Add rotate inertia for favSelectDialog

app/src/main/kotlin/com/hippo/ehviewer/ui/tools/CircularLayout.kt

@@ -1,9 +1,14 @@
 package com.hippo.ehviewer.ui.tools
 
+import androidx.compose.animation.core.FloatExponentialDecaySpec
+import androidx.compose.animation.core.animateDecay
 import androidx.compose.foundation.gestures.draggable2D
 import androidx.compose.foundation.gestures.rememberDraggable2DState
 import androidx.compose.runtime.Composable
 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.geometry.Offset
@@ -14,6 +19,8 @@ import kotlin.math.atan2
 import kotlin.math.cos
 import kotlin.math.roundToInt
 import kotlin.math.sin
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
 
 private const val FULL_CIRCLE: Float = (PI * 2).toFloat()
 private const val QUARTER_CIRCLE = PI / 2
@@ -21,13 +28,17 @@ private const val QUARTER_CIRCLE = PI / 2
 private var currentTheta: Float? = null
 private var currentOfs: Offset? = null
 
+private val rotateDecay = FloatExponentialDecaySpec()
+private var animJob: Job? = null
+
 @Composable
 fun CircularLayout(
     modifier: Modifier = Modifier,
     placeFirstItemInCenter: Boolean = false,
     content: @Composable () -> Unit,
 ) {
-    var delta by Settings::favDialogTheta.observed
+    val coroutineScope = rememberCoroutineScope()
+    var delta by remember { mutableFloatStateOf(Settings.favDialogTheta) }
     val state = rememberDraggable2DState {
         val prevOfs = currentOfs
         val prevTheta = currentTheta
@@ -46,12 +57,27 @@ fun CircularLayout(
             onDragStarted = {
                 // Get relative offset to center
                 val ofs = it - Offset(500f, 500f)
+                animJob?.cancel()
                 currentOfs = ofs
                 currentTheta = atan2(ofs.y, ofs.x)
             },
             onDragStopped = {
+                val current = currentOfs
+                if (current != null) {
+                    val dist = current.getDistance()
+                    val tanVec = Offset(-current.y / dist, current.x / dist)
+                    val tanV = it.x * tanVec.x + it.y * tanVec.y
+                    val omega = tanV / dist
+                    animJob = coroutineScope.launch {
+                        animateDecay(delta, omega, rotateDecay) { d, _ ->
+                            delta = d
+                        }
+                        Settings.favDialogTheta = delta
+                    }
+                }
                 currentOfs = null
                 currentTheta = null
+                Settings.favDialogTheta = delta
             },
         ),
         content = content,