Version: 3.1.0
wxHelpEvent Class Reference

#include <wx/event.h>

+ Inheritance diagram for wxHelpEvent:

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 wxHelpEvent::Origin values.
 
const wxPointGetPosition () 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.
 
- Public Member Functions inherited from wxCommandEvent
 wxCommandEvent (wxEventType commandEventType=wxEVT_NULL, int id=0)
 Constructor.
 
void * GetClientData () const
 Returns client data pointer for a listbox or choice selection event (not valid for a deselection).
 
wxClientDataGetClientObject () const
 Returns client object pointer for a listbox or choice selection event (not valid for a deselection).
 
long GetExtraLong () const
 Returns extra information dependent on the event objects type.
 
int GetInt () const
 Returns the integer identifier corresponding to a listbox, choice or radiobox selection (only if the event was a selection, not a deselection), or a boolean value representing the value of a checkbox.
 
int GetSelection () const
 Returns item index for a listbox or choice selection event (not valid for a deselection).
 
wxString GetString () const
 Returns item string for a listbox or choice selection event.
 
bool IsChecked () const
 This method can be used with checkbox and menu events: for the checkboxes, the method returns true for a selection event and false for a deselection one.
 
bool IsSelection () const
 For a listbox or similar event, returns true if it is a selection, false if it is a deselection.
 
void SetClientData (void *clientData)
 Sets the client data for this event.
 
void SetClientObject (wxClientData *clientObject)
 Sets the client object for this event.
 
void SetExtraLong (long extraLong)
 Sets the m_extraLong member.
 
void SetInt (int intCommand)
 Sets the m_commandInt member.
 
void SetString (const wxString &string)
 Sets the m_commandString member.
 
- Public Member Functions inherited from wxEvent
 wxEvent (int id=0, wxEventType eventType=wxEVT_NULL)
 Constructor.
 
virtual wxEventClone () const =0
 Returns a copy of the event.
 
wxObjectGetEventObject () const
 Returns the object (usually a window) associated with the event, if any.
 
wxEventType GetEventType () const
 Returns the identifier of the given event type, such as wxEVT_BUTTON.
 
virtual wxEventCategory GetEventCategory () const
 Returns a generic category for this event.
 
int GetId () const
 Returns the identifier associated with this event, such as a button command id.
 
wxObjectGetEventUserData () const
 Return the user data associated with a dynamically connected event handler.
 
bool GetSkipped () const
 Returns true if the event handler should be skipped, false otherwise.
 
long GetTimestamp () const
 Gets the timestamp for the event.
 
bool IsCommandEvent () const
 Returns true if the event is or is derived from wxCommandEvent else it returns false.
 
void ResumePropagation (int propagationLevel)
 Sets the propagation level to the given value (for example returned from an earlier call to wxEvent::StopPropagation).
 
void SetEventObject (wxObject *object)
 Sets the originating object.
 
void SetEventType (wxEventType type)
 Sets the event type.
 
void SetId (int id)
 Sets the identifier associated with this event, such as a button command id.
 
void SetTimestamp (long timeStamp=0)
 Sets the timestamp for the event.
 
bool ShouldPropagate () const
 Test if this event should be propagated or not, i.e. if the propagation level is currently greater than 0.
 
void Skip (bool skip=true)
 This method can be used inside an event handler to control whether further event handlers bound to this event will be called after the current one returns.
 
int StopPropagation ()
 Stop the event from propagating to its parent window.
 
- Public Member Functions inherited from wxObject
 wxObject ()
 Default ctor; initializes to NULL the internal reference data.
 
 wxObject (const wxObject &other)
 Copy ctor.
 
virtual ~wxObject ()
 Destructor.
 
virtual wxClassInfoGetClassInfo () const
 This virtual function is redefined for every class that requires run-time type information, when using the wxDECLARE_CLASS macro (or similar).
 
wxObjectRefDataGetRefData () const
 Returns the wxObject::m_refData pointer, i.e. the data referenced by this object.
 
bool IsKindOf (const wxClassInfo *info) const
 Determines whether this class is a subclass of (or the same class as) the given class.
 
bool IsSameAs (const wxObject &obj) const
 Returns true if this object has the same data pointer as obj.
 
void Ref (const wxObject &clone)
 Makes this object refer to the data in clone.
 
void SetRefData (wxObjectRefData *data)
 Sets the wxObject::m_refData pointer.
 
void UnRef ()
 Decrements the reference count in the associated data, and if it is zero, deletes the data.
 
void UnShare ()
 This is the same of AllocExclusive() but this method is public.
 
void operator delete (void *buf)
 The delete operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined.
 
void * operator new (size_t size, const wxString &filename=NULL, int lineNum=0)
 The new operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined.
 

Additional Inherited Members

- Protected Member Functions inherited from wxObject
void AllocExclusive ()
 Ensure that this object's data is not shared with any other object.
 
virtual wxObjectRefDataCreateRefData () const
 Creates a new instance of the wxObjectRefData-derived class specific to this object and returns it.
 
virtual wxObjectRefDataCloneRefData (const wxObjectRefData *data) const
 Creates a new instance of the wxObjectRefData-derived class specific to this object and initializes it copying data.
 
- Protected Attributes inherited from wxEvent
int m_propagationLevel
 Indicates how many levels the event can propagate.
 

Member Enumeration Documentation

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 wxHelpEvent::Origin 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.