/ocr/worldreader/src/com/google/marvin/worldreader/RectsView.java

 1/*
 2 * Copyright (C) 2009 Google Inc.
 3 * 
 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 5 * use this file except in compliance with the License. You may obtain a copy of
 6 * 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, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations under
14 * the License.
15 */
16package com.google.marvin.worldreader;
17
18import android.content.Context;
19import android.graphics.Canvas;
20import android.graphics.Matrix;
21import android.graphics.Paint;
22import android.graphics.Rect;
23import android.graphics.RectF;
24import android.util.AttributeSet;
25import android.util.Log;
26import android.view.View;
27
28import java.util.LinkedList;
29
30/**
31 * Displays colored bounding boxes scaled to screen resolution.
32 * 
33 * @author alanv@google.com (Alan Viverette)
34 */
35public class RectsView extends View {
36  private static final String TAG = "RectsView";
37
38  private Matrix mMatrix;
39  private Paint mPaint;
40  private LinkedList<Pair> mRects;
41
42  public RectsView(Context context, AttributeSet attrs) {
43    super(context, attrs);
44
45    mRects = new LinkedList<Pair>();
46    mPaint = new Paint();
47    mPaint.setStyle(Paint.Style.STROKE);
48    mPaint.setStrokeWidth(5.0f);
49  }
50
51  public void addRect(Rect rect) {
52    if (rect != null) {
53      RectF rectf = new RectF(rect);
54      int argb = (int) (Math.random() * Integer.MAX_VALUE) | 0xFF000000;
55      Pair entry = new Pair(rectf, argb);
56
57      mMatrix.mapRect(rectf);
58      mRects.add(entry);
59      postInvalidate();
60    }
61  }
62
63  public void setScaling(int srcW, int srcH, int dstW, int dstH) {
64    float scaleX = dstW / (float) srcW;
65    float scaleY = dstH / (float) srcH;
66    float scale = Math.min(scaleX, scaleY);
67
68    float scaledW = scale * srcW;
69    float scaledH = scale * srcH;
70
71    float deltaX = (dstW - scaledW) / 2.0f;
72    float deltaY = (dstH - scaledH) / 2.0f;
73
74    mMatrix = new Matrix();
75    mMatrix.postScale(scale, scale);
76    mMatrix.postTranslate(deltaX, deltaY);
77
78    Log.i(TAG, "Set scaling to scale " + scale + " transform (" + deltaX + "," + deltaY + ")");
79  }
80
81  @Override
82  public void onDraw(Canvas canvas) {
83    for (Pair entry : mRects) {
84      mPaint.setColor(entry.argb);
85      canvas.drawRect(entry.rectf, mPaint);
86    }
87  }
88
89  private class Pair {
90    public RectF rectf;
91    public int argb;
92
93    public Pair(RectF rectf, int argb) {
94      this.rectf = rectf;
95      this.argb = argb;
96    }
97  }
98}