More drag-and-drop functionality

build.sbt

@@ -1,6 +1,6 @@
 name := "sgine"
 ThisBuild / organization := "org.sgine"
-ThisBuild / version := "2.0.0b4-SNAPSHOT"
+ThisBuild / version := "2.0.0b4.1-SNAPSHOT"
 
 val scala213 = "2.13.11"
 
@@ -26,7 +26,7 @@ ThisBuild / scmInfo := Some(
   )
 )
 ThisBuild / developers := List(
-  Developer(id="darkfrog", name="Matt Hicks", email="matt@matthicks.com", url=url("http://matthicks.com"))
+  Developer(id="darkfrog", name="Matt Hicks", email="matt@matthicks.com", url=url("https://matthicks.com"))
 )
 
 ThisBuild / fork := true

core/src/main/scala/org/sgine/dnd/DragAndDropSupport.scala

@@ -6,9 +6,11 @@ import org.sgine.{Overlay, Pointer}
 import reactify._
 
 trait DragAndDropSupport extends DimensionedSupport with PointerSupport {
-  private var dragging: Option[DimensionedSupport] = None
+  type Drag <: DimensionedSupport
 
-  private var current: Option[DropSupport] = None
+  private var dragging: Option[Drag] = None
+
+  private var current: Option[(DropSupport, Boolean)] = None
 
   pointer.draggable @= true
   pointer.dragged.attach { evt =>
@@ -19,30 +21,42 @@ trait DragAndDropSupport extends DimensionedSupport with PointerSupport {
       Overlay.children += c
       dragging = Some(c)
     }
-    val d = dragging.get
+    val drag = dragging.get
     val previous = current
     val screen = screenOption().get
     current = screen.hitsAtPointer().collectFirst {
-      case drop: DropSupport if drop.accepts(this) => drop
+      case drop: DropSupport => (drop, drop.accepts(this))
     }
     if (current != previous) {
-      previous.foreach { drop =>
-        drop.out(this)
+      previous.foreach {
+        case (drop, accept) =>
+          drop.out(this, accept)
+          out(drag, drop, accept)
       }
-      current.foreach { drop =>
-        drop.over(this)
+      current.foreach {
+        case (drop, accept) =>
+          drop.over(this, accept)
+          over(drag, drop, accept)
       }
     }
     if (evt.finished) {
-      current.foreach { drop =>
-        drop.receive(this)
-        current = None
+      current.foreach {
+        case (drop, accept) =>
+          drop.receive(this, accept)
+          receive(drag, drop, accept)
+          current = None
       }
 
-      d.removeFromParent()
+      drag.removeFromParent()
       dragging = None
     }
   }
 
-  protected def createDragComponent(): DimensionedSupport
+  protected def createDragComponent(): Drag
+
+  protected def out(drag: Drag, drop: DropSupport, accept: Boolean): Unit = {}
+
+  protected def over(drag: Drag, drop: DropSupport, accept: Boolean): Unit = {}
+
+  protected def receive(drag: Drag, drop: DropSupport, accept: Boolean): Unit = {}
 }

core/src/main/scala/org/sgine/dnd/DropSupport.scala

@@ -5,9 +5,9 @@ import org.sgine.component.{DimensionedSupport, PointerSupport}
 trait DropSupport extends DimensionedSupport with PointerSupport {
   def accepts(c: DragAndDropSupport): Boolean
 
-  def over(c: DragAndDropSupport): Unit
+  def over(c: DragAndDropSupport, accept: Boolean): Unit
 
-  def out(c: DragAndDropSupport): Unit
+  def out(c: DragAndDropSupport, accept: Boolean): Unit
 
-  def receive(c: DragAndDropSupport): Unit
+  def receive(c: DragAndDropSupport, accept: Boolean): Unit
 }

core/src/main/scala/org/sgine/tooltip/Tooltip.scala

@@ -63,6 +63,8 @@ object Tooltip extends MutableContainer[Tooltip] {
     t.visible @= true
   }
 
+  def hide(): Unit = active @= None
+
   override def update(delta: Double): Unit = {
     super.update(delta)
 

core/src/test/scala/examples/DragAndDropExample.scala

@@ -8,30 +8,49 @@ import reactify._
 
 object DragAndDropExample extends Example {
   private object Ball extends Image("basketball.png") with DragAndDropSupport {
+    override type Drag = Image
+
     center := screen.center * 0.5
     middle := screen.middle
 
-    override protected def createDragComponent(): DimensionedSupport = {
+    override protected def createDragComponent(): Image = {
       val img = new Image("basketball.png")
       img.color @= Color.White.withAlpha(0.5)
       img
     }
+
+    override protected def out(drag: Image, drop: DropSupport, accept: Boolean): Unit = {
+      drag.color @= Color.White.withAlpha(0.5)
+    }
+
+    override protected def over(drag: Image, drop: DropSupport, accept: Boolean): Unit = if (accept) {
+      drag.color @= Color.White
+    } else {
+      drag.color @= Color.White.withAlpha(0.5)
+    }
   }
 
-  private object Crate extends Image("crate.jpg") with DropSupport {
-    center := screen.center * 1.5
-    middle := screen.middle
+  private class Crate(accept: Boolean) extends Image("crate.jpg") with DropSupport {
+    override def accepts(c: DragAndDropSupport): Boolean = accept
 
-    override def accepts(c: DragAndDropSupport): Boolean = true
+    override def over(c: DragAndDropSupport, accept: Boolean): Unit = color @= (if (accept) Color.Blue else Color.Red)
 
-    override def over(c: DragAndDropSupport): Unit = color @= Color.Blue
+    override def out(c: DragAndDropSupport, accept: Boolean): Unit = color @= Color.White
 
-    override def out(c: DragAndDropSupport): Unit = color @= Color.White
+    override def receive(c: DragAndDropSupport, accept: Boolean): Unit = color @= (if (accept) Color.Green else Color.Red)
+  }
+
+  private object AcceptCrate extends Crate(accept = true) {
+    center := screen.center * 1.5
+    middle := screen.middle
+  }
 
-    override def receive(c: DragAndDropSupport): Unit = color @= Color.Green
+  private object RejectCrate extends Crate(accept = false) {
+    center := screen.center
+    middle := screen.middle
   }
 
   override protected lazy val component: Component = Container(
-    Ball, Crate
+    Ball, RejectCrate, AcceptCrate
   )
 }