| /* |
| * Copyright 2019 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.foundation.layout |
| |
| import androidx.compose.Immutable |
| import androidx.compose.Stable |
| import androidx.compose.ui.unit.Constraints |
| import androidx.compose.ui.unit.LayoutDirection |
| import androidx.ui.core.Modifier |
| import androidx.ui.core.LayoutModifier |
| import androidx.ui.core.Measurable |
| import androidx.ui.core.MeasureScope |
| import androidx.compose.ui.unit.constrainHeight |
| import androidx.compose.ui.unit.constrainWidth |
| import androidx.compose.ui.unit.offset |
| import androidx.compose.ui.unit.Dp |
| import androidx.compose.ui.unit.dp |
| |
| /** |
| * Apply additional space along each edge of the content in [Dp]: [start], [top], [end] and |
| * [bottom]. The start and end edges will be determined by the current [LayoutDirection]. |
| * Padding is applied before content measurement and takes precedence; content may only be as large |
| * as the remaining space. |
| * |
| * Negative padding is not permitted. See [offset]. |
| * |
| * Example usage: |
| * @sample androidx.compose.foundation.layout.samples.PaddingModifier |
| */ |
| @Stable |
| fun Modifier.padding( |
| start: Dp = 0.dp, |
| top: Dp = 0.dp, |
| end: Dp = 0.dp, |
| bottom: Dp = 0.dp |
| ) = this + PaddingModifier( |
| start = start, |
| top = top, |
| end = end, |
| bottom = bottom, |
| rtlAware = true |
| ) |
| |
| /** |
| * Apply [horizontal] dp space along the left and right edges of the content, and [vertical] dp |
| * space along the top and bottom edges. |
| * Padding is applied before content measurement and takes precedence; content may only be as large |
| * as the remaining space. |
| * |
| * Negative padding is not permitted. See [offset]. |
| * |
| * Example usage: |
| * @sample androidx.compose.foundation.layout.samples.SymmetricPaddingModifier |
| */ |
| @Stable |
| fun Modifier.padding( |
| horizontal: Dp = 0.dp, |
| vertical: Dp = 0.dp |
| ) = this + PaddingModifier( |
| start = horizontal, |
| top = vertical, |
| end = horizontal, |
| bottom = vertical, |
| rtlAware = true |
| ) |
| |
| /** |
| * Apply [all] dp of additional space along each edge of the content, left, top, right and bottom. |
| * Padding is applied before content measurement and takes precedence; content may only be as large |
| * as the remaining space. |
| * |
| * Negative padding is not permitted. See [offset]. |
| * |
| * Example usage: |
| * @sample androidx.compose.foundation.layout.samples.PaddingAllModifier |
| */ |
| @Stable |
| fun Modifier.padding(all: Dp) = |
| this + PaddingModifier(start = all, top = all, end = all, bottom = all, rtlAware = true) |
| |
| /** |
| * Apply [InnerPadding] to the component as additional space along each edge of the content's left, |
| * top, right and bottom. Padding is applied before content measurement and takes precedence; |
| * content may only be as large as the remaining space. |
| * |
| * Negative padding is not permitted. See [offset]. |
| * |
| * Example usage: |
| * @sample androidx.compose.foundation.layout.samples.PaddingInnerPaddingModifier |
| */ |
| fun Modifier.padding(padding: InnerPadding) = |
| this + PaddingModifier( |
| start = padding.start, |
| top = padding.top, |
| end = padding.end, |
| bottom = padding.bottom, |
| rtlAware = true |
| ) |
| |
| /** |
| * Apply additional space along each edge of the content in [Dp]: [left], [top], [right] and |
| * [bottom]. These paddings are applied without regard to the current [LayoutDirection], see |
| * [padding] to apply relative paddings. Padding is applied before content measurement and takes |
| * precedence; content may only be as large as the remaining space. |
| * |
| * Negative padding is not permitted. See [offset]. |
| * |
| * Example usage: |
| * @sample androidx.compose.foundation.layout.samples.AbsolutePaddingModifier |
| */ |
| @Stable |
| fun Modifier.absolutePadding( |
| left: Dp = 0.dp, |
| top: Dp = 0.dp, |
| right: Dp = 0.dp, |
| bottom: Dp = 0.dp |
| ) = this + PaddingModifier( |
| start = left, |
| top = top, |
| end = right, |
| bottom = bottom, |
| rtlAware = false |
| ) |
| |
| private data class PaddingModifier( |
| val start: Dp = 0.dp, |
| val top: Dp = 0.dp, |
| val end: Dp = 0.dp, |
| val bottom: Dp = 0.dp, |
| val rtlAware: Boolean |
| ) : LayoutModifier { |
| init { |
| require(start.value >= 0f && top.value >= 0f && end.value >= 0f && bottom.value >= 0f) { |
| "Padding must be non-negative" |
| } |
| } |
| |
| override fun MeasureScope.measure( |
| measurable: Measurable, |
| constraints: Constraints, |
| layoutDirection: LayoutDirection |
| ): MeasureScope.MeasureResult { |
| val horizontal = start.toIntPx() + end.toIntPx() |
| val vertical = top.toIntPx() + bottom.toIntPx() |
| |
| val placeable = measurable.measure(constraints.offset(-horizontal, -vertical)) |
| |
| val width = constraints.constrainWidth(placeable.width + horizontal) |
| val height = constraints.constrainHeight(placeable.height + vertical) |
| return layout(width, height) { |
| if (rtlAware) { |
| placeable.place(start.toIntPx(), top.toIntPx()) |
| } else { |
| placeable.placeAbsolute(start.toIntPx(), top.toIntPx()) |
| } |
| } |
| } |
| } |
| |
| /** |
| * Describes a padding to be applied along the edges inside a box. |
| */ |
| @Immutable |
| data class InnerPadding( |
| @Stable |
| val start: Dp = 0.dp, |
| @Stable |
| val top: Dp = 0.dp, |
| @Stable |
| val end: Dp = 0.dp, |
| @Stable |
| val bottom: Dp = 0.dp |
| ) { |
| constructor(all: Dp) : this(all, all, all, all) |
| } |