diff options
| -rw-r--r-- | FL/Fl_Device.H | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/FL/Fl_Device.H b/FL/Fl_Device.H index ab216a0e0..764bcd114 100644 --- a/FL/Fl_Device.H +++ b/FL/Fl_Device.H @@ -38,16 +38,17 @@ class Fl_Image_Surface; an instance of the Fl_Display_Device class. A drawing surface other than the computer's display, is typically used as follows: - <ol><li> Create \c surface, an object from a particular Fl_Surface_Device derived class (e.g., Fl_Copy_Surface, Fl_Printer). + <ol><li> Create \c surface, an object from an Fl_Surface_Device derived class (e.g., Fl_Image_Surface, Fl_Printer, Fl_Copy_Surface). <li> Call \c Fl_Surface_Device::push_current(surface); to redirect all graphics requests to - \c surface which becomes the new current drawing surface (not necessary with classes Fl_Printer / Fl_PostScript_File_Device - because it is done by Fl_Paged_Device::begin_page()). + \c surface which becomes the new current drawing surface (not necessary with classes Fl_Printer / Fl_PostScript_File_Device / + Fl_PDF_File_Surface because it is done by Fl_Paged_Device::begin_page()). <li> At this point all of the \ref fl_drawings (e.g., fl_rect()) or the \ref fl_attributes or \ref drawing_images functions (e.g., fl_draw_image(), Fl_Image::draw()) operate on the new current drawing surface. - Drawing surfaces from Fl_Widget_Surface derived classes allow additional ways - to draw to them (e.g., Fl_Printer::print_widget(), Fl_Image_Surface::draw()). + It's also possible to draw to the current surface any widget with Fl_Widget_Surface::draw(Fl_Widget*, int, int), a window and its + titlebar with Fl_Widget_Surface::draw_decorated_window(), or the content of a rectangular zone of a window + with Fl_Widget_Surface::print_window_part(). <li> After all drawing requests have been performed, redirect graphics requests back to their previous destination - with \c Fl_Surface_Device::pop_current(); (not necessary with classes Fl_Printer / Fl_PostScript_File_Device). + with \c Fl_Surface_Device::pop_current(); (not necessary with classes Fl_Printer / Fl_PostScript_File_Device / Fl_PDF_File_Surface). <li> Delete \c surface. </ol> For back-compatibility, it is also possible to use the Fl_Surface_Device::set_current() member function |