AndroidMultiParagraphDraw.kt
/*
* Copyright 2022 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.graphics.Matrix
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Brush
import androidx.compose.ui.graphics.Canvas
import androidx.compose.ui.graphics.ShaderBrush
import androidx.compose.ui.graphics.Shadow
import androidx.compose.ui.graphics.SolidColor
import androidx.compose.ui.text.ExperimentalTextApi
import androidx.compose.ui.text.MultiParagraph
import androidx.compose.ui.text.style.TextDecoration
import androidx.compose.ui.util.fastForEach
@OptIn(ExperimentalTextApi::class)
internal actual fun MultiParagraph.drawMultiParagraph(
canvas: Canvas,
brush: Brush,
alpha: Float,
shadow: Shadow?,
decoration: TextDecoration?
) {
canvas.save()
if (paragraphInfoList.size <= 1) {
drawParagraphs(canvas, brush, alpha, shadow, decoration)
} else {
when (brush) {
is SolidColor -> drawParagraphs(canvas, brush, alpha, shadow, decoration)
is ShaderBrush -> {
var height = 0f
var width = 0f
paragraphInfoList.fastForEach {
height += it.paragraph.height
width = maxOf(width, it.paragraph.width)
}
val shader = brush.createShader(Size(width, height))
val matrix = Matrix()
shader.getLocalMatrix(matrix)
paragraphInfoList.fastForEach {
it.paragraph.paint(canvas, ShaderBrush(shader), alpha, shadow, decoration)
canvas.translate(0f, it.paragraph.height)
matrix.setTranslate(0f, -it.paragraph.height)
shader.setLocalMatrix(matrix)
}
}
}
}
canvas.restore()
}
@OptIn(ExperimentalTextApi::class)
private fun MultiParagraph.drawParagraphs(
canvas: Canvas,
brush: Brush,
alpha: Float,
shadow: Shadow?,
decoration: TextDecoration?
) {
paragraphInfoList.fastForEach {
it.paragraph.paint(canvas, brush, alpha, shadow, decoration)
canvas.translate(0f, it.paragraph.height)
}
}