Added ConsoleBrowser2 and WebpageSnapshot demos

- Split the Lazarus demos directory into "Lazarus_Windows" and "Lazarus_Linux".
- Added OSRExternalPumpBrowser and TinyBrowser2 demos to "Lazarus_Linux".
- Set TBufferPanel.GetScreenScale as virtual.
- Added DevTools to the SchemeRegistrationBrowser demo.
- Modified the SchemeRegistrationBrowser demo to receive XMLHttpRequest requests from JavaScript.

demos/Lazarus_Windows/ToolBoxBrowser/uMainForm.pas

@@ -0,0 +1,265 @@
+// ************************************************************************
+// ***************************** CEF4Delphi *******************************
+// ************************************************************************
+//
+// CEF4Delphi is based on DCEF3 which uses CEF to embed a chromium-based
+// browser in Delphi applications.
+//
+// The original license of DCEF3 still applies to CEF4Delphi.
+//
+// For more information about CEF4Delphi visit :
+//         https://www.briskbard.com/index.php?lang=en&pageid=cef
+//
+//        Copyright © 2020 Salvador Diaz Fau. All rights reserved.
+//
+// ************************************************************************
+// ************ vvvv Original license and comments below vvvv *************
+// ************************************************************************
+(*
+ *                       Delphi Chromium Embedded 3
+ *
+ * Usage allowed under the restrictions of the Lesser GNU General Public License
+ * or alternatively the restrictions of the Mozilla Public License 1.1
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
+ * the specific language governing rights and limitations under the License.
+ *
+ * Unit owner : Henri Gourvest <hgourvest@gmail.com>
+ * Web site   : http://www.progdigy.com
+ * Repository : http://code.google.com/p/delphichromiumembedded/
+ * Group      : http://groups.google.com/group/delphichromiumembedded
+ *
+ * Embarcadero Technologies, Inc is not permitted to use or redistribute
+ * this source code without explicit permission.
+ *
+ *)
+
+unit uMainForm;
+
+{$MODE Delphi}
+
+{$I cef.inc}
+
+interface
+
+uses
+  {$IFDEF DELPHI16_UP}
+  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
+  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls;
+  {$ELSE}
+  LCLIntf, LCLType, LMessages, Messages, SysUtils, Variants, Classes, Graphics,
+  Controls, Forms, Dialogs, StdCtrls, ExtCtrls, uCEFSentinel;
+  {$ENDIF}
+
+const
+  CEFBROWSER_CREATED          = WM_APP + $100;
+  CEFBROWSER_CHILDDESTROYED   = WM_APP + $101;
+  CEFBROWSER_DESTROY          = WM_APP + $102;
+  CEFBROWSER_INITIALIZED      = WM_APP + $103;
+
+type
+
+  { TMainForm }
+
+  TMainForm = class(TForm)
+    ButtonPnl: TPanel;
+    Edit1: TEdit;
+    Button1: TButton;
+    procedure CEFSentinel1Close(Sender: TObject);
+    procedure FormCreate(Sender: TObject);
+    procedure Button1Click(Sender: TObject);
+    procedure FormShow(Sender: TObject);
+  private
+    // Variables to control when can we destroy the form safely
+    FCanClose : boolean;  // Set to True when all the child forms are closed
+    FClosing  : boolean;  // Set to True in the CloseQuery event.
+
+    procedure CreateToolboxChild(const ChildCaption, URL: string);
+    procedure CloseAllChildForms;
+    function  GetChildClosing : boolean;
+    function  GetChildFormCount : integer;
+
+  protected
+    procedure ChildDestroyedMsg(var aMessage : TMessage); message CEFBROWSER_CHILDDESTROYED;
+    procedure CEFInitializedMsg(var aMessage : TMessage); message CEFBROWSER_INITIALIZED;
+
+  public
+    function CloseQuery: Boolean; override;
+
+    property ChildClosing : boolean read GetChildClosing;
+    property ChildFormCount : integer read GetChildFormCount;
+  end;
+
+var
+  MainForm: TMainForm;
+
+procedure CreateGlobalCEFApp;
+
+implementation
+
+{$R *.lfm}
+
+uses
+  uChildForm, uCEFApplication;
+
+// Destruction steps
+// =================
+// 1. Destroy all child forms
+// 2. Wait until all the child forms are closed before closing the main form.
+
+procedure GlobalCEFApp_OnContextInitialized;
+begin
+  if (MainForm <> nil) and MainForm.HandleAllocated then
+    PostMessage(MainForm.Handle, CEFBROWSER_INITIALIZED, 0, 0);
+end;
+
+procedure CreateGlobalCEFApp;
+begin
+  GlobalCEFApp                      := TCefApplication.Create;
+  GlobalCEFApp.OnContextInitialized := GlobalCEFApp_OnContextInitialized;    
+end;
+
+procedure TMainForm.CreateToolboxChild(const ChildCaption, URL: string);
+var
+  TempChild : TChildForm;
+begin
+  TempChild          := TChildForm.Create(self);
+  TempChild.Caption  := ChildCaption;
+  TempChild.Homepage := URL;
+  TempChild.Show;
+end;
+
+procedure TMainForm.FormCreate(Sender: TObject);
+begin
+  FCanClose := False;
+  FClosing  := False;
+end;
+
+procedure TMainForm.CEFSentinel1Close(Sender: TObject);
+begin
+
+end;
+
+procedure TMainForm.CloseAllChildForms;
+var
+  i : integer;
+  TempComponent : TComponent;
+begin
+  i := pred(ComponentCount);
+
+  while (i >= 0) do
+    begin
+      TempComponent := Components[i];
+
+      if (TempComponent <> nil) and
+         (TempComponent is TChildForm) and
+         not(TChildForm(Components[i]).Closing) then
+        PostMessage(TChildForm(Components[i]).Handle, WM_CLOSE, 0, 0);
+
+      dec(i);
+    end;
+end;
+
+function TMainForm.GetChildClosing : boolean;
+var
+  i : integer;
+  TempComponent : TComponent;
+begin
+  Result := false;
+  i      := pred(ComponentCount);
+
+  while (i >= 0) do
+    begin
+      TempComponent := Components[i];
+
+      if (TempComponent <> nil) and
+         (TempComponent is TChildForm) then
+        begin
+          if TChildForm(Components[i]).Closing then
+            begin
+              Result := True;
+              exit;
+            end
+           else
+            dec(i);
+        end
+       else
+        dec(i);
+    end;
+end;
+
+function TMainForm.GetChildFormCount : integer;
+var
+  i : integer;
+  TempComponent : TComponent;
+begin
+  Result := 0;
+  i      := pred(ComponentCount);
+
+  while (i >= 0) do
+    begin
+      TempComponent := Components[i];
+
+      if (TempComponent <> nil) and
+         (TempComponent is TChildForm) then
+        inc(Result);
+
+      dec(i);
+    end;
+end;
+
+procedure TMainForm.Button1Click(Sender: TObject);
+begin
+  CreateToolboxChild('Browser', Edit1.Text);
+end;
+
+procedure TMainForm.ChildDestroyedMsg(var aMessage : TMessage);
+begin
+  // If there are no more child forms we start the sentinel
+  if FClosing and (ChildFormCount = 0) then
+    begin
+      FCanClose := True;
+      PostMessage(Handle, WM_CLOSE, 0, 0);
+    end;
+end;
+
+function TMainForm.CloseQuery: Boolean;
+begin
+  if FClosing or ChildClosing then
+    Result := FCanClose
+   else
+    begin
+      FClosing := True;
+
+      if (ChildFormCount = 0) then
+        Result := True
+       else
+        begin
+          Result          := False;
+          Edit1.Enabled   := False;
+          Button1.Enabled := False;
+
+          CloseAllChildForms;
+        end;
+    end;
+end;
+
+procedure TMainForm.CEFInitializedMsg(var aMessage : TMessage);
+begin
+  Caption           := 'ToolBox Browser';
+  ButtonPnl.Enabled := True;
+  cursor            := crDefault;
+end;
+
+procedure TMainForm.FormShow(Sender: TObject);
+begin
+  if (GlobalCEFApp <> nil) and GlobalCEFApp.GlobalContextInitialized then
+    begin
+      Caption           := 'ToolBox Browser';
+      ButtonPnl.Enabled := True;
+      cursor            := crDefault;
+    end;
+end;
+
+end.