application.go

@@ -63,6 +63,12 @@ func (application *Application) OnMouseMove (
 	application.callbackManager.onMouseMove = onMouseMove
 }
 
+func (application *Application) OnScroll (
+	onScroll func (x, y int),
+) {
+	application.callbackManager.onScroll = onScroll
+}
+
 func (application *Application) OnStart (
 	onStart func (),
 ) {

backends/x/event.go

@@ -8,6 +8,23 @@ import "github.com/jezek/xgbutil/xevent"
 
 import "git.tebibyte.media/sashakoshka/stone"
 
+type scrollSum struct {
+	x, y int
+}
+
+func (sum *scrollSum) add (button xproto.Button) {
+	switch button {
+	case 4:
+		sum.y --
+	case 5:
+		sum.y ++
+	case 6:
+		sum.x --
+	case 7:
+		sum.x ++
+	}
+}
+
 func (backend *Backend) Run () {
 	backend.callbackManager.RunStart()
 	backend.Draw()
@@ -68,7 +85,14 @@ func (backend *Backend) handleButtonPress (
 	event xevent.ButtonPressEvent,
 ) {
 	buttonEvent := *event.ButtonPressEvent
+	if buttonEvent.Detail >= 4 && buttonEvent.Detail <= 7 {
+		sum := scrollSum { }
+		sum.add(buttonEvent.Detail)
+		backend.compressScrollSum(&sum)
+		backend.callbackManager.RunScroll(sum.x, sum.y)
+	} else {
 		backend.callbackManager.RunPress(stone.Button(buttonEvent.Detail + 127))
+	}
 }
 
 func (backend *Backend) handleButtonRelease (
@@ -76,6 +100,7 @@ func (backend *Backend) handleButtonRelease (
 	event xevent.ButtonReleaseEvent,
 ) {
 	buttonEvent := *event.ButtonReleaseEvent
+	if buttonEvent.Detail >= 4 && buttonEvent.Detail <= 7 { return }
 	backend.callbackManager.RunRelease(stone.Button(buttonEvent.Detail + 127))
 }
 
@@ -101,7 +126,7 @@ func (backend *Backend) handleMotionNotify (
 	connection *xgbutil.XUtil,
 	event xevent.MotionNotifyEvent,
 ) {
-	motionEvent := *event.MotionNotifyEvent
+	motionEvent := backend.compressMotionNotify(*event.MotionNotifyEvent)
 	x, y := backend.cellAt (image.Point {
 		X: int(motionEvent.EventX),
 		Y: int(motionEvent.EventY),
@@ -132,3 +157,47 @@ func (backend *Backend) compressConfigureNotify (
 
 	return
 }
+
+func (backend *Backend) compressMotionNotify (
+	firstEvent xproto.MotionNotifyEvent,
+) (
+	lastEvent xproto.MotionNotifyEvent,
+) {
+	backend.connection.Sync()
+	xevent.Read(backend.connection, false)
+	lastEvent = firstEvent
+	
+	for index, untypedEvent := range xevent.Peek(backend.connection) {
+		if untypedEvent.Err != nil { continue }
+		
+		typedEvent, ok := untypedEvent.Event.(xproto.MotionNotifyEvent)
+		if !ok { continue }
+
+		lastEvent = typedEvent
+		defer func (index int) {
+			xevent.DequeueAt(backend.connection, index)
+		} (index)
+	}
+
+	return
+}
+
+func (backend *Backend) compressScrollSum (sum *scrollSum) {
+	backend.connection.Sync()
+	xevent.Read(backend.connection, false)
+	
+	
+	for index, untypedEvent := range xevent.Peek(backend.connection) {
+		if untypedEvent.Err != nil { continue }
+		
+		typedEvent, ok := untypedEvent.Event.(xproto.ButtonPressEvent)
+		if !ok { continue }
+
+		sum.add(typedEvent.Detail)
+		defer func (index int) {
+			xevent.DequeueAt(backend.connection, index)
+		} (index)
+	}
+
+	return
+}

event.go

@@ -6,6 +6,7 @@ type CallbackManager struct {
 	onRelease   func (button Button)
 	onResize    func ()
 	onMouseMove func (x, y int)
+	onScroll    func (x, y int)
 	onStart     func ()
 }
 
@@ -34,6 +35,11 @@ func (manager *CallbackManager) RunMouseMove (x, y int) {
 	manager.onMouseMove(x, y)
 }
 
+func (manager *CallbackManager) RunScroll (x, y int) {
+	if manager.onScroll == nil { return }
+	manager.onScroll(x, y)
+}
+
 func (manager *CallbackManager) RunStart () {
 	if manager.onStart == nil { return }
 	manager.onStart()

input.go

@@ -52,10 +52,6 @@ const (
 	MouseButtonLeft        Button = MouseButton1
 	MouseButtonMiddle      Button = MouseButton2
 	MouseButtonRight       Button = MouseButton3
-	MouseButtonScrollUp    Button = MouseButton4
-	MouseButtonScrollDown  Button = MouseButton5
-	MouseButtonScrollLeft  Button = MouseButton6
-	MouseButtonScrollRight Button = MouseButton7
 	MouseButtonBack        Button = MouseButton8
 	MouseButtonForward     Button = MouseButton9