| /* |
| * 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.ui.core.test |
| |
| import android.graphics.Bitmap |
| import android.os.Build |
| import androidx.compose.Composable |
| import androidx.compose.emptyContent |
| import androidx.compose.remember |
| import androidx.compose.state |
| import androidx.test.filters.SdkSuppress |
| import androidx.test.filters.SmallTest |
| import androidx.test.rule.ActivityTestRule |
| import androidx.ui.core.Constraints |
| import androidx.ui.core.Layout |
| import androidx.ui.core.LayoutDirection |
| import androidx.ui.core.LayoutModifier |
| import androidx.ui.core.MeasureBlock |
| import androidx.ui.core.Modifier |
| import androidx.ui.core.OnPositioned |
| import androidx.ui.core.Ref |
| import androidx.ui.core.TextFieldDelegate.Companion.layout |
| import androidx.ui.core.WithConstraints |
| import androidx.ui.core.draw |
| import androidx.ui.core.setContent |
| import androidx.ui.framework.test.TestActivity |
| import androidx.ui.graphics.Color |
| import androidx.ui.graphics.Paint |
| import androidx.ui.graphics.vector.DrawVector |
| import androidx.ui.unit.Density |
| import androidx.ui.unit.IntPx |
| import androidx.ui.unit.IntPxSize |
| import androidx.ui.unit.PxPosition |
| import androidx.ui.unit.ipx |
| import androidx.ui.unit.px |
| import androidx.ui.unit.toRect |
| import org.junit.Assert.assertEquals |
| import org.junit.Assert.assertTrue |
| import org.junit.Before |
| import org.junit.Rule |
| import org.junit.Test |
| import org.junit.runner.RunWith |
| import org.junit.runners.JUnit4 |
| import java.util.concurrent.CountDownLatch |
| import java.util.concurrent.TimeUnit |
| |
| @SmallTest |
| @RunWith(JUnit4::class) |
| class WithConstraintsTest { |
| |
| @get:Rule |
| val rule = ActivityTestRule<TestActivity>( |
| TestActivity::class.java |
| ) |
| @get:Rule |
| val excessiveAssertions = AndroidOwnerExtraAssertionsRule() |
| |
| private lateinit var activity: TestActivity |
| private lateinit var drawLatch: CountDownLatch |
| |
| @Before |
| fun setup() { |
| activity = rule.activity |
| activity.hasFocusLatch.await(5, TimeUnit.SECONDS) |
| drawLatch = CountDownLatch(1) |
| } |
| |
| @Test |
| fun withConstraintsTest() { |
| val size = 20.ipx |
| |
| val countDownLatch = CountDownLatch(1) |
| val topConstraints = Ref<Constraints>() |
| val paddedConstraints = Ref<Constraints>() |
| val firstChildConstraints = Ref<Constraints>() |
| val secondChildConstraints = Ref<Constraints>() |
| rule.runOnUiThreadIR { |
| activity.setContentInFrameLayout { |
| WithConstraints { constraints, _ -> |
| topConstraints.value = constraints |
| Padding(size = size) { |
| val drawModifier = draw { _, _ -> |
| countDownLatch.countDown() |
| } |
| WithConstraints(drawModifier) { constraints, _ -> |
| paddedConstraints.value = constraints |
| Layout(measureBlock = { _, childConstraints, _ -> |
| firstChildConstraints.value = childConstraints |
| layout(size, size) { } |
| }, children = { }) |
| Layout(measureBlock = { _, chilConstraints, _ -> |
| secondChildConstraints.value = chilConstraints |
| layout(size, size) { } |
| }, children = { }) |
| } |
| } |
| } |
| } |
| } |
| assertTrue(countDownLatch.await(1, TimeUnit.SECONDS)) |
| |
| val expectedPaddedConstraints = Constraints( |
| 0.ipx, |
| topConstraints.value!!.maxWidth - size * 2, |
| 0.ipx, |
| topConstraints.value!!.maxHeight - size * 2 |
| ) |
| assertEquals(expectedPaddedConstraints, paddedConstraints.value) |
| assertEquals(paddedConstraints.value, firstChildConstraints.value) |
| assertEquals(paddedConstraints.value, secondChildConstraints.value) |
| } |
| |
| @Suppress("UNUSED_ANONYMOUS_PARAMETER") |
| @SdkSuppress(minSdkVersion = Build.VERSION_CODES.O) |
| @Test |
| fun withConstraints_layoutListener() { |
| val green = Color.Green |
| val white = Color.White |
| val model = SquareModel(size = 20.ipx, outerColor = green, innerColor = white) |
| |
| rule.runOnUiThreadIR { |
| activity.setContentInFrameLayout { |
| WithConstraints { constraints, _ -> |
| val outerModifier = draw { canvas, size -> |
| val paint = Paint() |
| paint.color = model.outerColor |
| canvas.drawRect(size.toRect(), paint) |
| } |
| Layout(children = { |
| val innerModifier = draw { canvas, size -> |
| drawLatch.countDown() |
| val paint = Paint() |
| paint.color = model.innerColor |
| canvas.drawRect(size.toRect(), paint) |
| } |
| Layout( |
| children = {}, |
| modifier = innerModifier |
| ) { measurables, constraints2, _ -> |
| layout(model.size, model.size) {} |
| } |
| }, modifier = outerModifier) { measurables, constraints3, _ -> |
| val placeable = measurables[0].measure( |
| Constraints.fixed( |
| model.size, |
| model.size |
| ) |
| ) |
| layout(model.size * 3, model.size * 3) { |
| placeable.place(model.size, model.size) |
| } |
| } |
| } |
| } |
| } |
| takeScreenShot(60).apply { |
| assertRect(color = white, size = 20) |
| assertRect(color = green, holeSize = 20) |
| } |
| |
| drawLatch = CountDownLatch(1) |
| rule.runOnUiThreadIR { |
| model.size = 10.ipx |
| } |
| |
| takeScreenShot(30).apply { |
| assertRect(color = white, size = 10) |
| assertRect(color = green, holeSize = 10) |
| } |
| } |
| |
| /** |
| * WithConstraints will cause a requestLayout during layout in some circumstances. |
| * The test here is the minimal example from a bug. |
| */ |
| @SdkSuppress(minSdkVersion = Build.VERSION_CODES.O) |
| @Test |
| fun requestLayoutDuringLayout() { |
| val offset = OffsetModel(0.ipx) |
| rule.runOnUiThreadIR { |
| activity.setContentInFrameLayout { |
| Scroller( |
| modifier = countdownLatchBackgroundModifier(Color.Yellow), |
| onScrollPositionChanged = { position, _ -> |
| offset.offset = position |
| }, |
| offset = offset |
| ) { |
| // Need to pass some param here to a separate function or else it works fine |
| TestLayout(5) |
| } |
| } |
| } |
| |
| takeScreenShot(30).apply { |
| assertRect(color = Color.Red, size = 10) |
| assertRect(color = Color.Yellow, holeSize = 10) |
| } |
| } |
| |
| @Test |
| fun subcomposionInsideWithConstraintsDoesntAffectModelReadsObserving() { |
| val model = ValueModel(0) |
| var latch = CountDownLatch(1) |
| |
| rule.runOnUiThreadIR { |
| activity.setContent { |
| WithConstraints { _, _ -> |
| // this block is called as a subcomposition from LayoutNode.measure() |
| // DrawVector introduces additional subcomposition which is closing the |
| // current frame and opens a new one. our model reads during measure() |
| // wasn't possible to survide Frames swicth previously so the model read |
| // within the child Layout wasn't recorded |
| DrawVector(100.px, 100.px) { _, _ -> } |
| Layout({}) { _, _, _ -> |
| // read the model |
| model.value |
| latch.countDown() |
| layout(10.ipx, 10.ipx) {} |
| } |
| } |
| } |
| } |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| |
| latch = CountDownLatch(1) |
| rule.runOnUiThread { model.value++ } |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| } |
| |
| @Test |
| fun withConstraintCallbackIsNotExecutedWithInnerRecompositions() { |
| val model = ValueModel(0) |
| var latch = CountDownLatch(1) |
| var recompositionsCount1 = 0 |
| var recompositionsCount2 = 0 |
| |
| rule.runOnUiThreadIR { |
| activity.setContentInFrameLayout { |
| WithConstraints { _, _ -> |
| recompositionsCount1++ |
| Container(100.ipx, 100.ipx) { |
| model.value // model read |
| recompositionsCount2++ |
| latch.countDown() |
| } |
| } |
| } |
| } |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| |
| latch = CountDownLatch(1) |
| rule.runOnUiThread { model.value++ } |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| assertEquals(1, recompositionsCount1) |
| assertEquals(2, recompositionsCount2) |
| } |
| |
| @Test |
| fun updateConstraintsRecomposingWithConstraints() { |
| val model = ValueModel(50.ipx) |
| var latch = CountDownLatch(1) |
| var actualConstraints: Constraints? = null |
| |
| rule.runOnUiThreadIR { |
| activity.setContentInFrameLayout { |
| ChangingConstraintsLayout(model) { |
| WithConstraints { constraints, _ -> |
| actualConstraints = constraints |
| assertEquals(1, latch.count) |
| latch.countDown() |
| Container(width = 100.ipx, height = 100.ipx, children = emptyContent()) |
| } |
| } |
| } |
| } |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| assertEquals(Constraints.fixed(50.ipx, 50.ipx), actualConstraints) |
| |
| latch = CountDownLatch(1) |
| rule.runOnUiThread { model.value = 100.ipx } |
| |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| assertEquals(Constraints.fixed(100.ipx, 100.ipx), actualConstraints) |
| } |
| |
| @Test |
| fun withConstsraintsBehavesAsWrap() { |
| val size = ValueModel(50.ipx) |
| var withConstLatch = CountDownLatch(1) |
| var childLatch = CountDownLatch(1) |
| var withConstSize: IntPxSize? = null |
| var childSize: IntPxSize? = null |
| |
| rule.runOnUiThreadIR { |
| activity.setContentInFrameLayout { |
| Container(width = 200.ipx, height = 200.ipx) { |
| WithConstraints { _, _ -> |
| OnPositioned { |
| // OnPositioned can be fired multiple times with the same value |
| // for example when requestLayout() was triggered on ComposeView. |
| // if we called twice, let's make sure we got the correct values. |
| assertTrue(withConstSize == null || withConstSize == it.size) |
| withConstSize = it.size |
| withConstLatch.countDown() |
| } |
| Container(width = size.value, height = size.value) { |
| OnPositioned { |
| // OnPositioned can be fired multiple times with the same value |
| // for example when requestLayout() was triggered on ComposeView. |
| // if we called twice, let's make sure we got the correct values. |
| assertTrue(childSize == null || childSize == it.size) |
| childSize = it.size |
| childLatch.countDown() |
| } |
| } |
| } |
| } |
| } |
| } |
| assertTrue(withConstLatch.await(1, TimeUnit.SECONDS)) |
| assertTrue(childLatch.await(1, TimeUnit.SECONDS)) |
| var expectedSize = IntPxSize(50.ipx, 50.ipx) |
| assertEquals(expectedSize, withConstSize) |
| assertEquals(expectedSize, childSize) |
| |
| withConstSize = null |
| childSize = null |
| withConstLatch = CountDownLatch(1) |
| childLatch = CountDownLatch(1) |
| rule.runOnUiThread { size.value = 100.ipx } |
| |
| assertTrue(withConstLatch.await(1, TimeUnit.SECONDS)) |
| assertTrue(childLatch.await(1, TimeUnit.SECONDS)) |
| expectedSize = IntPxSize(100.ipx, 100.ipx) |
| assertEquals(expectedSize, withConstSize) |
| assertEquals(expectedSize, childSize) |
| } |
| |
| @SdkSuppress(minSdkVersion = Build.VERSION_CODES.O) |
| @Test |
| fun withConstraintsIsNotSwallowingInnerRemeasureRequest() { |
| val model = ValueModel(100.ipx) |
| |
| rule.runOnUiThreadIR { |
| activity.setContentInFrameLayout { |
| Container(100.ipx, 100.ipx, backgroundModifier(Color.Red)) { |
| ChangingConstraintsLayout(model) { |
| WithConstraints { constraints, _ -> |
| Container(100.ipx, 100.ipx) { |
| Container(100.ipx, 100.ipx) { |
| Layout( |
| {}, |
| countdownLatchBackgroundModifier(Color.Yellow) |
| ) { _, _, _ -> |
| // the same as the value inside ValueModel |
| val size = constraints.maxWidth |
| layout(size, size) {} |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| takeScreenShot(100).apply { |
| assertRect(color = Color.Yellow) |
| } |
| |
| drawLatch = CountDownLatch(1) |
| rule.runOnUiThread { |
| model.value = 50.ipx |
| } |
| |
| takeScreenShot(100).apply { |
| assertRect(color = Color.Red, holeSize = 50) |
| assertRect(color = Color.Yellow, size = 50) |
| } |
| } |
| |
| @Test |
| fun updateModelInMeasuringAndReadItInCompositionWorksInsideWithConstraints() { |
| val latch = CountDownLatch(1) |
| rule.runOnUiThread { |
| activity.setContentInFrameLayout { |
| Container(width = 100.ipx, height = 100.ipx) { |
| WithConstraints { _, _ -> |
| // this replicates the popular pattern we currently use |
| // where we save some data calculated in the measuring block |
| // and then use it in the next composition frame |
| var model by state { false } |
| Layout({ |
| if (model) { |
| latch.countDown() |
| } |
| }) { _, _, _ -> |
| if (!model) { |
| model = true |
| } |
| layout(100.ipx, 100.ipx) {} |
| } |
| } |
| } |
| } |
| } |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| } |
| |
| @SdkSuppress(minSdkVersion = Build.VERSION_CODES.O) |
| @Test |
| fun removeLayoutNodeFromWithConstraintsDuringOnMeasure() { |
| val model = ValueModel(100.ipx) |
| drawLatch = CountDownLatch(2) |
| |
| rule.runOnUiThreadIR { |
| activity.setContentInFrameLayout { |
| Container( |
| 100.ipx, 100.ipx, |
| modifier = countdownLatchBackgroundModifier(Color.Red) |
| ) { |
| // this component changes the constraints which triggers subcomposition |
| // within onMeasure block |
| ChangingConstraintsLayout(model) { |
| WithConstraints { constraints, _ -> |
| if (constraints.maxWidth == 100.ipx) { |
| // we will stop emmitting this layouts after constraints change |
| // Additional Container is needed so the Layout will be |
| // marked as not affecting parent size which means the Layout |
| // will be added into relayoutNodes List separately |
| Container(100.ipx, 100.ipx) { |
| Layout( |
| children = {}, |
| modifier = countdownLatchBackgroundModifier(Color.Yellow) |
| ) { _, _, _ -> |
| layout(model.value, model.value) {} |
| } |
| } |
| } |
| } |
| Container(100.ipx, 100.ipx, Modifier.None, emptyContent()) |
| } |
| } |
| } |
| } |
| takeScreenShot(100).apply { |
| assertRect(color = Color.Yellow) |
| } |
| |
| drawLatch = CountDownLatch(1) |
| rule.runOnUiThread { |
| model.value = 50.ipx |
| } |
| |
| takeScreenShot(100).apply { |
| assertRect(color = Color.Red) |
| } |
| } |
| |
| @Test |
| fun withConstraintsSiblingWhichIsChangingTheModelInsideMeasureBlock() { |
| // WithConstraints is calling FrameManager.nextFrame() after composition |
| // so this code was causing an issue as the model value change is triggering |
| // remeasuring while our parent is measuring right now and this child was |
| // already measured |
| val drawlatch = CountDownLatch(1) |
| rule.runOnUiThread { |
| activity.setContent { |
| val state = state { false } |
| var lastLayoutValue: Boolean = false |
| val drawModifier = draw { _, _ -> |
| // this verifies the layout was remeasured before being drawn |
| assertTrue(lastLayoutValue) |
| drawlatch.countDown() |
| } |
| Layout(children = {}, modifier = drawModifier) { _, _, _ -> |
| lastLayoutValue = state.value |
| // this registers the value read |
| if (!state.value) { |
| // change the value right inside the measure block |
| // it will cause one more remeasure pass as we also read this value |
| state.value = true |
| } |
| layout(100.ipx, 100.ipx) {} |
| } |
| WithConstraints { _, _ -> } |
| } |
| } |
| assertTrue(drawlatch.await(1, TimeUnit.SECONDS)) |
| } |
| |
| @Test |
| fun allTheStepsCalledExactlyOnce() { |
| val outerComposeLatch = CountDownLatch(1) |
| val outerMeasureLatch = CountDownLatch(1) |
| val outerLayoutLatch = CountDownLatch(1) |
| val innerComposeLatch = CountDownLatch(1) |
| val innerMeasureLatch = CountDownLatch(1) |
| val innerLayoutLatch = CountDownLatch(1) |
| rule.runOnUiThread { |
| activity.setContent { |
| assertEquals(1, outerComposeLatch.count) |
| outerComposeLatch.countDown() |
| Layout(children = { |
| WithConstraints { _, _ -> |
| assertEquals(1, innerComposeLatch.count) |
| innerComposeLatch.countDown() |
| Layout(children = emptyContent()) { _, _, _ -> |
| assertEquals(1, innerMeasureLatch.count) |
| innerMeasureLatch.countDown() |
| layout(100.ipx, 100.ipx) { |
| assertEquals(1, innerLayoutLatch.count) |
| innerLayoutLatch.countDown() |
| } |
| } |
| } |
| }) { measurables, constraints, _ -> |
| assertEquals(1, outerMeasureLatch.count) |
| outerMeasureLatch.countDown() |
| layout(100.ipx, 100.ipx) { |
| assertEquals(1, outerLayoutLatch.count) |
| outerLayoutLatch.countDown() |
| measurables.forEach { it.measure(constraints).place(0.ipx, 0.ipx) } |
| } |
| } |
| } |
| } |
| assertTrue(outerComposeLatch.await(1, TimeUnit.SECONDS)) |
| assertTrue(outerMeasureLatch.await(1, TimeUnit.SECONDS)) |
| assertTrue(outerLayoutLatch.await(1, TimeUnit.SECONDS)) |
| assertTrue(innerComposeLatch.await(1, TimeUnit.SECONDS)) |
| assertTrue(innerMeasureLatch.await(1, TimeUnit.SECONDS)) |
| assertTrue(innerLayoutLatch.await(1, TimeUnit.SECONDS)) |
| } |
| |
| @Test |
| fun triggerRootRemeasureWhileRootIsLayouting() { |
| rule.runOnUiThread { |
| activity.setContent { |
| val state = state { 0 } |
| ContainerChildrenAffectsParentSize(100.ipx, 100.ipx) { |
| WithConstraints { _, _ -> |
| Layout( |
| children = {}, |
| modifier = countdownLatchBackgroundModifier(Color.Transparent) |
| ) { _, _, _ -> |
| // read and write once inside measureBlock |
| if (state.value == 0) { |
| state.value = 1 |
| } |
| layout(100.ipx, 100.ipx) {} |
| } |
| } |
| Container(100.ipx, 100.ipx) { |
| WithConstraints { _, _ -> } |
| } |
| } |
| } |
| } |
| |
| assertTrue(drawLatch.await(1, TimeUnit.SECONDS)) |
| // before the fix this was failing our internal assertions in AndroidOwner |
| // so nothing else to assert, apart from not crashing |
| } |
| |
| @Test |
| fun withConstraints_getsCorrectLayoutDirection() { |
| var latch = CountDownLatch(1) |
| var resultLayoutDirection: LayoutDirection? = null |
| rule.runOnUiThreadIR { |
| activity.setContent { |
| Layout( |
| children = @Composable { |
| WithConstraints { _, layoutDirection -> |
| resultLayoutDirection = layoutDirection |
| } |
| }, |
| modifier = layoutDirectionModifier(LayoutDirection.Rtl) |
| ) { m, c, _ -> |
| val p = m.first().measure(c) |
| layout(0.ipx, 0.ipx) { |
| p.place(PxPosition.Origin) |
| latch.countDown() |
| } |
| } |
| } |
| } |
| |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| assertEquals(LayoutDirection.Rtl, resultLayoutDirection) |
| } |
| |
| @Test |
| fun withConstraints_layoutDirectionSetByModifier() { |
| var latch = CountDownLatch(1) |
| var resultLayoutDirection: LayoutDirection? = null |
| rule.runOnUiThreadIR { |
| activity.setContent { |
| Layout( |
| children = @Composable { |
| WithConstraints( |
| modifier = layoutDirectionModifier(LayoutDirection.Rtl) |
| ) { _, layoutDirection -> |
| resultLayoutDirection = layoutDirection |
| latch.countDown() |
| } |
| }, |
| modifier = layoutDirectionModifier(LayoutDirection.Ltr) |
| ) { m, c, _ -> |
| val p = m.first().measure(c) |
| layout(0.ipx, 0.ipx) { |
| p.place(PxPosition.Origin) |
| latch.countDown() |
| } |
| } |
| } |
| } |
| |
| assertTrue(latch.await(1, TimeUnit.SECONDS)) |
| assertEquals(LayoutDirection.Rtl, resultLayoutDirection) |
| } |
| |
| private fun takeScreenShot(size: Int): Bitmap { |
| assertTrue(drawLatch.await(1, TimeUnit.SECONDS)) |
| val bitmap = rule.waitAndScreenShot() |
| assertEquals(size, bitmap.width) |
| assertEquals(size, bitmap.height) |
| return bitmap |
| } |
| |
| private fun countdownLatchBackgroundModifier(color: Color) = draw { |
| canvas, size -> |
| val paint = Paint() |
| paint.color = color |
| canvas.drawRect(size.toRect(), paint) |
| drawLatch.countDown() |
| } |
| |
| private fun layoutDirectionModifier(ld: LayoutDirection) = object : LayoutModifier { |
| override fun Density.modifyLayoutDirection(layoutDirection: LayoutDirection) = ld |
| } |
| } |
| |
| @Composable |
| private fun TestLayout(@Suppress("UNUSED_PARAMETER") someInput: Int) { |
| Layout(children = { |
| WithConstraints { _, _ -> |
| NeedsOtherMeasurementComposable(10.ipx) |
| } |
| }) { measurables, constraints, _ -> |
| val withConstraintsPlaceable = measurables[0].measure(constraints) |
| |
| layout(30.ipx, 30.ipx) { |
| withConstraintsPlaceable.place(10.ipx, 10.ipx) |
| } |
| } |
| } |
| |
| @Composable |
| private fun NeedsOtherMeasurementComposable(foo: IntPx) { |
| Layout( |
| children = {}, |
| modifier = backgroundModifier(Color.Red) |
| ) { _, _, _ -> |
| layout(foo, foo) { } |
| } |
| } |
| |
| @Composable |
| fun Container( |
| width: IntPx, |
| height: IntPx, |
| modifier: Modifier = Modifier.None, |
| children: @Composable() () -> |
| Unit |
| ) { |
| Layout( |
| children = children, |
| modifier = modifier, |
| measureBlock = remember<MeasureBlock>(width, height) { |
| { measurables, _, _ -> |
| val constraint = Constraints(maxWidth = width, maxHeight = height) |
| layout(width, height) { |
| measurables.forEach { |
| val placeable = it.measure(constraint) |
| placeable.place( |
| (width - placeable.width) / 2, |
| (height - placeable.height) / 2 |
| ) |
| } |
| } |
| } |
| } |
| ) |
| } |
| |
| @Composable |
| fun ContainerChildrenAffectsParentSize( |
| width: IntPx, |
| height: IntPx, |
| children: @Composable() () -> Unit |
| ) { |
| Layout(children = children, measureBlock = remember<MeasureBlock>(width, height) { |
| { measurables, _, _ -> |
| val constraint = Constraints(maxWidth = width, maxHeight = height) |
| val placeables = measurables.map { it.measure(constraint) } |
| layout(width, height) { |
| placeables.forEach { |
| it.place((width - width) / 2, (height - height) / 2) |
| } |
| } |
| } |
| }) |
| } |
| |
| @Composable |
| private fun ChangingConstraintsLayout(size: ValueModel<IntPx>, children: @Composable() () -> Unit) { |
| Layout(children) { measurables, _, _ -> |
| layout(100.ipx, 100.ipx) { |
| val constraints = Constraints.fixed(size.value, size.value) |
| measurables.first().measure(constraints).place(0.ipx, 0.ipx) |
| } |
| } |
| } |
| |
| fun backgroundModifier(color: Color) = draw { canvas, size -> |
| val paint = Paint() |
| paint.color = color |
| canvas.drawRect(size.toRect(), paint) |
| } |