plug-ins: implementation of the Freedesktop portal for screenshot.

I am told by the GNOME/Flatpak people that this is what we will
ultimately need to implement. Basically this portal is supposed to work
everywhere, in sandboxes (Flatpak, hopefully Snap too?), but also out
of sandboxes, i.e. in GNOME and KDE, whether Wayland or X11. So that
should be the unique API we will have to implement in the end, and every
desktop environment/sandbox will need to implement this API (which is
good!).
Apparently it is not part of default GNOME yet, but has to be installed
separately (on Fedora, package is xdg-desktop-portal-gtk for GNOME and
xdg-desktop-portal-kde for KDE).

Now there are currently many shortcomings, and in particular, the
screenshot API has apparently no advanced features (at all!). No window
snap, no rectangular selection, no delaying, no choice on including
cursor or decoration, nothing! Apparently this is normal that the API
presents no feature, because "the API itself is not meant to specify the
details how the screenshot is obtained. Instead the portal will present
the user a dialog to take a screenshot, and that screenshot will be
given back to the sandboxed app".
This is acceptable behavior, except that currently, the dialog has none
of the basic features so this is a very bad regression. This is why I
test the freedesktop API last, which basically means it will likely
never be actually used. That's on purpose. At least, the code is in and
will be easy to improve later. Of course, when the Freedesktop portal
for screenshot will finally be featureful, it is meant to be tested
first.

See: https://github.com/flatpak/xdg-desktop-portal/blob/master/data/org.freedesktop.portal.Screenshot.xml
This commit is contained in:
Jehan 2017-12-16 02:15:57 +01:00
parent 6fee1a413f
commit 53a03b38e5
5 changed files with 243 additions and 1 deletions

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@ -46,6 +46,8 @@ EXTRA_PROGRAMS = screenshot
screenshot_SOURCES = \
screenshot.c \
screenshot.h \
screenshot-freedesktop.c \
screenshot-freedesktop.h \
screenshot-gnome-shell.c \
screenshot-gnome-shell.h \
screenshot-icon.h \

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@ -0,0 +1,199 @@
/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* Screenshot plug-in
* Copyright 1998-2007 Sven Neumann <sven@gimp.org>
* Copyright 2003 Henrik Brix Andersen <brix@gimp.org>
* Copyright 2016 Michael Natterer <mitch@gimp.org>
* Copyright 2017 Jehan <jehan@gimp.org>
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <glib.h>
#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>
#include "screenshot.h"
#include "screenshot-freedesktop.h"
static GDBusProxy *proxy = NULL;
gboolean
screenshot_freedesktop_available (void)
{
proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SESSION,
G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
NULL,
"org.freedesktop.portal.Desktop",
"/org/freedesktop/portal/desktop",
"org.freedesktop.portal.Screenshot",
NULL, NULL);
if (proxy)
{
GError *error = NULL;
g_dbus_proxy_call_sync (proxy, "org.freedesktop.DBus.Peer.Ping",
NULL,
G_DBUS_CALL_FLAGS_NONE,
-1, NULL, &error);
if (! error)
return TRUE;
g_clear_error (&error);
g_object_unref (proxy);
proxy = NULL;
}
return FALSE;
}
ScreenshotCapabilities
screenshot_freedesktop_get_capabilities (void)
{
/* Portal has no capabilities other than root screenshot! */
return 0;
}
static void
screenshot_freedesktop_dbus_signal (GDBusProxy *proxy,
gchar *sender_name,
gchar *signal_name,
GVariant *parameters,
gint32 *image_ID)
{
if (g_strcmp0 (signal_name, "Response") == 0)
{
GVariant *results;
guint32 response;
g_variant_get (parameters, "(u@a{sv})",
&response,
&results);
/* Possible values:
* 0: Success, the request is carried out
* 1: The user cancelled the interaction
* 2: The user interaction was ended in some other way
* Cf. https://github.com/flatpak/xdg-desktop-portal/blob/master/data/org.freedesktop.portal.Request.xml
*/
if (response == 0)
{
gchar *uri;
if (g_variant_lookup (results, "uri", "s", &uri))
{
GFile *file = g_file_new_for_uri (uri);
gchar *path = g_file_get_path (file);
*image_ID = gimp_file_load (GIMP_RUN_NONINTERACTIVE,
path, path);
gimp_image_set_filename (*image_ID, "screenshot.png");
/* Delete the actual file. */
g_file_delete (file, NULL, NULL);
g_object_unref (file);
g_free (path);
g_free (uri);
}
}
g_variant_unref (results);
/* Quit anyway. */
gtk_main_quit ();
}
}
GimpPDBStatusType
screenshot_freedesktop_shoot (ScreenshotValues *shootvals,
GdkScreen *screen,
gint32 *image_ID,
GError **error)
{
GVariant *retval;
gchar *opath = NULL;
if (shootvals->shoot_type != SHOOT_ROOT)
{
/* This should not happen. */
return GIMP_PDB_EXECUTION_ERROR;
}
if (shootvals->screenshot_delay > 0)
screenshot_delay (shootvals->screenshot_delay);
retval = g_dbus_proxy_call_sync (proxy, "Screenshot",
g_variant_new ("(sa{sv})", "", NULL),
G_DBUS_CALL_FLAGS_NONE,
-1, NULL, error);
g_object_unref (proxy);
proxy = NULL;
if (retval)
{
g_variant_get (retval, "(o)", &opath);
g_variant_unref (retval);
}
if (opath)
{
GDBusProxy *proxy2 = NULL;
proxy2 = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SESSION,
G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
NULL,
"org.freedesktop.portal.Desktop",
opath,
"org.freedesktop.portal.Request",
NULL, NULL);
*image_ID = 0;
g_signal_connect (proxy2, "g-signal",
G_CALLBACK (screenshot_freedesktop_dbus_signal),
image_ID);
gtk_main ();
g_object_unref (proxy2);
g_free (opath);
/* Signal got a response. */
if (*image_ID)
{
GimpColorProfile *profile;
/* Just assign profile of current monitor. This will work only
* as long as this is a single-display setup.
* We need to figure out how to do better color management for
* portal screenshots.
* TODO!
*/
profile = gimp_screen_get_color_profile (screen,
shootvals->monitor);
if (profile)
{
gimp_image_set_color_profile (*image_ID, profile);
g_object_unref (profile);
}
return GIMP_PDB_SUCCESS;
}
}
return GIMP_PDB_EXECUTION_ERROR;
}

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@ -0,0 +1,32 @@
/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#ifndef __SCREENSHOT_FREEDESKTOP_H__
#define __SCREENSHOT_FREEDESKTOP_H__
gboolean screenshot_freedesktop_available (void);
ScreenshotCapabilities screenshot_freedesktop_get_capabilities (void);
GimpPDBStatusType screenshot_freedesktop_shoot (ScreenshotValues *shootvals,
GdkScreen *screen,
gint32 *image_ID,
GError **error);
#endif /* __SCREENSHOT_FREEDESKTOP_H__ */

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@ -27,6 +27,7 @@
#include <libgimp/gimpui.h>
#include "screenshot.h"
#include "screenshot-freedesktop.h"
#include "screenshot-gnome-shell.h"
#include "screenshot-icon.h"
#include "screenshot-kwin.h"
@ -219,6 +220,11 @@ run (const gchar *name,
capabilities = screenshot_x11_get_capabilities ();
}
#endif
else if (! backend && screenshot_freedesktop_available ())
{
backend = SCREENSHOT_BACKEND_FREEDESKTOP;
capabilities = screenshot_freedesktop_get_capabilities ();
}
/* how are we running today? */
switch (run_mode)
@ -364,7 +370,9 @@ shoot (GdkScreen *screen,
return screenshot_win32_shoot (&shootvals, screen, image_ID, error);
#endif
if (backend == SCREENSHOT_BACKEND_GNOME_SHELL)
if (backend == SCREENSHOT_BACKEND_FREEDESKTOP)
return screenshot_freedesktop_shoot (&shootvals, screen, image_ID, error);
else if (backend == SCREENSHOT_BACKEND_GNOME_SHELL)
return screenshot_gnome_shell_shoot (&shootvals, screen, image_ID, error);
else if (backend == SCREENSHOT_BACKEND_KWIN)
return screenshot_kwin_shoot (&shootvals, screen, image_ID, error);

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@ -24,6 +24,7 @@ typedef enum
SCREENSHOT_BACKEND_NONE,
SCREENSHOT_BACKEND_OSX,
SCREENSHOT_BACKEND_WIN32,
SCREENSHOT_BACKEND_FREEDESKTOP,
SCREENSHOT_BACKEND_GNOME_SHELL,
SCREENSHOT_BACKEND_KWIN,
SCREENSHOT_BACKEND_X11