CEF4Delphi/demos/Delphi_VCL/GestureBrowser/uGestureBrowser.pas

// ************************************************************************
// ***************************** 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> 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 uGestureBrowser;

{$I cef.inc}

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
  System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
  Vcl.StdCtrls, Vcl.ExtCtrls, Vcl.Touch.GestureMgr,
  uCEFChromium, uCEFWindowParent, uCEFInterfaces, uCEFConstants, uCEFTypes,
  uCEFWinControl, uCEFSentinel, uCEFChromiumCore;

type
  TForm1 = class(TForm)
    AddressPnl: TPanel;
    AddressEdt: TEdit;
    GoBtn: TButton;
    Timer1: TTimer;
    Chromium1: TChromium;
    CEFWindowParent1: TCEFWindowParent;
    GestureManager1: TGestureManager;
    procedure GoBtnClick(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure Chromium1AfterCreated(Sender: TObject; const browser: ICefBrowser);
    procedure FormCreate(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure Chromium1Close(Sender: TObject; const browser: ICefBrowser;
      var aAction : TCefCloseBrowserAction);
    procedure Chromium1BeforeClose(Sender: TObject;
      const browser: ICefBrowser);
    procedure Chromium1BeforePopup(Sender: TObject;
      const browser: ICefBrowser; const frame: ICefFrame; const targetUrl,
      targetFrameName: ustring;
      targetDisposition: TCefWindowOpenDisposition; userGesture: Boolean;
      const popupFeatures: TCefPopupFeatures;
      var windowInfo: TCefWindowInfo; var client: ICefClient;
      var settings: TCefBrowserSettings;
      var extra_info: ICefDictionaryValue; var noJavascriptAccess,
      Result: Boolean);
    procedure Chromium1OpenUrlFromTab(Sender: TObject;
      const browser: ICefBrowser; const frame: ICefFrame;
      const targetUrl: ustring;
      targetDisposition: TCefWindowOpenDisposition; userGesture: Boolean;
      out Result: Boolean);
    procedure Chromium1RenderCompMsg(var aMessage: TMessage;
      var aHandled: Boolean);
    procedure CEFWindowParent1Gesture(Sender: TObject;
      const EventInfo: TGestureEventInfo; var Handled: Boolean);
  protected
    // Variables to control when can we destroy the form safely
    FCanClose : boolean;  // Set to True in TChromium.OnBeforeClose
    FClosing  : boolean;  // Set to True in the CloseQuery event.

    // You have to handle this two messages to call NotifyMoveOrResizeStarted or some page elements will be misaligned.
    procedure WMMove(var aMessage : TWMMove); message WM_MOVE;
    procedure WMMoving(var aMessage : TMessage); message WM_MOVING;
    // You also have to handle these two messages to set GlobalCEFApp.OsmodalLoop
    procedure WMEnterMenuLoop(var aMessage: TMessage); message WM_ENTERMENULOOP;
    procedure WMExitMenuLoop(var aMessage: TMessage); message WM_EXITMENULOOP;

    procedure BrowserCreatedMsg(var aMessage : TMessage); message CEF_AFTERCREATED;
    procedure BrowserDestroyMsg(var aMessage : TMessage); message CEF_DESTROY;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses
  uCEFApplication, uCefMiscFunctions;

// This demo shows how to use touch/mouse gestures with a TChromium and
// TCEFWindowParent.

// It uses a TGestureManager which means that it needs Delphi 2010 or newer.

// This demo intercepts the mouse and touch related messages in the
// TChromium.OnRenderCompMsg event and sends them to TCEFWindowParent which
// has a linked TGestureManager.

// Enable the touch gestures you need in the TCEFWindowParent.Touch property
// and use the TCEFWindowParent.OnGesture event to handle them.

// Destruction steps
// =================
// 1. FormCloseQuery sets CanClose to FALSE calls TChromium.CloseBrowser which
//    triggers the TChromium.OnClose event.
// 2. TChromium.OnClose sends a CEFBROWSER_DESTROY message to destroy
//    CEFWindowParent1 in the main thread, which triggers the
//    TChromium.OnBeforeClose event.
// 3. TChromium.OnBeforeClose sets FCanClose := True and sends WM_CLOSE to the
//    form.

procedure TForm1.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
  CanClose := FCanClose;

  if not(FClosing) then
    begin
      FClosing := True;
      Visible  := False;
      Chromium1.CloseBrowser(True);
    end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  FCanClose := False;
  FClosing  := False;
  Chromium1.DefaultURL := AddressEdt.Text;
end;

procedure TForm1.FormShow(Sender: TObject);
begin
  // You *MUST* call CreateBrowser to create and initialize the browser.
  // This will trigger the AfterCreated event when the browser is fully
  // initialized and ready to receive commands.

  // GlobalCEFApp.GlobalContextInitialized has to be TRUE before creating any browser
  // If it's not initialized yet, we use a simple timer to create the browser later.
  if not(Chromium1.CreateBrowser(CEFWindowParent1)) then Timer1.Enabled := True;
end;

procedure TForm1.CEFWindowParent1Gesture(Sender: TObject;
  const EventInfo: TGestureEventInfo; var Handled: Boolean);
begin
  case EventInfo.GestureID of
    sgiLeft  : Chromium1.GoBack;
    sgiRight : Chromium1.GoForward;
  end;
end;

procedure TForm1.Chromium1AfterCreated(Sender: TObject; const browser: ICefBrowser);
begin
  // Now the browser is fully initialized we can send a message to the main form to load the initial web page.
  PostMessage(Handle, CEF_AFTERCREATED, 0, 0);
end;

procedure TForm1.Chromium1BeforeClose(Sender: TObject;
  const browser: ICefBrowser);
begin
  FCanClose := True;
  PostMessage(Handle, WM_CLOSE, 0, 0);
end;

procedure TForm1.Chromium1BeforePopup(Sender: TObject;
  const browser: ICefBrowser; const frame: ICefFrame; const targetUrl,
  targetFrameName: ustring; targetDisposition: TCefWindowOpenDisposition;
  userGesture: Boolean; const popupFeatures: TCefPopupFeatures;
  var windowInfo: TCefWindowInfo; var client: ICefClient;
  var settings: TCefBrowserSettings; var extra_info: ICefDictionaryValue;
  var noJavascriptAccess, Result: Boolean);
begin
  // For simplicity, this demo blocks all popup windows and new tabs
  Result := (targetDisposition in [WOD_NEW_FOREGROUND_TAB, WOD_NEW_BACKGROUND_TAB, WOD_NEW_POPUP, WOD_NEW_WINDOW]);
end;

procedure TForm1.Chromium1Close(Sender: TObject;
  const browser: ICefBrowser; var aAction : TCefCloseBrowserAction);
begin
  PostMessage(Handle, CEF_DESTROY, 0, 0);
  aAction := cbaDelay;
end;

procedure TForm1.Chromium1OpenUrlFromTab(Sender: TObject;
  const browser: ICefBrowser; const frame: ICefFrame;
  const targetUrl: ustring; targetDisposition: TCefWindowOpenDisposition;
  userGesture: Boolean; out Result: Boolean);
begin
  // For simplicity, this demo blocks all popup windows and new tabs
  Result := (targetDisposition in [WOD_NEW_FOREGROUND_TAB, WOD_NEW_BACKGROUND_TAB, WOD_NEW_POPUP, WOD_NEW_WINDOW]);
end;

procedure TForm1.Chromium1RenderCompMsg(var aMessage: TMessage;
  var aHandled: Boolean);
begin
  if FClosing then exit;

  case aMessage.Msg of
    WM_MOUSEFIRST..WM_MOUSELAST,
    WM_TOUCH,
    WM_GESTURE,
    WM_GESTURENOTIFY :
      PostMessage(CEFWindowParent1.Handle, aMessage.Msg, aMessage.wParam, aMessage.lParam);
  end;
end;

procedure TForm1.BrowserCreatedMsg(var aMessage : TMessage);
begin
  Caption            := 'Gesture Browser';
  AddressPnl.Enabled := True;
end;

procedure TForm1.BrowserDestroyMsg(var aMessage : TMessage);
begin
  CEFWindowParent1.Free;
end;

procedure TForm1.GoBtnClick(Sender: TObject);
begin
  // This will load the URL in the edit box
  Chromium1.LoadURL(AddressEdt.Text);
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  Timer1.Enabled := False;
  if not(Chromium1.CreateBrowser(CEFWindowParent1)) and not(Chromium1.Initialized) then
    Timer1.Enabled := True;
end;

procedure TForm1.WMMove(var aMessage : TWMMove);
begin
  inherited;

  if (Chromium1 <> nil) then Chromium1.NotifyMoveOrResizeStarted;
end;

procedure TForm1.WMMoving(var aMessage : TMessage);
begin
  inherited;

  if (Chromium1 <> nil) then Chromium1.NotifyMoveOrResizeStarted;
end;

procedure TForm1.WMEnterMenuLoop(var aMessage: TMessage);
begin
  inherited;

  if (aMessage.wParam = 0) and (GlobalCEFApp <> nil) then GlobalCEFApp.OsmodalLoop := True;
end;

procedure TForm1.WMExitMenuLoop(var aMessage: TMessage);
begin
  inherited;

  if (aMessage.wParam = 0) and (GlobalCEFApp <> nil) then GlobalCEFApp.OsmodalLoop := False;
end;

end.