[Qt-interest] transparent widget can't have parent widget

[Denis Akhmetzyanov]

If I used pure QtGui I would simply fill widget with transparent color. But
I don't know how it deal with MFC widgets like CView.


2010/5/19 cheng long <kevinclcn at gmail.com>

> Thank you Denis, is there any other approaches to make a child widget
> transparent?
>
> -Kevin
>
>
> On Wed, May 19, 2010 at 7:04 PM, Denis Akhmetzyanov <
> dakhmetzyanov at smartlabs.tv> wrote:
>
>> Hi,
>> As far as I know, attribute Qt::WA_TranslucentBackground is applicable to
>> the top-level widget only (i.e. without parent). The good reference for this
>> topic is Qt Quarterly http://doc.trolltech.com/qq/
>> *Issue 29 · Q1 2009, Translucent Widgets in Qt*
>>
>>
>> 2010/5/19 cheng long <kevinclcn at gmail.com>
>>
>>> I created a transparent QWinWidget and set the a CView as its parent, but
>>> the QWinWidget has an item in the task bar and it can be shown, hidden and
>>> closed regardless of the CView.
>>>
>>> Environment: Qt 4.5.2, Visual Studio 2008, Windows 7,
>>> Code:
>>>          QWinWidget* pQWinWidget = new QWinWidget(pWnd); // pWnd is a
>>> CView pointer
>>>          pQWinWidget->setWindowFlags(Qt::FramelessWindowHint);
>>>          pQWinWidget->setAttribute(Qt::WA_TranslucentBackground);
>>>
>>>          QHBoxLayout *pQHBoxLayout = new QHBoxLayout(pQWinWidget);
>>>          pQHBoxLayout->setMargin(0);
>>>
>>>          QGraphicsScene* scene = new QGraphicsScene();
>>>          QGraphicsView* view = new QGraphicsView(pQWinWidget);
>>>          pQHBoxLayout->addWidget(view);
>>>
>>>          view->setScene(scene);
>>>          view->setMinimumWidth(300);
>>>          view->setMinimumHeight(300);
>>>          view->setRenderHints(QPainter::Antialiasing |
>>> QPainter::TextAntialiasing);
>>>          view->setStyleSheet("background: transparent");
>>>
>>>          QGraphicsTextItem* text = new QGraphicsTextItem();
>>>          scene->addItem(text);
>>>          text->setPlainText("hello Qt!");
>>>
>>>          pQWinWidget->show();
>>>
>>> If I comment these two lines below, the QWinWidget will exist as the
>>> CView's child.
>>>          pQWinWidget->setWindowFlags(Qt::FramelessWindowHint);
>>>          pQWinWidget->setAttribute(Qt::WA_TranslucentBackground);
>>>
>>> Any suggestions?
>>>
>>> Thanks,
>>> Kevin
>>>
>>> _______________________________________________
>>> Qt-interest mailing list
>>> Qt-interest at trolltech.com
>>> http://lists.trolltech.com/mailman/listinfo/qt-interest
>>>
>>>
>>
>>
>> --
>> Best regards,
>> Denis Akhmetzyanov
>>
>
>


-- 
Best regards,
Denis Akhmetzyanov
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