From b4cacfc0fbb571c4f78adabc4963f2be366581a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Costa?= <jdpc557@gmail.com>
Date: Tue, 21 Nov 2023 23:06:52 +0100
Subject: [PATCH] Fix slider position

---
 .../eu/joaocosta/interim/api/Components.scala | 15 ++++--------
 .../joaocosta/interim/skins/SliderSkin.scala  | 24 +++++++------------
 2 files changed, 14 insertions(+), 25 deletions(-)

diff --git a/core/shared/src/main/scala/eu/joaocosta/interim/api/Components.scala b/core/shared/src/main/scala/eu/joaocosta/interim/api/Components.scala
index d162891..d766441 100644
--- a/core/shared/src/main/scala/eu/joaocosta/interim/api/Components.scala
+++ b/core/shared/src/main/scala/eu/joaocosta/interim/api/Components.scala
@@ -111,21 +111,16 @@ trait Components:
     new ComponentWithValue[Int]:
       def render(value: Ref[Int]): Component[Unit] =
         val sliderArea   = skin.sliderArea(area)
-        val sliderSize   = skin.sliderSize(area, min, max)
-        val range        = max - min
+        val steps        = max - min + 1
         val itemStatus   = UiContext.registerItem(id, sliderArea)
         val clampedValue = math.max(min, math.min(value.get, max))
         skin.renderSlider(area, min, clampedValue, max, itemStatus)
         if (itemStatus.active)
           summon[InputState].mouseInput.position.foreach: (mouseX, mouseY) =>
-            if (area.w > area.h)
-              val mousePos = mouseX - sliderArea.x - sliderSize / 2
-              val maxPos   = sliderArea.w - sliderSize
-              value := math.max(min, math.min(min + (mousePos * range) / maxPos, max))
-            else
-              val mousePos = mouseY - sliderArea.y - sliderSize / 2
-              val maxPos   = sliderArea.h - sliderSize
-              value := math.max(min, math.min((mousePos * range) / maxPos, max))
+            val intPosition =
+              if (area.w > area.h) steps * (mouseX - sliderArea.x) / sliderArea.w
+              else steps * (mouseY - sliderArea.y) / sliderArea.h
+            value := math.max(min, math.min(min + intPosition, max))
 
   /** Text input component. Returns the current string inputed.
     */
diff --git a/core/shared/src/main/scala/eu/joaocosta/interim/skins/SliderSkin.scala b/core/shared/src/main/scala/eu/joaocosta/interim/skins/SliderSkin.scala
index 03d4a54..33143f7 100644
--- a/core/shared/src/main/scala/eu/joaocosta/interim/skins/SliderSkin.scala
+++ b/core/shared/src/main/scala/eu/joaocosta/interim/skins/SliderSkin.scala
@@ -4,7 +4,6 @@ import eu.joaocosta.interim.*
 import eu.joaocosta.interim.api.Primitives.*
 
 trait SliderSkin:
-  def sliderSize(area: Rect, min: Int, max: Int): Int
   def sliderArea(area: Rect): Rect
   def renderSlider(area: Rect, min: Int, value: Int, max: Int, itemStatus: UiContext.ItemStatus)(using
       uiContext: UiContext
@@ -21,30 +20,25 @@ object SliderSkin extends DefaultSkin:
       activeColor: Color
   ) extends SliderSkin:
 
-    def sliderSize(area: Rect, min: Int, max: Int): Int =
-      val steps = (max - min) + 1
-      math.max(minSliderSize, math.max(area.w, area.h) / steps)
-
     def sliderArea(area: Rect): Rect = area.shrink(padding)
 
     def renderSlider(area: Rect, min: Int, value: Int, max: Int, itemStatus: UiContext.ItemStatus)(using
         uiContext: UiContext
     ): Unit =
       val sliderArea = this.sliderArea(area)
-      val sliderSize = this.sliderSize(area, min, max)
       val delta      = value - min
-      val maxDelta   = max - min
+      val steps      = (max - min) + 1
       val sliderRect =
         if (area.w > area.h)
-          val sliderFill = sliderArea.h
-          val lastX      = math.max(0, (sliderArea.w - sliderSize))
-          val deltaX     = if (lastX == 0) 0 else delta * lastX / maxDelta
-          Rect(area.x + padding + deltaX, area.y + padding, sliderSize, sliderFill)
+          val deltaX = delta * sliderArea.w / steps
+          Rect(0, 0, math.max(minSliderSize, sliderArea.w / steps), sliderArea.h)
+            .centerAt(0, sliderArea.centerY)
+            .copy(x = sliderArea.x + deltaX)
         else
-          val sliderFill = sliderArea.w
-          val lastY      = math.max(0, (sliderArea.h - sliderSize))
-          val deltaY     = if (lastY == 0) 0 else delta * lastY / maxDelta
-          Rect(area.x + padding, area.y + padding + deltaY, sliderFill, sliderSize)
+          val deltaY = delta * sliderArea.h / steps
+          Rect(0, 0, sliderArea.w, math.max(minSliderSize, sliderArea.h / steps))
+            .centerAt(sliderArea.centerX, 0)
+            .copy(y = sliderArea.y + deltaY)
       rectangle(area, scrollbarColor) // Scrollbar
       itemStatus match
         case UiContext.ItemStatus(false, false, _, _) =>