feat: swipe-back vers l'accueil depuis les scores et l'historique

sharedUI/src/commonMain/kotlin/com/livrets/App.kt

@@ -14,6 +14,7 @@ import com.livrets.ui.GameScreen
 import com.livrets.ui.HistoryScreen
 import com.livrets.ui.HomeScreen
 import com.livrets.ui.ResultsScreen
+import com.livrets.ui.SwipeBack
 import kotlinx.coroutines.launch
 import okio.Path.Companion.toPath
 
@@ -33,6 +34,10 @@ fun App(
     val history = remember { HistoryRepository("$filesDirPath/history.json".toPath()) }
     var screen by remember { mutableStateOf<Screen>(Screen.Home) }
 
+    val homePreview: @Composable () -> Unit = {
+        HomeScreen(onPlay = {}, onHistory = {})
+    }
+
     when (val current = screen) {
         Screen.Home -> HomeScreen(
             onPlay = { config -> screen = Screen.Game(config) },
@@ -48,15 +53,25 @@ fun App(
             onQuit = { screen = Screen.Home },
         )
 
-        is Screen.Results -> ResultsScreen(
+        is Screen.Results -> SwipeBack(
+            onBack = { screen = Screen.Home },
+            background = homePreview,
+        ) {
+            ResultsScreen(
                 result = current.result,
                 onReplay = { screen = Screen.Game(current.result.config) },
                 onHome = { screen = Screen.Home },
             )
+        }
 
-        Screen.History -> HistoryScreen(
+        Screen.History -> SwipeBack(
+            onBack = { screen = Screen.Home },
+            background = homePreview,
+        ) {
+            HistoryScreen(
                 history = history,
                 onBack = { screen = Screen.Home },
             )
         }
+    }
 }

sharedUI/src/commonMain/kotlin/com/livrets/ui/SwipeBack.kt

@@ -1,6 +1,30 @@
 package com.livrets.ui
 
+import androidx.compose.animation.core.Animatable
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.gestures.awaitEachGesture
+import androidx.compose.foundation.gestures.awaitFirstDown
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.input.pointer.PointerEventPass
+import androidx.compose.ui.input.pointer.changedToUpIgnoreConsumed
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.input.pointer.positionChange
+import androidx.compose.ui.input.pointer.util.VelocityTracker
+import androidx.compose.ui.layout.onSizeChanged
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.dp
+import kotlin.math.abs
+import kotlinx.coroutines.launch
 
 object SwipeBackGesture {
     val EdgeZone = 24.dp
@@ -13,3 +37,109 @@ object SwipeBackGesture {
             velocityDpPerSec >= CommitVelocityDpPerSec
     }
 }
+
+@Composable
+fun SwipeBack(
+    onBack: () -> Unit,
+    background: @Composable () -> Unit,
+    content: @Composable () -> Unit,
+) {
+    val density = LocalDensity.current
+    val scope = rememberCoroutineScope()
+    val offset = remember { Animatable(0f) }
+    val edgeZonePx = with(density) { SwipeBackGesture.EdgeZone.toPx() }
+    var widthPx by remember { mutableFloatStateOf(0f) }
+    val showBackground by remember { derivedStateOf { offset.value > 0f } }
+
+    Box(
+        Modifier
+            .fillMaxSize()
+            .onSizeChanged { widthPx = it.width.toFloat() },
+    ) {
+        if (showBackground) {
+            Box(Modifier.fillMaxSize()) { background() }
+        }
+        Box(
+            Modifier
+                .fillMaxSize()
+                .graphicsLayer { translationX = offset.value }
+                .pointerInput(Unit) {
+                    awaitEachGesture {
+                        val down = awaitFirstDown()
+                        if (down.position.x > edgeZonePx) return@awaitEachGesture
+
+                        val tracker = VelocityTracker()
+                        tracker.addPosition(down.uptimeMillis, down.position)
+                        var dragging = false
+                        var accumulatedX = 0f
+                        var accumulatedY = 0f
+                        var dragged = 0f
+
+                        while (true) {
+                            val event = awaitPointerEvent(PointerEventPass.Main)
+                            val change = event.changes.firstOrNull { it.id == down.id } ?: break
+
+                            if (change.isConsumed && !change.pressed && change.previousPressed) {
+                                if (dragging) {
+                                    scope.launch { offset.animateTo(0f, tween(200)) }
+                                }
+                                break
+                            }
+
+                            if (!dragging && change.isConsumed) break
+
+                            val delta = change.positionChange()
+                            accumulatedX += delta.x
+                            accumulatedY += delta.y
+
+                            if (dragging) {
+                                change.consume()
+                                tracker.addPosition(change.uptimeMillis, change.position)
+                                dragged = (dragged + delta.x).coerceAtLeast(0f)
+                                scope.launch { offset.snapTo(dragged) }
+                            } else {
+                                val slop = viewConfiguration.touchSlop
+                                if (abs(accumulatedX) > slop || abs(accumulatedY) > slop) {
+                                    if (abs(accumulatedX) > abs(accumulatedY)) {
+                                        dragging = true
+                                        change.consume()
+                                        tracker.resetTracking()
+                                        tracker.addPosition(change.uptimeMillis, change.position)
+                                        dragged = accumulatedX.coerceAtLeast(0f)
+                                        scope.launch { offset.snapTo(dragged) }
+                                    } else {
+                                        break
+                                    }
+                                }
+                            }
+
+                            if (change.changedToUpIgnoreConsumed()) {
+                                if (dragging) {
+                                    val velocityDpPerSec =
+                                        tracker.calculateVelocity().x / density.density
+                                    val commit = SwipeBackGesture.shouldCommit(
+                                        offsetPx = dragged,
+                                        containerWidthPx = widthPx,
+                                        velocityDpPerSec = velocityDpPerSec,
+                                    )
+                                    scope.launch {
+                                        if (commit) {
+                                            offset.snapTo(dragged)
+                                            offset.animateTo(widthPx, tween(200))
+                                            onBack()
+                                        } else {
+                                            offset.snapTo(dragged)
+                                            offset.animateTo(0f, tween(200))
+                                        }
+                                    }
+                                }
+                                break
+                            }
+                        }
+                    }
+                },
+        ) {
+            content()
+        }
+    }
+}