like painter program ,, problem in erasing from frame

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R.M

Beginner

Posts: 11

Sunday, May 4th 2008, 6:26pm

like painter program ,, problem in erasing from frame

Hello everyone ,,

I posted my problem in Qt Disigner but no one help me , may be I posted it a wrong place

I explain my problem in the link :

Problem in QPainter

any help is really really great appreciated

Thanks in advance ,,

This post has been edited 1 times, last edit by "R.M" (May 4th 2008, 6:29pm)

Messenger

Intermediate

Posts: 325

Location: Lt

Monday, May 5th 2008, 7:39am

RE: like painter program ,, problem in erasing from frame

Full compilable code would be nice.
Yes it is not related to Qt Designer.

Quoted

The problem was once I write on the frame and erase it ( using QWidget::erase())
and another window come over my window ,, all what was erased before is draw on the frame

You paint _buffer in paintEvent. Then other window travels over the window then the window recieves paintEvent and your buffered image is drawn.

	Source code
1 2 3 4 5 6 7	void TextFrame :: paintEvent(QPaintEvent*) { bitBlt(this , 0 , 0 , &_buffer) ; // maybe better use // bitBlt(this, 0, 0, &_buffer, e->rect()); }

QWidget::erase() does not erases the _buffer. "Erase" _buffer too or just erase _buffer and update the frame. For example.

Source code

bufferpainter.begin(&_buffer);
bufferpainter.setPen...
... other setup...
bufferpainter.fill...Something(...
bufferpainter.end();
this->update(x, y, w, h); // update (repaint) changed rectangle.

Fighting fire with fire.

This post has been edited 1 times, last edit by "Messenger" (May 5th 2008, 7:40am)