# wxHelpEvent Class Reference
[Events]

`#include </home/work/projects/wx/2.9/wx/interface/wx/event.h>`

Inheritance diagram for wxHelpEvent:
[legend]

## Detailed Description

A help event is sent when the user has requested context-sensitive help.

This can either be caused by the application requesting context-sensitive help mode via wxContextHelp, or (on MS Windows) by the system generating a WM_HELP message when the user pressed F1 or clicked on the query button in a dialog caption.

A help event is sent to the window that the user clicked on, and is propagated up the window hierarchy until the event is processed or there are no more event handlers.

The application should call wxEvent::GetId to check the identity of the clicked-on window, and then either show some suitable help or call wxEvent::Skip() if the identifier is unrecognised.

Calling Skip is important because it allows wxWidgets to generate further events for ancestors of the clicked-on window. Otherwise it would be impossible to show help for container windows, since processing would stop after the first window found.

## Events using this class

The following event handler macros redirect the events to member function handlers 'func' with prototypes like:

void handlerFuncName(wxHelpEvent& event)

Event macros:

- EVT_HELP(id, func):
  Process a `wxEVT_HELP` event.
- EVT_HELP_RANGE(id1, id2, func):
  Process a `wxEVT_HELP` event for a range of ids.

##

Library: wxCore
Category: Events

See also:
  wxContextHelp, wxDialog, Events and Event Handling

## Public Types

enum | Origin { Origin_Unknown, Origin_Keyboard, Origin_HelpButton }
| Indicates how a wxHelpEvent was generated. More...

## Public Member Functions

| wxHelpEvent (wxEventType type=wxEVT_NULL, wxWindowID winid=0, const wxPoint &pt=wxDefaultPosition, wxHelpEvent::Origin origin=Origin_Unknown)
| Constructor.
wxHelpEvent::Origin | GetOrigin () const
| Returns the origin of the help event which is one of the wxHelpEventOrigin values.
const wxPoint & | GetPosition () const
| Returns the left-click position of the mouse, in screen coordinates.
void | SetOrigin (wxHelpEvent::Origin origin)
| Set the help event origin, only used internally by wxWidgets normally.
void | SetPosition (const wxPoint &pt)
| Sets the left-click position of the mouse, in screen coordinates.

List of all members.

## Member Enumeration Documentation

enum wxHelpEvent::Origin

Indicates how a wxHelpEvent was generated.

Enumerator:

  Origin_Unknown | unrecognized event source.
  Origin_Keyboard | event generated from F1 key press.
  Origin_HelpButton | event generated by wxContextHelp or from the [?] button on the title bar (Windows).

## Constructor & Destructor Documentation

wxHelpEvent::wxHelpEvent | ( | wxEventType | type = `wxEVT_NULL`,
|  | wxWindowID | winid = `0`,
|  | const wxPoint & | pt = `wxDefaultPosition`,
|  | wxHelpEvent::Origin | origin = `Origin_Unknown` |
| ) |  |  |

Constructor.

## Member Function Documentation

wxHelpEvent::Origin wxHelpEvent::GetOrigin | ( |  | ) | const

Returns the origin of the help event which is one of the wxHelpEventOrigin values.

The application may handle events generated using the keyboard or mouse differently, e.g. by using wxGetMousePosition() for the mouse events.

See also:
  SetOrigin()

const wxPoint& wxHelpEvent::GetPosition | ( |  | ) | const

Returns the left-click position of the mouse, in screen coordinates.

This allows the application to position the help appropriately.

void wxHelpEvent::SetOrigin | ( | wxHelpEvent::Origin | origin | ) |

Set the help event origin, only used internally by wxWidgets normally.

See also:
  GetOrigin()

void wxHelpEvent::SetPosition | ( | const wxPoint & | pt | ) |

Sets the left-click position of the mouse, in screen coordinates.

|  | [ top ]