internal/glfw: refactoring: make callback handlers consistent

internal/glfw/callback_notwindows.go

@@ -25,6 +25,7 @@ var (
 	charModsCallbacks        = map[CharModsCallback]glfw.CharModsCallback{}
 	closeCallbacks           = map[CloseCallback]glfw.CloseCallback{}
 	framebufferSizeCallbacks = map[FramebufferSizeCallback]glfw.FramebufferSizeCallback{}
+	monitorCallbacks         = map[MonitorCallback]glfw.MonitorCallback{}
 	scrollCallbacks          = map[ScrollCallback]glfw.ScrollCallback{}
 	sizeCallbacks            = map[SizeCallback]glfw.SizeCallback{}
 )
@@ -65,6 +66,22 @@ func ToFramebufferSizeCallback(cb func(window *Window, width int, height int)) F
 	return id
 }
 
+func ToMonitorCallback(cb func(monitor *Monitor, event PeripheralEvent)) MonitorCallback {
+	if cb == nil {
+		return 0
+	}
+	id := MonitorCallback(len(monitorCallbacks) + 1)
+	var gcb glfw.MonitorCallback = func(monitor *glfw.Monitor, event glfw.PeripheralEvent) {
+		var m *Monitor
+		if monitor != nil {
+			m = &Monitor{monitor}
+		}
+		cb(m, PeripheralEvent(event))
+	}
+	monitorCallbacks[id] = gcb
+	return id
+}
+
 func ToScrollCallback(cb func(window *Window, xoff float64, yoff float64)) ScrollCallback {
 	if cb == nil {
 		return 0

internal/glfw/callback_windows.go

@@ -48,6 +48,20 @@ func ToFramebufferSizeCallback(cb func(window *Window, width int, height int)) F
 	}))
 }
 
+func ToMonitorCallback(cb func(monitor *Monitor, event PeripheralEvent)) MonitorCallback {
+	if cb == nil {
+		return 0
+	}
+	return MonitorCallback(windows.NewCallbackCDecl(func(monitor uintptr, event PeripheralEvent) uintptr {
+		var m *Monitor
+		if monitor != 0 {
+			m = &Monitor{monitor}
+		}
+		cb(m, event)
+		return 0
+	}))
+}
+
 func ToScrollCallback(cb func(window *Window, xoff float64, yoff float64)) ScrollCallback {
 	if cb == nil {
 		return 0

internal/glfw/glfw_notwindows.go

@@ -301,18 +301,9 @@ func PostEmptyEvent() {
 	glfw.PostEmptyEvent()
 }
 
-func SetMonitorCallback(cbfun func(monitor *Monitor, event PeripheralEvent)) {
+func SetMonitorCallback(cbfun MonitorCallback) MonitorCallback {
-	var gcb func(monitor *glfw.Monitor, event glfw.PeripheralEvent)
+	glfw.SetMonitorCallback(monitorCallbacks[cbfun])
-	if cbfun != nil {
+	return ToMonitorCallback(nil)
-		gcb = func(monitor *glfw.Monitor, event glfw.PeripheralEvent) {
-			var m *Monitor
-			if monitor != nil {
-				m = &Monitor{monitor}
-			}
-			cbfun(m, PeripheralEvent(event))
-		}
-	}
-	glfw.SetMonitorCallback(gcb)
 }
 
 func SwapInterval(interval int) {

internal/glfw/glfw_windows.go

@@ -22,8 +22,6 @@ import (
 	"runtime"
 	"sync"
 	"unsafe"
-
-	"golang.org/x/sys/windows"
 )
 
 type glfwImage struct {
@@ -414,20 +412,10 @@ func PostEmptyEvent() {
 	panicError()
 }
 
-func SetMonitorCallback(cbfun func(monitor *Monitor, event PeripheralEvent)) {
+func SetMonitorCallback(cbfun MonitorCallback) MonitorCallback {
-	var gcb uintptr
+	glfwDLL.call("glfwSetMonitorCallback", uintptr(cbfun))
-	if cbfun != nil {
-		gcb = windows.NewCallbackCDecl(func(monitor uintptr, event PeripheralEvent) uintptr {
-			var m *Monitor
-			if monitor != 0 {
-				m = &Monitor{monitor}
-			}
-			cbfun(m, event)
-			return 0
-		})
-	}
-	glfwDLL.call("glfwSetMonitorCallback", gcb)
 	panicError()
+	return ToMonitorCallback(nil) // TODO
 }
 
 func SwapInterval(interval int) {

internal/glfw/type.go

@@ -21,6 +21,7 @@ type (
 	CharModsCallback        uintptr
 	CloseCallback           uintptr
 	FramebufferSizeCallback uintptr
+	MonitorCallback         uintptr
 	ScrollCallback          uintptr
 	SizeCallback            uintptr
 )

internal/ui/ui_glfw.go

@@ -150,9 +150,9 @@ func init() {
 	if err := initialize(); err != nil {
 		panic(err)
 	}
-	glfw.SetMonitorCallback(func(monitor *glfw.Monitor, event glfw.PeripheralEvent) {
+	glfw.SetMonitorCallback(glfw.ToMonitorCallback(func(monitor *glfw.Monitor, event glfw.PeripheralEvent) {
 		updateMonitors()
-	})
+	}))
 	updateMonitors()
 }