[v3 mac] Refactor drag to use common code

v3/pkg/application/webview_window_darwin.go

@@ -818,6 +818,18 @@ static void windowSetFrameless(void *window, bool frameless) {
 	});
 }
 
+static void startDrag(void *window) {
+	dispatch_async(dispatch_get_main_queue(), ^{
+		// get main window
+		WebviewWindow* nsWindow = (WebviewWindow*)window;
+
+		// Get delegate
+		WebviewWindowDelegate* windowDelegate = (WebviewWindowDelegate*)[nsWindow delegate];
+
+		// start drag
+		[windowDelegate startDrag:nsWindow];
+	});
+}
 */
 import "C"
 import (
@@ -1239,6 +1251,6 @@ func (w *macosWebviewWindow) setHTML(html string) {
 }
 
 func (w *macosWebviewWindow) startDrag() error {
-	// Unused - handled by the native code
+	C.startDrag(w.nsWindow)
 	return nil
 }

v3/pkg/application/webview_window_darwin.h

@@ -27,6 +27,7 @@
 
 - (void)handleLeftMouseUp:(NSWindow *)window;
 - (void)handleLeftMouseDown:(NSEvent*)event;
+- (void)startDrag:(WebviewWindow*)window;
 
 @end
 

v3/pkg/application/webview_window_darwin.m

@@ -57,26 +57,18 @@ extern bool hasListeners(unsigned int);
     self.leftMouseEvent = nil;
     [super dealloc];
 }
+
+- (void) startDrag:(WebviewWindow*)window {
+    [window performWindowDragWithEvent:self.leftMouseEvent];
+}
+
 // Handle script messages from the external bridge
 - (void)userContentController:(nonnull WKUserContentController *)userContentController didReceiveScriptMessage:(nonnull WKScriptMessage *)message {
     NSString *m = message.body;
-    // TODO: Standardise drag by sending the drag event back to Go
-    if ( [m isEqualToString:@"drag"] ) {
-        /*
-        if( [self IsFullScreen] ) {
-            return;
-        }
-        */
-        if( self.leftMouseEvent != nil ) {
-            WKWebView *webView = message.webView;
-            WebviewWindow *window = (WebviewWindow*)webView.window;
-            [window performWindowDragWithEvent:self.leftMouseEvent];
-        }
-        return;
-    }
     const char *_m = [m UTF8String];
     processMessage(self.windowId, _m);
 }
+
 - (void)handleLeftMouseDown:(NSEvent *)event {
     self.leftMouseEvent = event;
     NSWindow *window = [event window];