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/////////////////////////////////////////////////////////////////////////////
// Name: dcclient.h
// Purpose: interface of wxClientDC and wxPaintDC
// Author: wxWidgets team
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
/**
@class wxPaintDC
A wxPaintDC must be constructed if an application wishes to paint on the
client area of a window from within an EVT_PAINT() event handler. This
should normally be constructed as a temporary stack object; don't store a
wxPaintDC object. If you have an EVT_PAINT() handler, you @e must create a
wxPaintDC object within it even if you don't actually use it.
Using wxPaintDC within your EVT_PAINT() handler is important because it
automatically sets the clipping area to the damaged area of the window.
Attempts to draw outside this area do not appear.
A wxPaintDC object is initialized to use the same font and colours as the
window it is associated with.
@library{wxcore}
@category{dc}
@see wxDC, wxClientDC, wxMemoryDC, wxWindowDC, wxScreenDC
*/
class wxPaintDC : public wxClientDC
{
public:
/**
Constructor. Pass a pointer to the window on which you wish to paint.
*/
wxPaintDC(wxWindow* window);
};
/**
@class wxClientDC
wxClientDC is primarily useful for obtaining information about the window
from outside EVT_PAINT() handler.
Typical use of this class is to obtain the extent of some text string in
order to allocate enough size for a window, e.g.
@code
// Create the initially empty label with the size big enough to show
// the given string.
wxClientDC dc(this);
wxStaticText* text = new wxStaticText
(
this, wxID_ANY, "",
wxPoint(),
dc.GetTextExtent("String of max length"),
wxST_NO_AUTORESIZE
);
}
@endcode
@note While wxClientDC may also be used for drawing on the client area of a
window from outside an EVT_PAINT() handler in some ports, this does @em not
work on all platforms (neither wxOSX nor wxGTK with GTK 3 Wayland backend
support this, so drawing using wxClientDC simply doesn't have any effect
there) and the only portable way of drawing is via wxPaintDC. To redraw a
small part of the window, use wxWindow::RefreshRect() to invalidate just
this part and check wxWindow::GetUpdateRegion() in the paint event handler
to redraw this part only.
wxClientDC objects should normally be constructed as temporary stack
objects, i.e. don't store a wxClientDC object.
A wxClientDC object is initialized to use the same font and colours as the
window it is associated with.
@library{wxcore}
@category{dc}
@see wxDC, wxMemoryDC, wxPaintDC, wxWindowDC, wxScreenDC
*/
class wxClientDC : public wxWindowDC
{
public:
/**
Constructor. Pass a pointer to the window on which you wish to paint.
*/
wxClientDC(wxWindow* window);
};
/**
@class wxWindowDC
A wxWindowDC must be constructed if an application wishes to paint on the
whole area of a window (client and decorations). This should normally be
constructed as a temporary stack object; don't store a wxWindowDC object.
To draw on a window from inside an EVT_PAINT() handler, construct a
wxPaintDC object instead.
To draw on the client area of a window from outside an EVT_PAINT() handler,
construct a wxClientDC object.
A wxWindowDC object is initialized to use the same font and colours as the
window it is associated with.
@library{wxcore}
@category{dc}
@see wxDC, wxMemoryDC, wxPaintDC, wxClientDC, wxScreenDC
*/
class wxWindowDC : public wxDC
{
public:
/**
Constructor. Pass a pointer to the window on which you wish to paint.
*/
wxWindowDC(wxWindow* window);
};
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