Add octave controls to KeyboardComponent

Introduced buttons to dynamically adjust the octave within the range of 0 to 8. Added new CSS classes for layout and styling of octave controls, updated component logic with range validation, and reorganized the title and octave display for improved UI.

src/jsMain/kotlin/nl/astraeus/vst/ui/components/KeyboardComponent.kt

@@ -6,8 +6,14 @@ import kotlinx.html.js.onMouseLeaveFunction
 import kotlinx.html.js.onMouseUpFunction
 import kotlinx.html.style
 import kotlinx.html.svg
+import nl.astraeus.css.properties.AlignItems
+import nl.astraeus.css.properties.Display
+import nl.astraeus.css.properties.FlexDirection
+import nl.astraeus.css.properties.FontWeight
+import nl.astraeus.css.properties.JustifyContent
 import nl.astraeus.css.properties.Position
 import nl.astraeus.css.properties.TextAlign
+import nl.astraeus.css.properties.prc
 import nl.astraeus.css.properties.px
 import nl.astraeus.css.properties.rem
 import nl.astraeus.css.style.cls
@@ -28,13 +34,26 @@ import org.w3c.dom.events.MouseEvent
  */
 class KeyboardComponent(
   val title: String = "Keyboard",
-  val octave: Int = 4,
+  initialOctave: Int = 4,
   val keyboardWidth: Int = 210,
   val keyboardHeight: Int = keyboardWidth / 2,
   val onNoteDown: (Int) -> Unit = {},
   val onNoteUp: (Int) -> Unit = {}
 ) : Komponent() {
 
+  // Current octave with range validation
+  private var _octave: Int = initialOctave
+  var octave: Int
+    get() = _octave
+    set(value) {
+      _octave = when {
+        value < 0 -> 0
+        value > 8 -> 8
+        else -> value
+      }
+      requestUpdate()
+    }
+
   // Set to track which notes are currently pressed
   private val pressedNotes = mutableSetOf<Int>()
 
@@ -87,14 +106,43 @@ class KeyboardComponent(
         }
       }
 
-      div(KeyboardTitleCls.name) {
-        // Show title of the keyboard
-        +title
-      }
+      div(KeyboardControlsCls.name) {
+        // Decrease octave button
+        div(OctaveButtonCls.name) {
+          style = "width: ${whiteKeyWidth}px"
+          +"<"
+          onMouseDownFunction = { event ->
+            if (event is MouseEvent) {
+              octave--
+              event.preventDefault()
+            }
+          }
+        }
 
-      div(KeyboardOctaveCls.name) {
-        // Show current octave the piano is being played at
-        +"Octave: $octave"
+        // Title and octave display container
+        div(KeyboardInfoCls.name) {
+          div(KeyboardTitleCls.name) {
+            // Show title of the keyboard
+            +title
+          }
+
+          div(KeyboardOctaveCls.name) {
+            // Show current octave the piano is being played at
+            +"Octave: $octave"
+          }
+        }
+
+        // Increase octave button
+        div(OctaveButtonCls.name) {
+          style = "width: ${whiteKeyWidth}px"
+          +">"
+          onMouseDownFunction = { event ->
+            if (event is MouseEvent) {
+              octave++
+              event.preventDefault()
+            }
+          }
+        }
       }
 
       div(KeyboardKeysCls.name) {
@@ -207,9 +255,12 @@ class KeyboardComponent(
 
   companion object : CssId("keyboard") {
     object KeyboardCls : CssName()
+    object KeyboardControlsCls : CssName()
+    object KeyboardInfoCls : CssName()
     object KeyboardTitleCls : CssName()
     object KeyboardOctaveCls : CssName()
     object KeyboardKeysCls : CssName()
+    object OctaveButtonCls : CssName()
     object WhiteKeyCls : CssName()
     object BlackKeyCls : CssName()
 
@@ -219,31 +270,57 @@ class KeyboardComponent(
           position(Position.relative)
           margin(5.px)
 
+          select(cls(KeyboardControlsCls)) {
+            position(Position.relative)
+            display(Display.flex)
+            flexDirection(FlexDirection.row)
+            justifyContent(JustifyContent.spaceBetween)
+            alignItems(AlignItems.center)
+            width(100.prc)
+            height(50.px)
+            marginBottom(10.px)
+          }
+
+          select(cls(KeyboardInfoCls)) {
+            display(Display.flex)
+            flexDirection(FlexDirection.column)
+            alignItems(AlignItems.center)
+            justifyContent(JustifyContent.center)
+            flex("1")
+          }
+
           select(cls(KeyboardTitleCls)) {
-            position(Position.absolute)
-            width(100.px)
             textAlign(TextAlign.center)
             fontSize(1.2.rem)
             color(Css.currentStyle.mainFontColor)
-            top(5.px)
-            left(0.px)
-            right(0.px)
           }
 
           select(cls(KeyboardOctaveCls)) {
-            position(Position.absolute)
-            width(100.px)
             textAlign(TextAlign.center)
             fontSize(1.0.rem)
             color(Css.currentStyle.mainFontColor)
-            top(30.px)
-            left(0.px)
-            right(0.px)
+            marginTop(5.px)
+          }
+
+          select(cls(OctaveButtonCls)) {
+            height(50.px)
+            plain("background-color", Css.currentStyle.buttonBackgroundColor.toString())
+            color(Css.currentStyle.mainFontColor)
+            border("1px solid ${Css.currentStyle.buttonBorderColor}")
+            textAlign(TextAlign.center)
+            lineHeight(50.px)
+            fontSize(1.5.rem)
+            fontWeight(FontWeight.bold)
+            cursor("pointer")
+            plain("-webkit-touch-callout", "none")
+            plain("-webkit-user-select", "none")
+            plain("-moz-user-select", "none")
+            plain("-ms-user-select", "none")
+            plain("user-select", "none")
           }
 
           select(cls(KeyboardKeysCls)) {
-            position(Position.absolute)
-            top(60.px)
+            position(Position.relative)
           }
         }