Create class Fl_Unix_Screen_Driver used by X11 and Wayland platforms

1 files changed, 96 insertions, 0 deletions

diff --git a/src/drivers/Unix/Fl_Unix_Screen_Driver.cxx b/src/drivers/Unix/Fl_Unix_Screen_Driver.cxx
new file mode 100644
index 000000000..0b33b0a20
--- /dev/null
+++ b/src/drivers/Unix/Fl_Unix_Screen_Driver.cxx
@@ -0,0 +1,96 @@
+//
+// Definition of the part of the Screen interface shared by X11/Wayland
+//
+// Copyright 2022 by Bill Spitzak and others.
+//
+// This library is free software. Distribution and use rights are outlined in
+// the file "COPYING" which should have been included with this file.  If this
+// file is missing or damaged, see the license at:
+//
+//     https://www.fltk.org/COPYING.php
+//
+// Please see the following page on how to report bugs and issues:
+//
+//     https://www.fltk.org/bugs.php
+//
+
+#include <config.h>
+#include "Fl_Unix_Screen_Driver.H"
+
+fd_set Fl_Unix_Screen_Driver::fdsets[3];
+int Fl_Unix_Screen_Driver::maxfd = 0;
+int Fl_Unix_Screen_Driver::nfds = 0;
+Fl_Unix_Screen_Driver::FD *Fl_Unix_Screen_Driver::fd = NULL;
+
+// these pointers are set by the Fl::lock() function:
+static void nothing() {}
+void (*fl_lock_function)() = nothing;
+void (*fl_unlock_function)() = nothing;
+
+
+// This is never called with time_to_wait < 0.0:
+// It should return negative on error, 0 if nothing happens before
+// timeout, and >0 if any callbacks were done.
+int Fl_Unix_Screen_Driver::poll_or_select_with_delay(double time_to_wait) {
+#  if !USE_POLL
+  fd_set fdt[3];
+  fdt[0] = fdsets[0];
+  fdt[1] = fdsets[1];
+  fdt[2] = fdsets[2];
+#  endif
+  int n;
+
+  fl_unlock_function();
+
+  if (time_to_wait < 2147483.648) {
+#  if USE_POLL
+    n = ::poll(pollfds, nfds, int(time_to_wait*1000 + .5));
+#  else
+    timeval t;
+    t.tv_sec = int(time_to_wait);
+    t.tv_usec = int(1000000 * (time_to_wait-t.tv_sec));
+    n = ::select(maxfd+1,&fdt[0],&fdt[1],&fdt[2],&t);
+#  endif
+  } else {
+#  if USE_POLL
+    n = ::poll(pollfds, nfds, -1);
+#  else
+    n = ::select(maxfd+1,&fdt[0],&fdt[1],&fdt[2],0);
+#  endif
+  }
+
+  fl_lock_function();
+
+  if (n > 0) {
+    for (int i=0; i<nfds; i++) {
+#  if USE_POLL
+      if (pollfds[i].revents) fd[i].cb(pollfds[i].fd, fd[i].arg);
+#  else
+      int f = fd[i].fd;
+      short revents = 0;
+      if (FD_ISSET(f,&fdt[0])) revents |= POLLIN;
+      if (FD_ISSET(f,&fdt[1])) revents |= POLLOUT;
+      if (FD_ISSET(f,&fdt[2])) revents |= POLLERR;
+      if (fd[i].events & revents) fd[i].cb(f, fd[i].arg);
+#  endif
+    }
+  }
+  return n;
+}
+
+
+int Fl_Unix_Screen_Driver::poll_or_select() {
+  if (!nfds) return 0; // nothing to select or poll
+#  if USE_POLL
+  return ::poll(pollfds, nfds, 0);
+#  else
+  timeval t;
+  t.tv_sec = 0;
+  t.tv_usec = 0;
+  fd_set fdt[3];
+  fdt[0] = fdsets[0];
+  fdt[1] = fdsets[1];
+  fdt[2] = fdsets[2];
+  return ::select(maxfd+1,&fdt[0],&fdt[1],&fdt[2],&t);
+#  endif
+}