I am developing a custom browser using the Microsoft Foundation Class (MFC) CHtmlView class. I want to make all windows open within my custom browser, and not in Microsoft Internet Explorer.
Dhiren Vyas
The Web Team replies:
As you probably already know, developing your own custom browser gives you complete control over your user interface whilst making use of the incredible technology that Internet Explorer has to offer. You get to choose what your browser looks like and what it can do for your customers. Microsoft Visual C++ makes this task even easier by providing an MFC class, CHtmlView, that implements a view based on the WebBrowser control—a reusable component of Internet Explorer.
There are obstacles, though. When a Web page opens a window (by calling window.open, for example) an Internet Explorer object is created. This means that the Web page will appear in an Internet Explorer window. If you want all windows to appear in your application, you can use the NewWindow2 event, available on the DWebBrowserEvents2 interface. We'll demonstrate how this event can be used in a multiple document interface (MDI) MFC application. We'll be brief because this subject is covered in detail in the Knowledge Base article HOWTO: Use the WebBrowser Control NewWindow2 Event (Q184876).
First let's create an MDI MFC application using the AppWizard. During the final page of the wizard, select a view class that is derived from CHtmlView. Then use the ClassWizard to add an event handler for the NewWindow2 event. Finally, add code to your NewWindow2 event handler function:
void CMyHtmlView::OnNewWindow2(LPDISPATCH* ppDisp, BOOL* Cancel)
{
// Get a pointer to the application object.
CWinApp* pApp = AfxGetApp();
// Get the correct document template.
POSITION pos = pApp->GetFirstDocTemplatePosition();
CDocTemplate* pDocTemplate = pApp->GetNextDocTemplate( pos );
// Create a new frame.
CFrameWnd* pFrame = pDocTemplate->CreateNewFrame(
GetDocument(),
(CFrameWnd*)AfxGetMainWnd() );
// Activate the frame.
pDocTemplate->InitialUpdateFrame( pFrame, NULL );
CNewWindow2View* pView = (CNewWindow2View*)pFrame->GetActiveView();
// Pass pointer of WebBrowser object.
pView->SetRegisterAsBrowser( TRUE );
*ppDisp = pView->GetApplication();
}
Navigate to a Web page that opens a new window and you'll see the Web page displayed in your application. This works because your application intercepts the NewWindow2 event, creates a new document/frame/view combination, and passes the IDispatch for the WebBrowser object. This causes your CHtmlView-derived class to be used to display the Web page. Note that the WebBrowser object must be created each time and not have navigated to a URL, or this won’t work.
You'll probably want to make this more useful by obtaining the window information, such as the height and width, so that you can modify your view accordingly. A simple approach to this is to handle the BeforeNavigate2 event that is fired after the new window is created. Add the following code to your application to resize the view to the size of the new window. Note that this is an overridden method that allows access to the WebBrowser object, and that an additional Boolean member, m_bResizeWindow, is required. Set this to false in the constructor and true in the NewWindow2 event handler to ensure this code is only called for new windows.
void CMyHtmlView::BeforeNavigate2(LPDISPATCH pDisp, VARIANT* URL,
VARIANT* Flags, VARIANT* TargetFrameName,
VARIANT* PostData, VARIANT* Headers, BOOL* Cancel)
{
if ( m_bResizeWindow )
{
IWebBrowser2* pWB = NULL;
// QI the dispatch for WebBrowser control.
HRESULT hr = pDisp->QueryInterface( IID_IWebBrowser2,
(void**)pWB );
if ( SUCCEEDED(hr) )
{
long x,y;
// Get dimensions.
pWB->get_Width( x );
pWB->get_Height( y );
// Resize frame.
SetScrollSizes( MM_TEXT, CSize(x,y) );
ResizeParentToFit();
pWB->Release();
}
m_bResizeWindow = false;
}
}