app: [Windows] include keyboard modifiers in move, drag, and scroll pointer events

This matches the behavior on Linux and macOS.

Signed-off-by: Dominik Honnef <dominik@honnef.co>

app/os_windows.go

@@ -304,16 +304,17 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		x, y := coordsFromlParam(lParam)
 		p := f32.Point{X: float32(x), Y: float32(y)}
 		w.w.Event(pointer.Event{
-			Type:     pointer.Move,
-			Source:   pointer.Mouse,
-			Position: p,
-			Buttons:  w.pointerBtns,
-			Time:     windows.GetMessageTime(),
+			Type:      pointer.Move,
+			Source:    pointer.Mouse,
+			Position:  p,
+			Buttons:   w.pointerBtns,
+			Time:      windows.GetMessageTime(),
+			Modifiers: getModifiers(),
 		})
 	case windows.WM_MOUSEWHEEL:
-		w.scrollEvent(wParam, lParam, false)
+		w.scrollEvent(wParam, lParam, false, getModifiers())
 	case windows.WM_MOUSEHWHEEL:
-		w.scrollEvent(wParam, lParam, true)
+		w.scrollEvent(wParam, lParam, true, getModifiers())
 	case windows.WM_DESTROY:
 		w.w.Event(ViewEvent{})
 		w.w.Event(system.DestroyEvent{})
@@ -518,7 +519,7 @@ func coordsFromlParam(lParam uintptr) (int, int) {
 	return x, y
 }
 
-func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool) {
+func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool, kmods key.Modifiers) {
 	x, y := coordsFromlParam(lParam)
 	// The WM_MOUSEWHEEL coordinates are in screen coordinates, in contrast
 	// to other mouse events.
@@ -533,12 +534,13 @@ func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool) {
 		sp.Y = -dist
 	}
 	w.w.Event(pointer.Event{
-		Type:     pointer.Scroll,
-		Source:   pointer.Mouse,
-		Position: p,
-		Buttons:  w.pointerBtns,
-		Scroll:   sp,
-		Time:     windows.GetMessageTime(),
+		Type:      pointer.Scroll,
+		Source:    pointer.Mouse,
+		Position:  p,
+		Buttons:   w.pointerBtns,
+		Scroll:    sp,
+		Modifiers: kmods,
+		Time:      windows.GetMessageTime(),
 	})
 }