Add SetModal() widget interface to nsIWidget, and provide an implementation

for Gtk+. Now, when we do modal dialogs, Gtk+ calls a routine that makes the
dialog modal within Gtk+; this is in addition to the code in nsWebShellWindow
that is being invoked to support modals on the other platforms. For Gtk+, the
nsWebShellWindow code doesn't appear to be enough; in order for the event
plumbing to stay alive, we need to call into Gtk+, and unless we actually make
the dialog modal using Gtk+ mechanisms, the user can still get to the menu bar, which is not good.

widget/public/nsIWidget.h

@@ -253,6 +253,14 @@ class nsIWidget : public nsISupports {
      */
     NS_IMETHOD Show(PRBool aState) = 0;
 
+    /**
+     * Make the window modal 
+     *
+     * 
+     *
+     */
+    NS_IMETHOD SetModal(void) = 0;
+
     /**
      * Returns whether the window is visible
      *

widget/src/gtk/nsWidget.cpp

@@ -248,6 +248,19 @@ NS_METHOD nsWidget::Show(PRBool bState)
   return NS_OK;
 }
 
+NS_METHOD nsWidget::SetModal(void)
+{
+	GtkWindow *toplevel;
+
+	if (!mWidget)
+		return NS_ERROR_FAILURE;
+	toplevel = (GtkWindow *) ::gtk_widget_get_toplevel( mWidget );
+	if ( !toplevel )
+		return NS_ERROR_FAILURE;
+	::gtk_window_set_modal(toplevel, PR_TRUE);
+	return NS_OK;
+}
+
 NS_METHOD nsWidget::IsVisible(PRBool &aState)
 {
   if (mWidget) {

widget/src/gtk/nsWidget.h

@@ -64,6 +64,7 @@ class nsWidget : public nsBaseWidget
     NS_IMETHOD Destroy(void);
     nsIWidget* GetParent(void);
 
+    NS_IMETHOD SetModal(void);
     NS_IMETHOD Show(PRBool state);
     NS_IMETHOD IsVisible(PRBool &aState);
 

widget/src/xpwidgets/nsBaseWidget.cpp

@@ -784,3 +784,7 @@ NS_METHOD nsBaseWidget::EnableFileDrop(PRBool aEnable)
   return NS_OK;
 }
 
+NS_METHOD nsBaseWidget::SetModal(void)
+{
+  return NS_ERROR_FAILURE;
+}

widget/src/xpwidgets/nsBaseWidget.h

@@ -74,6 +74,7 @@ public:
     virtual nsIDeviceContext* GetDeviceContext();
     virtual nsIAppShell *   GetAppShell();
     virtual nsIToolkit*     GetToolkit();  
+    NS_IMETHOD              SetModal(void); 
     NS_IMETHOD              SetBorderStyle(nsBorderStyle aBorderStyle); 
     NS_IMETHOD              SetTitle(const nsString& aTitle); 
     NS_IMETHOD              SetTooltips(PRUint32 aNumberOfTips,nsRect* aTooltipAreas[]);   

xpfe/appshell/src/nsWebShellWindow.cpp

@@ -1380,6 +1380,7 @@ nsWebShellWindow::ShowModalInternal()
   subshell->Spinup();
 
   nsIWidget *window = GetWidget();
+  window->SetModal();
   NS_ADDREF(window);
   mContinueModalLoop = PR_TRUE;
   while (NS_SUCCEEDED(rv) && mContinueModalLoop == PR_TRUE) {