CEF4Delphi/demos/Delphi_VCL/ToolBoxSubProcessBrowser/uMainForm.pas

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// ************************************************************************
// ***************************** 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 <20> 2019 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;
{$I cef.inc}
interface
uses
{$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,
{$ELSE}
Windows, Messages, SysUtils, Variants, Classes, Graphics,
Controls, Forms, Dialogs, StdCtrls, ExtCtrls,
{$ENDIF}
uCEFSentinel;
const
CEFBROWSER_CREATED = WM_APP + $100;
CEFBROWSER_CHILDDESTROYED = WM_APP + $101;
CEFBROWSER_DESTROY = WM_APP + $102;
type
TMainForm = class(TForm)
ButtonPnl: TPanel;
Edit1: TEdit;
Button1: TButton;
CEFSentinel1: TCEFSentinel;
Timer1: TTimer;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure FormShow(Sender: TObject);
procedure CEFSentinel1Close(Sender: TObject);
procedure Timer1Timer(Sender: TObject);
private
// Variables to control when can we destroy the form safely
FCanClose : boolean; // Set to True when all the child forms are closed
FClosing : boolean; // Set to True in the CloseQuery event.
procedure CreateToolboxChild(const ChildCaption, URL: string);
procedure CloseAllChildForms;
function GetChildClosing : boolean;
function GetChildFormCount : integer;
procedure CheckCEFInitialization;
protected
procedure ChildDestroyedMsg(var aMessage : TMessage); message CEFBROWSER_CHILDDESTROYED;
public
function CloseQuery: Boolean; override;
property ChildClosing : boolean read GetChildClosing;
property ChildFormCount : integer read GetChildFormCount;
end;
var
MainForm: TMainForm;
implementation
{$R *.dfm}
uses
uChildForm, uCEFApplication;
// Destruction steps
// =================
// 1. Destroy all child forms
// 2. Wait until all the child forms are closed before calling TCEFSentinel.Start, which will trigger TCEFSentinel.OnClose when all renderer processes are closed
// 3. TCEFSentinel.OnClose closes the main form.
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.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.CheckCEFInitialization;
begin
Timer1.Enabled := False;
if (GlobalCEFApp <> nil) and GlobalCEFApp.GlobalContextInitialized then
begin
Caption := 'ToolBox SubProcess Browser';
ButtonPnl.Enabled := True;
cursor := crDefault;
end
else
Timer1.Enabled := True;
end;
procedure TMainForm.Timer1Timer(Sender: TObject);
begin
CheckCEFInitialization;
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 can destroy the main form
if FClosing and (ChildFormCount = 0) then CEFSentinel1.Start;
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.CEFSentinel1Close(Sender: TObject);
begin
FCanClose := True;
PostMessage(Handle, WM_CLOSE, 0, 0);
end;
procedure TMainForm.FormShow(Sender: TObject);
begin
CheckCEFInitialization;
end;
end.