feat: add bouncy FAB entrance and press animations

app/src/main/java/com/swoosh/microblog/ui/feed/FeedScreen.kt

@@ -6,8 +6,11 @@ import android.content.Context
 import android.content.Intent
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.animateColorAsState
+import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.fadeIn
 import androidx.compose.animation.fadeOut
+import androidx.compose.foundation.gestures.detectTapGestures
+import com.swoosh.microblog.ui.animation.SwooshMotion
 import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
@@ -112,6 +115,23 @@ fun FeedScreen(
     var showDeleteConfirmation by remember { mutableStateOf<GhostAccount?>(null) }
     var showRenameDialog by remember { mutableStateOf<GhostAccount?>(null) }
 
+    // FAB entrance animation
+    var fabVisible by remember { mutableStateOf(false) }
+    val fabScale by animateFloatAsState(
+        targetValue = if (fabVisible) 1f else 0f,
+        animationSpec = SwooshMotion.bouncy(),
+        label = "fabEntrance"
+    )
+    LaunchedEffect(Unit) { fabVisible = true }
+
+    // FAB press animation
+    var fabPressed by remember { mutableStateOf(false) }
+    val fabPressScale by animateFloatAsState(
+        targetValue = if (fabPressed) 0.85f else 1f,
+        animationSpec = SwooshMotion.bouncyQuick(),
+        label = "fabPress"
+    )
+
     // Pull-to-refresh
     val pullRefreshState = rememberPullRefreshState(
         refreshing = state.isRefreshing,
@@ -232,7 +252,23 @@ fun FeedScreen(
         },
         floatingActionButton = {
             if (!isSearchActive) {
-                FloatingActionButton(onClick = onCompose) {
+                FloatingActionButton(
+                    onClick = onCompose,
+                    modifier = Modifier
+                        .graphicsLayer {
+                            scaleX = fabScale * fabPressScale
+                            scaleY = fabScale * fabPressScale
+                        }
+                        .pointerInput(Unit) {
+                            detectTapGestures(
+                                onPress = {
+                                    fabPressed = true
+                                    tryAwaitRelease()
+                                    fabPressed = false
+                                }
+                            )
+                        }
+                ) {
                     Icon(Icons.Default.Add, contentDescription = "New post")
                 }
             }