gstreamer/subprojects/gst-plugins-base/tools/gst-play-kb.c
Seungha Yang f465156bf9 gst-play: Improve Win32 keyboard input handling
The console HANDLE will be keep signalled state unless application
reads console input buffer immediately. So we should read and flush
console input buffer from the thread where the event is signalled,
instead of GMain context thread.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2058>
2022-03-30 20:37:54 +00:00

318 lines
7.8 KiB
C

/* GStreamer command line playback testing utility - keyboard handling helpers
*
* Copyright (C) 2013 Tim-Philipp Müller <tim centricular net>
* Copyright (C) 2013 Centricular Ltd
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gst-play-kb.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef G_OS_UNIX
#include <unistd.h>
#include <termios.h>
#endif
#ifdef G_OS_WIN32
#include <windows.h>
#include <io.h>
#endif
#include <gst/gst.h>
/* This is all not thread-safe, but doesn't have to be really */
static GstPlayKbFunc kb_callback;
static gpointer kb_callback_data;
#ifdef G_OS_UNIX
static struct termios term_settings;
static gboolean term_settings_saved = FALSE;
static gulong io_watch_id;
static gboolean
gst_play_kb_io_cb (GIOChannel * ioc, GIOCondition cond, gpointer user_data)
{
GIOStatus status;
if (cond & G_IO_IN) {
gchar buf[16] = { 0, };
gsize read;
status = g_io_channel_read_chars (ioc, buf, sizeof (buf) - 1, &read, NULL);
if (status == G_IO_STATUS_ERROR)
return FALSE;
if (status == G_IO_STATUS_NORMAL) {
if (kb_callback)
kb_callback (buf, kb_callback_data);
}
}
return TRUE; /* call us again */
}
gboolean
gst_play_kb_set_key_handler (GstPlayKbFunc kb_func, gpointer user_data)
{
GIOChannel *ioc;
if (!isatty (STDIN_FILENO)) {
GST_INFO ("stdin is not connected to a terminal");
return FALSE;
}
if (io_watch_id > 0) {
g_source_remove (io_watch_id);
io_watch_id = 0;
}
if (kb_func == NULL && term_settings_saved) {
/* restore terminal settings */
if (tcsetattr (STDIN_FILENO, TCSAFLUSH, &term_settings) == 0)
term_settings_saved = FALSE;
else
g_warning ("could not restore terminal attributes");
setvbuf (stdin, NULL, _IOLBF, 0);
}
if (kb_func != NULL) {
struct termios new_settings;
if (!term_settings_saved) {
if (tcgetattr (STDIN_FILENO, &term_settings) != 0) {
g_warning ("could not save terminal attributes");
return FALSE;
}
term_settings_saved = TRUE;
/* Echo off, canonical mode off, extended input processing off */
new_settings = term_settings;
new_settings.c_lflag &= ~(ECHO | ICANON | IEXTEN);
new_settings.c_cc[VMIN] = 0;
new_settings.c_cc[VTIME] = 0;
if (tcsetattr (STDIN_FILENO, TCSAFLUSH, &new_settings) != 0) {
g_warning ("Could not set terminal state");
return FALSE;
}
setvbuf (stdin, NULL, _IONBF, 0);
}
}
ioc = g_io_channel_unix_new (STDIN_FILENO);
io_watch_id = g_io_add_watch_full (ioc, G_PRIORITY_DEFAULT, G_IO_IN,
(GIOFunc) gst_play_kb_io_cb, user_data, NULL);
g_io_channel_unref (ioc);
kb_callback = kb_func;
kb_callback_data = user_data;
return TRUE;
}
#elif defined(G_OS_WIN32)
typedef struct
{
GThread *thread;
HANDLE event_handle;
HANDLE console_handle;
gboolean closing;
GMutex lock;
} Win32KeyHandler;
static Win32KeyHandler *win32_handler = NULL;
typedef struct
{
gboolean is_ascii;
WORD vkcode;
gchar key_val[2];
} KbSourceData;
static gboolean
gst_play_kb_source_cb (KbSourceData * data)
{
if (!kb_callback)
return G_SOURCE_REMOVE;
if (data->is_ascii) {
kb_callback (data->key_val, kb_callback_data);
} else {
switch (data->vkcode) {
case VK_RIGHT:
kb_callback (GST_PLAY_KB_ARROW_RIGHT, kb_callback_data);
break;
case VK_LEFT:
kb_callback (GST_PLAY_KB_ARROW_LEFT, kb_callback_data);
break;
case VK_UP:
kb_callback (GST_PLAY_KB_ARROW_UP, kb_callback_data);
break;
case VK_DOWN:
kb_callback (GST_PLAY_KB_ARROW_DOWN, kb_callback_data);
break;
default:
break;
}
}
return G_SOURCE_REMOVE;
}
static gpointer
gst_play_kb_win32_thread (gpointer user_data)
{
Win32KeyHandler *handler = (Win32KeyHandler *) user_data;
HANDLE handles[2];
INPUT_RECORD buffer;
DWORD n;
handles[0] = handler->event_handle;
handles[1] = handler->console_handle;
if (!kb_callback)
return NULL;
while (TRUE) {
DWORD ret = WaitForMultipleObjects (2, handles, FALSE, INFINITE);
if (ret == WAIT_FAILED) {
GST_WARNING ("WaitForMultipleObject Failed");
return NULL;
}
g_mutex_lock (&handler->lock);
if (handler->closing) {
g_mutex_unlock (&handler->lock);
return NULL;
}
g_mutex_unlock (&handler->lock);
if (PeekConsoleInput (handler->console_handle, &buffer, 1, &n) && n == 1) {
if (ReadConsoleInput (handler->console_handle, &buffer, 1, &n) &&
buffer.EventType == KEY_EVENT && buffer.Event.KeyEvent.bKeyDown) {
KbSourceData *data = g_new0 (KbSourceData, 1);
switch (buffer.Event.KeyEvent.wVirtualKeyCode) {
case VK_RIGHT:
case VK_LEFT:
case VK_UP:
case VK_DOWN:
data->is_ascii = FALSE;
data->vkcode = buffer.Event.KeyEvent.wVirtualKeyCode;
break;
default:
data->is_ascii = TRUE;
data->key_val[0] = buffer.Event.KeyEvent.uChar.AsciiChar;
data->key_val[1] = '\0';
break;
}
g_idle_add_full (G_PRIORITY_DEFAULT_IDLE,
(GSourceFunc) gst_play_kb_source_cb, data, g_free);
}
}
}
return NULL;
}
gboolean
gst_play_kb_set_key_handler (GstPlayKbFunc kb_func, gpointer user_data)
{
gint fd = _fileno (stdin);
if (!_isatty (fd)) {
GST_INFO ("stdin is not connected to a terminal");
return FALSE;
}
if (win32_handler) {
g_mutex_lock (&win32_handler->lock);
win32_handler->closing = TRUE;
g_mutex_unlock (&win32_handler->lock);
SetEvent (win32_handler->event_handle);
g_thread_join (win32_handler->thread);
CloseHandle (win32_handler->event_handle);
g_mutex_clear (&win32_handler->lock);
g_free (win32_handler);
win32_handler = NULL;
}
if (kb_func) {
SECURITY_ATTRIBUTES sec_attrs;
sec_attrs.nLength = sizeof (SECURITY_ATTRIBUTES);
sec_attrs.lpSecurityDescriptor = NULL;
sec_attrs.bInheritHandle = FALSE;
win32_handler = g_new0 (Win32KeyHandler, 1);
/* create cancellable event handle */
win32_handler->event_handle = CreateEvent (&sec_attrs, TRUE, FALSE, NULL);
if (!win32_handler->event_handle) {
GST_WARNING ("Couldn't create event handle");
g_free (win32_handler);
win32_handler = NULL;
return FALSE;
}
win32_handler->console_handle = GetStdHandle (STD_INPUT_HANDLE);
if (!win32_handler->console_handle) {
GST_WARNING ("Couldn't get console handle");
CloseHandle (win32_handler->event_handle);
g_free (win32_handler);
win32_handler = NULL;
return FALSE;
}
g_mutex_init (&win32_handler->lock);
win32_handler->thread =
g_thread_new ("gst-play-kb", gst_play_kb_win32_thread, win32_handler);
}
kb_callback = kb_func;
kb_callback_data = user_data;
return TRUE;
}
#else
gboolean
gst_play_kb_set_key_handler (GstPlayKbFunc key_func, gpointer user_data)
{
GST_FIXME ("Keyboard handling for this OS needs to be implemented");
return FALSE;
}
#endif /* !G_OS_UNIX */