// ************************************************************************
// ***************************** 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 © 2023 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 uJSEval;
{$I cef.inc}
interface
uses
{$IFDEF DELPHI16_UP}
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics, Vcl.Menus,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls, System.Types, Vcl.ComCtrls, Vcl.ClipBrd,
System.UITypes, Soap.EncdDecd,
{$ELSE}
Windows, Messages, SysUtils, Variants, Classes, Graphics, Menus,
Controls, Forms, Dialogs, StdCtrls, ExtCtrls, Types, ComCtrls, ClipBrd, EncdDecd,
{$ENDIF}
uCEFChromium, uCEFWindowParent, uCEFInterfaces, uCEFApplication, uCEFTypes, uCEFConstants,
uCEFWinControl, uCEFSentinel, uCEFChromiumCore;
const
MINIBROWSER_SHOWTEXTVIEWER = WM_APP + $101;
MINIBROWSER_EVALJSCODE = WM_APP + $102;
MINIBROWSER_JSBINPARAM = WM_APP + $103;
MINIBROWSER_GETSCROLLPOS = WM_APP + $104;
MINIBROWSER_CONTEXTMENU_EVALJSCODE = MENU_ID_USER_FIRST + 1;
MINIBROWSER_CONTEXTMENU_JSBINPARAM = MENU_ID_USER_FIRST + 2;
MINIBROWSER_CONTEXTMENU_GETSCROLLPOS = MENU_ID_USER_FIRST + 3;
EVAL_JS = 'JSContextEvalDemo';
BINARY_PARAM_JS = 'JSBinaryParameter';
type
TJSEvalFrm = class(TForm)
CEFWindowParent1: TCEFWindowParent;
Chromium1: TChromium;
AddressBarPnl: TPanel;
GoBtn: TButton;
AddressEdt: TEdit;
Timer1: TTimer;
procedure Chromium1AfterCreated(Sender: TObject; const browser: ICefBrowser);
procedure GoBtnClick(Sender: TObject);
procedure FormShow(Sender: TObject);
procedure Chromium1ProcessMessageReceived(Sender: TObject;
const browser: ICefBrowser; const frame: ICefFrame; sourceProcess: TCefProcessId;
const message: ICefProcessMessage; out Result: Boolean);
procedure Chromium1BeforeContextMenu(Sender: TObject;
const browser: ICefBrowser; const frame: ICefFrame;
const params: ICefContextMenuParams; const model: ICefMenuModel);
procedure Chromium1ContextMenuCommand(Sender: TObject;
const browser: ICefBrowser; const frame: ICefFrame;
const params: ICefContextMenuParams; commandId: Integer;
eventFlags: Cardinal; out Result: Boolean);
procedure Timer1Timer(Sender: TObject);
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: Boolean; var Result: Boolean);
procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
procedure Chromium1Close(Sender: TObject; const browser: ICefBrowser;
var aAction : TCefCloseBrowserAction);
procedure Chromium1BeforeClose(Sender: TObject;
const browser: ICefBrowser);
private
{ Private declarations }
protected
FText : string;
// 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.
procedure BrowserCreatedMsg(var aMessage : TMessage); message CEF_AFTERCREATED;
procedure BrowserDestroyMsg(var aMessage : TMessage); message CEF_DESTROY;
procedure ShowTextViewerMsg(var aMessage : TMessage); message MINIBROWSER_SHOWTEXTVIEWER;
procedure EvalJSCodeMsg(var aMessage : TMessage); message MINIBROWSER_EVALJSCODE;
procedure GetScrollPosMsg(var aMessage : TMessage); message MINIBROWSER_GETSCROLLPOS;
procedure EvalJSBinParamMsg(var aMessage : TMessage); message MINIBROWSER_JSBINPARAM;
procedure WMMove(var aMessage : TWMMove); message WM_MOVE;
procedure WMMoving(var aMessage : TMessage); message WM_MOVING;
procedure WMEnterMenuLoop(var aMessage: TMessage); message WM_ENTERMENULOOP;
procedure WMExitMenuLoop(var aMessage: TMessage); message WM_EXITMENULOOP;
end;
var
JSEvalFrm: TJSEvalFrm;
procedure CreateGlobalCEFApp;
implementation
{$R *.dfm}
uses
uSimpleTextViewer, uCefProcessMessage, uCefBinaryValue, uCefMiscFunctions;
// 99.9% of the code in this demo was created by xpert13 and shared in the CEF4Delphi forum.
// Steps to evaluate some JavaScript code using the V8Context
// ----------------------------------------------------------
// 1. Set GlobalCEFApp.OnProcessMessageReceived to RenderProcessHandler_OnProcessMessageReceivedEvent.
// 2. To get the Javascript code in this demo we use a context menu that sends a MINIBROWSER_EVALJSCODE to the form.
// 3. The EvalJSCodeMsg asks for the Javascript code and sends it to the renderer using a process message.
// 4. RenderProcessHandler_OnProcessMessageReceivedEvent receives the process message and calls ParseEvalJsAnswer
// to evaluate the code.
// 5. ParseEvalJsAnswer evaluates the code and sends a message with the results to the browser process using a
// process message.
// 6. Chromium1ProcessMessageReceived receives the message, stores the results and sends a
// MINIBROWSER_SHOWTEXTVIEWER message to the form.
// 7. ShowTextViewerMsg shows the results safely using a SimpleTextViewer.
// This demo also has an example of binary parameters in process messages
// ----------------------------------------------------------------------
// 1. Set GlobalCEFApp.OnProcessMessageReceived to RenderProcessHandler_OnProcessMessageReceivedEvent.
// 2. The context menu has a 'Send JPEG image' option that sends a MINIBROWSER_JSBINPARAM message to the form.
// 3. EvalJSBinParamMsg asks for a JPEG image and sends a process message with a ICefBinaryValue parameter to the
// renderer process.
// 4. The renderer process parses the binary parameter in the ParseBinaryValue function and sends back the image
// size and encoded image data to the browser process.
// 5. Chromium1ProcessMessageReceived receives the message, stores the results and sends a
// MINIBROWSER_SHOWTEXTVIEWER message to the form.
// 6. ShowTextViewerMsg shows the results safely using a SimpleTextViewer.
// About binary parameters
// -----------------------
// There is a size limit in the binary parameters of only a few kilobytes.
// For more info and alternatives read this thread in the official CEF forum :
// http://www.magpcss.org/ceforum/viewtopic.php?f=6&t=10590
//
// Compress the binary data if necessary!
// 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 TJSEvalFrm.Chromium1AfterCreated(Sender: TObject; const browser: ICefBrowser);
begin
PostMessage(Handle, CEF_AFTERCREATED, 0, 0);
end;
procedure TJSEvalFrm.Chromium1BeforeClose(Sender: TObject;
const browser: ICefBrowser);
begin
FCanClose := True;
PostMessage(Handle, WM_CLOSE, 0, 0);
end;
procedure TJSEvalFrm.Chromium1BeforeContextMenu( Sender : TObject;
const browser : ICefBrowser;
const frame : ICefFrame;
const params : ICefContextMenuParams;
const model : ICefMenuModel);
begin
model.AddItem(MINIBROWSER_CONTEXTMENU_EVALJSCODE, 'Evaluate JavaScript code...');
model.AddItem(MINIBROWSER_CONTEXTMENU_GETSCROLLPOS, 'Get vertical scroll position...');
model.AddItem(MINIBROWSER_CONTEXTMENU_JSBINPARAM, 'Send JPEG image...');
end;
procedure TJSEvalFrm.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: Boolean;
var 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 TJSEvalFrm.Chromium1Close(Sender: TObject;
const browser: ICefBrowser; var aAction : TCefCloseBrowserAction);
begin
PostMessage(Handle, CEF_DESTROY, 0, 0);
aAction := cbaDelay;
end;
procedure TJSEvalFrm.Chromium1ContextMenuCommand( Sender : TObject;
const browser : ICefBrowser;
const frame : ICefFrame;
const params : ICefContextMenuParams;
commandId : Integer;
eventFlags : Cardinal;
out Result : Boolean);
begin
Result := False;
case commandId of
MINIBROWSER_CONTEXTMENU_EVALJSCODE : PostMessage(Handle, MINIBROWSER_EVALJSCODE, 0, 0);
MINIBROWSER_CONTEXTMENU_JSBINPARAM : PostMessage(Handle, MINIBROWSER_JSBINPARAM, 0, 0);
MINIBROWSER_CONTEXTMENU_GETSCROLLPOS : PostMessage(Handle, MINIBROWSER_GETSCROLLPOS, 0, 0);
end;
end;
procedure TJSEvalFrm.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
CanClose := FCanClose;
if not(FClosing) then
begin
FClosing := True;
Visible := False;
Chromium1.CloseBrowser(True);
end;
end;
procedure TJSEvalFrm.FormShow(Sender: TObject);
begin
// 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 TJSEvalFrm.GoBtnClick(Sender: TObject);
begin
Chromium1.LoadURL(AddressEdt.Text);
end;
procedure TJSEvalFrm.BrowserCreatedMsg(var aMessage : TMessage);
begin
CEFWindowParent1.UpdateSize;
AddressBarPnl.Enabled := True;
GoBtn.Click;
end;
procedure TJSEvalFrm.BrowserDestroyMsg(var aMessage : TMessage);
begin
CEFWindowParent1.Free;
end;
procedure TJSEvalFrm.ShowTextViewerMsg(var aMessage : TMessage);
begin
SimpleTextViewerFrm.Memo1.Lines.Text := FText;
SimpleTextViewerFrm.ShowModal;
end;
procedure TJSEvalFrm.Timer1Timer(Sender: TObject);
begin
Timer1.Enabled := False;
if not(Chromium1.CreateBrowser(CEFWindowParent1, '')) and not(Chromium1.Initialized) then
Timer1.Enabled := True;
end;
procedure TJSEvalFrm.WMMove(var aMessage : TWMMove);
begin
inherited;
if (Chromium1 <> nil) then Chromium1.NotifyMoveOrResizeStarted;
end;
procedure TJSEvalFrm.WMMoving(var aMessage : TMessage);
begin
inherited;
if (Chromium1 <> nil) then Chromium1.NotifyMoveOrResizeStarted;
end;
procedure TJSEvalFrm.WMEnterMenuLoop(var aMessage: TMessage);
begin
inherited;
if (aMessage.wParam = 0) and (GlobalCEFApp <> nil) then GlobalCEFApp.OsmodalLoop := True;
end;
procedure TJSEvalFrm.WMExitMenuLoop(var aMessage: TMessage);
begin
inherited;
if (aMessage.wParam = 0) and (GlobalCEFApp <> nil) then GlobalCEFApp.OsmodalLoop := False;
end;
procedure TJSEvalFrm.EvalJSCodeMsg(var aMessage : TMessage);
var
TempMsg : ICefProcessMessage;
TempScript : string;
begin
TempScript := InputBox('JSEval demo', 'Please type some JavaScript code', 'document.title;');
if (length(TempScript) > 0) then
begin
TempMsg := TCefProcessMessageRef.New(EVAL_JS);
if TempMsg.ArgumentList.SetString(0, TempScript) then
Chromium1.SendProcessMessage(PID_RENDERER, TempMsg);
end;
end;
procedure TJSEvalFrm.GetScrollPosMsg(var aMessage : TMessage);
var
TempMsg : ICefProcessMessage;
begin
TempMsg := TCefProcessMessageRef.New(EVAL_JS);
if TempMsg.ArgumentList.SetString(0, 'window.pageYOffset') then
Chromium1.SendProcessMessage(PID_RENDERER, TempMsg);
end;
procedure TJSEvalFrm.EvalJSBinParamMsg(var aMessage : TMessage);
var
TempMsg : ICefProcessMessage;
TempOpenDialog : TOpenDialog;
TempStream : TFileStream;
TempBinValue : ICefBinaryValue;
TempBuffer : TBytes;
TempSize : NativeUInt;
TempPointer : pointer;
begin
TempOpenDialog := nil;
TempStream := nil;
try
try
TempOpenDialog := TOpenDialog.Create(nil);
TempOpenDialog.Options := TempOpenDialog.Options + [ofFileMustExist];
TempOpenDialog.Filter := 'JPEG files (*.jpg)|*.JPG';
if TempOpenDialog.Execute then
begin
TempStream := TFileStream.Create(TempOpenDialog.FileName, fmOpenRead);
TempSize := TempStream.Size;
if (TempSize > 0) then
begin
SetLength(TempBuffer, TempSize);
TempSize := TempStream.Read(TempBuffer[0], TempSize);
if (TempSize > 0) then
begin
TempPointer := @TempBuffer[0];
TempBinValue := TCefBinaryValueRef.New(TempPointer, TempSize);
TempMsg := TCefProcessMessageRef.New(BINARY_PARAM_JS);
if TempMsg.ArgumentList.SetBinary(0, TempBinValue) then
Chromium1.SendProcessMessage(PID_RENDERER, TempMsg);
end;
end;
end;
except
on e : exception do
if CustomExceptionHandler('TJSEvalFrm.EvalJSBinParamMsg', e) then raise;
end;
finally
if (TempOpenDialog <> nil) then FreeAndNil(TempOpenDialog);
if (TempStream <> nil) then FreeAndNil(TempStream);
SetLength(TempBuffer, 0);
end;
end;
procedure ParseEvalJsAnswer(const pMessage : ICefProcessMessage;
const pBrowser : ICefBrowser;
const pFrame : ICefFrame;
const pReturnValue : ICefv8Value;
const pException : ICefV8Exception);
var
pAnswer : ICefProcessMessage;
strResult : String;
bGoodDataType : Boolean;
begin
pAnswer := TCefProcessMessageRef.New(EVAL_JS);
if (pReturnValue = nil) or not(pReturnValue.IsValid) then
begin
pAnswer.ArgumentList.SetBool(0, false);
pAnswer.ArgumentList.SetString(1, pException.Message);
end
else
begin
bGoodDataType := True;
if pReturnValue.IsString then strResult := pReturnValue.GetStringValue
else if pReturnValue.IsBool then strResult := BoolToStr(pReturnValue.GetBoolValue)
else if pReturnValue.IsInt then strResult := IntToStr(pReturnValue.GetIntValue)
else if pReturnValue.IsUInt then strResult := IntToStr(pReturnValue.GetUIntValue)
else if pReturnValue.IsDouble then strResult := FloatToStr(pReturnValue.GetDoubleValue)
else bGoodDataType := False;
if bGoodDataType then
begin
pAnswer.ArgumentList.SetBool(0, true);
pAnswer.ArgumentList.SetString(1, strResult);
end
else
begin
pAnswer.ArgumentList.SetBool(0, false);
pAnswer.ArgumentList.SetString(1, 'Result data type need to be string, int, uint or double!');
end;
end;
if (pFrame <> nil) and pFrame.IsValid then
pFrame.SendProcessMessage(PID_BROWSER, pAnswer);
end;
procedure ParseBinaryValue(const pBrowser : ICefBrowser; const pFrame : ICefFrame; const aBinaryValue : ICefBinaryValue);
var
pAnswer : ICefProcessMessage;
TempBuffer : TBytes;
TempPointer : pointer;
TempSize : NativeUInt;
TempString : string;
begin
if (aBinaryValue = nil) then exit;
try
try
TempSize := aBinaryValue.GetSize;
if (TempSize > 0) then
begin
SetLength(TempBuffer, TempSize);
TempPointer := @TempBuffer[0];
TempSize := aBinaryValue.GetData(TempPointer, TempSize, 0);
if (TempSize > 0) then
begin
pAnswer := TCefProcessMessageRef.New(BINARY_PARAM_JS);
TempString := 'Image size : ' + inttostr(TempSize) + #13 + #10 +
'Encoded image : ' + EncodeBase64(TempPointer, TempSize);
if (pFrame <> nil) and pFrame.IsValid and pAnswer.ArgumentList.SetString(0, TempString) then
pFrame.SendProcessMessage(PID_BROWSER, pAnswer);
end;
end;
except
on e : exception do
if CustomExceptionHandler('ParseBinaryValue', e) then raise;
end;
finally
SetLength(TempBuffer, 0);
end;
end;
procedure RenderProcessHandler_OnProcessMessageReceivedEvent(const pBrowser : ICefBrowser;
const pFrame : ICefFrame;
uSourceProcess : TCefProcessId;
const pMessage : ICefProcessMessage;
var aHandled : boolean);
var
pV8Context : ICefv8Context;
pReturnValue : ICefv8Value;
pException : ICefV8Exception;
TempScript : string;
TempBinValue : ICefBinaryValue;
begin
aHandled := False;
if (pMessage = nil) or (pMessage.ArgumentList = nil) then exit;
if (pMessage.Name = EVAL_JS) then
begin
TempScript := pMessage.ArgumentList.GetString(0);
if (length(TempScript) > 0) and (pFrame <> nil) and pFrame.IsValid then
begin
pV8Context := pFrame.GetV8Context;
if pV8Context.Enter then
begin
pV8Context.Eval(TempScript, '', 1, pReturnValue, pException);
ParseEvalJsAnswer(pMessage, pBrowser, pFrame, pReturnValue, pException);
pV8Context.Exit;
end;
end;
aHandled := True;
end
else
if (pMessage.Name = BINARY_PARAM_JS) then
begin
TempBinValue := pMessage.ArgumentList.GetBinary(0);
ParseBinaryValue(pBrowser, pFrame, TempBinValue);
aHandled := True;
end;
end;
procedure CreateGlobalCEFApp;
begin
GlobalCEFApp := TCefApplication.Create;
GlobalCEFApp.OnProcessMessageReceived := RenderProcessHandler_OnProcessMessageReceivedEvent;
end;
procedure TJSEvalFrm.Chromium1ProcessMessageReceived( Sender : TObject;
const browser : ICefBrowser;
const frame : ICefFrame;
sourceProcess : TCefProcessId;
const message : ICefProcessMessage;
out Result : Boolean);
begin
Result := False;
if (message = nil) or (message.ArgumentList = nil) then exit;
if (message.Name = EVAL_JS) then
begin
FText := message.ArgumentList.GetString(1);
PostMessage(Handle, MINIBROWSER_SHOWTEXTVIEWER, 0, 0);
Result := True;
end
else
if (message.Name = BINARY_PARAM_JS) then
begin
FText := message.ArgumentList.GetString(0);
PostMessage(Handle, MINIBROWSER_SHOWTEXTVIEWER, 0, 0);
Result := True;
end;
end;
end.