NAME

       QwtPanner - QwtPanner provides panning of a widget.

SYNOPSIS

       #include <qwt_panner.h>

       Inherits QWidget.

       Inherited by QwtPlotPanner.

   Signals
       void panned (int dx, int dy)
       void moved (int dx, int dy)

   Public Member Functions
       QwtPanner (QWidget *parent)
       virtual ~QwtPanner ()
           Destructor.
       void setEnabled (bool)
           En/disable the panner.
       bool isEnabled () const
       void setMouseButton (Qt::MouseButton, Qt::KeyboardModifiers=Qt::NoModifier)
       void getMouseButton (Qt::MouseButton &button, Qt::KeyboardModifiers &) const
           Get mouse button and modifiers used for panning.
       void setAbortKey (int key, Qt::KeyboardModifiers=Qt::NoModifier)
       void getAbortKey (int &key, Qt::KeyboardModifiers &) const
           Get the abort key and modifiers.
       void setCursor (const QCursor &)
       const QCursor cursor () const
       void setOrientations (Qt::Orientations)
       Qt::Orientations orientations () const
           Return the orientation, where paning is enabled.
       bool isOrientationEnabled (Qt::Orientation) const
       virtual bool eventFilter (QObject *, QEvent *)
           Event filter.

   Protected Member Functions
       virtual void widgetMousePressEvent (QMouseEvent *)
       virtual void widgetMouseReleaseEvent (QMouseEvent *)
       virtual void widgetMouseMoveEvent (QMouseEvent *)
       virtual void widgetKeyPressEvent (QKeyEvent *)
       virtual void widgetKeyReleaseEvent (QKeyEvent *)
       virtual void paintEvent (QPaintEvent *)
           Paint event.
       virtual QBitmap contentsMask () const
           Calculate a mask for the contents of the panned widget.
       virtual QPixmap grab () const

Detailed Description

       QwtPanner provides panning of a widget.

       QwtPanner grabs the contents of a widget, that can be dragged in all directions. The
       offset between the start and the end position is emitted by the panned signal.

       QwtPanner grabs the content of the widget into a pixmap and moves the pixmap around,
       without initiating any repaint events for the widget. Areas, that are not part of content
       are not painted while panning. This makes panning fast enough for widgets, where repaints
       are too slow for mouse movements.

       For widgets, where repaints are very fast it might be better to implement panning manually
       by mapping mouse events into paint events.

Constructor & Destructor Documentation

   QwtPanner::QwtPanner (QWidget * parent)
       Creates an panner that is enabled for the left mouse button.

       Parameters:
           parent Parent widget to be panned

Member Function Documentation

   QBitmap QwtPanner::contentsMask () const [protected],  [virtual]
       Calculate a mask for the contents of the panned widget. Sometimes only parts of the
       contents of a widget should be panned. F.e. for a widget with a styled background with
       rounded borders only the area inside of the border should be panned.

       Returns:
           An empty bitmap, indicating no mask

       Reimplemented in QwtPlotPanner.

   const QCursor QwtPanner::cursor () const
       Returns:
           Cursor that is active while panning

       See also:
           setCursor()

   bool QwtPanner::eventFilter (QObject * object, QEvent * event) [virtual]
       Event filter. When isEnabled() is true mouse events of the observed widget are filtered.

       Parameters:
           object Object to be filtered
           event Event

       Returns:
           Always false, beside for paint events for the parent widget.

       See also:
           widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseMoveEvent()

   QPixmap QwtPanner::grab () const [protected],  [virtual]
       Grab the widget into a pixmap.

       Returns:
           Grabbed pixmap

       Reimplemented in QwtPlotPanner.

   bool QwtPanner::isEnabled () const
       Returns:
           true when enabled, false otherwise

       See also:
           setEnabled, eventFilter()

   bool QwtPanner::isOrientationEnabled (Qt::Orientation o) const
       Returns:
           True if an orientation is enabled

       See also:
           orientations(), setOrientations()

   void QwtPanner::moved (int dx, int dy) [signal]
       Signal emitted, while the widget moved, but panning is not finished.

       Parameters:
           dx Offset in horizontal direction
           dy Offset in vertical direction

   void QwtPanner::paintEvent (QPaintEvent * event) [protected],  [virtual]
       Paint event. Repaint the grabbed pixmap on its current position and fill the empty spaces
       by the background of the parent widget.

       Parameters:
           event Paint event

   void QwtPanner::panned (int dx, int dy) [signal]
       Signal emitted, when panning is done

       Parameters:
           dx Offset in horizontal direction
           dy Offset in vertical direction

   void QwtPanner::setAbortKey (int key, Qt::KeyboardModifiers modifiers = Qt::NoModifier)
       Change the abort key The defaults are Qt::Key_Escape and Qt::NoModifiers

       Parameters:
           key Key ( See Qt::Keycode )
           modifiers Keyboard modifiers

   void QwtPanner::setCursor (const QCursor & cursor)
       Change the cursor, that is active while panning The default is the cursor of the parent
       widget.

       Parameters:
           cursor New cursor

       See also:
           setCursor()

   void QwtPanner::setEnabled (bool on)
       En/disable the panner. When enabled is true an event filter is installed for the observed
       widget, otherwise the event filter is removed.

       Parameters:
           on true or false

       See also:
           isEnabled(), eventFilter()

   void QwtPanner::setMouseButton (Qt::MouseButton button, Qt::KeyboardModifiers modifiers =
       Qt::NoModifier)
       Change the mouse button and modifiers used for panning The defaults are Qt::LeftButton and
       Qt::NoModifier

   void QwtPanner::setOrientations (Qt::Orientations o)
       Set the orientations, where panning is enabled The default value is in both directions:
       Qt::Horizontal | Qt::Vertical

       /param o Orientation

   void QwtPanner::widgetKeyPressEvent (QKeyEvent * keyEvent) [protected],  [virtual]
       Handle a key press event for the observed widget.

       Parameters:
           keyEvent Key event

       See also:
           eventFilter(), widgetKeyReleaseEvent()

   void QwtPanner::widgetKeyReleaseEvent (QKeyEvent * keyEvent) [protected],  [virtual]
       Handle a key release event for the observed widget.

       Parameters:
           keyEvent Key event

       See also:
           eventFilter(), widgetKeyReleaseEvent()

   void QwtPanner::widgetMouseMoveEvent (QMouseEvent * mouseEvent) [protected],  [virtual]
       Handle a mouse move event for the observed widget.

       Parameters:
           mouseEvent Mouse event

       See also:
           eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent()

   void QwtPanner::widgetMousePressEvent (QMouseEvent * mouseEvent) [protected],  [virtual]
       Handle a mouse press event for the observed widget.

       Parameters:
           mouseEvent Mouse event

       See also:
           eventFilter(), widgetMouseReleaseEvent(), widgetMouseMoveEvent(),

   void QwtPanner::widgetMouseReleaseEvent (QMouseEvent * mouseEvent) [protected],  [virtual]
       Handle a mouse release event for the observed widget.

       Parameters:
           mouseEvent Mouse event

       See also:
           eventFilter(), widgetMousePressEvent(), widgetMouseMoveEvent(),

Author

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