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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//
// Description:
// WebBrowserEvent is used to listen to the DWebBrowserEvent2
// of the webbrowser control
//
// Copied from WebBrowse.cs in winforms
//
using System.Runtime.InteropServices;
using System.Windows.Navigation;
using System.Windows.Controls;
using MS.Win32;
using MS.Internal.AppModel;
using MS.Internal.Interop;
//In order to avoid generating warnings about unknown message numbers and
//unknown pragmas when compiling your C# source code with the actual C# compiler,
//you need to disable warnings 1634 and 1691. (Presharp Documentation)
#pragma warning disable 1634, 1691
namespace MS.Internal.Controls
{
[ClassInterface(ClassInterfaceType.None)]
internal class WebBrowserEvent :
InternalDispatchObject<UnsafeNativeMethods.DWebBrowserEvents2>,
UnsafeNativeMethods.DWebBrowserEvents2
{
private WebBrowser _parent;
public WebBrowserEvent(WebBrowser parent)
{
_parent = parent;
Debug.Assert(parent != null, "WebBrowser control required for hooking webbrowser events");
}
public void BeforeNavigate2(object pDisp, ref object url, ref object flags, ref object targetFrameName, ref object postData, ref object headers, ref bool cancel)
{
bool newNavigationInitiated = false;
bool cancelRequested = false;
try
{
Debug.Assert(url == null || url is string, "invalid url type");
Debug.Assert(targetFrameName == null || targetFrameName is string, "invalid targetFrameName type");
Debug.Assert(headers == null || headers is string, "invalid headers type");
//
// Due to a bug in the interop code where the variant.bstr value gets set
// to -1 on return back to native code, if the original value was null, we
// have to set targetFrameName and headers to "".
if (targetFrameName == null)
{
targetFrameName = "";
}
if (headers == null)
{
headers = "";
}
string urlString = (string)url;
Uri source = String.IsNullOrEmpty(urlString) ? null : new Uri(urlString);
UnsafeNativeMethods.IWebBrowser2 axIWebBrowser2 = (UnsafeNativeMethods.IWebBrowser2)pDisp;
// If _parent.AxIWebBrowser2 != axIWebBrowser2, navigation happens in a nested [i]frame.
// in that case we do not want to enforce site locking as we want the default IE behavior to take
// over.
if (_parent.AxIWebBrowser2 == axIWebBrowser2)
{
// The NavigatingToAboutBlank property indicates whether we are navigating to "about:blank"
// as a result of navigating to null or stream/string navigation.
// We set the NavigatingToAboutBlank bit to true in the WebBrowser DoNavigate method. When the above
// conditions occur, the NavigatingToAboutBlank is true and the source must be "about:blank".
//
// But when end user navigates away from the current about:blank page (by clicking
// on a hyperlink, Goback/Forward), or programmatically call GoBack and Forward,
// When we get the navigating event, NavigatingToAboutBlank is true, but the source is not "about:blank".
// Clear the NavigatingToAboutBlank bit in that case.
if ((_parent.NavigatingToAboutBlank) && !string.Equals(urlString, WebBrowser.AboutBlankUriString, StringComparison.OrdinalIgnoreCase))
{
_parent.NavigatingToAboutBlank = false;
}
// When source set to null or navigating to stream/string, we navigate to "about:blank"
// internally. Make sure we pass null in the event args.
if (_parent.NavigatingToAboutBlank)
{
source = null;
}
NavigatingCancelEventArgs e = new NavigatingCancelEventArgs(source,
null, null, null, NavigationMode.New, null, null, true);
// Launching a navigation from the Navigating event handler causes reentrancy.
// For more info, see WebBrowser.LastNavigation. This is a point of possible reentrancy. Whenever
// a new navigation is started during the call to the Navigating event handler, we need to cancel
// out the current navigation.
Guid lastNavigation = _parent.LastNavigation;
// Fire navigating event. Events are only fired for top level navigation.
_parent.OnNavigating(e);
// Launching a navigation from the Navigating event handler causes reentrancy.
// For more info, see WebBrowser.LastNavigation. If _lastNavigation has changed during the call to
// the event handlers for Navigating, we know a new navigation has been initialized.
if (_parent.LastNavigation != lastNavigation)
{
newNavigationInitiated = true;
}
cancelRequested = e.Cancel;
}
}
// We disable this to suppress FXCop warning since in this case we really want to catch all exceptions
// please refer to comment below
#pragma warning disable 6502
catch
{
// This is an interesting pattern of putting a try catch block around this that catches everything,
// The reason I do this is based on a conversation with Changov. What happens here is if there is
// an exception in any of the code above then navigation still continues since COM interop eats up
// the exception. But what we want is for this navigation to fail.
// There fore I catch all exceptions and cancel navigation
cancelRequested = true;
}
#pragma warning restore 6502
finally
{
// Clean the WebBrowser control state if navigation cancelled.
//
// Launching a navigation from the Navigating event handler causes reentrancy.
// For more info, see WebBrowser.LastNavigation. A new navigation started during event handling for
// the Navigating event will have touched the control's global state. In case the navigation was
// cancelled in order to start a new navigation, we shouldn't tamper with that new state.
if (cancelRequested && !newNavigationInitiated)
{
_parent.CleanInternalState();
}
// Launching a navigation from the Navigating event handler causes reentrancy.
// For more info, see WebBrowser.LastNavigation. Whenever a new navigation is started during the
// call to the Navigating event handler, we need to cancel out the current navigation.
if (cancelRequested || newNavigationInitiated)
{
cancel = true;
}
}
}
/// <summary>
/// Determines whether a URI has a recognized and allowed URI scheme that we shouldn't block on navigation
/// attempts from the browser, regardless of whether we are partial trust or not.
/// </summary>
private static bool IsAllowedScriptScheme(Uri uri)
{
return uri != null && (uri.Scheme == "javascript" || uri.Scheme == "vbscript");
}
/// <summary>
/// Critical: This code extracts the IWebBrowser2, IHTMLDocument interface.
/// TreatAsSafe: This does not expose the interface.
/// </summary>
public void NavigateComplete2(object pDisp, ref object url)
{
Debug.Assert(url == null || url is string, "invalid url type");
// Events only fired for top level navigation.
UnsafeNativeMethods.IWebBrowser2 axIWebBrowser2 = (UnsafeNativeMethods.IWebBrowser2)pDisp;
if (_parent.AxIWebBrowser2 == axIWebBrowser2 && !ShouldIgnoreCompletionEvent(ref url))
{
// If we are loading from stream.
if (_parent.DocumentStream != null)
{
Invariant.Assert(_parent.NavigatingToAboutBlank && string.Equals((string)url, WebBrowser.AboutBlankUriString, StringComparison.OrdinalIgnoreCase));
try
{
UnsafeNativeMethods.IHTMLDocument nativeHTMLDocument = _parent.NativeHTMLDocument;
if (nativeHTMLDocument != null)
{
UnsafeNativeMethods.IPersistStreamInit psi = nativeHTMLDocument as UnsafeNativeMethods.IPersistStreamInit;
Debug.Assert(psi != null, "The Document does not implement IPersistStreamInit");
System.Runtime.InteropServices.ComTypes.IStream iStream =
new MS.Internal.IO.Packaging.ManagedIStream(_parent.DocumentStream);
psi.Load(iStream);
}
}
finally
{
_parent.DocumentStream = null;
}
}
else
{
string urlString = (string)url;
// When source set to null or navigating to stream/string, we navigate to "about:blank"
// internally. Make sure we pass null in the event args.
if (_parent.NavigatingToAboutBlank)
{
Invariant.Assert(string.Equals(urlString, WebBrowser.AboutBlankUriString, StringComparison.OrdinalIgnoreCase));
urlString = null;
}
Uri source = string.IsNullOrEmpty(urlString) ? null : new Uri(urlString);
NavigationEventArgs e = new NavigationEventArgs(source, null, null, null, null, true);
_parent.OnNavigated(e);
}
}
}
/// <summary>
/// Critical: This code accesses the IWebBrowser2, IHTMLDocument interface.
/// TreatAsSafe: This does not expose the interface.
/// </summary>
public void DocumentComplete(object pDisp, ref object url)
{
Debug.Assert(url == null || url is string, "invalid url type");
// Events only fired for top level navigation.
UnsafeNativeMethods.IWebBrowser2 axIWebBrowser2 = (UnsafeNativeMethods.IWebBrowser2)pDisp;
if (_parent.AxIWebBrowser2 == axIWebBrowser2 && !ShouldIgnoreCompletionEvent(ref url))
{
string urlString = (string)url;
// When source set to null or navigating to stream/string, we navigate to "about:blank"
// internally. Make sure we pass null in the event args.
if (_parent.NavigatingToAboutBlank)
{
Invariant.Assert(string.Equals(urlString, WebBrowser.AboutBlankUriString, StringComparison.OrdinalIgnoreCase));
urlString = null;
}
Uri source = string.IsNullOrEmpty(urlString) ? null : new Uri(urlString);
NavigationEventArgs e = new NavigationEventArgs(source, null, null, null, null, true);
_parent.OnLoadCompleted(e);
}
}
// if we are navigating to "about:blank", ignore completion events
// for any other url. These can happen despite our attempt to cancel
// outstanding navigations (see WebBrowser.DoNavigate), due to race
// conditions between the browser and us.
private bool ShouldIgnoreCompletionEvent(ref object url)
{
string urlString = url as string;
return _parent.NavigatingToAboutBlank && !string.Equals(urlString, WebBrowser.AboutBlankUriString, StringComparison.OrdinalIgnoreCase);
}
public void CommandStateChange(long command, bool enable)
{
if (command == NativeMethods.CSC_NAVIGATEBACK)
{
_parent._canGoBack = enable;
}
else if (command == NativeMethods.CSC_NAVIGATEFORWARD)
{
_parent._canGoForward = enable;
}
}
public void TitleChange(string text)
{
//this.parent.OnDocumentTitleChanged(EventArgs.Empty);
}
public void SetSecureLockIcon(int secureLockIcon)
{
//this.parent.encryptionLevel = (WebBrowserEncryptionLevel)secureLockIcon;
//this.parent.OnEncryptionLevelChanged(EventArgs.Empty);
}
public void NewWindow2(ref object ppDisp, ref bool cancel)
{
//CancelEventArgs e = new CancelEventArgs();
//this.parent.OnNewWindow(e);
//cancel = e.Cancel;
}
public void ProgressChange(int progress, int progressMax)
{
//WebBrowserProgressChangedEventArgs e = new WebBrowserProgressChangedEventArgs(progress, progressMax);
//this.parent.OnProgressChanged(e);
}
public void StatusTextChange(string text)
{
_parent.RaiseEvent(new RequestSetStatusBarEventArgs(text));
}
public void DownloadBegin()
{
//this.parent.OnFileDownload(EventArgs.Empty);
}
public void FileDownload(ref bool activeDocument, ref bool cancel) { }
public void PrivacyImpactedStateChange(bool bImpacted) { }
public void UpdatePageStatus(object pDisp, ref object nPage, ref object fDone) { }
public void PrintTemplateTeardown(object pDisp) { }
public void PrintTemplateInstantiation(object pDisp) { }
public void NavigateError(object pDisp, ref object url, ref object frame, ref object statusCode, ref bool cancel) { }
public void ClientToHostWindow(ref long cX, ref long cY) { }
public void WindowClosing(bool isChildWindow, ref bool cancel) { }
public void WindowSetHeight(int height) { }
public void WindowSetWidth(int width) { }
public void WindowSetTop(int top) { }
public void WindowSetLeft(int left) { }
public void WindowSetResizable(bool resizable) { }
public void OnTheaterMode(bool theaterMode) { }
public void OnFullScreen(bool fullScreen) { }
public void OnStatusBar(bool statusBar) { }
public void OnMenuBar(bool menuBar) { }
public void OnToolBar(bool toolBar) { }
public void OnVisible(bool visible) { }
public void OnQuit() { }
public void PropertyChange(string szProperty) { }
public void DownloadComplete() { }
public void SetPhishingFilterStatus(uint phishingFilterStatus) { }
public void WindowStateChanged(uint dwFlags, uint dwValidFlagsMask) { }
}
}
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