Added wxPATH_NORM_SHORTCUT

[wxWidgets.git] / docs / latex / wx / mouseevt.tex

diff --git a/docs/latex/wx/mouseevt.tex b/docs/latex/wx/mouseevt.tex
index eff02f8b6d0907b66b62f0ffe0ae6abc2f8acf9c..e7078931bd9470ec4989560e3d7fa6d09c8e761a 100644 (file)
--- a/docs/latex/wx/mouseevt.tex
+++ b/docs/latex/wx/mouseevt.tex
@@ -1,24 +1,30 @@
 \section{\class{wxMouseEvent}}\label{wxmouseevent}
 
 \section{\class{wxMouseEvent}}\label{wxmouseevent}
 

-This event class contains information about mouse events.
-See \helpref{wxWindow::OnMouseEvent}{wxwindowonmouseevent}.
+This event class contains information about the events generated by the mouse:
+they include mouse buttons press and release events and mouse move events.

 
 

-{\bf NB: } Note that under Windows mouse enter and leave events are not natively supported
+All mouse events involving the buttons use {\tt wxMOUSE\_BTN\_LEFT} for the
+left mouse button, {\tt wxMOUSE\_BTN\_MIDDLE} for the middle one and
+{\tt wxMOUSE\_BTN\_RIGHT} for the right one. Note that not all mice have a
+middle button so a portable application should avoid relying on the events from
+it.
+
+{\bf NB:} Note that under Windows mouse enter and leave events are not natively supported

 by the system but are generated by wxWindows itself. This has several
 drawbacks: the LEAVE\_WINDOW event might be received some time after the mouse
 left the window and the state variables for it may have changed during this
 time.
 
 by the system but are generated by wxWindows itself. This has several
 drawbacks: the LEAVE\_WINDOW event might be received some time after the mouse
 left the window and the state variables for it may have changed during this
 time.
 

-{\bf NB: } Note the difference between methods like
+{\bf NB:} Note the difference between methods like

 \helpref{LeftDown}{wxmouseeventleftdown} and
 \helpref{LeftDown}{wxmouseeventleftdown} and

-\helpref{LeftIsDown}{wxmouseeventleftisdown}: the formet returns {\tt TRUE}
+\helpref{LeftIsDown}{wxmouseeventleftisdown}: the former returns {\tt true}

 when the event corresponds to the left mouse button click while the latter
 when the event corresponds to the left mouse button click while the latter

-returns {\tt TRUE} if the left mouse button is currently being pressed. For
+returns {\tt true} if the left mouse button is currently being pressed. For

 example, when the user is dragging the mouse you can use
 \helpref{LeftIsDown}{wxmouseeventleftisdown} to test
 whether the left mouse button is (still) depressed. Also, by convention, if
 example, when the user is dragging the mouse you can use
 \helpref{LeftIsDown}{wxmouseeventleftisdown} to test
 whether the left mouse button is (still) depressed. Also, by convention, if

-\helpref{LeftDown}{wxmouseeventleftdown} returns {\tt TRUE},
-\helpref{LeftIsDown}{wxmouseeventleftisdown} will also return {\tt TRUE} in
+\helpref{LeftDown}{wxmouseeventleftdown} returns {\tt true},
+\helpref{LeftIsDown}{wxmouseeventleftisdown} will also return {\tt true} in

 wxWindows whatever the underlying GUI behaviour is (which is
 platform-dependent). The same applies, of course, to other mouse buttons as
 well.
 wxWindows whatever the underlying GUI behaviour is (which is
 platform-dependent). The same applies, of course, to other mouse buttons as
 well.


@@ -56,47 +62,55 @@ functions that take a wxMouseEvent argument.
 
 \latexignore{\rtfignore{\wxheading{Members}}}
 
 
 \latexignore{\rtfignore{\wxheading{Members}}}
 

+

 \membersection{wxMouseEvent::m\_altDown}
 
 \member{bool}{m\_altDown}
 
 \membersection{wxMouseEvent::m\_altDown}
 
 \member{bool}{m\_altDown}
 

-TRUE if the Alt key is pressed down.
+true if the Alt key is pressed down.
+

 
 \membersection{wxMouseEvent::m\_controlDown}
 
 \member{bool}{m\_controlDown}
 
 
 \membersection{wxMouseEvent::m\_controlDown}
 
 \member{bool}{m\_controlDown}
 

-TRUE if control key is pressed down.
+true if control key is pressed down.
+

 
 \membersection{wxMouseEvent::m\_leftDown}
 
 \member{bool}{m\_leftDown}
 
 
 \membersection{wxMouseEvent::m\_leftDown}
 
 \member{bool}{m\_leftDown}
 

-TRUE if the left mouse button is currently pressed down.
+true if the left mouse button is currently pressed down.
+

 
 \membersection{wxMouseEvent::m\_middleDown}
 
 \member{bool}{m\_middleDown}
 
 
 \membersection{wxMouseEvent::m\_middleDown}
 
 \member{bool}{m\_middleDown}
 

-TRUE if the middle mouse button is currently pressed down.
+true if the middle mouse button is currently pressed down.
+

 
 \membersection{wxMouseEvent::m\_rightDown}
 
 \member{bool}{m\_rightDown}
 
 
 \membersection{wxMouseEvent::m\_rightDown}
 
 \member{bool}{m\_rightDown}
 

-TRUE if the right mouse button is currently pressed down.
+true if the right mouse button is currently pressed down.
+

 
 \membersection{wxMouseEvent::m\_metaDown}
 
 \member{bool}{m\_metaDown}
 
 
 \membersection{wxMouseEvent::m\_metaDown}
 
 \member{bool}{m\_metaDown}
 

-TRUE if the Meta key is pressed down.
+true if the Meta key is pressed down.
+

 
 \membersection{wxMouseEvent::m\_shiftDown}
 
 \member{bool}{m\_shiftDown}
 
 
 \membersection{wxMouseEvent::m\_shiftDown}
 
 \member{bool}{m\_shiftDown}
 

-TRUE if shift is pressed down.
+true if shift is pressed down.
+

 
 \membersection{wxMouseEvent::m\_x}
 
 
 \membersection{wxMouseEvent::m\_x}
 


@@ -104,23 +118,27 @@ TRUE if shift is pressed down.
 
 X-coordinate of the event.
 
 
 X-coordinate of the event.
 

+

 \membersection{wxMouseEvent::m\_y}
 
 \member{long}{m\_y}
 
 Y-coordinate of the event.
 
 \membersection{wxMouseEvent::m\_y}
 
 \member{long}{m\_y}
 
 Y-coordinate of the event.
 

+

 \membersection{wxMouseEvent::m\_wheelRotation}
 
 \member{int}{m\_wheelRotation}
 
 The distance the mouse wheel is rotated.
 
 \membersection{wxMouseEvent::m\_wheelRotation}
 
 \member{int}{m\_wheelRotation}
 
 The distance the mouse wheel is rotated.
 

+

 \membersection{wxMouseEvent::m\_wheelDelta}
 
 \member{int}{m\_wheelDelta}
 
 \membersection{wxMouseEvent::m\_wheelDelta}
 
 \member{int}{m\_wheelDelta}
 

-The wheel delta, normally 120.
+The wheel delta, normally $120$.
+

 
 \membersection{wxMouseEvent::m\_linesPerAction}
 
 
 \membersection{wxMouseEvent::m\_linesPerAction}
 


@@ -130,6 +148,7 @@ The configured number of lines (or whatever) to be scrolled per wheel
 action.
 
 
 action.
 
 

+

 \membersection{wxMouseEvent::wxMouseEvent}
 
 \func{}{wxMouseEvent}{\param{WXTYPE}{ mouseEventType = 0}, \param{int}{ id = 0}}
 \membersection{wxMouseEvent::wxMouseEvent}
 
 \func{}{wxMouseEvent}{\param{WXTYPE}{ mouseEventType = 0}, \param{int}{ id = 0}}


@@ -153,67 +172,99 @@ Constructor. Valid event types are:
 \item {\bf wxEVT\_MOUSEWHEEL}
 \end{itemize}
 
 \item {\bf wxEVT\_MOUSEWHEEL}
 \end{itemize}
 

+

 \membersection{wxMouseEvent::AltDown}
 
 \func{bool}{AltDown}{\void}
 
 \membersection{wxMouseEvent::AltDown}
 
 \func{bool}{AltDown}{\void}
 

-Returns TRUE if the Alt key was down at the time of the event.
+Returns true if the Alt key was down at the time of the event.

 
 

-\membersection{wxMouseEvent::Button}
+
+\membersection{wxMouseEvent::Button}\label{wxmouseeventbutton}

 
 \func{bool}{Button}{\param{int}{ button}}
 
 
 \func{bool}{Button}{\param{int}{ button}}
 

-Returns TRUE if the identified mouse button is changing state. Valid
-values of {\it button} are 1, 2 or 3 for left, middle and right
-buttons respectively.
+Returns true if the identified mouse button is changing state. Valid
+values of {\it button} are:
+
+\begin{twocollist}\itemsep=0pt
+\twocolitem{{\tt wxMOUSE\_BTN\_LEFT}}{check if left button was pressed}
+\twocolitem{{\tt wxMOUSE\_BTN\_MIDDLE}}{check if left button was pressed}
+\twocolitem{{\tt wxMOUSE\_BTN\_RIGHT}}{check if left button was pressed}
+\twocolitem{{\tt wxMOUSE\_BTN\_ANY}}{check if any button was pressed}
+\end{twocollist}

 
 

-Not all mice have middle buttons so a portable application should avoid
-this one.

 
 

-\membersection{wxMouseEvent::ButtonDClick}\label{buttondclick}
+\membersection{wxMouseEvent::ButtonDClick}

 
 

-\func{bool}{ButtonDClick}{\param{int}{ but = -1}}
+\func{bool}{ButtonDClick}{\param{int}{ but = wxMOUSE\_BTN\_ANY}}

 
 

-If the argument is omitted, this returns TRUE if the event was a mouse
+If the argument is omitted, this returns true if the event was a mouse

 double click event. Otherwise the argument specifies which double click event
 double click event. Otherwise the argument specifies which double click event

-was generated (1, 2 or 3 for left, middle and right buttons respectively).
+was generated (see \helpref{Button}{wxmouseeventbutton} for the possible
+values).
+

 
 \membersection{wxMouseEvent::ButtonDown}
 
 \func{bool}{ButtonDown}{\param{int}{ but = -1}}
 
 
 \membersection{wxMouseEvent::ButtonDown}
 
 \func{bool}{ButtonDown}{\param{int}{ but = -1}}
 

-If the argument is omitted, this returns TRUE if the event was a mouse
+If the argument is omitted, this returns true if the event was a mouse

 button down event. Otherwise the argument specifies which button-down event
 button down event. Otherwise the argument specifies which button-down event

-was generated (1, 2 or 3 for left, middle and right buttons respectively).
+was generated (see \helpref{Button}{wxmouseeventbutton} for the possible
+values).
+
+

 
 \membersection{wxMouseEvent::ButtonUp}
 
 \func{bool}{ButtonUp}{\param{int}{ but = -1}}
 
 
 \membersection{wxMouseEvent::ButtonUp}
 
 \func{bool}{ButtonUp}{\param{int}{ but = -1}}
 

-If the argument is omitted, this returns TRUE if the event was a mouse
+If the argument is omitted, this returns true if the event was a mouse

 button up event. Otherwise the argument specifies which button-up event
 button up event. Otherwise the argument specifies which button-up event

-was generated (1, 2 or 3 for left, middle and right buttons respectively).
+was generated (see \helpref{Button}{wxmouseeventbutton} for the possible
+values).
+
+

 
 \membersection{wxMouseEvent::ControlDown}
 
 \func{bool}{ControlDown}{\void}
 
 
 \membersection{wxMouseEvent::ControlDown}
 
 \func{bool}{ControlDown}{\void}
 

-Returns TRUE if the control key was down at the time of the event.
+Returns true if the control key was down at the time of the event.

 
 

-\membersection{wxMouseEvent::Dragging}
+
+\membersection{wxMouseEvent::Dragging}\label{wxmouseeventdragging}

 
 \func{bool}{Dragging}{\void}
 
 
 \func{bool}{Dragging}{\void}
 

-Returns TRUE if this was a dragging event (motion while a button is depressed).
+Returns true if this was a dragging event (motion while a button is depressed).
+
+\wxheading{See also}
+
+\helpref{Moving}{wxmouseeventmoving}
+

 
 \membersection{wxMouseEvent::Entering}\label{wxmouseevententering}
 
 \func{bool}{Entering}{\void}
 
 
 \membersection{wxMouseEvent::Entering}\label{wxmouseevententering}
 
 \func{bool}{Entering}{\void}
 

-Returns TRUE if the mouse was entering the window.
+Returns true if the mouse was entering the window.

 
 See also \helpref{wxMouseEvent::Leaving}{wxmouseeventleaving}.
 
 
 See also \helpref{wxMouseEvent::Leaving}{wxmouseeventleaving}.
 

+
+\membersection{wxMouseEvent::GetButton}\label{wxmouseeventgetbutton}
+
+\constfunc{int}{GetButton}{\void}
+
+Returns the mouse button which generated this event or {\tt wxMOUSE\_BTN\_NONE} 
+if no button is involved (for mouse move, enter or leave event, for example).
+Otherwise {\tt wxMOUSE\_BTN\_LEFT} is returned for the left button down, up and
+double click events, {\tt wxMOUSE\_BTN\_MIDDLE} and {\tt wxMOUSE\_BTN\_RIGHT} 
+for the same events for the middle and the right buttons respectively.
+
+

 \membersection{wxMouseEvent::GetPosition}\label{wxmouseeventgetposition}
 
 \constfunc{wxPoint}{GetPosition}{\void}
 \membersection{wxMouseEvent::GetPosition}\label{wxmouseeventgetposition}
 
 \constfunc{wxPoint}{GetPosition}{\void}


@@ -226,6 +277,7 @@ Sets *x and *y to the position at which the event occurred.
 
 Returns the physical mouse position in pixels.
 
 
 Returns the physical mouse position in pixels.
 

+

 \membersection{wxMouseEvent::GetLogicalPosition}\label{wxmouseeventgetlogicalposition}
 
 \constfunc{wxPoint}{GetLogicalPosition}{\param{const wxDC\&}{ dc}}
 \membersection{wxMouseEvent::GetLogicalPosition}\label{wxmouseeventgetlogicalposition}
 
 \constfunc{wxPoint}{GetLogicalPosition}{\param{const wxDC\&}{ dc}}


@@ -234,12 +286,14 @@ Returns the logical mouse position in pixels (i.e. translated according to the
 translation set for the DC, which usually indicates that the window has been scrolled).
 
 
 translation set for the DC, which usually indicates that the window has been scrolled).
 
 

+

 \membersection{wxMouseEvent::GetLinesPerAction}\label{wxmouseeventgetlinesperaction}
 
 \constfunc{int}{GetLinesPerAction}{\void}
 
 Returns the configured number of lines (or whatever) to be scrolled per
 \membersection{wxMouseEvent::GetLinesPerAction}\label{wxmouseeventgetlinesperaction}
 
 \constfunc{int}{GetLinesPerAction}{\void}
 
 Returns the configured number of lines (or whatever) to be scrolled per

-wheel action.  Defaults to one.
+wheel action.  Defaults to three.
+

 
 \membersection{wxMouseEvent::GetWheelRotation}\label{wxmouseeventgetwheelrotation}
 
 
 \membersection{wxMouseEvent::GetWheelRotation}\label{wxmouseeventgetwheelrotation}
 


@@ -253,139 +307,169 @@ event is equal to 1 line or whatever, but you should be able to either
 do partial line scrolling or wait until +/-WheelDelta rotation values
 have been accumulated before scrolling.
 
 do partial line scrolling or wait until +/-WheelDelta rotation values
 have been accumulated before scrolling.
 

+

 \membersection{wxMouseEvent::GetWheelDelta}\label{wxmouseeventgetwheeldelta}
 
 \constfunc{int}{GetWheelDelta}{\void}
 
 \membersection{wxMouseEvent::GetWheelDelta}\label{wxmouseeventgetwheeldelta}
 
 \constfunc{int}{GetWheelDelta}{\void}
 

-Get wheel delta, normally 120.  This is the threshold for action to be
+Get wheel delta, normally $120$.  This is the threshold for action to be

 taken, and one such action (for example, scrolling one increment)
 should occur for each delta.
 
 taken, and one such action (for example, scrolling one increment)
 should occur for each delta.
 

+

 \membersection{wxMouseEvent::GetX}\label{wxmouseeventgetx}
 
 \constfunc{long}{GetX}{\void}
 
 Returns X coordinate of the physical mouse event position.
 
 \membersection{wxMouseEvent::GetX}\label{wxmouseeventgetx}
 
 \constfunc{long}{GetX}{\void}
 
 Returns X coordinate of the physical mouse event position.
 

+

 \membersection{wxMouseEvent::GetY}\label{wxmouseeventgety}
 
 \func{long}{GetY}{\void}
 
 Returns Y coordinate of the physical mouse event position.
 
 \membersection{wxMouseEvent::GetY}\label{wxmouseeventgety}
 
 \func{long}{GetY}{\void}
 
 Returns Y coordinate of the physical mouse event position.
 

+

 \membersection{wxMouseEvent::IsButton}
 
 \constfunc{bool}{IsButton}{\void}
 
 \membersection{wxMouseEvent::IsButton}
 
 \constfunc{bool}{IsButton}{\void}
 

-Returns TRUE if the event was a mouse button event (not necessarily a button down event -
+Returns true if the event was a mouse button event (not necessarily a button down event -

 that may be tested using {\it ButtonDown}).
 
 that may be tested using {\it ButtonDown}).
 

+
+\membersection{wxMouseEvent::IsPageScroll}
+
+\constfunc{bool}{IsPageScroll}{\void}
+
+Returns true if the system has been setup to do page scrolling with
+the mouse wheel instead of line scrolling.
+
+

 \membersection{wxMouseEvent::Leaving}\label{wxmouseeventleaving}
 
 \constfunc{bool}{Leaving}{\void}
 
 \membersection{wxMouseEvent::Leaving}\label{wxmouseeventleaving}
 
 \constfunc{bool}{Leaving}{\void}
 

-Returns TRUE if the mouse was leaving the window.
+Returns true if the mouse was leaving the window.

 
 See also \helpref{wxMouseEvent::Entering}{wxmouseevententering}.
 
 
 See also \helpref{wxMouseEvent::Entering}{wxmouseevententering}.
 

+

 \membersection{wxMouseEvent::LeftDClick}
 
 \constfunc{bool}{LeftDClick}{\void}
 
 \membersection{wxMouseEvent::LeftDClick}
 
 \constfunc{bool}{LeftDClick}{\void}
 

-Returns TRUE if the event was a left double click.
+Returns true if the event was a left double click.
+

 
 \membersection{wxMouseEvent::LeftDown}\label{wxmouseeventleftdown}
 
 \constfunc{bool}{LeftDown}{\void}
 
 
 \membersection{wxMouseEvent::LeftDown}\label{wxmouseeventleftdown}
 
 \constfunc{bool}{LeftDown}{\void}
 

-Returns TRUE if the left mouse button changed to down.
+Returns true if the left mouse button changed to down.
+

 
 \membersection{wxMouseEvent::LeftIsDown}\label{wxmouseeventleftisdown}
 
 \constfunc{bool}{LeftIsDown}{\void}
 
 
 \membersection{wxMouseEvent::LeftIsDown}\label{wxmouseeventleftisdown}
 
 \constfunc{bool}{LeftIsDown}{\void}
 

-Returns TRUE if the left mouse button is currently down, independent
+Returns true if the left mouse button is currently down, independent

 of the current event type.
 
 Please notice that it is {\bf not} the same as
 of the current event type.
 
 Please notice that it is {\bf not} the same as

-\helpref{LeftDown}{wxmouseeventleftdown} which returns TRUE if the left mouse
+\helpref{LeftDown}{wxmouseeventleftdown} which returns true if the left mouse

 button was just pressed. Rather, it describes the state of the mouse button
 before the event happened.
 
 This event is usually used in the mouse event handlers which process "move
 mouse" messages to determine whether the user is (still) dragging the mouse.
 
 button was just pressed. Rather, it describes the state of the mouse button
 before the event happened.
 
 This event is usually used in the mouse event handlers which process "move
 mouse" messages to determine whether the user is (still) dragging the mouse.
 

+

 \membersection{wxMouseEvent::LeftUp}
 
 \constfunc{bool}{LeftUp}{\void}
 
 \membersection{wxMouseEvent::LeftUp}
 
 \constfunc{bool}{LeftUp}{\void}
 

-Returns TRUE if the left mouse button changed to up.
+Returns true if the left mouse button changed to up.
+

 
 \membersection{wxMouseEvent::MetaDown}
 
 \constfunc{bool}{MetaDown}{\void}
 
 
 \membersection{wxMouseEvent::MetaDown}
 
 \constfunc{bool}{MetaDown}{\void}
 

-Returns TRUE if the Meta key was down at the time of the event.
+Returns true if the Meta key was down at the time of the event.
+

 
 \membersection{wxMouseEvent::MiddleDClick}
 
 \constfunc{bool}{MiddleDClick}{\void}
 
 
 \membersection{wxMouseEvent::MiddleDClick}
 
 \constfunc{bool}{MiddleDClick}{\void}
 

-Returns TRUE if the event was a middle double click.
+Returns true if the event was a middle double click.
+

 
 \membersection{wxMouseEvent::MiddleDown}
 
 \constfunc{bool}{MiddleDown}{\void}
 
 
 \membersection{wxMouseEvent::MiddleDown}
 
 \constfunc{bool}{MiddleDown}{\void}
 

-Returns TRUE if the middle mouse button changed to down.
+Returns true if the middle mouse button changed to down.
+

 
 \membersection{wxMouseEvent::MiddleIsDown}\label{wxmouseeventmiddleisdown}
 
 \constfunc{bool}{MiddleIsDown}{\void}
 
 
 \membersection{wxMouseEvent::MiddleIsDown}\label{wxmouseeventmiddleisdown}
 
 \constfunc{bool}{MiddleIsDown}{\void}
 

-Returns TRUE if the middle mouse button is currently down, independent
+Returns true if the middle mouse button is currently down, independent

 of the current event type.
 
 of the current event type.
 

+

 \membersection{wxMouseEvent::MiddleUp}
 
 \constfunc{bool}{MiddleUp}{\void}
 
 \membersection{wxMouseEvent::MiddleUp}
 
 \constfunc{bool}{MiddleUp}{\void}
 

-Returns TRUE if the middle mouse button changed to up.
+Returns true if the middle mouse button changed to up.
+

 
 

-\membersection{wxMouseEvent::Moving}
+\membersection{wxMouseEvent::Moving}\label{wxmouseeventmoving}

 
 \constfunc{bool}{Moving}{\void}
 
 
 \constfunc{bool}{Moving}{\void}
 

-Returns TRUE if this was a motion event (no buttons depressed).
+Returns true if this was a motion event and no mouse buttons were pressed. 
+If any mouse button is held pressed, then this method returns \false and 
+\helpref{Dragging}{wxmouseeventdragging} returns \true.
+

 
 \membersection{wxMouseEvent::RightDClick}
 
 \constfunc{bool}{RightDClick}{\void}
 
 
 \membersection{wxMouseEvent::RightDClick}
 
 \constfunc{bool}{RightDClick}{\void}
 

-Returns TRUE if the event was a right double click.
+Returns true if the event was a right double click.
+

 
 \membersection{wxMouseEvent::RightDown}
 
 \constfunc{bool}{RightDown}{\void}
 
 
 \membersection{wxMouseEvent::RightDown}
 
 \constfunc{bool}{RightDown}{\void}
 

-Returns TRUE if the right mouse button changed to down.
+Returns true if the right mouse button changed to down.
+

 
 \membersection{wxMouseEvent::RightIsDown}\label{wxmouseeventrightisdown}
 
 \constfunc{bool}{RightIsDown}{\void}
 
 
 \membersection{wxMouseEvent::RightIsDown}\label{wxmouseeventrightisdown}
 
 \constfunc{bool}{RightIsDown}{\void}
 

-Returns TRUE if the right mouse button is currently down, independent
+Returns true if the right mouse button is currently down, independent

 of the current event type.
 
 of the current event type.
 

+

 \membersection{wxMouseEvent::RightUp}
 
 \constfunc{bool}{RightUp}{\void}
 
 \membersection{wxMouseEvent::RightUp}
 
 \constfunc{bool}{RightUp}{\void}
 

-Returns TRUE if the right mouse button changed to up.
+Returns true if the right mouse button changed to up.
+

 
 \membersection{wxMouseEvent::ShiftDown}
 
 \constfunc{bool}{ShiftDown}{\void}
 
 
 \membersection{wxMouseEvent::ShiftDown}
 
 \constfunc{bool}{ShiftDown}{\void}
 

-Returns TRUE if the shift key was down at the time of the event.
+Returns true if the shift key was down at the time of the event.