| Version: 3.3.1

Public Member Functions | List of all members
wxPaintEvent Class Reference
Class List by Category » Events

`#include <wx/event.h>`

Inheritance diagram for wxPaintEvent:
[legend]

## Detailed Description

A paint event is sent when a window's contents needs to be repainted.

The handler of this event must create a wxPaintDC object and use it for painting the window contents. For example:

void MyWindow::OnPaint(wxPaintEvent& event)
{
wxPaintDC dc(this);
DrawMyDocument(dc);
}
wxPaintDC
A wxPaintDC must be constructed if an application wishes to paint on the client area of a window from...
Definition: dcclient.h:30
wxPaintEvent
A paint event is sent when a window's contents needs to be repainted.
Definition: event.h:2321

Notice that you must not create other kinds of wxDC (e.g. wxClientDC or wxWindowDC) in EVT_PAINT handlers and also don't create wxPaintDC outside of this event handlers.

You can optimize painting by retrieving the rectangles that have been damaged and only repainting these. The rectangles are in terms of the client area, and are unscrolled, so you will need to do some calculations using the current view position to obtain logical, scrolled units. Here is an example of using the wxRegionIterator class:

// Called when window needs to be repainted.
void MyWindow::OnPaint(wxPaintEvent& event)
{
wxPaintDC dc(this);
// Find Out where the window is scrolled to
int vbX,vbY; // Top left corner of client
GetViewStart(&vbX,&vbY);
int vX,vY,vW,vH; // Dimensions of client area in pixels
wxRegionIterator upd(GetUpdateRegion()); // get the update rect list
while (upd)
{
vX = upd.GetX();
vY = upd.GetY();
vW = upd.GetW();
vH = upd.GetH();
// Alternatively we can do this:
// wxRect rect(upd.GetRect());
// Repaint this rectangle
...some code...
upd ++ ;
}
}
wxRegionIterator
This class is used to iterate through the rectangles in a region, typically when examining the damage...
Definition: region.h:54

Remarks
  Please notice that in general it is impossible to change the drawing of a standard control (such as wxButton) and so you shouldn't attempt to handle paint events for them as even if it might work on some platforms, this is inherently not portable and won't work everywhere.

## Events using this class

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

void handlerFuncName(wxPaintEvent& event)

Event macros:

- EVT_PAINT(func):
  Process a `wxEVT_PAINT` event.

##

Library: wxCore
Category: Events

See also
  Events and Event Handling

## Public Member Functions
| wxPaintEvent (wxWindow *window)
| Constructor for exclusive use of wxWidgets itself. More...
Public Member Functions inherited from wxEvent
| wxEvent (int id=0, wxEventType eventType=wxEVT_NULL)
| Constructor. More...
virtual wxEvent * | Clone () const =0
| Returns a copy of the event. More...
wxObject * | GetEventObject () const
| Returns the object (usually a window) associated with the event, if any. More...
wxEventType | GetEventType () const
| Returns the identifier of the given event type, such as `wxEVT_BUTTON`. More...
virtual wxEventCategory | GetEventCategory () const
| Returns a generic category for this event. More...
int | GetId () const
| Returns the identifier associated with this event, such as a button command id. More...
wxObject * | GetEventUserData () const
| Return the user data associated with a dynamically connected event handler. More...
bool | GetSkipped () const
| Returns true if the event handler should be skipped, false otherwise. More...
long | GetTimestamp () const
| Gets the timestamp for the event. More...
bool | IsCommandEvent () const
| Returns true if the event is or is derived from wxCommandEvent else it returns false. More...
void | ResumePropagation (int propagationLevel)
| Sets the propagation level to the given value (for example returned from an earlier call to wxEvent::StopPropagation). More...
void | SetEventObject (wxObject *object)
| Sets the originating object. More...
void | SetEventType (wxEventType type)
| Sets the event type. More...
void | SetId (int id)
| Sets the identifier associated with this event, such as a button command id. More...
void | SetTimestamp (long timeStamp=0)
| Sets the timestamp for the event. More...
bool | ShouldPropagate () const
| Test if this event should be propagated or not, i.e. if the propagation level is currently greater than 0. More...
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. More...
int | StopPropagation ()
| Stop the event from propagating to its parent window. More...
Public Member Functions inherited from wxObject
| wxObject ()
| Default ctor; initializes to nullptr the internal reference data. More...
| wxObject (const wxObject &other)
| Copy ctor. More...
virtual | ~wxObject ()
| Destructor. More...
virtual wxClassInfo * | GetClassInfo () const
| This virtual function is redefined for every class that requires run-time type information, when using the wxDECLARE_CLASS macro (or similar). More...
wxObjectRefData * | GetRefData () const
| Returns the wxObject::m_refData pointer, i.e. the data referenced by this object. More...
bool | IsKindOf (const wxClassInfo *info) const
| Determines whether this class is a subclass of (or the same class as) the given class. More...
bool | IsSameAs (const wxObject &obj) const
| Returns true if this object has the same data pointer as obj. More...
void | Ref (const wxObject &clone)
| Makes this object refer to the data in clone. More...
void | SetRefData (wxObjectRefData *data)
| Sets the wxObject::m_refData pointer. More...
void | UnRef ()
| Decrements the reference count in the associated data, and if it is zero, deletes the data. More...
void | UnShare ()
| This is the same of AllocExclusive() but this method is public. More...
void | operator delete (void *buf)
| The delete operator is defined for debugging versions of the library only, when the identifier `__WXDEBUG__` is defined. More...
void * | operator new (size_t size, const wxString &filename=nullptr, int lineNum=0)
| The new operator is defined for debugging versions of the library only, when the identifier `__WXDEBUG__` is defined. More...

## Additional Inherited Members
Protected Member Functions inherited from wxObject
void | AllocExclusive ()
| Ensure that this object's data is not shared with any other object. More...
virtual wxObjectRefData * | CreateRefData () const
| Creates a new instance of the wxObjectRefData-derived class specific to this object and returns it. More...
virtual wxObjectRefData * | CloneRefData (const wxObjectRefData *data) const
| Creates a new instance of the wxObjectRefData-derived class specific to this object and initializes it copying data. More...
Protected Attributes inherited from wxEvent
int | m_propagationLevel
| Indicates how many levels the event can propagate. More...
Protected Attributes inherited from wxObject
wxObjectRefData * | m_refData
| Pointer to an object which is the object's reference-counted data. More...

## Constructor & Destructor Documentation

## ◆ wxPaintEvent()

wxPaintEvent::wxPaintEvent | ( | wxWindow * | window | ) |
| explicit

Constructor for exclusive use of wxWidgets itself.

Note that the objects of this class can not be created from application code, they're only created by the library itself. If you need a window to be repainted, use wxWindow::Refresh() instead of trying to manually create an event of this class.