Add scrollbar desing for android on MyVerticalScrollbar

composeApp/src/androidMain/kotlin/mg/dot/feufaro/ui/MyVerticalScrollbar.kt

@@ -1,16 +1,119 @@
 package mg.dot.feufaro.ui
 
 import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.background
+import androidx.compose.foundation.gestures.Orientation
+import androidx.compose.foundation.gestures.draggable
+import androidx.compose.foundation.gestures.rememberDraggableState
+import androidx.compose.foundation.gestures.scrollBy
+import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.lazy.LazyListState
-import androidx.compose.runtime.Composable
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.blur
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.launch
 
 @Composable
-actual fun  MyVerticalScrollbar (
+actual fun MyVerticalScrollbar(
     modifier: Modifier,
     scrollState: ScrollState?,
     lazyListState: LazyListState?,
     content: @Composable () -> Unit
-){
+) {
+    val coroutineScope = rememberCoroutineScope()
+    val density = LocalDensity.current
+
+    var containerHeight by remember { mutableStateOf(1f) }
+    val thumbHeight = 75.dp
+
+    val scrollPercentage by remember(scrollState, lazyListState) {
+        derivedStateOf {
+            if (scrollState != null && scrollState.maxValue > 0) {
+                scrollState.value.toFloat() / scrollState.maxValue
+            } else if (lazyListState != null) {
+                val layoutInfo = lazyListState.layoutInfo
+                val totalItems = layoutInfo.totalItemsCount
+                if (totalItems == 0) 0f else {
+                    val firstVisibleItem = lazyListState.firstVisibleItemIndex
+                    firstVisibleItem.toFloat() / totalItems
+                }
+            } else {
+                0f
+            }
+        }
+    }
+
+    Box(
+        modifier = modifier.onGloballyPositioned { coordinates ->
+            containerHeight = coordinates.size.height.toFloat()
+        }
+    ) {
         content()
+
+        Box(
+            modifier = Modifier
+                .align(Alignment.CenterEnd)
+                .fillMaxHeight()
+                .width(15.dp)
+                .background(Color.Transparent)
+        ) {
+            val thumbHeightPx = with(density) { thumbHeight.toPx() }
+            val maxOffset = containerHeight - thumbHeightPx
+            val currentThumbOffset = (scrollPercentage * maxOffset).coerceIn(0f, maxOffset.coerceAtLeast(0f))
+
+            Box(
+                modifier = Modifier
+                    .offset(y = with(density) { currentThumbOffset.toDp() })
+                    .width(10.dp)
+                    .height(thumbHeight)
+                    .align(Alignment.TopEnd)
+                    .clip(RoundedCornerShape(5.dp))
+                    .background(
+                        brush = Brush.verticalGradient(
+                            colors = listOf(
+                                MaterialTheme.colorScheme.secondary.copy(alpha = 1f),
+                                MaterialTheme.colorScheme.secondary.copy(alpha = 0.75f),
+                                MaterialTheme.colorScheme.secondary.copy(alpha = 0.5f)
+                            )
+                        )
+                    )
+                    .draggable(
+                        orientation = Orientation.Vertical,
+                        state = rememberDraggableState { delta ->
+                            coroutineScope.launch {
+                                if (maxOffset > 0) {
+                                    val scrollRatio = delta / maxOffset
+                                    if (scrollState != null) {
+                                        scrollState.scrollBy(scrollRatio * scrollState.maxValue)
+                                    } else if (lazyListState != null) {
+                                        val totalItems = lazyListState.layoutInfo.totalItemsCount
+                                        lazyListState.scrollBy(scrollRatio * totalItems * 120f)
+                                    }
+                                }
+                            }
+                        }
+                    )
+            ) {
+                Box(
+                    modifier = Modifier
+                        .align(Alignment.TopCenter)
+                        .padding(top = 4.dp)
+                        .size(6.dp)
+                        .blur(1.dp)
+                        .background(MaterialTheme.colorScheme.background, RoundedCornerShape(3.dp))
+                )
+            }
+        }
+    }
 }