AndroidTextPaint.android.kt

/*
 * Copyright 2020 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package androidx.compose.ui.text.platform

import android.text.TextPaint
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.geometry.isSpecified
import androidx.compose.ui.graphics.Brush
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.ShaderBrush
import androidx.compose.ui.graphics.Shadow
import androidx.compose.ui.graphics.SolidColor
import androidx.compose.ui.graphics.isSpecified
import androidx.compose.ui.graphics.toArgb
import androidx.compose.ui.text.style.TextDecoration

internal class AndroidTextPaint(flags: Int, density: Float) : TextPaint(flags) {
    init {
        this.density = density
    }
    private var textDecoration: TextDecoration = TextDecoration.None
    private var shadow: Shadow = Shadow.None
    private var brush: Brush? = null
    private var brushSize: Size? = null

    fun setTextDecoration(textDecoration: TextDecoration?) {
        val tmpTextDecoration = textDecoration ?: TextDecoration.None
        if (this.textDecoration != tmpTextDecoration) {
            this.textDecoration = tmpTextDecoration
            isUnderlineText = TextDecoration.Underline in this.textDecoration
            isStrikeThruText = TextDecoration.LineThrough in this.textDecoration
        }
    }

    fun setShadow(shadow: Shadow?) {
        val tmpShadow = shadow ?: Shadow.None
        if (this.shadow != tmpShadow) {
            this.shadow = tmpShadow
            if (this.shadow == Shadow.None) {
                clearShadowLayer()
            } else {
                setShadowLayer(
                    this.shadow.blurRadius,
                    this.shadow.offset.x,
                    this.shadow.offset.y,
                    this.shadow.color.toArgb()
                )
            }
        }
    }

    fun setColor(color: Color) {
        if (color.isSpecified) {
            val argbColor = color.toArgb()
            if (this.color != argbColor) {
                this.color = argbColor
            }
        }
    }

    fun setBrush(brush: Brush?, size: Size) {
        if (brush == null) {
            this.shader = null
            return
        }
        if (this.brush != brush || this.brushSize != size) {
            this.brush = brush
            this.brushSize = size
            when (brush) {
                is SolidColor -> {
                    this.shader = null
                    setColor(brush.value)
                }
                is ShaderBrush -> {
                    if (size.isSpecified) {
                        shader = brush.createShader(size)
                    }
                }
            }
        }
    }
}