refactor: enhance PlayerSeekBar with custom progress indicator and improved layout

app/src/main/java/hu/bbara/purefin/player/ui/components/PlayerSeekBar.kt

@@ -10,6 +10,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Slider
 import androidx.compose.material3.SliderDefaults
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Size
@@ -35,29 +36,47 @@ fun PlayerSeekBar(
     val position = positionMs.coerceIn(0, safeDuration)
     val bufferRatio = (bufferedMs.toFloat() / safeDuration).coerceIn(0f, 1f)
     val combinedMarkers = chapterMarkers.map { it.copy(type = MarkerType.CHAPTER) } + adMarkers.map { it.copy(type = MarkerType.AD) }
+    val progressRatio = (position.toFloat() / safeDuration).coerceIn(0f, 1f)
 
     Box(
         modifier = modifier
             .fillMaxWidth()
             .padding(horizontal = 8.dp)
-            .height(32.dp)
+            .height(32.dp),
+        contentAlignment = Alignment.Center
     ) {
         Canvas(
             modifier = Modifier
                 .fillMaxSize()
                 .padding(horizontal = 2.dp, vertical = 10.dp)
         ) {
+            val trackHeight = 4f
+            val trackTop = size.height / 2 - trackHeight / 2
             // Buffered bar
             val bufferWidth = bufferRatio * size.width
             drawRect(
                 color = scheme.onSurface.copy(alpha = 0.2f),
-                size = Size(width = size.width, height = 4f),
+                size = Size(width = size.width, height = trackHeight),
-                topLeft = Offset(0f, size.height / 2 - 2f)
+                topLeft = Offset(0f, trackTop)
             )
             drawRect(
                 color = scheme.onSurface.copy(alpha = 0.4f),
-                size = Size(width = bufferWidth, height = 4f),
+                size = Size(width = bufferWidth, height = trackHeight),
-                topLeft = Offset(0f, size.height / 2 - 2f)
+                topLeft = Offset(0f, trackTop)
+            )
+            // Primary progress sits on top of the buffer line to match its width
+            val progressWidth = progressRatio * size.width
+            drawRect(
+                color = scheme.primary,
+                size = Size(width = progressWidth, height = trackHeight),
+                topLeft = Offset(0f, trackTop)
+            )
+            // Draw a compact dot indicator instead of the default thumb
+            val thumbRadius = 6.dp.toPx()
+            drawCircle(
+                color = scheme.primary,
+                radius = thumbRadius,
+                center = Offset(progressWidth.coerceIn(0f, size.width), size.height / 2)
             )
             // Markers
             combinedMarkers.forEach { marker ->
@@ -79,8 +98,8 @@ fun PlayerSeekBar(
             onValueChangeFinished = onScrubFinished,
             valueRange = 0f..safeDuration.toFloat(),
             colors = SliderDefaults.colors(
-                thumbColor = scheme.primary,
+                thumbColor = Color.Transparent,
-                activeTrackColor = scheme.primary,
+                activeTrackColor = Color.Transparent,
                 inactiveTrackColor = Color.Transparent
             ),
             modifier = Modifier.fillMaxSize()