Method
GdkDrawContextbegin_frame
Declaration [src]
void
gdk_draw_context_begin_frame (
GdkDrawContext* context,
const cairo_region_t* region
)
Description [src]
Indicates that you are beginning the process of redrawing region
on the context‘s surface.
Calling this function begins a drawing operation using context on the
surface that context was created from. The actual requirements and
guarantees for the drawing operation vary for different implementations
of drawing, so a GdkCairoContext and a GdkGLContext
need to be treated differently.
A call to this function is a requirement for drawing and must be
followed by a call to gdk_draw_context_end_frame(), which will
complete the drawing operation and ensure the contents become visible
on screen.
Note that the region passed to this function is the minimum region that
needs to be drawn and depending on implementation, windowing system and
hardware in use, it might be necessary to draw a larger region. Drawing
implementation must use gdk_draw_context_get_frame_region() to
query the region that must be drawn.
When using GTK, the widget system automatically places calls to
gdk_draw_context_begin_frame() and gdk_draw_context_end_frame() via the
use of GskRenderers, so application code
does not need to call these functions explicitly.
Parameters
region-
Type:
cairo_region_tMinimum region that should be drawn.
The data is owned by the caller of the method.