fix: Correctly calculate size when using Modifier.size on Paginated and Scrollable composables

Author: 0ffz

guiy-example/src/main/kotlin/com/mineinabyss/guiy/example/gui/PaginatedMenu.kt

@@ -10,6 +10,7 @@ import com.mineinabyss.guiy.inventory.LocalGuiyOwner
 import com.mineinabyss.guiy.modifiers.Modifier
 import com.mineinabyss.guiy.modifiers.click.clickable
 import com.mineinabyss.guiy.modifiers.fillMaxSize
+import com.mineinabyss.guiy.modifiers.size
 import org.bukkit.Material
 import org.bukkit.entity.Player
 import org.bukkit.inventory.ItemStack
@@ -35,7 +36,7 @@ fun PaginatedMenu(player: Player) {
             previousButton = { Item(Material.RED_CONCRETE, "Previous", modifier = Modifier.clickable { page-- }) },
             nextButton = { Item(Material.BLUE_CONCRETE, "Next", modifier = Modifier.clickable { page++ }) },
         ) { pageItems ->
-            HorizontalGrid {
+            HorizontalGrid(Modifier.size(4, 5)) {
                 pageItems.forEach { item ->
                     Item(item)
                 }

guiy-example/src/main/kotlin/com/mineinabyss/guiy/example/gui/ScrollingMenu.kt

@@ -20,7 +20,7 @@ fun ScrollingMenu(player: Player) {
     val owner = LocalGuiyOwner.current
     Chest(
         setOf(player),
-        "Pagination example",
+        "Scrolling example",
         onClose = { owner.exit() },
         modifier = Modifier.fillMaxSize()
     ) {
@@ -37,7 +37,7 @@ fun ScrollingMenu(player: Player) {
             previousButton = { Item(Material.RED_CONCRETE, "Previous", modifier = Modifier.clickable { line-- }) },
             nextButton = { Item(Material.BLUE_CONCRETE, "Next", modifier = Modifier.clickable { line++ }) },
         ) { pageItems ->
-            VerticalGrid {
+            VerticalGrid(Modifier.fillMaxSize()) {
                 pageItems.forEach { item ->
                     Item(item)
                 }

src/main/kotlin/com/mineinabyss/guiy/components/lists/Paginated.kt

@@ -15,6 +15,11 @@ import com.mineinabyss.idofront.items.editItemMeta
 import org.bukkit.Material
 import org.bukkit.inventory.ItemStack
 
+/**
+ * A paginated list of items, with buttons to go to the next and previous pages.
+ *
+ * Content must set a size or fillMaxSize Modifier to be visible.
+ */
 @Composable
 fun <T> Paginated(
     items: List<T>,
@@ -49,7 +54,7 @@ fun <T> Paginated(
                 }
             },
             content = {
-                Box(Modifier.fillMaxSize().onSizeChanged {
+                Box(Modifier.onSizeChanged {
                     size = it
                 }) {
                     content(pageItems)

src/main/kotlin/com/mineinabyss/guiy/components/lists/Scrollable.kt

@@ -15,6 +15,11 @@ enum class ScrollDirection {
     VERTICAL, HORIZONTAL;
 }
 
+/**
+ * A scrollable list of items, with buttons to go to the next and previous lines.
+ *
+ * Content must set a size or fillMaxSize Modifier to be visible.
+ */
 @Composable
 fun <T> Scrollable(
     items: List<T>,
@@ -35,7 +40,7 @@ fun <T> Scrollable(
     val totalLines = if (scrollDirection == ScrollDirection.VERTICAL) size.height else size.width
     Box(Modifier.fillMaxSize()) {
         val start = line * itemsPerLine
-        val end = (line + 1) * itemsPerLine * totalLines
+        val end = start + (itemsPerLine * totalLines)
         val pageItems = remember(start, end) {
             if (start < 0) emptyList()
             else items.subList(start, end.coerceAtMost(items.size))
@@ -51,7 +56,7 @@ fun <T> Scrollable(
                 }
             },
             content = {
-                Box(Modifier.fillMaxSize().onSizeChanged {
+                Box(Modifier.onSizeChanged {
                     size = it
                 }) {
                     content(pageItems)