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FLTK - Fast Light Tool Kit - https://github.com/fltk/fltk - cross platform GUI development
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123 lines
3.2 KiB
123 lines
3.2 KiB
// |
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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 1998-2008 by Bill Spitzak and others. |
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// |
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// This library is free software; you can redistribute it and/or |
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// modify it under the terms of the GNU Library General Public |
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// License as published by the Free Software Foundation; either |
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// version 2 of the License, or (at your option) any later version. |
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// |
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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// Library General Public License for more details. |
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// |
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// You should have received a copy of the GNU Library General Public |
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// License along with this library; if not, write to the Free Software |
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
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// USA. |
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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(void (*cb)(void*), 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(void (*cb)(void*), 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(void (*cb)(void*), 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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