Mouse wheel support for scroll panes

PurpleKingdomGames · Aug 1, 2024 · ea1af01 · ea1af01
1 parent 19a770b
commit ea1af01
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Showing 3 changed files with 16 additions and 3 deletions.
diff --git a/ui/src/main/scala/roguelikestarterkit/ui/components/group/ScrollOptions.scala b/ui/src/main/scala/roguelikestarterkit/ui/components/group/ScrollOptions.scala
@@ -18,7 +18,7 @@ final case class ScrollOptions(
     scrollMode == ScrollMode.None
 
 object ScrollOptions:
-  val default: ScrollOptions = ScrollOptions(ScrollMode.Vertical, 1)
+  val default: ScrollOptions = ScrollOptions(ScrollMode.Vertical, 4)
 
 enum ScrollMode:
   case None

diff --git a/ui/src/main/scala/roguelikestarterkit/ui/components/group/ScrollPane.scala b/ui/src/main/scala/roguelikestarterkit/ui/components/group/ScrollPane.scala
@@ -190,7 +190,21 @@ object ScrollPane:
         context: UIContext[ReferenceData],
         model: ScrollPane[A, ReferenceData]
     ): GlobalEvent => Outcome[ScrollPane[A, ReferenceData]] =
-      e =>
+      case MouseEvent.Wheel(pos, deltaY)
+          if model.scrollOptions.isEnabled && Bounds(context.bounds.coords, model.dimensions)
+            .contains(context.mouseCoords) =>
+        val scrollBy =
+          val coords =
+            if deltaY < 0 then -model.scrollOptions.scrollSpeed else model.scrollOptions.scrollSpeed
+          coords.toDouble / model.dimensions.height.toDouble
+
+        Outcome(
+          model.copy(
+            scrollAmount = Math.min(1.0d, Math.max(0.0d, model.scrollAmount + scrollBy))
+          )
+        )
+
+      case e =>
         val scrollingActive =
           model.scrollOptions.isEnabled && model.contentBounds.height > model.dimensions.height
         val ctx = context.copy(bounds = Bounds(context.bounds.coords, model.dimensions))

diff --git a/ui/src/main/scala/roguelikestarterkit/ui/window/Window.scala b/ui/src/main/scala/roguelikestarterkit/ui/window/Window.scala
@@ -13,7 +13,6 @@ import roguelikestarterkit.ui.datatypes.UIContext
 Scrolling TODOs:
 
 - scroll up/down/left/right arrow buttons (use scroll speed in options)
-- mouse wheel events (use scroll speed in options?)
 - ways to describe scrolling: Fixed amount, proportional, etc.
 - scroll button size can be adjusted based on the content size.
 - horizontal scrolling