react-native-enriched-html/android/src/main/java/com/swmansion/enriched/MeasurementStore.kt at 28148678251c22ed30cb04a2cab59dcd32a7e3ff · software-mansion/react-native-enriched-html · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
package com.swmansion.enriched

import android.content.Context
import android.graphics.Typeface
import android.graphics.text.LineBreaker
import android.os.Build
import android.text.Spannable
import android.text.StaticLayout
import android.text.TextPaint
import android.util.Log
import com.facebook.react.bridge.ReadableMap
import com.facebook.react.uimanager.PixelUtil
import com.facebook.react.views.text.ReactTypefaceUtils.applyStyles
import com.facebook.react.views.text.ReactTypefaceUtils.parseFontStyle
import com.facebook.react.views.text.ReactTypefaceUtils.parseFontWeight
import com.facebook.yoga.YogaMeasureOutput
import com.swmansion.enriched.styles.HtmlStyle
import com.swmansion.enriched.utils.EnrichedParser
import java.util.concurrent.ConcurrentHashMap
import kotlin.math.ceil

object MeasurementStore {
  data class PaintParams(
    val typeface: Typeface,
    val fontSize: Float,
  )

  data class MeasurementParams(
    val initialized: Boolean,

    val cachedWidth: Float,
    val cachedSize: Long,

    val spannable: CharSequence?,
    val paintParams: PaintParams,
  )

  private val data = ConcurrentHashMap<Int, MeasurementParams>()

  fun store(id: Int, spannable: Spannable?, paint: TextPaint): Boolean {
    val cachedWidth = data[id]?.cachedWidth ?: 0f
    val cachedSize = data[id]?.cachedSize ?: 0L
    val initialized = data[id]?.initialized ?: true

    val size = measure(cachedWidth, spannable, paint)
    val paintParams = PaintParams(paint.typeface, paint.textSize)

    data[id] = MeasurementParams(initialized, cachedWidth, size, spannable, paintParams)
    return cachedSize != size
  }

  fun release(id: Int) {
    data.remove(id)
  }

  private fun measure(maxWidth: Float, spannable: CharSequence?, paintParams: PaintParams): Long {
    val paint = TextPaint().apply {
      typeface = paintParams.typeface
      textSize = paintParams.fontSize
    }

    return measure(maxWidth, spannable, paint)
  }

  private fun measure(maxWidth: Float, spannable: CharSequence?, paint: TextPaint): Long {
    val text = spannable ?: ""
    val textLength = text.length
    val builder = StaticLayout.Builder
      .obtain(text, 0, textLength, paint, maxWidth.toInt())
      .setIncludePad(true)
      .setLineSpacing(0f, 1f)

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
      builder.setBreakStrategy(LineBreaker.BREAK_STRATEGY_HIGH_QUALITY)
    }

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
      builder.setUseLineSpacingFromFallbacks(true)
    }

    val staticLayout = builder.build()
    val heightInSP = PixelUtil.toDIPFromPixel(staticLayout.height.toFloat())
    val widthInSP = PixelUtil.toDIPFromPixel(maxWidth)
    return YogaMeasureOutput.make(widthInSP, heightInSP)
  }

  // Returns either: Spannable parsed from HTML defaultValue, or plain text defaultValue, or "I" if no defaultValue
  private fun getInitialText(defaultView: EnrichedTextInputView, props: ReadableMap?): CharSequence {
    val defaultValue = props?.getString("defaultValue")

    // If there is no default value, assume text is one line, "I" is a good approximation of height
    if (defaultValue == null) return "I"

    val isHtml = defaultValue.startsWith("<html>") && defaultValue.endsWith("</html>")
    if (!isHtml) return defaultValue

    try {
      val htmlStyle = HtmlStyle(defaultView, props.getMap("htmlStyle"))
      val parsed = EnrichedParser.fromHtml(defaultValue, htmlStyle, null)
      return parsed.trimEnd('\n')
    } catch (e: Exception) {
      Log.w("MeasurementStore", "Error parsing initial HTML text: ${e.message}")
      return defaultValue
    }
  }

  private fun getInitialFontSize(defaultView: EnrichedTextInputView, props: ReadableMap?): Float {
    val propsFontSize = props?.getDouble("fontSize")?.toFloat()
    if (propsFontSize == null) return defaultView.textSize

    return ceil(PixelUtil.toPixelFromSP(propsFontSize))
  }

  // Called when view measurements are not available in the store
  // Most likely first measurement, we can use defaultValue, as no native state is set yet
  private fun initialMeasure(context: Context, id: Int?, width: Float, props: ReadableMap?): Long {
    val defaultView = EnrichedTextInputView(context)

    val text = getInitialText(defaultView, props)
    val fontSize = getInitialFontSize(defaultView, props)

    val fontFamily = props?.getString("fontFamily")
    val fontStyle = parseFontStyle(props?.getString("fontStyle"))
    val fontWeight = parseFontWeight(props?.getString("fontWeight"))

    val typeface = applyStyles(defaultView.typeface, fontStyle, fontWeight, fontFamily, context.assets)
    val paintParams = PaintParams(typeface, fontSize)
    val size = measure(width, text, PaintParams(typeface, fontSize))

    if (id != null) {
      data[id] = MeasurementParams(true, width, size, text, paintParams)
    }

    return size
  }

  fun getMeasureById(context: Context, id: Int?, width: Float, props: ReadableMap?): Long {
    val id = id ?: return initialMeasure(context, id, width, props)
    val value = data[id] ?: return initialMeasure(context, id, width, props)

    // First measure has to be done using initialMeasure
    // That way it's free of any side effects and async initializations
    if (!value.initialized) return initialMeasure(context, id, width, props)

    if (width == value.cachedWidth) {
      return value.cachedSize
    }

    val paint = TextPaint().apply {
      typeface = value.paintParams.typeface
      textSize = value.paintParams.fontSize
    }

    val size = measure(width, value.spannable, paint)
    data[id] = MeasurementParams(true, width, size, value.spannable, value.paintParams)
    return size
  }
}