do not draw a garbage frame while we are moving a window

Author: aarzilli

nucular.go

@@ -216,13 +216,26 @@ func (win *Window) style() *nstyle.Window {
 }
 
 func panelBegin(ctx *context, win *Window, title string) {
-	win.usingSub = false
+	in := &ctx.Input
 	style := &ctx.Style
 	font := style.Font
-	in := &ctx.Input
+	wstyle := win.style()
+
+	// window dragging
+	if win.moving {
+		if in == nil || !in.Mouse.Down(mouse.ButtonLeft) {
+			if win.flags&windowDocked == 0 && in != nil {
+				win.ctx.DockedWindows.Dock(win, in.Mouse.Pos, win.ctx.Windows[0].Bounds, win.ctx.Style.Scaling)
+			}
+			win.moving = false
+		} else {
+			win.move(in.Mouse.Delta, in.Mouse.Pos)
+		}
+	}
+
+	win.usingSub = false
 	in.Mouse.clip = nk_null_rect
 	layout := win.layout
-	wstyle := win.style()
 
 	window_padding := wstyle.Padding
 	item_spacing := wstyle.Spacing
@@ -358,17 +371,7 @@ func panelBegin(ctx *context, win *Window, title string) {
 		dwh.Draw(&win.ctx.Style, &win.cmds)
 	}
 
-	// window dragging
-	if win.moving {
-		if in == nil || !in.Mouse.Down(mouse.ButtonLeft) {
-			if win.flags&windowDocked == 0 && in != nil {
-				win.ctx.DockedWindows.Dock(win, in.Mouse.Pos, win.ctx.Windows[0].Bounds, win.ctx.Style.Scaling)
-			}
-			win.moving = false
-		} else {
-			win.move(in.Mouse.Delta, in.Mouse.Pos)
-		}
-	} else if (win.flags&WindowMovable != 0) && win.toplevel() {
+	if (win.flags&WindowMovable != 0) && win.toplevel() {
 		var move rect.Rect
 		move.X = win.Bounds.X
 		move.Y = win.Bounds.Y