mirror of https://github.com/fltk/fltk
60 lines
2.5 KiB
HTML
60 lines
2.5 KiB
HTML
<HTML>
|
|
<HEAD>
|
|
<TITLE>Fl_Overlay_Window</TITLE>
|
|
</HEAD>
|
|
<BODY>
|
|
<!-- NEW PAGE -->
|
|
<H2><A name=Fl_Overlay_Window>class Fl_Overlay_Window</A></H2>
|
|
<HR>
|
|
<H3>Class Hierarchy</H3>
|
|
<UL>
|
|
<PRE>
|
|
<A href=Fl_Double_Window.html#Fl_Double_Window>Fl_Double_Window</A>
|
|
|
|
|
+----<B>Fl_Overlay_Window</B>
|
|
</PRE>
|
|
</UL>
|
|
<H3>Include Files</H3>
|
|
<UL>
|
|
<PRE>
|
|
#include <FL/Fl_Overlay_Window.H>
|
|
</PRE>
|
|
</UL>
|
|
<H3>Description</H3>
|
|
This window provides double buffering and also the ability to draw the
|
|
"overlay" which is another picture placed on top of the main image. The
|
|
overlay is designed to be a rapidly-changing but simple graphic such as
|
|
a mouse selection box. <TT>Fl_Overlay_Window</TT> uses the overlay
|
|
planes provided by your graphics hardware if they are available.
|
|
<P>If no hardware support is found the overlay is simulated by drawing
|
|
directly into the on-screen copy of the double-buffered window, and
|
|
"erased" by copying the backbuffer over it again. This means the
|
|
overlay will blink if you change the image in the window. </P>
|
|
<H3>Methods</H3>
|
|
<UL>
|
|
<LI><A href=#Fl_Overlay_Window.Fl_Overlay_Window>Fl_Overlay_Window</A></LI>
|
|
<LI><A href=#Fl_Overlay_Window.~Fl_Overlay_Window>~Fl_Overlay_Window</A></LI>
|
|
<LI><A href=#Fl_Overlay_Window.draw_overlay>draw_overlay</A></LI>
|
|
<LI><A href=#Fl_Overlay_Window.redraw_overlay>redraw_overlay</A></LI>
|
|
</UL>
|
|
<H4><A name=Fl_Overlay_Window.Fl_Overlay_Window>
|
|
Fl_Overlay_Window::Fl_Overlay_Window(int x, int y, int w, int h, const
|
|
char *label = 0)</A></H4>
|
|
Creates a new <TT>Fl_Overlay_Window</TT> widget using the given
|
|
position, size, and label (title) string.
|
|
<H4><A name=Fl_Overlay_Window.~Fl_Overlay_Window>virtual
|
|
Fl_Overlay_Window::~Fl_Overlay_Window()</A></H4>
|
|
Destroys the window and all child widgets.
|
|
<H4><A name=Fl_Overlay_Window.draw_overlay>virtual void
|
|
Fl_Overlay_Window::draw_overlay() = 0</A></H4>
|
|
You must subclass <TT>Fl_Overlay_Window</TT> and provide this method.
|
|
It is just like a <TT>draw()</TT> method, except it draws the overlay.
|
|
The overlay will have already been "cleared" when this is called. You
|
|
can use any of the routines described in <A href="drawing.html#drawing"><FL/fl_draw.H></A>.
|
|
<H4><A name=Fl_Overlay_Window.redraw_overlay>void Fl_Overlay_Window::redraw_overlay()</A>
|
|
</H4>
|
|
Call this to indicate that the overlay data has changed and needs to
|
|
be redrawn. The overlay will be clear until the first time this is
|
|
called, so if you want an initial display you must call this after
|
|
calling <TT>show()</TT>. </BODY></HTML>
|