[gnome-remote-desktop] vnc: Add VNC virtual monitor config

[Jonas Ådahl <jadahl src gnome org>]

commit 145ce940e37f0a0caa0fa6a030650b92c03b143b
Author: Vasilis Liaskovitis <vliaskovitis suse com>
Date:   Thu Jul 14 17:48:18 2022 +0200

    vnc: Add VNC virtual monitor config
    
    VNC clients do not submit an initial monitor configuration upon connection.
    However the monitor configuration can be changed during the session with
    a setDesktopSize RFB request:
    
    https://vncdotool.readthedocs.io/en/0.8.0/rfbproto.html#setdesktopsize
    
    This commit adds a configuration struct for rudimentary virtual
    monitors to be used in VNC sessions. Currently, only the size (width x
    height) of the virtual monitor can be manipulated through the
    setDesktopSize hook (to be implemented in a later commit).
    
    Based on RDP virtual monitor commits by Pascal Nowack <Pascal Nowack gmx de>
    https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/merge_requests/69

 src/grd-session-vnc.c        |  8 ++++++++
 src/grd-vnc-monitor-config.h | 48 ++++++++++++++++++++++++++++++++++++++++++++
 src/meson.build              |  1 +
 3 files changed, 57 insertions(+)
---
diff --git a/src/grd-session-vnc.c b/src/grd-session-vnc.c
index fbc66a41..44a9d44d 100644
--- a/src/grd-session-vnc.c
+++ b/src/grd-session-vnc.c
@@ -211,6 +211,14 @@ grd_session_vnc_set_client_clipboard_text (GrdSessionVnc *session_vnc,
   rfbSendServerCutText(session_vnc->rfb_screen, text, text_length);
 }
 
+static void
+grd_vnc_monitor_config_free (GrdVncMonitorConfig *monitor_config)
+{
+  g_clear_pointer (&monitor_config->connectors, g_strfreev);
+  g_free (monitor_config->virtual_monitors);
+  g_free (monitor_config);
+}
+
 static void
 maybe_queue_close_session_idle (GrdSessionVnc *session_vnc)
 {
diff --git a/src/grd-vnc-monitor-config.h b/src/grd-vnc-monitor-config.h
new file mode 100644
index 00000000..d7baa496
--- /dev/null
+++ b/src/grd-vnc-monitor-config.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2022 Pascal Nowack
+ * Copyright (C) 2022 SUSE Software Solutions Germany GmbH
+ *
+ * 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.
+ */
+
+#ifndef GRD_VNC_MONITOR_CONFIG_H
+#define GRD_VNC_MONITOR_CONFIG_H
+
+#define GRD_VNC_CLAMP_DESKTOP_SIZE(value) MAX (MIN (value, 8192), 200)
+#define GRD_VNC_DEFAULT_WIDTH             1920
+#define GRD_VNC_DEFAULT_HEIGHT            1080
+
+typedef struct _GrdVncVirtualMonitor
+{
+  uint16_t pos_x;
+  uint16_t pos_y;
+  uint16_t width;  /* Valid values are in range of [200, 8192] */
+  uint16_t height; /* Valid values are in range of [200, 8192] */
+} GrdVncVirtualMonitor;
+
+typedef struct _GrdVncMonitorConfig
+{
+  gboolean is_virtual;
+
+  /* Server configs only */
+  char **connectors;
+  /* Client configs only */
+  GrdVncVirtualMonitor *virtual_monitors;
+  /* Count of items in connectors or virtual_monitors */
+  uint32_t monitor_count;
+} GrdVncMonitorConfig;
+
+#endif /* GRD_VNC_MONITOR_CONFIG_H */
diff --git a/src/meson.build b/src/meson.build
index 3def890f..6c0bf845 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -111,6 +111,7 @@ if have_vnc
     'grd-session-vnc.h',
     'grd-vnc-cursor.c',
     'grd-vnc-cursor.h',
+    'grd-vnc-monitor-config.h',
     'grd-vnc-pipewire-stream.c',
     'grd-vnc-pipewire-stream.h',
     'grd-vnc-server.c',