1 /* 2 * Copyright (C) 2007 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.*; 23 24 public class TextAlign extends GraphicsActivity { 25 26 @Override onCreate(Bundle savedInstanceState)27 protected void onCreate(Bundle savedInstanceState) { 28 super.onCreate(savedInstanceState); 29 setContentView(new SampleView(this)); 30 } 31 32 private static class SampleView extends View { 33 private Paint mPaint; 34 private float mX; 35 private float[] mPos; 36 37 private Path mPath; 38 private Paint mPathPaint; 39 40 private static final int DY = 30; 41 private static final String TEXT_L = "Left"; 42 private static final String TEXT_C = "Center"; 43 private static final String TEXT_R = "Right"; 44 private static final String POSTEXT = "Positioned"; 45 private static final String TEXTONPATH = "Along a path"; 46 makePath(Path p)47 private static void makePath(Path p) { 48 p.moveTo(10, 0); 49 p.cubicTo(100, -50, 200, 50, 300, 0); 50 } 51 buildTextPositions(String text, float y, Paint paint)52 private float[] buildTextPositions(String text, float y, Paint paint) { 53 float[] widths = new float[text.length()]; 54 // initially get the widths for each char 55 int n = paint.getTextWidths(text, widths); 56 // now popuplate the array, interleaving spaces for the Y values 57 float[] pos = new float[n * 2]; 58 float accumulatedX = 0; 59 for (int i = 0; i < n; i++) { 60 pos[i*2 + 0] = accumulatedX; 61 pos[i*2 + 1] = y; 62 accumulatedX += widths[i]; 63 } 64 return pos; 65 } 66 SampleView(Context context)67 public SampleView(Context context) { 68 super(context); 69 setFocusable(true); 70 71 mPaint = new Paint(); 72 mPaint.setAntiAlias(true); 73 mPaint.setTextSize(30); 74 mPaint.setTypeface(Typeface.SERIF); 75 76 mPos = buildTextPositions(POSTEXT, 0, mPaint); 77 78 mPath = new Path(); 79 makePath(mPath); 80 81 mPathPaint = new Paint(); 82 mPathPaint.setAntiAlias(true); 83 mPathPaint.setColor(0x800000FF); 84 mPathPaint.setStyle(Paint.Style.STROKE); 85 } 86 onDraw(Canvas canvas)87 @Override protected void onDraw(Canvas canvas) { 88 canvas.drawColor(Color.WHITE); 89 90 Paint p = mPaint; 91 float x = mX; 92 float y = 0; 93 float[] pos = mPos; 94 95 // draw the normal strings 96 97 p.setColor(0x80FF0000); 98 canvas.drawLine(x, y, x, y+DY*3, p); 99 p.setColor(Color.BLACK); 100 101 canvas.translate(0, DY); 102 p.setTextAlign(Paint.Align.LEFT); 103 canvas.drawText(TEXT_L, x, y, p); 104 105 canvas.translate(0, DY); 106 p.setTextAlign(Paint.Align.CENTER); 107 canvas.drawText(TEXT_C, x, y, p); 108 109 canvas.translate(0, DY); 110 p.setTextAlign(Paint.Align.RIGHT); 111 canvas.drawText(TEXT_R, x, y, p); 112 113 canvas.translate(100, DY*2); 114 115 // now draw the positioned strings 116 117 p.setColor(0xBB00FF00); 118 for (int i = 0; i < pos.length/2; i++) { 119 canvas.drawLine(pos[i*2+0], pos[i*2+1]-DY, 120 pos[i*2+0], pos[i*2+1]+DY*2, p); 121 } 122 p.setColor(Color.BLACK); 123 124 p.setTextAlign(Paint.Align.LEFT); 125 canvas.drawPosText(POSTEXT, pos, p); 126 127 canvas.translate(0, DY); 128 p.setTextAlign(Paint.Align.CENTER); 129 canvas.drawPosText(POSTEXT, pos, p); 130 131 canvas.translate(0, DY); 132 p.setTextAlign(Paint.Align.RIGHT); 133 canvas.drawPosText(POSTEXT, pos, p); 134 135 // now draw the text on path 136 137 canvas.translate(-100, DY*2); 138 139 canvas.drawPath(mPath, mPathPaint); 140 p.setTextAlign(Paint.Align.LEFT); 141 canvas.drawTextOnPath(TEXTONPATH, mPath, 0, 0, p); 142 143 canvas.translate(0, DY*1.5f); 144 canvas.drawPath(mPath, mPathPaint); 145 p.setTextAlign(Paint.Align.CENTER); 146 canvas.drawTextOnPath(TEXTONPATH, mPath, 0, 0, p); 147 148 canvas.translate(0, DY*1.5f); 149 canvas.drawPath(mPath, mPathPaint); 150 p.setTextAlign(Paint.Align.RIGHT); 151 canvas.drawTextOnPath(TEXTONPATH, mPath, 0, 0, p); 152 } 153 154 @Override onSizeChanged(int w, int h, int ow, int oh)155 protected void onSizeChanged(int w, int h, int ow, int oh) { 156 super.onSizeChanged(w, h, ow, oh); 157 mX = w * 0.5f; // remember the center of the screen 158 } 159 } 160 } 161 162