4f4a8fc3c7
(to clarify static exception LGPL by changing license references) git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@8864 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
115 lines
2.8 KiB
C++
115 lines
2.8 KiB
C++
//
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// "$Id$"
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//
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// Idle routine support for the Fast Light Tool Kit (FLTK).
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//
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// Copyright 1998-2010 by Bill Spitzak and others.
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//
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// This library is free software. Distribution and use rights are outlined in
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// the file "COPYING" which should have been included with this file. If this
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// file is missing or damaged, see the license at:
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//
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// http://www.fltk.org/COPYING.php
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//
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// Please report all bugs and problems on the following page:
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//
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// http://www.fltk.org/str.php
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//
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// Allows you to manage an arbitrary set of idle() callbacks.
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// Replaces the older set_idle() call (which is used to implement this)
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#include <FL/Fl.H>
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struct idle_cb {
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void (*cb)(void*);
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void* data;
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idle_cb *next;
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};
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// the callbacks are stored linked in a ring. last points at the one
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// just called, first at the next to call. last->next == first.
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static idle_cb* first;
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static idle_cb* last;
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static idle_cb* freelist;
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static void call_idle() {
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idle_cb* p = first;
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last = p; first = p->next;
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p->cb(p->data); // this may call add_idle() or remove_idle()!
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}
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/**
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Adds a callback function that is called every time by Fl::wait() and also
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makes it act as though the timeout is zero (this makes Fl::wait() return
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immediately, so if it is in a loop it is called repeatedly, and thus the
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idle fucntion is called repeatedly). The idle function can be used to get
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background processing done.
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You can have multiple idle callbacks. To remove an idle callback use
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Fl::remove_idle().
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Fl::wait() and Fl::check() call idle callbacks, but Fl::ready() does not.
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The idle callback can call any FLTK functions, including Fl::wait(),
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Fl::check(), and Fl::ready().
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FLTK will not recursively call the idle callback.
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*/
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void Fl::add_idle(Fl_Idle_Handler cb, void* data) {
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idle_cb* p = freelist;
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if (p) freelist = p->next;
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else p = new idle_cb;
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p->cb = cb;
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p->data = data;
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if (first) {
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last->next = p;
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last = p;
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p->next = first;
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} else {
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first = last = p;
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p->next = p;
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set_idle(call_idle);
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}
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}
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/**
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Returns true if the specified idle callback is currently installed.
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*/
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int Fl::has_idle(Fl_Idle_Handler cb, void* data) {
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idle_cb* p = first;
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if (!p) return 0;
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for (;; p = p->next) {
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if (p->cb == cb && p->data == data) return 1;
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if (p==last) return 0;
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}
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}
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/**
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Removes the specified idle callback, if it is installed.
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*/
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void Fl::remove_idle(Fl_Idle_Handler cb, void* data) {
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idle_cb* p = first;
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if (!p) return;
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idle_cb* l = last;
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for (;; p = p->next) {
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if (p->cb == cb && p->data == data) break;
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if (p==last) return; // not found
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l = p;
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}
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if (l == p) { // only one
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first = last = 0;
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set_idle(0);
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} else {
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last = l;
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first = l->next = p->next;
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}
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p->next = freelist;
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freelist = p;
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}
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//
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// End of "$Id$".
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//
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