1+ package org.ninetripods.mq.study.span
2+
3+ import android.graphics.Canvas
4+ import android.graphics.Color
5+ import android.graphics.Paint
6+ import android.graphics.RectF
7+ import android.text.style.ReplacementSpan
8+ import org.ninetripods.mq.study.kotlin.ktx.dp2px
9+ import org.ninetripods.mq.study.kotlin.ktx.log
10+ import org.ninetripods.mq.study.kotlin.ktx.sp2px
11+
12+ /* *
13+ * 自定义Tag Span
14+ * Created by mq on 2023/7/31
15+ *
16+ * @property tagColor tag外框颜色
17+ * @property tagRadius tag圆角半径
18+ * @property tagStrokeWidth tag外框宽度
19+ * @property tagMarginLeft tag外框左侧的margin
20+ * @property tagMarginRight tag外框右侧的margin
21+ * @property tagPadding tag内侧文字padding
22+ * @property txtSize 文字大小
23+ * @property txtColor 文字颜色
24+ */
25+ class TagSpan (
26+ private val tagColor : Int = Color .RED ,
27+ private val tagRadius : Float = 2 .dp2px().toFloat(),
28+ private val tagStrokeWidth : Float = 1 .dp2px().toFloat(),
29+ private val tagMarginLeft : Float = 0 .dp2px().toFloat(),
30+ private val tagMarginRight : Float = 5 .dp2px().toFloat(),
31+ private val tagPadding : Float = 2 .dp2px().toFloat(),
32+ private val txtSize : Float = 14 .sp2px().toFloat(),
33+ private val txtColor : Int = Color .RED ,
34+ ) : ReplacementSpan() {
35+
36+ private var mSpanWidth = 0 // 包含了Span文字左右间距在内的宽度
37+
38+ /* *
39+ * 返回Span的宽度。子类可以通过更新Paint.FontMetricsInt的属性来设置Span的高度。
40+ * 如果Span覆盖了整个文本，并且高度没有设置，那么draw(Canvas, CharSequence, int, int, float, int, int, int, Paint)方法将不会调用。
41+ *
42+ * @param paint Paint画笔
43+ * @param text 当前文本
44+ * @param start Span开始索引
45+ * @param end Span结束索引
46+ * @param fm Paint.FontMetricsInt，可能是空
47+ * @return 返回Span的宽度
48+ */
49+ override fun getSize (
50+ paint : Paint ,
51+ text : CharSequence? ,
52+ start : Int ,
53+ end : Int ,
54+ fm : Paint .FontMetricsInt ? ,
55+ ): Int {
56+ if (text.isNullOrEmpty()) return 0
57+ paint.textSize = txtSize
58+ // 测量包含了Span文字左右间距在内的宽度
59+ mSpanWidth = (paint.measureText(text, start, end) + getTxtLeftW() + getTxtRightW()).toInt()
60+ log(" getSize-> text:$text ,start:$start ,end：$end ,fm:$fm ,mSpanWidth:$mSpanWidth "
61+ return mSpanWidth
62+ }
63+
64+ /* *
65+ * 将Span绘制到Canvas中
66+ *
67+ * @param canvas Canvas画布
68+ * @param text 当前文本
69+ * @param start Span开始索引
70+ * @param end Span结束索引
71+ * @param x Edge of the replacement closest to the leading margin.
72+ * @param top 行文字显示区域的Top
73+ * @param y Baseline基线
74+ * @param bottom 行文字显示区域的Bottom 当在XML中设置lineSpacingExtra时，这里也会受影响
75+ * @param paint Paint画笔
76+ */
77+ override fun draw (
78+ canvas : Canvas ,
79+ text : CharSequence? ,
80+ start : Int ,
81+ end : Int ,
82+ x : Float ,
83+ top : Int ,
84+ y : Int ,
85+ bottom : Int ,
86+ paint : Paint ,
87+ ) {
88+ log(" draw -> text:$text ,start:$start ,end:$end ,x:$x ,top:$top ,y:$y ,bottom:$bottom "
89+ if (text.isNullOrEmpty()) return
90+ paint.run {
91+ color = tagColor
92+ isAntiAlias = true
93+ isDither = true
94+ style = Paint .Style .STROKE
95+ strokeWidth = tagStrokeWidth
96+ }
97+ // 文字高度
98+ val txtHeight = paint.fontMetricsInt.descent - paint.fontMetricsInt.ascent
99+ // 1、绘制标签
100+ val tagRect = RectF (
101+ x + getTagLeft(), top.toFloat(),
102+ x + mSpanWidth - tagMarginRight, (top + txtHeight).toFloat()
103+ )
104+ canvas.drawRoundRect(tagRect, tagRadius, tagRadius, paint)
105+
106+ // 2、绘制文字
107+ paint.run {
108+ color = txtColor
109+ style = Paint .Style .FILL
110+ }
111+ // 计算Baseline绘制的Y坐标 ，计算方式：画布高度的一半 - 文字总高度的一半
112+ val baseY = tagRect.height() / 2 - (paint.descent() + paint.ascent()) / 2
113+ // 绘制标签内文字
114+ canvas.drawText(text, start, end, x + getTxtLeftW(), baseY, paint)
115+ }
116+
117+ private fun getTagLeft (): Float {
118+ return tagMarginLeft + tagStrokeWidth
119+ }
120+
121+ /* *
122+ * Span文字左侧所有的间距
123+ */
124+ private fun getTxtLeftW (): Float {
125+ return tagPadding + tagMarginLeft + tagStrokeWidth
126+ }
127+
128+ /* *
129+ * Span文字右侧所有的间距
130+ */
131+ private fun getTxtRightW (): Float {
132+ return tagPadding + tagMarginRight + tagStrokeWidth
133+ }
134+ }
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