Add mouse motion event

box.go

@@ -313,6 +313,18 @@ func (this *box) handleFocusLeave () {
 	this.on.focusLeave.Broadcast()
 }
 
+func (this *box) handleMouseEnter () {
+	this.on.mouseEnter.Broadcast()
+}
+
+func (this *box) handleMouseLeave () {
+	this.on.mouseLeave.Broadcast()
+}
+
+func (this *box) handleMouseMove () {
+	this.on.mouseMove.Broadcast()
+}
+
 func (this *box) handleMouseDown (button input.Button) {
 	if this.focusable {
 		this.SetFocused(true)

event.go

@@ -261,6 +261,7 @@ func (window *window) handleButtonPress (
 	if !insideWindow && window.shy && !scrolling {
 		window.Close()
 	} else if scrolling {
+		// TODO
 		// underneath := window.scrollTargetChildAt(point)
 		// if underneath != nil {
 			// if child, ok := underneath.element.(ability.ScrollTarget); ok {
@@ -298,6 +299,27 @@ func (window *window) handleButtonRelease (
 	}
 }
 
+func (window *window) handleMotionNotify (
+	connection *xgbutil.XUtil,
+	event xevent.MotionNotifyEvent,
+) {
+	if window.hasModal { return }
+	
+	motionEvent := window.compressMotionNotify(*event.MotionNotifyEvent)
+	x := int(motionEvent.EventX)
+	y := int(motionEvent.EventY)
+
+	handled := false
+	for _, child := range window.drags {
+		if child == nil { continue }
+		child.handleMouseMove()
+		handled = true
+	}
+
+	if !handled {
+		window.boxUnder(image.Pt(x, y)).handleMouseMove()
+	}
+}
 
 func (window *window) compressExpose (
 	firstEvent xproto.ExposeEvent,
@@ -364,6 +386,32 @@ func (window *window) compressConfigureNotify (
 	return
 }
 
+func (window *window) compressMotionNotify (
+	firstEvent xproto.MotionNotifyEvent,
+) (
+	lastEvent xproto.MotionNotifyEvent,
+) {
+	window.backend.x.Sync()
+	xevent.Read(window.backend.x, false)
+	lastEvent = firstEvent
+	
+	for index, untypedEvent := range xevent.Peek(window.backend.x) {
+		if untypedEvent.Err != nil { continue }
+		
+		typedEvent, ok := untypedEvent.Event.(xproto.MotionNotifyEvent)
+		if !ok { continue }
+
+		if firstEvent.Event == typedEvent.Event {
+			lastEvent = typedEvent
+			defer func (index int) {
+				xevent.DequeueAt(window.backend.x, index)
+			} (index)
+		}
+	}
+
+	return
+}
+
 func (window *window) updateModifiers (state uint16) {
 	modifiers := xgbkb.StateToModifiers(state)
 	window.modifiers.Shift   = modifiers.Shift || modifiers.ShiftLock

system.go

@@ -58,7 +58,7 @@ type anyBox interface {
 	// handleDndDrop    (data.Data)
 	// handleMouseEnter ()
 	// handleMouseLeave ()
-	// handleMouseMove  ()
+	handleMouseMove  ()
 	handleMouseDown  (input.Button)
 	handleMouseUp    (input.Button)
 	// handleScroll     (float64, float64)