如何将上下文菜单附加到 TChromium 浏览器

Question

我有一个来自 Delphi Chromium Embedded 的 TChromium broser (http://code.google.com/p/delphichromiumembedded)。我想为其附加一个上下文菜单。我怎样才能做到这一点？

Answer 1

您需要处理 OnBeforeMenu 事件。在该事件处理程序中，将输出参数 Result 设置为 True 即可，这将禁止弹出默认上下文菜单。之后，您可以在从 menuInfo 结构。

下面是带有自定义弹出菜单的代码示例：

uses
  ceflib, cefvcl;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Chromium1.Load('www.example.com');
end;

procedure TForm1.Chromium1BeforeMenu(Sender: TObject;
  const browser: ICefBrowser; const menuInfo: PCefHandlerMenuInfo;
  out Result: Boolean);
begin
  Result := True;
  PopupMenu1.Popup(menuInfo.x, menuInfo.y);
end;

procedure TForm1.PopupMenuItemClick(Sender: TObject);
begin
  ShowMessage('You''ve clicked on a custom popup item :)');
end;

更新：

对于动态创建的实例，您必须手动分配事件处理程序。尝试以下代码。

uses
  ceflib, cefvcl;

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    Button1: TButton;
    PopupMenu1: TPopupMenu;
    procedure Button1Click(Sender: TObject);
  private
    procedure ChromiumOnBeforeMenu(Sender: TObject;
      const browser: ICefBrowser; const menuInfo: PCefHandlerMenuInfo;
      out Result: Boolean);
  public
    { Public declarations }
  end;

implementation

procedure Form1.ChromiumOnBeforeMenu(Sender: TObject; const browser: ICefBrowser;
  const menuInfo: PCefHandlerMenuInfo; out Result: Boolean);
begin
  Result := True;
  PopupMenu1.Popup(menuInfo.x, menuInfo.y);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  Chromium: TChromium;
begin
  // owner is responsible for destroying the component
  // in this case you are telling to Panel1 to destroy
  // the Chromium instance before he destroys itself,
  // it doesn't affect the event handling
  Chromium := TChromium.Create(Panel1);

  Chromium.Parent := Panel1;
  Chromium.Left := 10;
  Chromium.Top := 10;
  Chromium.Width := Panel1.Width - 20;
  Chromium.Height := Panel1.Height - 20;

  // this line is important, you are assigning the event
  // handler for OnBeforeMenu event, so in fact you tell
  // to the Chromium; hey if the OnBeforeMenu fires, run
  // the code I'm pointing at, in this case will execute
  // the ChromiumOnBeforeMenu procedure
  Chromium.OnBeforeMenu := ChromiumOnBeforeMenu;

  Chromium.Load('www.example.com');
end;

Answer 2

实际上，如果您已经可以构建 chromium 的上下文菜单，则不需要 popupmenu 并且不必将 vcl.menus 单元添加到您的应用程序中。而且 chromium 自己的菜单比使用老式 win32 api 库的 vcl 更现代、更清晰，并且绘制性能更快。

cef3 的菜单完全可以像这样配置。

 procedure Tfmmain.Chromium1BeforeContextMenu(Sender: TObject;
    const browser: ICefBrowser; const frame: ICefFrame;
    const params: ICefContextMenuParams; const model: ICefMenuModel);
  begin
    model.Clear;
    model.AddItem(1, 'Your Command 1');
    model.AddItem(2, 'Your Command 2');
    model.AddSeparator;
    model.AddItem(3, 'Your Command 3');
    model.AddItem(4, 'your Command 4');
    model.AddSeparator;
    model.AddItem(999, 'Quit');

    model.SetAccelerator(1, VK_RIGHT, false, false, false);
    model.SetAccelerator(2, VK_LEFT, false, false, false);

    model.SetAccelerator(3, VK_DOWN, false, false, false);
    model.SetAccelerator(4, VK_UP, false, false, false);

    model.SetAccelerator(999, VK_ESCAPE, false, false, false);

  end;

---

  procedure Tfmmain.Chromium1ContextMenuCommand(Sender: TObject;
    const browser: ICefBrowser; const frame: ICefFrame;
    const params: ICefContextMenuParams; commandId: Integer;
    eventFlags: TCefEventFlags; out Result: Boolean);
  begin
    case commandId of
      1:
        begin
           DoIt1;
          Result := true;
        end;
      2:
        begin
         DoIt2;
          Result := true;
        end;
      3:
        begin
        DoIt3;
          Result := true;
        end;
      4:
       DoIt4;
          Result := true;
        end;
      999:
        begin
          Application.MainForm.Close;
           Result := true;
        end;
    end;

  end;

---

note:SetAccelerator shortcuts only functional if popup appears.so you may need onPreKeyEvent