add a mini player progress bar and drag-to-expand

app/src/main/kotlin/com/subtracks/ui/playback/MiniPlayer.kt

@@ -2,11 +2,15 @@ package com.subtracks.ui.playback
 
 import androidx.compose.foundation.basicMarquee
 import androidx.compose.foundation.clickable
+import androidx.compose.foundation.gestures.Orientation
+import androidx.compose.foundation.gestures.draggable
+import androidx.compose.foundation.gestures.rememberDraggableState
 import androidx.compose.foundation.interaction.MutableInteractionSource
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.navigationBarsPadding
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
@@ -18,15 +22,20 @@ import androidx.compose.material.icons.rounded.SkipNext
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
+import androidx.compose.material3.LinearProgressIndicator
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.lerp
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.dp
 import com.subtracks.data.model.CoverArtRef
 import com.subtracks.playback.PlaybackState
@@ -34,6 +43,8 @@ import com.subtracks.ui.components.CoverArt
 import com.subtracks.ui.theme.ArtworkColors
 import com.subtracks.ui.theme.ArtworkTheme
 
+private val EXPAND_DRAG = 48.dp
+
 @Composable
 fun MiniPlayer(
     state: PlaybackState,
@@ -45,6 +56,10 @@ fun MiniPlayer(
     modifier: Modifier = Modifier,
 ) {
     val item = state.item ?: return
+    val expandThresholdPx = with(LocalDensity.current) { EXPAND_DRAG.toPx() }
+    var dragUpPx by remember { mutableFloatStateOf(0f) }
+    val progress = if (state.durationMs > 0) (state.positionMs.toFloat() / state.durationMs).coerceIn(0f, 1f) else 0f
+
     ArtworkTheme(artwork) {
         Surface(
             color =
@@ -52,67 +67,90 @@ fun MiniPlayer(
                     ?: MaterialTheme.colorScheme.surfaceContainerHigh,
             contentColor = MaterialTheme.colorScheme.onSurface,
             modifier =
-                modifier.fillMaxWidth().clickable(
-                    interactionSource = remember { MutableInteractionSource() },
-                    indication = null,
-                    onClick = onExpand,
-                ),
+                modifier
+                    .fillMaxWidth()
+                    .draggable(
+                        orientation = Orientation.Vertical,
+                        onDragStarted = { dragUpPx = 0f },
+                        state =
+                            rememberDraggableState { delta ->
+                                dragUpPx = (dragUpPx - delta).coerceAtLeast(0f)
+                                if (dragUpPx >= expandThresholdPx) {
+                                    dragUpPx = 0f
+                                    onExpand()
+                                }
+                            },
+                    ).clickable(
+                        interactionSource = remember { MutableInteractionSource() },
+                        indication = null,
+                        onClick = onExpand,
+                    ),
         ) {
-            Row(
-                modifier =
-                    Modifier
-                        .fillMaxWidth()
-                        .navigationBarsPadding()
-                        .padding(10.dp),
-                verticalAlignment = Alignment.CenterVertically,
-                horizontalArrangement = Arrangement.spacedBy(12.dp),
-            ) {
-                CoverArt(
-                    ref = coverArt,
-                    name = item.title,
-                    modifier = Modifier.size(48.dp).clip(RoundedCornerShape(6.dp)),
+            Column {
+                LinearProgressIndicator(
+                    progress = { progress },
+                    modifier = Modifier.fillMaxWidth().height(2.dp),
+                    color = MaterialTheme.colorScheme.primary,
+                    trackColor = MaterialTheme.colorScheme.primary.copy(alpha = 0.24f),
+                    gapSize = 0.dp,
+                    drawStopIndicator = {},
                 )
-                Column(Modifier.weight(1f)) {
-                    Text(
-                        text = item.title,
-                        style = MaterialTheme.typography.bodyMedium,
-                        color = MaterialTheme.colorScheme.onSurface,
-                        maxLines = 1,
-                        modifier = Modifier.basicMarquee(),
+                Row(
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .navigationBarsPadding()
+                            .padding(10.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.spacedBy(12.dp),
+                ) {
+                    CoverArt(
+                        ref = coverArt,
+                        name = item.title,
+                        modifier = Modifier.size(48.dp).clip(RoundedCornerShape(6.dp)),
                     )
-                    Text(
-                        text = item.artist ?: item.album.orEmpty(),
-                        style = MaterialTheme.typography.bodySmall,
-                        color = MaterialTheme.colorScheme.onSurfaceVariant,
-                        maxLines = 1,
-                        modifier = Modifier.basicMarquee(),
-                    )
-                }
-                Row(verticalAlignment = Alignment.CenterVertically) {
-                    IconButton(onClick = onPlayPause, modifier = Modifier.size(48.dp)) {
-                        if (state.isBuffering && state.isPlaying) {
-                            CircularProgressIndicator(
-                                color = MaterialTheme.colorScheme.onSurface,
-                                strokeWidth = 3.dp,
-                                modifier = Modifier.size(24.dp),
-                            )
-                        } else {
+                    Column(Modifier.weight(1f)) {
+                        Text(
+                            text = item.title,
+                            style = MaterialTheme.typography.bodyMedium,
+                            color = MaterialTheme.colorScheme.onSurface,
+                            maxLines = 1,
+                            modifier = Modifier.basicMarquee(),
+                        )
+                        Text(
+                            text = item.artist ?: item.album.orEmpty(),
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            maxLines = 1,
+                            modifier = Modifier.basicMarquee(),
+                        )
+                    }
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        IconButton(onClick = onPlayPause, modifier = Modifier.size(48.dp)) {
+                            if (state.isBuffering && state.isPlaying) {
+                                CircularProgressIndicator(
+                                    color = MaterialTheme.colorScheme.onSurface,
+                                    strokeWidth = 3.dp,
+                                    modifier = Modifier.size(24.dp),
+                                )
+                            } else {
+                                Icon(
+                                    imageVector = if (state.isPlaying) Icons.Rounded.Pause else Icons.Rounded.PlayArrow,
+                                    contentDescription = if (state.isPlaying) "Pause" else "Play",
+                                    tint = MaterialTheme.colorScheme.onSurface,
+                                    modifier = Modifier.size(36.dp),
+                                )
+                            }
+                        }
+                        IconButton(onClick = onNext, enabled = state.hasNext, modifier = Modifier.size(48.dp)) {
                             Icon(
-                                imageVector = if (state.isPlaying) Icons.Rounded.Pause else Icons.Rounded.PlayArrow,
-                                contentDescription = if (state.isPlaying) "Pause" else "Play",
+                                imageVector = Icons.Rounded.SkipNext,
+                                contentDescription = "Next",
                                 tint = MaterialTheme.colorScheme.onSurface,
                                 modifier = Modifier.size(36.dp),
                             )
                         }
                     }
-                    IconButton(onClick = onNext, enabled = state.hasNext, modifier = Modifier.size(48.dp)) {
-                        Icon(
-                            imageVector = Icons.Rounded.SkipNext,
-                            contentDescription = "Next",
-                            tint = MaterialTheme.colorScheme.onSurface,
-                            modifier = Modifier.size(36.dp),
-                        )
-                    }
                 }
             }
         }