1 package com.example.administrator.yunstore.widget;
2
3 import android.content.Context;
4 import android.graphics.Canvas;
5 import android.graphics.Color;
6 import android.graphics.Paint;
7 import android.graphics.Typeface;
8 import android.util.AttributeSet;
9 import android.view.MotionEvent;
10 import android.widget.Button;
11
12 /**
13 * Created by Administrator on 2016/10/19.
14 * 自定义的一个字母button
15 */
16
17 public class LetterButton extends Button {
18
19 // 分类字母
20 private String[] assort = { "A", "B", "C", "D", "E", "F", "G",
21 "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T",
22 "U", "V", "W", "X", "Y", "Z" };
23
24 private Paint paint = new Paint();
25
26 private int selectIndex = -1;
27
28 public LetterButton(Context context) {
29 super(context);
30 }
31
32 public LetterButton(Context context, AttributeSet attrs) {
33 super(context, attrs);
34 }
35
36 public LetterButton(Context context, AttributeSet attrs, int defStyleAttr) {
37 super(context, attrs, defStyleAttr);
38 }
39
40 /**
41 * @param canvas
42 * 对按钮进行绘制
43 */
44 @Override
45 protected void onDraw(Canvas canvas) {
46 super.onDraw(canvas);
47
48 int height=getHeight();
49 int width=getWidth();
50 int interval = height / assort.length;
51
52 for (int i = 0, length = assort.length; i < length; i++) {
53 // 抗锯齿
54 paint.setAntiAlias(true);
55 // 默认粗体
56 paint.setTypeface(Typeface.DEFAULT_BOLD);
57 // 白色
58 paint.setColor(Color.BLUE);
59 if (i == selectIndex) {
60 // 被选择的字母改变颜色和粗体
61 paint.setColor(Color.parseColor("#33bb99"));
62 paint.setFakeBoldText(true);
63 paint.setTextSize(30);
64 }
65 // 计算字母的X坐标
66 float xPos = width / 2 - paint.measureText(assort[i]) / 2;
67 // 计算字母的Y坐标
68 float yPos = interval * i + interval;
69 canvas.drawText(assort[i], xPos, yPos, paint);
70 paint.reset();
71 }
72 }
73
74 @Override
75 public boolean dispatchTouchEvent(MotionEvent event) {
76 float y = event.getY();
77 int index = (int) (y / getHeight() * assort.length);
78 if (index >= 0 && index < assort.length) {
79
80 switch (event.getAction()) {
81 case MotionEvent.ACTION_MOVE:
82 // 如果滑动改变
83 if (selectIndex != index) {
84 selectIndex = index;
85 if (onTouch != null) {
86 onTouch.onTouchAssortListener(assort[selectIndex]);
87 }
88
89 }
90 break;
91 case MotionEvent.ACTION_DOWN:
92 selectIndex = index;
93 if (onTouch != null) {
94 onTouch.onTouchAssortListener(assort[selectIndex]);
95 }
96
97 break;
98 case MotionEvent.ACTION_UP:
99 if (onTouch != null) {
100 onTouch.onTouchAssortUP();
101 }
102 selectIndex = -1;
103 break;
104 }
105 } else {
106 selectIndex = -1;
107 if (onTouch != null) {
108 onTouch.onTouchAssortUP();
109 }
110 }
111 invalidate();
112
113 return true;
114 }
115
116 @Override
117 public boolean onTouchEvent(MotionEvent event) {
118 return super.onTouchEvent(event);
119 }
120 //字母监听器
121 private OnTouchAssortListener onTouch;
122
123 public interface OnTouchAssortListener {
124 void onTouchAssortListener(String s);
125 void onTouchAssortUP();
126 }
127
128
129 public void setOnTouchAssortListener(OnTouchAssortListener onTouch) {
130 this.onTouch = onTouch;
131 }
132 }
