rect r = mDrawable.getBounds();
    130             float x = (r.left + r.right) * 0.5f;
    131             float y = (r.top + r.bottom) * 0.5f - mPaintTextOffset;
    132 
    133             mDrawable.setColorFilter(filter);
    134             mDrawable.draw(canvas);
    135             canvas.drawText("Label", x+1, y+1, mPaint2);
    136             canvas.drawText("Label", x, y, mPaint);
    137 
    138             for (Drawable dr : mDrawables) {
    139                 dr.setColorFilter(filter);
    140                 dr.draw(canvas);
    141             }
    142         }
    143 
    144         @Override protected void onDraw(Canvas canvas) {
    145             canvas.drawColor(0xFFCCCCCC);
    146 
    147             canvas.translate(8, 12);
    148             for (int color : mColors) {
    149                 ColorFilter filter;
    150                 if (color == 0) {
    151                     filter = null;
    152                 } else {
    153                     filter = new PorterDuffColorFilter(color,
    154                                                        mModes[mModeIndex]);
    155                 }
    156                 drawSample(canvas, filter);
    157                 canvas.translate(0, 55);
    158             }
    159         }
    160 
    161         @Override
    162         public boolean onTouchEvent(MotionEvent event) {
    163             float x = event.getX();
    164             float y = event.getY();
    165             switch (event.getAction()) {
    166                 case MotionEvent.ACTION_DOWN:
    167                     break;
    168                 case MotionEvent.ACTION_MOVE:
    169                     break;
    170                 case MotionEvent.ACTION_UP:
    171                     // update mode every other time we change paint colors
    172                     if (mPaint.getColor() == 0xFFFFFFFF) {
    173                         mModeIndex = (mModeIndex + 1) % mModes.length;
    174                         updateTitle();
    175                     }
    176                     swapPaintColors();
    177                     invalidate();
    178                     break;
    179             }
    180             return true;
    181         }
    182     }
    183 }
    184 
    185