mutter/src/uislave.c
2001-06-03 07:41:36 +00:00

308 lines
7.8 KiB
C

/* Metacity UI Slave */
/*
* Copyright (C) 2001 Havoc Pennington
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include "uislave.h"
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
static void respawn_child (MetaUISlave *uislave);
static gboolean error_callback (GIOChannel *source,
GIOCondition condition,
gpointer data);
static void kill_child (MetaUISlave *uislave);
static void reset_vals (MetaUISlave *uislave);
static void message_queue_func (MetaMessageQueue *mq,
MetaMessage* message,
gpointer data);
MetaUISlave*
meta_ui_slave_new (const char *display_name,
MetaUISlaveFunc func,
gpointer data)
{
MetaUISlave *uislave;
uislave = g_new (MetaUISlave, 1);
uislave->display_name = g_strdup (display_name);
uislave->func = func;
uislave->data = data;
uislave->no_respawn = FALSE;
reset_vals (uislave);
/* This may fail; all UISlave functions become no-ops
* if uislave->child_pids == 0, and metacity just runs
* with no UI features other than window borders.
*/
respawn_child (uislave);
return uislave;
}
void
meta_ui_slave_free (MetaUISlave *uislave)
{
meta_verbose ("Deleting UI slave for display '%s'\n",
uislave->display_name);
kill_child (uislave);
g_free (uislave->display_name);
g_free (uislave);
}
void
meta_ui_slave_disable (MetaUISlave *uislave)
{
/* Change UI slave into "black hole" mode,
* we found out it's hosed for some reason.
*/
kill_child (uislave);
uislave->no_respawn = TRUE;
}
static void
message_queue_func (MetaMessageQueue *mq,
MetaMessage* message,
gpointer data)
{
MetaUISlave *uislave;
uislave = data;
(* uislave->func) (uislave, message, uislave->data);
}
static void
respawn_child (MetaUISlave *uislave)
{
GError *error;
const char *uislavedir;
char *argv[] = { "./metacity-uislave", NULL };
char *envp[2] = { NULL, NULL };
int child_pid, inpipe, outpipe, errpipe;
if (uislave->no_respawn)
return;
uislavedir = g_getenv ("METACITY_UISLAVE_DIR");
if (uislavedir == NULL)
uislavedir = METACITY_LIBEXECDIR;
envp[0] = g_strconcat ("DISPLAY=", uislave->display_name, NULL);
error = NULL;
if (g_spawn_async_with_pipes (uislavedir,
argv,
envp,
/* flags */
0,
/* setup func, data */
NULL, NULL,
&child_pid,
&inpipe, &outpipe, &errpipe,
&error))
{
uislave->child_pid = child_pid;
uislave->in_pipe = inpipe;
uislave->err_pipe = errpipe;
uislave->out_pipe = outpipe;
uislave->err_channel = g_io_channel_unix_new (errpipe);
uislave->errwatch = g_io_add_watch (uislave->err_channel,
G_IO_IN,
error_callback,
uislave);
uislave->mq = meta_message_queue_new (outpipe,
message_queue_func,
uislave);
meta_verbose ("Spawned UI slave with PID %d\n", uislave->child_pid);
}
else
{
meta_warning ("Failed to create user interface process: %s\n",
error->message);
g_error_free (error);
}
g_free (envp[0]);
}
static gboolean
error_callback (GIOChannel *source,
GIOCondition condition,
gpointer data)
{
/* Relay slave errors to WM stderr */
#define BUFSIZE 1024
MetaUISlave *uislave;
char buf[1024];
int n;
uislave = data;
/* Classic loop from Stevens */
n = read (uislave->err_pipe, buf, BUFSIZE);
if (n > 0)
{
if (write (2, buf, n) != n)
; /* error, but printing a message to stderr will hardly help. */
}
else if (n < 0)
meta_warning (_("Error reading errors from UI slave: %s\n"),
g_strerror (errno));
return TRUE;
#undef BUFSIZE
}
static void
kill_child (MetaUISlave *uislave)
{
if (uislave->mq)
meta_message_queue_free (uislave->mq);
if (uislave->errwatch != 0)
g_source_remove (uislave->errwatch);
if (uislave->err_channel)
g_io_channel_unref (uislave->err_channel);
if (uislave->out_pipe >= 0)
close (uislave->out_pipe);
if (uislave->in_pipe >= 0)
close (uislave->in_pipe);
if (uislave->err_pipe >= 0)
close (uislave->err_pipe);
if (uislave->child_pid > 0)
{
/* don't care if this fails except in verbose mode */
if (kill (uislave->child_pid, SIGTERM) != 0)
{
meta_verbose ("Kill of UI slave process %d failed: %s\n",
uislave->child_pid, g_strerror (errno));
}
uislave->child_pid = 0;
}
reset_vals (uislave);
}
static void
reset_vals (MetaUISlave *uislave)
{
uislave->mq = NULL;
uislave->child_pid = 0;
uislave->in_pipe = -1;
uislave->err_pipe = -1;
uislave->out_pipe = -1;
uislave->err_channel = NULL;
uislave->errwatch = 0;
/* don't reset no_respawn, it's a permanent thing. */
}
/*
* Message delivery
*/
static int
write_bytes (int fd, void *buf, int bytes)
{
const char *p;
int left;
left = bytes;
p = (char*) buf;
while (left > 0)
{
int written;
written = write (fd, p, left);
if (written < 0)
return -1;
left -= written;
p += written;
}
g_assert (p == ((char*)buf) + bytes);
return 0;
}
static void
send_message (MetaUISlave *uislave, MetaMessage *message)
{
static int serial = 0;
MetaMessageFooter *footer;
message->header.serial = serial;
footer = META_MESSAGE_FOOTER (message);
footer->checksum = META_MESSAGE_CHECKSUM (message);
++serial;
if (write_bytes (uislave->in_pipe,
META_MESSAGE_ESCAPE, META_MESSAGE_ESCAPE_LEN) < 0)
meta_warning ("Failed to write escape sequence: %s\n",
g_strerror (errno));
if (write_bytes (uislave->in_pipe,
message, message->header.length) < 0)
meta_warning ("Failed to write message: %s\n",
g_strerror (errno));
}
void
meta_ui_slave_show_tip (MetaUISlave *uislave,
int root_x,
int root_y,
const char *markup_text)
{
MetaMessageShowTip showtip;
memset (&showtip, 0, META_MESSAGE_LENGTH (MetaMessageShowTip));
showtip.header.message_code = MetaMessageShowTipCode;
showtip.header.length = META_MESSAGE_LENGTH (MetaMessageShowTip);
showtip.root_x = root_x;
showtip.root_y = root_y;
strncpy (showtip.markup, markup_text, META_MESSAGE_MAX_TIP_LEN);
showtip.markup[META_MESSAGE_MAX_TIP_LEN] = '\0';
send_message (uislave, (MetaMessage*)&showtip);
}