-
-
Save bmonjoie/8506040b2ea534eac931378348622725 to your computer and use it in GitHub Desktop.
Compose Circular Reveal
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import android.graphics.Path | |
import android.view.MotionEvent | |
import androidx.annotation.FloatRange | |
import androidx.compose.animation.core.FiniteAnimationSpec | |
import androidx.compose.animation.core.MutableTransitionState | |
import androidx.compose.animation.core.animateFloat | |
import androidx.compose.animation.core.tween | |
import androidx.compose.animation.core.updateTransition | |
import androidx.compose.foundation.layout.Box | |
import androidx.compose.foundation.layout.LayoutScopeMarker | |
import androidx.compose.runtime.Composable | |
import androidx.compose.runtime.Immutable | |
import androidx.compose.runtime.getValue | |
import androidx.compose.runtime.key | |
import androidx.compose.runtime.mutableStateListOf | |
import androidx.compose.runtime.mutableStateOf | |
import androidx.compose.runtime.remember | |
import androidx.compose.runtime.setValue | |
import androidx.compose.ui.Modifier | |
import androidx.compose.ui.draw.clip | |
import androidx.compose.ui.geometry.Offset | |
import androidx.compose.ui.geometry.Size | |
import androidx.compose.ui.graphics.Outline | |
import androidx.compose.ui.graphics.Shape | |
import androidx.compose.ui.graphics.asComposePath | |
import androidx.compose.ui.input.pointer.pointerInteropFilter | |
import androidx.compose.ui.unit.Density | |
import androidx.compose.ui.unit.LayoutDirection | |
@Composable | |
fun <T> CircularReveal( | |
targetState: T, | |
modifier: Modifier = Modifier, | |
animationSpec: FiniteAnimationSpec<Float> = tween(), | |
content: @Composable CircularRevealScope.(T) -> Unit | |
) { | |
val items = remember { mutableStateListOf<CircularRevealAnimationItem<T>>() } | |
val transitionState = remember { MutableTransitionState(targetState) } | |
val targetChanged = (targetState != transitionState.targetState) | |
var offset: Offset? by remember { mutableStateOf(null) } | |
transitionState.targetState = targetState | |
val transition = updateTransition(transitionState, label = "transition") | |
if (targetChanged || items.isEmpty()) { | |
// Only manipulate the list when the state is changed, or in the first run. | |
val keys = items.map { it.key }.run { | |
if (!contains(targetState)) { | |
toMutableList().also { it.add(targetState) } | |
} else { | |
this | |
} | |
} | |
items.clear() | |
keys.mapIndexedTo(items) { index, key -> | |
CircularRevealAnimationItem(key) { | |
val progress by transition.animateFloat( | |
transitionSpec = { animationSpec }, label = "" | |
) { | |
if (index == keys.size - 1) { | |
if (it == key) 1f else 0f | |
} else 1f | |
} | |
Box(Modifier.circularReveal(progress = progress, offset = offset)) { | |
with(CircularRevealScope) { | |
content(key) | |
} | |
} | |
} | |
} | |
} else if (transitionState.currentState == transitionState.targetState) { | |
// Remove all the intermediate items from the list once the animation is finished. | |
items.removeAll { it.key != transitionState.targetState } | |
} | |
Box(modifier.pointerInteropFilter { | |
offset = when (it.action) { | |
MotionEvent.ACTION_DOWN -> Offset(it.x, it.y) | |
else -> null | |
} | |
false | |
}) { | |
items.forEach { | |
key(it.key) { | |
it.content() | |
} | |
} | |
} | |
} | |
private data class CircularRevealAnimationItem<T>( | |
val key: T, | |
val content: @Composable () -> Unit | |
) | |
fun Modifier.circularReveal(@FloatRange(from = 0.0, to = 1.0) progress: Float, offset: Offset? = null) = then( | |
clip(CircularRevealShape(progress, offset)) | |
) | |
private class CircularRevealShape( | |
@FloatRange(from = 0.0, to = 1.0) private val progress: Float, | |
private val offset: Offset? = null | |
) : Shape { | |
override fun createOutline(size: Size, layoutDirection: LayoutDirection, density: Density): Outline { | |
return Outline.Generic(Path().apply { | |
addCircle( | |
offset?.x ?: (size.width / 2f), | |
offset?.y ?: (size.height / 2f), | |
longestDistanceToACorner(size, offset) * progress, | |
Path.Direction.CW | |
) | |
}.asComposePath()) | |
} | |
private fun longestDistanceToACorner(size: Size, offset: Offset?): Float { | |
if (offset == null) { | |
return hypot(size.width /2f, size.height / 2f) | |
} | |
val topLeft = hypot(offset.x, offset.y) | |
val topRight = hypot(size.width - offset.x, offset.y) | |
val bottomLeft = hypot(offset.x, size.height - offset.y) | |
val bottomRight = hypot(size.width - offset.x, size.height - offset.y) | |
return topLeft.coerceAtLeast(topRight).coerceAtLeast(bottomLeft).coerceAtLeast(bottomRight) | |
} | |
} | |
@LayoutScopeMarker | |
@Immutable | |
object CircularRevealScope |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import android.os.Bundle | |
import androidx.activity.ComponentActivity | |
import androidx.activity.compose.setContent | |
import androidx.compose.animation.core.tween | |
import androidx.compose.foundation.background | |
import androidx.compose.foundation.clickable | |
import androidx.compose.foundation.layout.Column | |
import androidx.compose.foundation.layout.fillMaxSize | |
import androidx.compose.foundation.layout.padding | |
import androidx.compose.material.Icon | |
import androidx.compose.material.MaterialTheme | |
import androidx.compose.runtime.getValue | |
import androidx.compose.runtime.setValue | |
import androidx.compose.material.Surface | |
import androidx.compose.material.Text | |
import androidx.compose.material.icons.Icons | |
import androidx.compose.material.icons.filled.Person | |
import androidx.compose.material.icons.filled.Star | |
import androidx.compose.runtime.Composable | |
import androidx.compose.runtime.mutableStateOf | |
import androidx.compose.runtime.remember | |
import androidx.compose.ui.Modifier | |
import androidx.compose.ui.tooling.preview.Preview | |
import androidx.compose.ui.unit.dp | |
import be.xzan.themerevealeffect.ui.theme.AppTheme | |
class MainActivity : ComponentActivity() { | |
override fun onCreate(savedInstanceState: Bundle?) { | |
super.onCreate(savedInstanceState) | |
setContent { | |
var darkMode by remember { mutableStateOf(false) } | |
CircularReveal(targetState = darkMode, animationSpec = tween(500)) { localTheme -> | |
AppTheme(localTheme) { | |
Column(modifier = Modifier | |
.background(MaterialTheme.colors.background) | |
.padding(8.dp) | |
.fillMaxSize() | |
) { | |
Icon(if (localTheme) { | |
Icons.Default.Star | |
} else Icons.Default.Person, | |
"Toggle", | |
Modifier.clickable { darkMode = !darkMode }, | |
tint = MaterialTheme.colors.onBackground) | |
Greeting("Android") | |
} | |
} | |
} | |
} | |
} | |
} | |
@Composable | |
fun Greeting(name: String) { | |
Surface(color = MaterialTheme.colors.background) { | |
Text(text = "Hello $name!") | |
} | |
} | |
@Preview(showBackground = true) | |
@Composable | |
fun DefaultPreview() { | |
AppTheme { | |
Greeting("Android") | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment