/*
* 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.
*/
@file:Suppress("NOTHING_TO_INLINE")
package androidx.compose.ui.node
import androidx.compose.ui.focus.FocusOrder
import androidx.compose.ui.focus.FocusState
import androidx.compose.ui.geometry.MutableRect
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Rect
import androidx.compose.ui.geometry.toRect
import androidx.compose.ui.graphics.Canvas
import androidx.compose.ui.graphics.GraphicsLayerScope
import androidx.compose.ui.graphics.Matrix
import androidx.compose.ui.graphics.Paint
import androidx.compose.ui.graphics.ReusableGraphicsLayerScope
import androidx.compose.ui.input.nestedscroll.NestedScrollDelegatingWrapper
import androidx.compose.ui.input.pointer.PointerInputFilter
import androidx.compose.ui.layout.LayoutCoordinates
import androidx.compose.ui.layout.Measurable
import androidx.compose.ui.layout.MeasureResult
import androidx.compose.ui.layout.MeasureScope
import androidx.compose.ui.layout.Placeable
import androidx.compose.ui.layout.findRoot
import androidx.compose.ui.layout.positionInRoot
import androidx.compose.ui.unit.Constraints
import androidx.compose.ui.unit.IntOffset
import androidx.compose.ui.unit.IntSize
import androidx.compose.ui.unit.minus
import androidx.compose.ui.unit.plus
/**
* Measurable and Placeable type that has a position.
*/
internal abstract class LayoutNodeWrapper(
internal val layoutNode: LayoutNode
) : Placeable(), Measurable, LayoutCoordinates, OwnerScope, (Canvas) -> Unit {
internal open val wrapped: LayoutNodeWrapper? get() = null
internal var wrappedBy: LayoutNodeWrapper? = null
/**
* The scope used to measure the wrapped. InnerPlaceables are using the MeasureScope
* of the LayoutNode. For fewer allocations, everything else is reusing the measure scope of
* their wrapped.
*/
abstract val measureScope: MeasureScope
// Size exposed to LayoutCoordinates.
final override val size: IntSize get() = measuredSize
private var isClipping: Boolean = false
protected var layerBlock: (GraphicsLayerScope.() -> Unit)? = null
private set
private var _isAttached = false
final override val isAttached: Boolean
get() {
if (_isAttached) {
require(layoutNode.isAttached)
}
return _isAttached
}
private var _measureResult: MeasureResult? = null
var measureResult: MeasureResult
get() = _measureResult ?: error(UnmeasuredError)
internal set(value) {
val old = _measureResult
if (value !== old) {
_measureResult = value
if (old == null || value.width != old.width || value.height != old.height) {
onMeasureResultChanged(value.width, value.height)
}
}
}
/**
* Called when the width or height of [measureResult] change. The object instance pointed to
* by [measureResult] may or may not have changed.
*/
protected open fun onMeasureResultChanged(width: Int, height: Int) {
val layer = layer
if (layer != null) {
layer.resize(IntSize(width, height))
} else {
wrappedBy?.invalidateLayer()
}
layoutNode.owner?.onLayoutChange(layoutNode)
measuredSize = IntSize(width, height)
}
var position: IntOffset = IntOffset.Zero
private set
var zIndex: Float = 0f
protected set
final override val parentLayoutCoordinates: LayoutCoordinates?
get() {
check(isAttached) { ExpectAttachedLayoutCoordinates }
return layoutNode.outerLayoutNodeWrapper.wrappedBy
}
final override val parentCoordinates: LayoutCoordinates?
get() {
check(isAttached) { ExpectAttachedLayoutCoordinates }
return wrappedBy?.getWrappedByCoordinates()
}
protected open fun getWrappedByCoordinates(): LayoutCoordinates? {
return wrappedBy?.getWrappedByCoordinates()
}
// True when the wrapper is running its own placing block to obtain the position of the
// wrapped, but is not interested in the position of the wrapped of the wrapped.
var isShallowPlacing = false
private var _rectCache: MutableRect? = null
private val rectCache: MutableRect
get() = _rectCache ?: MutableRect(0f, 0f, 0f, 0f).also {
_rectCache = it
}
private val snapshotObserver get() = layoutNode.requireOwner().snapshotObserver
// TODO (njawad): This cache matrix is not thread safe
private var _matrixCache: Matrix? = null
private val matrixCache: Matrix
get() = _matrixCache ?: Matrix().also { _matrixCache = it }
/**
* Whether a pointer that is relative to the [LayoutNodeWrapper] is in the bounds of this
* LayoutNodeWrapper.
*/
fun isPointerInBounds(pointerPosition: Offset): Boolean {
val x = pointerPosition.x
val y = pointerPosition.y
return x >= 0f && y >= 0f && x < measuredWidth && y < measuredHeight
}
protected inline fun performingMeasure(
constraints: Constraints,
block: () -> Placeable
): Placeable {
measurementConstraints = constraints
val result = block()
layer?.resize(measuredSize)
return result
}
/**
* Places the modified child.
*/
/*@CallSuper*/
override fun placeAt(
position: IntOffset,
zIndex: Float,
layerBlock: (GraphicsLayerScope.() -> Unit)?
) {
onLayerBlockUpdated(layerBlock)
if (this.position != position) {
this.position = position
val layer = layer
if (layer != null) {
layer.move(position)
} else {
wrappedBy?.invalidateLayer()
}
layoutNode.owner?.onLayoutChange(layoutNode)
}
this.zIndex = zIndex
}
/**
* Draws the content of the LayoutNode
*/
fun draw(canvas: Canvas) {
val layer = layer
if (layer != null) {
layer.drawLayer(canvas)
} else {
val x = position.x.toFloat()
val y = position.y.toFloat()
canvas.translate(x, y)
performDraw(canvas)
canvas.translate(-x, -y)
}
}
protected abstract fun performDraw(canvas: Canvas)
// implementation of draw block passed to the OwnedLayer
override fun invoke(canvas: Canvas) {
if (layoutNode.isPlaced) {
snapshotObserver.observeReads(this, onCommitAffectingLayer) {
performDraw(canvas)
}
lastLayerDrawingWasSkipped = false
} else {
// The invalidation is requested even for nodes which are not placed. As we are not
// going to display them we skip the drawing. It is safe to just draw nothing as the
// layer will be invalidated again when the node will be finally placed.
lastLayerDrawingWasSkipped = true
}
}
fun onLayerBlockUpdated(layerBlock: (GraphicsLayerScope.() -> Unit)?) {
val blockHasBeenChanged = this.layerBlock !== layerBlock
this.layerBlock = layerBlock
if (isAttached && layerBlock != null) {
if (layer == null) {
layer = layoutNode.requireOwner().createLayer(
this,
invalidateParentLayer
).apply {
resize(measuredSize)
move(position)
}
updateLayerParameters()
layoutNode.innerLayerWrapperIsDirty = true
invalidateParentLayer()
} else if (blockHasBeenChanged) {
updateLayerParameters()
}
} else {
layer?.let {
it.destroy()
layoutNode.innerLayerWrapperIsDirty = true
invalidateParentLayer()
}
layer = null
}
}
private fun updateLayerParameters() {
val layer = layer
if (layer != null) {
val layerBlock = requireNotNull(layerBlock)
graphicsLayerScope.reset()
graphicsLayerScope.graphicsDensity = layoutNode.density
snapshotObserver.observeReads(this, onCommitAffectingLayerParams) {
layerBlock.invoke(graphicsLayerScope)
}
layer.updateLayerProperties(
scaleX = graphicsLayerScope.scaleX,
scaleY = graphicsLayerScope.scaleY,
alpha = graphicsLayerScope.alpha,
translationX = graphicsLayerScope.translationX,
translationY = graphicsLayerScope.translationY,
shadowElevation = graphicsLayerScope.shadowElevation,
rotationX = graphicsLayerScope.rotationX,
rotationY = graphicsLayerScope.rotationY,
rotationZ = graphicsLayerScope.rotationZ,
cameraDistance = graphicsLayerScope.cameraDistance,
transformOrigin = graphicsLayerScope.transformOrigin,
shape = graphicsLayerScope.shape,
clip = graphicsLayerScope.clip,
layoutDirection = layoutNode.layoutDirection
)
isClipping = graphicsLayerScope.clip
} else {
require(layerBlock == null)
}
}
private val invalidateParentLayer: () -> Unit = {
wrappedBy?.invalidateLayer()
}
/**
* True when the last drawing of this layer didn't draw the real content as the LayoutNode
* containing this layer was not placed by the parent.
*/
internal var lastLayerDrawingWasSkipped = false
private set
var layer: OwnedLayer? = null
private set
override val isValid: Boolean
get() = layer != null
/**
* Executes a hit test on any appropriate type associated with this [LayoutNodeWrapper].
*
* Override appropriately to either add a [PointerInputFilter] to [hitPointerInputFilters] or
* to pass the execution on.
*
* @param pointerPosition The tested pointer position, which is relative to
* the [LayoutNodeWrapper].
* @param hitPointerInputFilters The collection that the hit [PointerInputFilter]s will be
* added to if hit.
*/
abstract fun hitTest(
pointerPosition: Offset,
hitPointerInputFilters: MutableList<PointerInputFilter>
)
override fun windowToLocal(relativeToWindow: Offset): Offset {
check(isAttached) { ExpectAttachedLayoutCoordinates }
val root = findRoot()
val positionInRoot = layoutNode.requireOwner()
.calculateLocalPosition(relativeToWindow) - root.positionInRoot()
return localPositionOf(root, positionInRoot)
}
override fun localToWindow(relativeToLocal: Offset): Offset {
val positionInRoot = localToRoot(relativeToLocal)
val owner = layoutNode.requireOwner()
return owner.calculatePositionInWindow(positionInRoot)
}
override fun localPositionOf(
sourceCoordinates: LayoutCoordinates,
relativeToSource: Offset
): Offset {
val layoutNodeWrapper = sourceCoordinates as LayoutNodeWrapper
val commonAncestor = findCommonAncestor(sourceCoordinates)
var position = relativeToSource
var wrapper = layoutNodeWrapper
while (wrapper !== commonAncestor) {
position = wrapper.toParentPosition(position)
wrapper = wrapper.wrappedBy!!
}
return ancestorToLocal(commonAncestor, position)
}
override fun localBoundingBoxOf(
sourceCoordinates: LayoutCoordinates,
clipBounds: Boolean
): Rect {
check(isAttached) { ExpectAttachedLayoutCoordinates }
check(sourceCoordinates.isAttached) {
"LayoutCoordinates $sourceCoordinates is not attached!"
}
val layoutNodeWrapper = sourceCoordinates as LayoutNodeWrapper
val commonAncestor = findCommonAncestor(sourceCoordinates)
val bounds = rectCache
bounds.left = 0f
bounds.top = 0f
bounds.right = sourceCoordinates.size.width.toFloat()
bounds.bottom = sourceCoordinates.size.height.toFloat()
var wrapper = layoutNodeWrapper
while (wrapper !== commonAncestor) {
wrapper.rectInParent(bounds, clipBounds)
if (bounds.isEmpty) {
return Rect.Zero
}
wrapper = wrapper.wrappedBy!!
}
ancestorToLocal(commonAncestor, bounds, clipBounds)
return bounds.toRect()
}
private fun ancestorToLocal(ancestor: LayoutNodeWrapper, offset: Offset): Offset {
if (ancestor === this) {
return offset
}
val wrappedBy = wrappedBy
if (wrappedBy == null || ancestor == wrappedBy) {
return fromParentPosition(offset)
}
return fromParentPosition(wrappedBy.ancestorToLocal(ancestor, offset))
}
private fun ancestorToLocal(
ancestor: LayoutNodeWrapper,
rect: MutableRect,
clipBounds: Boolean
) {
if (ancestor === this) {
return
}
wrappedBy?.ancestorToLocal(ancestor, rect, clipBounds)
return fromParentRect(rect, clipBounds)
}
override fun localToRoot(relativeToLocal: Offset): Offset {
check(isAttached) { ExpectAttachedLayoutCoordinates }
var wrapper: LayoutNodeWrapper? = this
var position = relativeToLocal
while (wrapper != null) {
position = wrapper.toParentPosition(position)
wrapper = wrapper.wrappedBy
}
return position
}
protected inline fun withPositionTranslation(canvas: Canvas, block: (Canvas) -> Unit) {
val x = position.x.toFloat()
val y = position.y.toFloat()
canvas.translate(x, y)
block(canvas)
canvas.translate(-x, -y)
}
/**
* Converts [position] in the local coordinate system to a [Offset] in the
* [parentLayoutCoordinates] coordinate system.
*/
open fun toParentPosition(position: Offset): Offset {
val layer = layer
val targetPosition = if (layer == null) {
position
} else {
val matrix = matrixCache
layer.getMatrix(matrix)
matrix.map(position)
}
return targetPosition + this.position
}
/**
* Converts [position] in the [parentLayoutCoordinates] coordinate system to a [Offset] in the
* local coordinate system.
*/
open fun fromParentPosition(position: Offset): Offset {
val relativeToWrapperPosition = position - this.position
val layer = layer
return if (layer == null) {
relativeToWrapperPosition
} else {
val inverse = matrixCache
layer.getMatrix(inverse)
inverse.invert()
inverse.map(relativeToWrapperPosition)
}
}
protected fun drawBorder(canvas: Canvas, paint: Paint) {
val rect = Rect(
left = 0.5f,
top = 0.5f,
right = measuredSize.width.toFloat() - 0.5f,
bottom = measuredSize.height.toFloat() - 0.5f
)
canvas.drawRect(rect, paint)
}
/**
* Attaches the [LayoutNodeWrapper] and its wrapped [LayoutNodeWrapper] to an active
* LayoutNode.
*
* This will be called when the [LayoutNode] associated with this [LayoutNodeWrapper] is
* attached to the [Owner].
*
* It is also called whenever the modifier chain is replaced and the [LayoutNodeWrapper]s are
* recreated.
*/
open fun attach() {
_isAttached = true
onLayerBlockUpdated(layerBlock)
}
/**
* Detaches the [LayoutNodeWrapper] and its wrapped [LayoutNodeWrapper] from an active
* LayoutNode.
*
* This will be called when the [LayoutNode] associated with this [LayoutNodeWrapper] is
* detached from the [Owner].
*
* It is also called whenever the modifier chain is replaced and the [LayoutNodeWrapper]s are
* recreated.
*/
open fun detach() {
_isAttached = false
onLayerBlockUpdated(layerBlock)
// The layer has been removed and we need to invalidate the containing layer. We've lost
// which layer contained this one, but all layers in this modifier chain will be invalidated
// in onModifierChanged(). Therefore the only possible layer that won't automatically be
// invalidated is the parent's layer. We'll invalidate it here:
layoutNode.parent?.invalidateLayer()
}
/**
* Modifies bounds to be in the parent LayoutNodeWrapper's coordinates, including clipping,
* if [clipBounds] is true.
*/
private fun rectInParent(bounds: MutableRect, clipBounds: Boolean) {
val layer = layer
if (layer != null) {
if (isClipping && clipBounds) {
bounds.intersect(0f, 0f, size.width.toFloat(), size.height.toFloat())
if (bounds.isEmpty) {
return
}
}
val matrix = matrixCache
layer.getMatrix(matrix)
matrix.map(bounds)
}
val x = position.x
bounds.left += x
bounds.right += x
val y = position.y
bounds.top += y
bounds.bottom += y
}
/**
* Modifies bounds in the parent's coordinates to be in this LayoutNodeWrapper's
* coordinates, including clipping, if [clipBounds] is true.
*/
private fun fromParentRect(bounds: MutableRect, clipBounds: Boolean) {
val x = position.x
bounds.left -= x
bounds.right -= x
val y = position.y
bounds.top -= y
bounds.bottom -= y
val layer = layer
if (layer != null) {
val matrix = matrixCache
layer.getMatrix(matrix)
matrix.invert()
matrix.map(bounds)
if (isClipping && clipBounds) {
bounds.intersect(0f, 0f, size.width.toFloat(), size.height.toFloat())
if (bounds.isEmpty) {
return
}
}
}
}
protected fun withinLayerBounds(pointerPosition: Offset): Boolean {
if (layer != null && isClipping) {
return isPointerInBounds(pointerPosition)
}
// If we are here, either we aren't clipping to bounds or we are and the pointer was in
// bounds.
return true
}
/**
* Invalidates the layer that this wrapper will draw into.
*/
open fun invalidateLayer() {
val layer = layer
if (layer != null) {
layer.invalidate()
} else {
wrappedBy?.invalidateLayer()
}
}
/**
* Returns the first [NestedScrollDelegatingWrapper] in the wrapper list that wraps this
* [LayoutNodeWrapper].
*
* Note: This method tried to find [NestedScrollDelegatingWrapper] in the
* modifiers before the one wrapped with this [LayoutNodeWrapper] and goes up the hierarchy of
* [LayoutNode]s if needed.
*/
abstract fun findPreviousNestedScrollWrapper(): NestedScrollDelegatingWrapper?
/**
* Returns the first [NestedScrollDelegatingWrapper] in the wrapper list that is wrapped by this
* [LayoutNodeWrapper].
*
* Note: This method only goes to the modifiers that follow the one wrapped by
* this [LayoutNodeWrapper], it doesn't to the children [LayoutNode]s.
*/
abstract fun findNextNestedScrollWrapper(): NestedScrollDelegatingWrapper?
/**
* Returns the first [focus node][ModifiedFocusNode] in the wrapper list that wraps this
* [LayoutNodeWrapper].
*
* Note: This method tried to find [NestedScrollDelegatingWrapper] in the
* modifiers before the one wrapped with this [LayoutNodeWrapper] and goes up the hierarchy of
* [LayoutNode]s if needed.
*/
abstract fun findPreviousFocusWrapper(): ModifiedFocusNode?
/**
* Returns the next [focus node][ModifiedFocusNode] in the wrapper list that is wrapped by
* this [LayoutNodeWrapper].
*
* Note: This method only goes to the modifiers that follow the one wrapped by
* this [LayoutNodeWrapper], it doesn't to the children [LayoutNode]s.
*/
abstract fun findNextFocusWrapper(): ModifiedFocusNode?
/**
* Returns the last [focus node][ModifiedFocusNode] found following this [LayoutNodeWrapper].
* It searches the wrapper list associated with this [LayoutNodeWrapper].
*/
abstract fun findLastFocusWrapper(): ModifiedFocusNode?
/**
* When the focus state changes, a [LayoutNodeWrapper] calls this function on the wrapper
* that wraps it. The focus state change must be propagated to the parents until we reach
* another [focus node][ModifiedFocusNode].
*/
open fun propagateFocusEvent(focusState: FocusState) {
wrappedBy?.propagateFocusEvent(focusState)
}
/**
* Search up the component tree for any parent/parents that have specified a custom focus order.
* Allowing parents higher up the hierarchy to overwrite the focus order specified by their
* children.
*/
open fun populateFocusOrder(focusOrder: FocusOrder) {
wrappedBy?.populateFocusOrder(focusOrder)
}
/**
* Find the first ancestor that is a [ModifiedFocusNode].
*/
internal fun findParentFocusNode(): ModifiedFocusNode? {
// TODO(b/152066829): We shouldn't need to search through the parentLayoutNode, as the
// wrappedBy property should automatically point to the last layoutWrapper of the parent.
// Find out why this doesn't work.
var focusParent = wrappedBy?.findPreviousFocusWrapper()
if (focusParent != null) {
return focusParent
}
var parentLayoutNode = layoutNode.parent
while (parentLayoutNode != null) {
focusParent = parentLayoutNode.outerLayoutNodeWrapper.findLastFocusWrapper()
if (focusParent != null) {
return focusParent
}
parentLayoutNode = parentLayoutNode.parent
}
return null
}
/**
* Find the first ancestor that is a [ModifiedKeyInputNode].
*/
internal fun findParentKeyInputNode(): ModifiedKeyInputNode? {
// TODO(b/152066829): We shouldn't need to search through the parentLayoutNode, as the
// wrappedBy property should automatically point to the last layoutWrapper of the parent.
// Find out why this doesn't work.
var keyInputParent = wrappedBy?.findPreviousKeyInputWrapper()
if (keyInputParent != null) {
return keyInputParent
}
var parentLayoutNode = layoutNode.parent
while (parentLayoutNode != null) {
keyInputParent = parentLayoutNode.outerLayoutNodeWrapper.findLastKeyInputWrapper()
if (keyInputParent != null) {
return keyInputParent
}
parentLayoutNode = parentLayoutNode.parent
}
return null
}
/**
* Returns the first [ModifiedKeyInputNode] in the wrapper list that wraps this
* [LayoutNodeWrapper].
*
* Note: This method tried to find [NestedScrollDelegatingWrapper] in the
* modifiers before the one wrapped with this [LayoutNodeWrapper] and goes up the hierarchy of
* [LayoutNode]s if needed.
*/
abstract fun findPreviousKeyInputWrapper(): ModifiedKeyInputNode?
/**
* Returns the next [ModifiedKeyInputNode] in the wrapper list that is wrapped by this
* [LayoutNodeWrapper].
*
* Note: This method only goes to the modifiers that follow the one wrapped by
* this [LayoutNodeWrapper], it doesn't to the children [LayoutNode]s.
*/
abstract fun findNextKeyInputWrapper(): ModifiedKeyInputNode?
/**
* Returns the last [focus node][ModifiedFocusNode] found following this [LayoutNodeWrapper].
* It searches the wrapper list associated with this [LayoutNodeWrapper]
*/
abstract fun findLastKeyInputWrapper(): ModifiedKeyInputNode?
/**
* Called when [LayoutNode.modifier] has changed and all the LayoutNodeWrappers have been
* configured.
*/
open fun onModifierChanged() {
layer?.invalidate()
}
internal fun findCommonAncestor(other: LayoutNodeWrapper): LayoutNodeWrapper {
var ancestor1 = other.layoutNode
var ancestor2 = layoutNode
if (ancestor1 === ancestor2) {
// They are on the same node, but we don't know which is the deeper of the two
val tooFar = layoutNode.outerLayoutNodeWrapper
var tryMe = this
while (tryMe !== tooFar && tryMe !== other) {
tryMe = tryMe.wrappedBy!!
}
if (tryMe === other) {
return other
}
return this
}
while (ancestor1.depth > ancestor2.depth) {
ancestor1 = ancestor1.parent!!
}
while (ancestor2.depth > ancestor1.depth) {
ancestor2 = ancestor2.parent!!
}
while (ancestor1 !== ancestor2) {
val parent1 = ancestor1.parent
val parent2 = ancestor2.parent
if (parent1 == null || parent2 == null) {
throw IllegalArgumentException("layouts are not part of the same hierarchy")
}
ancestor1 = parent1
ancestor2 = parent2
}
return when {
ancestor2 === layoutNode -> this
ancestor1 === other.layoutNode -> other
else -> ancestor1.innerLayoutNodeWrapper
}
}
internal companion object {
const val ExpectAttachedLayoutCoordinates = "LayoutCoordinate operations are only valid " +
"when isAttached is true"
const val UnmeasuredError = "Asking for measurement result of unmeasured layout modifier"
private val onCommitAffectingLayerParams: (LayoutNodeWrapper) -> Unit = { wrapper ->
if (wrapper.isValid) {
wrapper.updateLayerParameters()
}
}
private val onCommitAffectingLayer: (LayoutNodeWrapper) -> Unit = { wrapper ->
wrapper.layer?.invalidate()
}
private val graphicsLayerScope = ReusableGraphicsLayerScope()
}
}