Fork DrawablePainter for compose

/*

 * Copyright (C) 2022 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 com.android.compose.ui.graphics.painter

import android.graphics.drawable.Animatable

import android.graphics.drawable.ColorDrawable

import android.graphics.drawable.Drawable

import android.os.Build

import android.os.Handler

import android.os.Looper

import android.view.View

import androidx.compose.runtime.Composable

import androidx.compose.runtime.RememberObserver

import androidx.compose.runtime.getValue

import androidx.compose.runtime.mutableStateOf

import androidx.compose.runtime.remember

import androidx.compose.runtime.setValue

import androidx.compose.ui.geometry.Size

import androidx.compose.ui.graphics.Color

import androidx.compose.ui.graphics.ColorFilter

import androidx.compose.ui.graphics.asAndroidColorFilter

import androidx.compose.ui.graphics.drawscope.DrawScope

import androidx.compose.ui.graphics.drawscope.drawIntoCanvas

import androidx.compose.ui.graphics.nativeCanvas

import androidx.compose.ui.graphics.painter.ColorPainter

import androidx.compose.ui.graphics.painter.Painter

import androidx.compose.ui.graphics.withSave

import androidx.compose.ui.unit.LayoutDirection

import kotlin.math.roundToInt

/**

 * *************************************************************************************************

 * This file was forked from

 * https://github.com/google/accompanist/blob/main/drawablepainter/src/main/java/com/google/accompanist/drawablepainter/DrawablePainter.kt

 */

private val MAIN_HANDLER by lazy(LazyThreadSafetyMode.NONE) { Handler(Looper.getMainLooper()) }

/**

 * A [Painter] which draws an Android [Drawable] and supports [Animatable] drawables. Instances

 * should be remembered to be able to start and stop [Animatable] animations.

 *

 * Instances are usually retrieved from [rememberDrawablePainter].

 */

public class DrawablePainter(public val drawable: Drawable) : Painter(), RememberObserver {

    private var drawInvalidateTick by mutableStateOf(0)

    private var drawableIntrinsicSize by mutableStateOf(drawable.intrinsicSize)

    private val callback: Drawable.Callback by lazy {

        object : Drawable.Callback {

            override fun invalidateDrawable(d: Drawable) {

                // Update the tick so that we get re-drawn

                drawInvalidateTick++

                // Update our intrinsic size too

                drawableIntrinsicSize = drawable.intrinsicSize

            }

            override fun scheduleDrawable(d: Drawable, what: Runnable, time: Long) {

                MAIN_HANDLER.postAtTime(what, time)

            }

            override fun unscheduleDrawable(d: Drawable, what: Runnable) {

                MAIN_HANDLER.removeCallbacks(what)

            }

        }

    }

    init {

        if (drawable.intrinsicWidth >= 0 && drawable.intrinsicHeight >= 0) {

            // Update the drawable's bounds to match the intrinsic size

            drawable.setBounds(0, 0, drawable.intrinsicWidth, drawable.intrinsicHeight)

        }

    }

    override fun onRemembered() {

        drawable.callback = callback

        drawable.setVisible(true, true)

        if (drawable is Animatable) drawable.start()

    }

    override fun onAbandoned(): Unit = onForgotten()

    override fun onForgotten() {

        if (drawable is Animatable) drawable.stop()

        drawable.setVisible(false, false)

        drawable.callback = null

    }

    override fun applyAlpha(alpha: Float): Boolean {

        drawable.alpha = (alpha * 255).roundToInt().coerceIn(0, 255)

        return true

    }

    override fun applyColorFilter(colorFilter: ColorFilter?): Boolean {

        drawable.colorFilter = colorFilter?.asAndroidColorFilter()

        return true

    }

    override fun applyLayoutDirection(layoutDirection: LayoutDirection): Boolean {

        if (Build.VERSION.SDK_INT >= 23) {

            return drawable.setLayoutDirection(

                when (layoutDirection) {

                    LayoutDirection.Ltr -> View.LAYOUT_DIRECTION_LTR

                    LayoutDirection.Rtl -> View.LAYOUT_DIRECTION_RTL

                }

            )

        }

        return false

    }

    override val intrinsicSize: Size

        get() = drawableIntrinsicSize

    override fun DrawScope.onDraw() {

        drawIntoCanvas { canvas ->

            // Reading this ensures that we invalidate when invalidateDrawable() is called

            drawInvalidateTick

            // Update the Drawable's bounds

            drawable.setBounds(0, 0, size.width.roundToInt(), size.height.roundToInt())

            canvas.withSave { drawable.draw(canvas.nativeCanvas) }

        }

    }

}

/**

 * Remembers [Drawable] wrapped up as a [Painter]. This function attempts to un-wrap the drawable

 * contents and use Compose primitives where possible.

 *

 * If the provided [drawable] is `null`, an empty no-op painter is returned.

 *

 * This function tries to dispatch lifecycle events to [drawable] as much as possible from within

 * Compose.

 *

 * @sample com.google.accompanist.sample.drawablepainter.BasicSample

 */

@Composable

public fun rememberDrawablePainter(drawable: Drawable?): Painter =

    remember(drawable) {

        when (drawable) {

            null -> EmptyPainter

            is ColorDrawable -> ColorPainter(Color(drawable.color))

            // Since the DrawablePainter will be remembered and it implements RememberObserver, it

            // will receive the necessary events

            else -> DrawablePainter(drawable.mutate())

        }

    }

private val Drawable.intrinsicSize: Size

    get() =

        when {

            // Only return a finite size if the drawable has an intrinsic size

            intrinsicWidth >= 0 && intrinsicHeight >= 0 -> {

                Size(width = intrinsicWidth.toFloat(), height = intrinsicHeight.toFloat())

            }

            else -> Size.Unspecified

        }

internal object EmptyPainter : Painter() {

    override val intrinsicSize: Size

        get() = Size.Unspecified

    override fun DrawScope.onDraw() {}

}