commonMain.androidx.compose.ui.node.OwnedLayer.kt Maven / Gradle / Ivy

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/*
 * 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.node

import androidx.compose.ui.geometry.MutableRect
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Canvas
import androidx.compose.ui.graphics.Matrix
import androidx.compose.ui.graphics.ReusableGraphicsLayerScope
import androidx.compose.ui.graphics.layer.GraphicsLayer
import androidx.compose.ui.unit.IntOffset
import androidx.compose.ui.unit.IntSize

/** A layer returned by [Owner.createLayer] to separate drawn content. */
internal interface OwnedLayer {

    /** Applies the new layer properties, causing this layer to be redrawn. */
    fun updateLayerProperties(scope: ReusableGraphicsLayerScope)

    /**
     * Returns `false` if [position] is outside the clipped region or `true` if clipping is disabled
     * or it is within the clipped region.
     */
    fun isInLayer(position: Offset): Boolean

    /** Changes the position of the layer contents. */
    fun move(position: IntOffset)

    /** Changes the size of the layer's drawn area. */
    fun resize(size: IntSize)

    /** Causes the layer to be drawn into [canvas] */
    fun drawLayer(canvas: Canvas, parentLayer: GraphicsLayer?)

    /** Updates the drawing on the current canvas. */
    fun updateDisplayList()

    /** Asks to the layer to redraw itself without forcing all of its parents to redraw. */
    fun invalidate()

    /** Indicates that the layer is no longer needed. */
    fun destroy()

    /**
     * Transforms [point] to this layer's bounds, returning an [Offset] with the transformed x and y
     * values.
     *
     * @param point the [Offset] to transform to this layer's bounds
     * @param inverse whether to invert this layer's transform [Matrix] first, such as when
     *   converting an offset in a parent layer to be in this layer's coordinates.
     */
    fun mapOffset(point: Offset, inverse: Boolean): Offset

    /**
     * Transforms the provided [rect] to this layer's bounds, then updates [rect] to match the new
     * bounds after the transform.
     *
     * @param rect the bounds to transform to this layer's bounds, and then mutate with the
     *   resulting value
     * @param inverse whether to invert this layer's transform [Matrix] first, such as when
     *   converting bounds in a parent layer to be in this layer's coordinates.
     */
    fun mapBounds(rect: MutableRect, inverse: Boolean)

    /**
     * Reuse this layer after it was [destroy]ed, setting the new [drawBlock] and
     * [invalidateParentLayer] values. The layer will be reinitialized as new after this call.
     */
    fun reuseLayer(
        drawBlock: (canvas: Canvas, parentLayer: GraphicsLayer?) -> Unit,
        invalidateParentLayer: () -> Unit
    )

    /**
     * Calculates the transform from the parent to the local coordinates and multiplies [matrix] by
     * the transform.
     */
    fun transform(matrix: Matrix)

    /** The matrix associated with the affine transform of this layer */
    val underlyingMatrix: Matrix

    /**
     * Calculates the transform from the layer to the parent and multiplies [matrix] by the
     * transform.
     */
    fun inverseTransform(matrix: Matrix)
}