qcanvasview.3qt

Linux 下的图形编程环境。

'\" t
.TH QCanvasView 3qt "5 March 2001" "Trolltech AS" \" -*- nroff -*-
.\" Copyright 1992-2001 Trolltech AS.  All rights reserved.  See the
.\" license file included in the distribution for a complete license
.\" statement.
.\"
.ad l
.nh
.SH NAME
QCanvasView \- A
.br
.PP
\fC#include <qcanvas.h>\fR
.PP
Inherits QScrollView.
.PP
.SS "Public Members"
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.ti -1c
.BI "\fBQCanvasView\fR ( QCanvas * " "viewing" "=0, QWidget * " "parent" "=0, const char * " "name" "=0, WFlags " "f" "=0 ) "
.br
.ti -1c
.BI "\fB~QCanvasView\fR () "
.br
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.BI "QCanvas* \fBcanvas\fR () const"
.br
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.BI "void \fBsetCanvas\fR ( QCanvas * v ) "
.br
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.SS "Protected Members"
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.BI "virtual void \fBdrawContents\fR ( QPainter *, int " "cx" ", int " "cy" ", int " "cw" ", int ch ) "
.br
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.BI "virtual QSize \fBsizeHint\fR () const"
.br
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.SH DESCRIPTION
A QWidget which views a QCanvas.
.PP
Displays a view of a QCanvas, with scrollbars available if desired. There can be more than one view of a canvas.
.PP
The view of a canvas is the object which the user can see and interact with, hence any interactivity will be based on events from a view. For example, by subclassing QCanvasView and overriding QScrollView::contentsMousePressEvent(), an application can provide a canvas where the user can interact with items on the canvas.
.PP
.nf
.br
  void MyCanvasView::contentsMousePressEvent(QMouseEvent* e)
.br
  {
.br
      QCanvasItemList list = canvas()->collisions(e->pos());
.br
      if ( !list.isEmpty() ) {
.br
          QCanvasItem* item = list.first();
.br
.br
          // Process the top item
.br
          ...
.br
      }
.br
  }
.fi
.PP
Most of the functionality of QCanvasView is the functionality available for all QScrollView subclasses.
.SH MEMBER FUNCTION DOCUMENTATION
.SH "QCanvasView::QCanvasView ( QCanvas * canvas=0, QWidget * parent=0, const char * name=0, WFlags f=0 )"
Constructs a QCanvasView which views \fIcanvas.\fR The usual QWidget parameters may also be supplied.
.SH "QCanvasView::~QCanvasView ()"
Destructs the view. The associated canvas is \fInot\fR deleted.
.SH "QCanvas* QCanvasView::canvas () const"
Returns the canvas which the view is currently viewing.
.SH "void QCanvasView::drawContents ( QPainter * p, int cx, int cy, int cw, int ch ) \fC[virtual protected]\fR"
Repaints the appropriate area of the QCanvas which this QCanvasView is viewing.
.PP
Reimplemented from QScrollView.
.SH "void QCanvasView::setCanvas ( QCanvas * canvas )"
Changes the QCanvas which the QCanvasView is viewing to \fIcanvas.\fR
.SH "QSize QCanvasView::sizeHint () const \fC[virtual protected]\fR"
Suggests a size sufficient to view the entire canvas.
.PP
Reimplemented from QWidget.
.SH "SEE ALSO"
.BR http://doc.trolltech.com/qcanvasview.html
.BR http://www.trolltech.com/faq/tech.html
.SH COPYRIGHT
Copyright 1992-2001 Trolltech AS, http://www.trolltech.com.  See the
license file included in the distribution for a complete license
statement.
.SH AUTHOR
Generated automatically from the source code.
.SH BUGS
If you find a bug in Qt, please report it as described in
.BR http://doc.trolltech.com/bughowto.html .
Good bug reports make our job much simpler. Thank you.
.P
In case of content or formattting problems with this manual page, please
report them to
.BR [e-mail] .
Please include the name of the manual page (qcanvasview.3qt) and the Qt
version (2.3.0).