1 /*
2  * Copyright (C) 2010 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.android.test.hwui;
18 
19 import android.app.Activity;
20 import android.content.Context;
21 import android.graphics.Canvas;
22 import android.graphics.Paint;
23 import android.graphics.Path;
24 import android.graphics.PathMeasure;
25 import android.os.Bundle;
26 import android.view.View;
27 
28 @SuppressWarnings({"UnusedDeclaration"})
29 public class TextOnPathActivity extends Activity {
30     private Path mPath;
31     private Path mStraightPath;
32 
33     @Override
onCreate(Bundle savedInstanceState)34     protected void onCreate(Bundle savedInstanceState) {
35         super.onCreate(savedInstanceState);
36 
37         mPath = makePath();
38         mStraightPath = makeStraightPath();
39 
40         final TextOnPathView view = new TextOnPathView(this);
41         setContentView(view);
42     }
43 
makePath()44     private static Path makePath() {
45         Path path = new Path();
46         buildPath(path);
47         return path;
48     }
49 
buildPath(Path path)50     private static void buildPath(Path path) {
51         path.moveTo(0.0f, 0.0f);
52         path.cubicTo(0.0f, 0.0f, 100.0f, 150.0f, 100.0f, 200.0f);
53         path.cubicTo(100.0f, 200.0f, 50.0f, 300.0f, -80.0f, 200.0f);
54         path.cubicTo(-80.0f, 200.0f, 100.0f, 200.0f, 200.0f, 0.0f);
55     }
56 
makeStraightPath()57     private static Path makeStraightPath() {
58         Path path = new Path();
59         buildStraightPath(path);
60         return path;
61     }
62 
buildStraightPath(Path path)63     private static void buildStraightPath(Path path) {
64         path.moveTo(0.0f, 0.0f);
65         path.lineTo(400.0f, 0.0f);
66     }
67 
68     public class TextOnPathView extends View {
69         private static final String TEST_STRING = "Hello OpenGL renderer, text on path! ";
70 
71         private final Paint mPaint;
72         private final Paint mPathPaint;
73         private final String mText;
74         private final PathMeasure mMeasure;
75         private final float mLength;
76         private final float[] mLines;
77         private final float[] mPos;
78         private final float[] mTan;
79 
TextOnPathView(Context c)80         public TextOnPathView(Context c) {
81             super(c);
82 
83             mPaint = new Paint();
84             mPaint.setAntiAlias(true);
85             mPaint.setColor(0xff000000);
86 
87             mPathPaint = new Paint();
88             mPathPaint.setAntiAlias(true);
89             mPathPaint.setStyle(Paint.Style.STROKE);
90             mPathPaint.setColor(0xff000099);
91 
92             StringBuilder builder = new StringBuilder(TEST_STRING.length() * 2);
93             for (int i = 0; i < 2; i++) {
94                 builder.append(TEST_STRING);
95             }
96             mText = builder.toString();
97 
98             mMeasure = new PathMeasure(mPath, false);
99             mLength = mMeasure.getLength();
100 
101             mLines = new float[100 * 4];
102             mPos = new float[2];
103             mTan = new float[2];
104         }
105 
106         @Override
onDraw(Canvas canvas)107         protected void onDraw(Canvas canvas) {
108             super.onDraw(canvas);
109 
110             canvas.drawARGB(255, 255, 255, 255);
111 
112             canvas.save();
113             canvas.translate(400.0f, 350.0f);
114             mPaint.setTextAlign(Paint.Align.LEFT);
115             canvas.drawTextOnPath(mText + mText, mPath, 0.0f, 0.0f, mPaint);
116             canvas.drawPath(mPath, mPathPaint);
117 
118             for (int i = 0; i < 100; i++) {
119                 mMeasure.getPosTan(i * mLength / 100.0f, mPos, mTan);
120                 mLines[i * 4    ] = mPos[0];
121                 mLines[i * 4 + 1] = mPos[1];
122                 mLines[i * 4 + 2] = mPos[0] + mTan[1] * 15;
123                 mLines[i * 4 + 3] = mPos[1] - mTan[0] * 15;
124             }
125             canvas.drawLines(mLines, mPathPaint);
126 
127             canvas.translate(200.0f, 0.0f);
128             canvas.drawTextOnPath(mText + mText, mStraightPath, 0.0f, 0.0f, mPaint);
129             canvas.drawPath(mStraightPath, mPathPaint);
130 
131             canvas.restore();
132 
133             canvas.save();
134             canvas.translate(150.0f, 60.0f);
135             canvas.drawTextOnPath(mText, mPath, 0.0f, 10.0f, mPaint);
136             mMeasure.getPosTan(5.0f, mPos, mTan);
137             canvas.drawLine(mPos[0], mPos[1], mPos[0] + mTan[1] * 10, mPos[1] - mTan[0] * 10,
138                     mPathPaint);
139             canvas.drawPath(mPath, mPathPaint);
140 
141             canvas.translate(250.0f, 0.0f);
142             mPaint.setTextAlign(Paint.Align.CENTER);
143             canvas.drawTextOnPath(mText, mPath, 0.0f, 0.0f, mPaint);
144             canvas.drawPath(mPath, mPathPaint);
145 
146             canvas.translate(250.0f, 0.0f);
147             mPaint.setTextAlign(Paint.Align.RIGHT);
148             canvas.drawTextOnPath(mText, mPath, 0.0f, 0.0f, mPaint);
149             canvas.drawPath(mPath, mPathPaint);
150             canvas.restore();
151         }
152     }
153 }
154