JAVA高级面试进阶训练营视频教程

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 1 package com.sixin.view;
 2 
 3 import android.content.Context;
 4 import android.graphics.Canvas;
 5 import android.text.Layout;
 6 import android.text.StaticLayout;
 7 import android.text.TextPaint;
 8 import android.util.AttributeSet;
 9 import android.widget.TextView;
10 
11 /**
12  * 能够自动修正的textview，解决android自带textview右侧文字不能对齐的问题
13  */
14 public class JustifyTextView extends TextView {
15 
16     private int mLineY;
17     private int mViewWidth;
18 
19     public JustifyTextView(Context context, AttributeSet attrs) {
20         super(context, attrs);
21     }
22 
23     @Override
24     protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
25         super.onLayout(changed, left, top, right, bottom);
26     }
27 
28     @Override
29     protected void onDraw(Canvas canvas) {
30         TextPaint paint = getPaint();
31         paint.setColor(getCurrentTextColor());
32         paint.drawableState = getDrawableState();
33         mViewWidth = getMeasuredWidth();
34         String text = (String) getText();
35         mLineY = 0;
36         mLineY += getTextSize();
37         Layout layout = getLayout();
38         for (int i = 0; i < layout.getLineCount(); i++) {
39             int lineStart = layout.getLineStart(i);
40             int lineEnd = layout.getLineEnd(i);
41             String line = text.substring(lineStart, lineEnd);
42 
43             float width = StaticLayout.getDesiredWidth(text, lineStart, lineEnd, getPaint());
44             if (needScale(line)) {
45                 drawScaledText(canvas, lineStart, line, width);
46             } else {
47                 canvas.drawText(line, 0, mLineY, paint);
48             }
49 
50             mLineY += getLineHeight();
51         }
52     }
53 
54     private void drawScaledText(Canvas canvas, int lineStart, String line, float lineWidth) {
55         float x = 0;
56         if (isFirstLineOfParagraph(lineStart, line)) {
57             String blanks = "  ";
58             canvas.drawText(blanks, x, mLineY, getPaint());
59             float bw = StaticLayout.getDesiredWidth(blanks, getPaint());
60             x += bw;
61 
62             line = line.substring(3);
63         }
64 
65         float d = (mViewWidth - lineWidth) / line.length() - 1;
66         for (int i = 0; i < line.length(); i++) {
67             String c = String.valueOf(line.charAt(i));
68             float cw = StaticLayout.getDesiredWidth(c, getPaint());
69             canvas.drawText(c, x, mLineY, getPaint());
70             x += cw + d;
71         }
72     }
73 
74     private boolean isFirstLineOfParagraph(int lineStart, String line) {
75         return line.length() > 3 && line.charAt(0) == ' ' && line.charAt(1) == ' ';
76     }
77 
78     private boolean needScale(String line) {
79         if (line.length() == 0) {
80             return false;
81         } else {
82             return line.charAt(line.length() - 1) != '\n';
83         }
84     }
85 
86 }