Make mouse position optional

core/src/main/scala/eu/joaocosta/interim/InputState.scala

@@ -35,11 +35,22 @@ sealed trait InputState:
         .filterNot(Character.isISOControl)
         .mkString
 
-  /** Clips the mouse position to a rectagle. If the mouse is outside of the region, it will be moved to (Int.MinValue, Int.MinValue) */
+  /** Clips the mouse position to a rectagle. If the mouse is outside of the region, the position is set to None */
   def clip(area: Rect): InputState
 
 object InputState:
 
+  /** Creates a new InputState.
+    *
+    * @param mousePosition optional mouse (x, y) position, from the top-left
+    * @param mousePressed whether the mouse is pressed
+    * @param keyboardInput
+    *   String generated from the keyboard inputs since the last frame. Usually this will be a single character.
+    *   A `\u0008` character is interpreted as a backspace.
+    */
+  def apply(mousePosition: Option[(Int, Int)], mouseDown: Boolean, keyboardInput: String): InputState =
+    InputState.Current(InputState.MouseInput(mousePosition, mouseDown), keyboardInput)
+
   /** Creates a new InputState.
     *
     * @param mouseX mouse X position, from the left
@@ -50,15 +61,36 @@ object InputState:
     *   A `\u0008` character is interpreted as a backspace.
     */
   def apply(mouseX: Int, mouseY: Int, mouseDown: Boolean, keyboardInput: String): InputState =
-    InputState.Current(InputState.MouseInput(mouseX, mouseY, mouseDown), keyboardInput)
+    InputState.Current(InputState.MouseInput(Some((mouseX, mouseY)), mouseDown), keyboardInput)
+
+  /** Creates a new InputState with an unknown mouse position.
+    *
+    * @param mousePressed whether the mouse is pressed
+    * @param keyboardInput
+    *   String generated from the keyboard inputs since the last frame. Usually this will be a single character.
+    *   A `\u0008` character is interpreted as a backspace.
+    */
+  def apply(mouseDown: Boolean, keyboardInput: String): InputState =
+    InputState.Current(InputState.MouseInput(None, mouseDown), keyboardInput)
 
   /** Mouse position and button state.
     *
-    * @param x mouse X position, from the left
-    * @param y mouse Y position, from the top
+    * @param position mouse position in a (x, y) tuple. None if the mouse is off-screen.
     * @param isPressed whether the mouse is pressed
     */
-  final case class MouseInput(x: Int, y: Int, isPressed: Boolean)
+  final case class MouseInput(position: Option[(Int, Int)], isPressed: Boolean):
+    def x = position.map(_._1)
+    def y = position.map(_._2)
+
+  object MouseInput:
+    /** Mouse position and button state.
+      *
+      * @param x mouse position from the left side
+      * @param y mouse position from the top
+      * @param isPressed whether the mouse is pressed
+      */
+    def apply(x: Int, y: Int, isPressed: Boolean): MouseInput =
+      MouseInput(position = Some((x, y)), isPressed = isPressed)
 
   /** Input state at the current point in time
     *
@@ -71,7 +103,7 @@ object InputState:
 
     def clip(area: Rect): InputState.Current =
       if (area.isMouseOver(using this)) this
-      else this.copy(mouseInput = mouseInput.copy(x = Int.MinValue, y = Int.MinValue))
+      else this.copy(mouseInput = mouseInput.copy(position = None))
 
   /** Input state at the current point in time and in the previous frame
     *
@@ -95,14 +127,12 @@ object InputState:
 
     /** How much the mouse moved in the X axis */
     lazy val deltaX: Int =
-      if (previousMouseInput.x == Int.MinValue || mouseInput.x == Int.MinValue) 0
-      else mouseInput.x - previousMouseInput.x
+      mouseInput.x.zip(previousMouseInput.x).fold(0)((curr, prev) => curr - prev)
 
     /** How much the mouse moved in the Y axis */
     lazy val deltaY: Int =
-      if (previousMouseInput.y == Int.MinValue || mouseInput.y == Int.MinValue) 0
-      else mouseInput.y - previousMouseInput.y
+      mouseInput.y.zip(previousMouseInput.y).fold(0)((curr, prev) => curr - prev)
 
     def clip(area: Rect): InputState.Historical =
       if (area.isMouseOver(using this)) this
-      else this.copy(mouseInput = mouseInput.copy(x = Int.MinValue, y = Int.MinValue))
+      else this.copy(mouseInput = mouseInput.copy(position = None))

core/src/main/scala/eu/joaocosta/interim/Rect.scala

@@ -23,7 +23,9 @@ final case class Rect(x: Int, y: Int, w: Int, h: Int):
   /** Checks if the mouse is over this area.
     */
   def isMouseOver(using inputState: InputState): Boolean =
-    !(inputState.mouseInput.x < x || inputState.mouseInput.y < y || inputState.mouseInput.x >= x + w || inputState.mouseInput.y >= y + h)
+    inputState.mouseInput.position.exists((mouseX, mouseY) =>
+      !(mouseX < x || mouseY < y || mouseX >= x + w || mouseY >= y + h)
+    )
 
   /** Translates the area to another position.
     */

core/src/main/scala/eu/joaocosta/interim/UiContext.scala

@@ -39,7 +39,7 @@ final class UiContext private (
     val history = InputState.Historical(
       previousMouseInput = previousInputState
         .map(_.mouseInput)
-        .getOrElse(InputState.MouseInput(Int.MinValue, Int.MinValue, false)),
+        .getOrElse(InputState.MouseInput(None, false)),
       mouseInput = inputState.mouseInput,
       keyboardInput = inputState.keyboardInput
     )

core/src/main/scala/eu/joaocosta/interim/api/Components.scala

@@ -117,14 +117,15 @@ trait Components:
         val clampedValue = math.max(min, math.min(value.get, max))
         skin.renderSlider(area, min, clampedValue, max, itemStatus)
         if (itemStatus.active)
-          if (area.w > area.h)
-            val mousePos = summon[InputState].mouseInput.x - sliderArea.x - sliderSize / 2
-            val maxPos   = sliderArea.w - sliderSize
-            value := math.max(min, math.min(min + (mousePos * range) / maxPos, max))
-          else
-            val mousePos = summon[InputState].mouseInput.y - sliderArea.y - sliderSize / 2
-            val maxPos   = sliderArea.h - sliderSize
-            value := math.max(min, math.min((mousePos * range) / maxPos, max))
+          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))
 
   /** Text input component. Returns the current string inputed.
     */

core/src/main/scala/eu/joaocosta/interim/api/Layouts.scala

@@ -131,6 +131,6 @@ trait Layouts:
   final def mouseArea[T](area: Rect)(body: Option[InputState.MouseInput] => T)(using inputState: InputState): T =
     body(
       Option.when(area.isMouseOver)(
-        inputState.mouseInput.copy(x = inputState.mouseInput.x - area.x, y = inputState.mouseInput.y - area.y)
+        inputState.mouseInput.copy(position = inputState.mouseInput.position.map((x, y) => (x - area.x, y - area.y)))
       )
     )

core/src/test/scala/eu/joaocosta/interim/UiContextSpec.scala

@@ -111,6 +111,6 @@ class UiContextSpec extends munit.FunSuite:
     val inputState2 = uiContext.pushInputState(InputState(6, 7, false, ""))
     assertEquals(inputState2.deltaX, 1)
     assertEquals(inputState2.deltaY, 2)
-    val inputState3 = uiContext.pushInputState(InputState(Int.MinValue, 6, false, ""))
+    val inputState3 = uiContext.pushInputState(InputState(false, ""))
     assertEquals(inputState3.deltaX, 0)
-    assertEquals(inputState3.deltaY, -1)
+    assertEquals(inputState3.deltaY, 0)

examples/snapshot/example-minart-backend.scala

@@ -71,8 +71,7 @@ object MinartBackend:
       .mkString
 
   private def getInputState(canvas: Canvas): InputState = InputState(
-    canvas.getPointerInput().position.map(_.x).getOrElse(Int.MinValue),
-    canvas.getPointerInput().position.map(_.y).getOrElse(Int.MinValue),
+    canvas.getPointerInput().position.map(pos => (pos.x, pos.y)),
     canvas.getPointerInput().isPressed,
     processKeyboard(canvas.getKeyboardInput())
   )