.TH wxBufferedDC 3erl "wx 2.4.1" "wxWidgets team." "Erlang Module Definition"
.SH NAME
wxBufferedDC \- Functions for wxBufferedDC class
.SH DESCRIPTION
.LP
This class provides a simple way to avoid flicker: when drawing on it, everything is in fact first drawn on an in-memory buffer (a \fIwxBitmap\fR\&) and then copied to the screen, using the associated \fIwxDC\fR\&, only once, when this object is destroyed\&. \fIwxBufferedDC\fR\& itself is typically associated with \fIwxClientDC\fR\&, if you want to use it in your \fIEVT_PAINT\fR\& handler, you should look at \fIwxBufferedPaintDC\fR\& instead\&.
.LP
When used like this, a valid \fIDC\fR\& must be specified in the constructor while the \fIbuffer\fR\& bitmap doesn\&'t have to be explicitly provided, by default this class will allocate the bitmap of required size itself\&. However using a dedicated bitmap can speed up the redrawing process by eliminating the repeated creation and destruction of a possibly big bitmap\&. Otherwise, \fIwxBufferedDC\fR\& can be used in the same way as any other device context\&.
.LP
Another possible use for \fIwxBufferedDC\fR\& is to use it to maintain a backing store for the window contents\&. In this case, the associated \fIDC\fR\& may be NULL but a valid backing store bitmap should be specified\&.
.LP
Finally, please note that GTK+ 2\&.0 as well as macOS provide double buffering themselves natively\&. You can either use \fIwxWindow:isDoubleBuffered/1\fR\& to determine whether you need to use buffering or not, or use \fIwxAutoBufferedPaintDC\fR\& (not implemented in wx) to avoid needless double buffering on the systems which already do it automatically\&.
.LP
See: \fIwxDC\fR\&, \fIwxMemoryDC\fR\&, \fIwxBufferedPaintDC\fR\&, \fIwxAutoBufferedPaintDC\fR\& (not implemented in wx)
.LP
This class is derived (and can use functions) from: \fIwxMemoryDC\fR\& \fIwxDC\fR\&
.LP
wxWidgets docs: wxBufferedDC
.SH DATA TYPES
.nf

\fBwxBufferedDC()\fR\& = wx:wx_object()
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.SH EXPORTS
.LP
.nf

.B
new() -> wxBufferedDC()
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.RS
.LP
Default constructor\&.
.LP
You must call one of the \fIinit/4\fR\& methods later in order to use the device context\&.
.RE

.LP
.nf

.B
new(Dc) -> wxBufferedDC()
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.RS
.LP
Types:

.RS 3
Dc = wxDC:wxDC()
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.RE
.RE
.LP
.nf

.B
new(Dc, Area) -> wxBufferedDC()
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.B
new(Dc, Area :: [Option]) -> wxBufferedDC()
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.RS
.LP
Types:

.RS 3
Dc = wxDC:wxDC()
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Option = {buffer, wxBitmap:wxBitmap()} | {style, integer()}
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.RE
.RE
.RS
.LP
Creates a buffer for the provided dc\&.
.LP
\fIinit/4\fR\& must not be called when using this constructor\&.
.RE

.LP
.nf

.B
new(Dc, Area, Options :: [Option]) -> wxBufferedDC()
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.RS
.LP
Types:

.RS 3
Dc = wxDC:wxDC()
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Area = {W :: integer(), H :: integer()}
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Option = {style, integer()}
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.RE
.RE
.RS
.LP
Creates a buffer for the provided \fIdc\fR\&\&.
.LP
\fIinit/4\fR\& must not be called when using this constructor\&.
.RE

.LP
.nf

.B
destroy(This :: wxBufferedDC()) -> ok
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.RS
.LP
Copies everything drawn on the DC so far to the underlying DC associated with this object, if any\&.
.RE

.LP
.nf

.B
init(This, Dc) -> ok
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.RS
.LP
Types:

.RS 3
This = wxBufferedDC()
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Dc = wxDC:wxDC()
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.RE
.RE
.LP
.nf

.B
init(This, Dc, Area) -> ok
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.nf

.B
init(This, Dc, Area :: [Option]) -> ok
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.fi
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.RS
.LP
Types:

.RS 3
This = wxBufferedDC()
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Dc = wxDC:wxDC()
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Option = {buffer, wxBitmap:wxBitmap()} | {style, integer()}
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.RE
.RE
.RS
.RE

.LP
.nf

.B
init(This, Dc, Area, Options :: [Option]) -> ok
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.fi
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.RS
.LP
Types:

.RS 3
This = wxBufferedDC()
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Dc = wxDC:wxDC()
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Area = {W :: integer(), H :: integer()}
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Option = {style, integer()}
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.RE
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.RS
.LP
Initializes the object created using the default constructor\&.
.LP
Please see the constructors for parameter details\&.
.RE