LayoutInfo.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.layout
import androidx.compose.ui.Modifier
import androidx.compose.ui.platform.ViewConfiguration
import androidx.compose.ui.unit.Density
import androidx.compose.ui.unit.LayoutDirection
/**
* The public information about the layouts used internally as nodes in the Compose UI hierarchy.
*/
interface LayoutInfo {
/**
* This returns a new List of [Modifier]s and the coordinates and any extra information
* that may be useful. This is used for tooling to retrieve layout modifier and layer
* information.
*/
fun getModifierInfo(): List<ModifierInfo>
/**
* The measured width of this layout and all of its modifiers.
*/
val width: Int
/**
* The measured height of this layout and all of its modifiers.
*/
val height: Int
/**
* Coordinates of just the contents of the layout, after being affected by all modifiers.
*/
val coordinates: LayoutCoordinates
/**
* Whether or not this layout and all of its parents have been placed in the hierarchy.
*/
val isPlaced: Boolean
/**
* Parent of this layout.
*/
val parentInfo: LayoutInfo?
/**
* The density in use for this layout.
*/
val density: Density
/**
* The layout direction in use for this layout.
*/
val layoutDirection: LayoutDirection
/**
* The [ViewConfiguration] in use for this layout.
*/
val viewConfiguration: ViewConfiguration
/**
* Returns true if this layout is currently a part of the layout tree.
*/
val isAttached: Boolean
}
/**
* Used by tooling to examine the modifiers on a [LayoutInfo].
*/
class ModifierInfo(
val modifier: Modifier,
val coordinates: LayoutCoordinates,
val extra: Any? = null
)