Added code comments to GTKBrowser

Removed overloaded UseDefaultX11VisualForGtk
Removed overloaded FlushDisplay
Added Linux Mint 22.2 mention

README.md

@@ -15,7 +15,7 @@ The CEF binaries used by CEF4Delphi are available for download at Spotify :
 
 CEF4Delphi was developed and tested on Delphi 12.3 and it has been tested in Delphi 6, Delphi XE, Delphi 10, Delphi 11 and Lazarus 4.2/FPC 3.2.2. CEF4Delphi includes VCL, FireMonkey (FMX) and Lazarus components.
 
-CEF4Delphi demos have been tested in Windows 10, Windows 11, Linux Mint 22.1 and Raspberry Pi OS.
+CEF4Delphi demos have been tested in Windows 10, Windows 11, Linux Mint 22.2 and Raspberry Pi OS.
 
 ## Links
 * [Installation instructions and more information about CEF4Delphi](https://www.briskbard.com/index.php?lang=en&pageid=cef)

demos/Lazarus_Linux_GTK3/GTKBrowser/umainwindow.pas

@@ -15,8 +15,6 @@ type
     private                     
       FCanClose     : boolean;
       FClosing      : boolean;
-      FInitializing : boolean;
-      FLoading      : boolean;
       FWindow       : PGtkWidget;
       FChromium     : TChromium;
 
@@ -63,6 +61,30 @@ function StartMainProcess: boolean;
 
 implementation
 
+// This demo is a rough and incomplete translation of the official cefclient
+// application for GTK3.
+
+// There are several missing features and pending issues. This demo was just
+// used to test the CEF initialization in GTK3 using low level API functions in
+// Lazarus.
+
+// If you need to add a CEF browser to your GTK3 application then use the code
+// in SimpleOSRBrowser.
+
+// Trying to use the GTK3 WidgetSet in Lazarus to initialize CEF is not possible
+// at this moment because:
+// - GTK >3.15.1 uses an X11 visual optimized for GTK+'s OpenGL stuff which
+//   breaks CEF/Chromium.
+// - It's necessary to call the UseDefaultX11VisualForGtk procedure before the
+//   GtkWindow is realized to use the default X11 visual.
+// - TGtk3Window.CreateWidget (Gtk3Widgets.pas) realizes the window almost
+//   immediately after its creation.
+
+// At this point we can only wait until the CEF/Chromium requirements change.
+// Perhaps with Wayland support.
+
+// Meanwhile GTK3 applications can use CEF browsers in OSR mode only.
+
 var
   MainAppEvent : TEventObject = nil;
 
@@ -151,8 +173,6 @@ begin
 
   FCanClose              := False;
   FClosing               := False;
-  FInitializing          := True;
-  FLoading               := False;
   FWindow                := nil;
   FChromium              := nil;
 end;
@@ -195,6 +215,7 @@ procedure TMainWindow.Show;
 begin
   // Show the GTK window.
   UseDefaultX11VisualForGtk(FWindow);
+
   gtk_widget_show_all(FWindow);
 
   // Flush the display to make sure the underlying X11 window gets created
@@ -235,13 +256,20 @@ end;
 {%Region}
 procedure TMainWindow.OnAfterCreated(Sender: TObject; const browser: ICefBrowser);
 begin
-  TThread.Synchronize(nil, @DoAfterCreated);
+  if GlobalCEFApp.MultiThreadedMessageLoop then
+    TThread.Synchronize(nil, @DoAfterCreated)
+   else
+    DoAfterCreated;
 end;
 
 procedure TMainWindow.OnBeforeClose(Sender: TObject; const browser: ICefBrowser);
 begin
   FCanClose := True;
-  TThread.Synchronize(nil, @DoBeforeClose);
+
+  if GlobalCEFApp.MultiThreadedMessageLoop then
+    TThread.Synchronize(nil, @DoBeforeClose)
+   else
+    DoBeforeClose;
 end;              
 
 procedure TMainWindow.OnBeforePopup(Sender: TObject;

source/uCEFLinuxFunctions.pas

@@ -65,10 +65,8 @@ procedure gdk_set_allowed_backends(const backends: PGchar); cdecl; external 'lib
 function gdk_x11_display_get_xdisplay(display: PGdkDisplay): PDisplay; cdecl; external 'libgdk-3.so.0';
 function gdk_x11_screen_get_screen_number(screen: PGdkScreen): longint; cdecl; external 'libgdk-3.so.0';
 function gdk_x11_visual_get_xvisual(visual: PGdkVisual): PVisual; cdecl; external 'libgdk-3.so.0';
-procedure UseDefaultX11VisualForGtk(widget : PGtkWidget); overload;
-procedure UseDefaultX11VisualForGtk(aHandle : TCefWindowHandle); overload;
-procedure FlushDisplay(widget : PGtkWidget); overload;
-procedure FlushDisplay(aHandle : TCefWindowHandle); overload;
+procedure UseDefaultX11VisualForGtk(widget : PGtkWidget); 
+procedure FlushDisplay(widget : PGtkWidget); 
 {$ENDIF}
 procedure ShowX11Message(const aMessage : string);
 {$ENDIF}{$ENDIF}
@@ -735,11 +733,6 @@ begin
   g_list_free(visuals);
 end;
 
-procedure UseDefaultX11VisualForGtk(aHandle : TCefWindowHandle);
-begin
-  UseDefaultX11VisualForGtk(TGtk3Widget(aHandle).Widget);
-end;
-
 procedure FlushDisplay(widget : PGtkWidget);
 var
   gdk_window : PGdkWindow;
@@ -749,11 +742,6 @@ begin
   display    := gdk_window_get_display(gdk_window);
   gdk_display_flush(display);
 end;
-
-procedure FlushDisplay(aHandle : TCefWindowHandle);
-begin
-  FlushDisplay(TGtk3Widget(aHandle).Widget);
-end;
 {$ENDIF}
 {$ENDIF}
 

update_CEF4Delphi.json

@@ -2,7 +2,7 @@
   "UpdateLazPackages" : [
     {
       "ForceNotify" : true,
-      "InternalVersion" : 780,
+      "InternalVersion" : 781,
       "Name" : "cef4delphi_lazarus.lpk",
       "Version" : "139.0.38"
     }