Add the ability to enable / disable and check for the editable property of a rendering engine. Implement for all three backends and extend the sample, document and unit test.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/SOC2011_WEBVIEW@68193 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/webview_ie.cpp

@@ -544,6 +544,26 @@ void wxWebViewIE::Redo()
     ExecCommand("Redo");
 }
 
+void wxWebViewIE::SetEditable(bool enable)
+{
+    IHTMLDocument2* document = GetDocument();
+    if( enable )
+        document->put_designMode(SysAllocString(L"On"));
+    else
+        document->put_designMode(SysAllocString(L"Off"));
+}
+
+bool wxWebViewIE::IsEditable()
+{
+    IHTMLDocument2* document = GetDocument();
+    BSTR mode;
+    document->get_designMode(&mode);
+    if(wxString(mode) == "On")
+        return true;
+    else
+        return false;
+}
+
 bool wxWebViewIE::CanExecCommand(wxString command)
 {
     IHTMLDocument2* document = GetDocument();