Merge pull request 'Compress mouse scroll and motion events' (#4) from compress-scroll into main

Reviewed-on: #4

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
-	backend.callbackManager.RunPress(stone.Button(buttonEvent.Detail + 127))
+	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 (