| /* |
| * 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.ui.core |
| |
| import androidx.ui.graphics.Canvas |
| import androidx.ui.graphics.Color |
| import androidx.ui.graphics.Paint |
| import androidx.ui.graphics.PaintingStyle |
| |
| @OptIn(ExperimentalLayoutNodeApi::class) |
| internal class ModifiedLayoutNode( |
| wrapped: LayoutNodeWrapper, |
| modifier: LayoutModifier |
| ) : DelegatingLayoutNodeWrapper<LayoutModifier>(wrapped, modifier) { |
| |
| override val measureScope = ModifierMeasureScope() |
| |
| override fun performMeasure( |
| constraints: Constraints, |
| layoutDirection: LayoutDirection |
| ): Placeable = with(modifier) { |
| measureScope.layoutDirection = layoutDirection |
| measureResult = measureScope.measure(wrapped, constraints, layoutDirection) |
| this@ModifiedLayoutNode |
| } |
| |
| override fun minIntrinsicWidth(height: Int, layoutDirection: LayoutDirection): Int = |
| with(modifier) { |
| measureScope.layoutDirection = layoutDirection |
| measureScope.minIntrinsicWidth(wrapped, height, layoutDirection) |
| } |
| |
| override fun maxIntrinsicWidth(height: Int, layoutDirection: LayoutDirection): Int = |
| with(modifier) { |
| measureScope.layoutDirection = layoutDirection |
| measureScope.maxIntrinsicWidth(wrapped, height, layoutDirection) |
| } |
| |
| override fun minIntrinsicHeight(width: Int, layoutDirection: LayoutDirection): Int = |
| with(modifier) { |
| measureScope.layoutDirection = layoutDirection |
| measureScope.minIntrinsicHeight(wrapped, width, layoutDirection) |
| } |
| |
| override fun maxIntrinsicHeight(width: Int, layoutDirection: LayoutDirection): Int = |
| with(modifier) { |
| measureScope.layoutDirection = layoutDirection |
| measureScope.maxIntrinsicHeight(wrapped, width, layoutDirection) |
| } |
| |
| override operator fun get(line: AlignmentLine): Int { |
| if (measureResult.alignmentLines.containsKey(line)) { |
| return measureResult.alignmentLines[line] ?: AlignmentLine.Unspecified |
| } |
| val positionInWrapped = wrapped[line] |
| if (positionInWrapped == AlignmentLine.Unspecified) { |
| return AlignmentLine.Unspecified |
| } |
| // Place our wrapped to obtain their position inside ourselves. |
| isShallowPlacing = true |
| place(this.position) |
| isShallowPlacing = false |
| return if (line is HorizontalAlignmentLine) { |
| positionInWrapped + wrapped.position.y |
| } else { |
| positionInWrapped + wrapped.position.x |
| } |
| } |
| |
| override fun draw(canvas: Canvas) { |
| withPositionTranslation(canvas) { |
| wrapped.draw(canvas) |
| if (layoutNode.requireOwner().showLayoutBounds) { |
| drawBorder(canvas, modifierBoundsPaint) |
| } |
| } |
| } |
| |
| internal companion object { |
| val modifierBoundsPaint = Paint().also { paint -> |
| paint.color = Color.Blue |
| paint.strokeWidth = 1f |
| paint.style = PaintingStyle.stroke |
| } |
| } |
| |
| inner class ModifierMeasureScope : MeasureScope() { |
| override var layoutDirection: LayoutDirection = LayoutDirection.Ltr |
| override val density: Float |
| get() = layoutNode.measureScope.density |
| override val fontScale: Float |
| get() = layoutNode.measureScope.fontScale |
| } |
| } |