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| 1 | +<?xml version="1.0"?> |
| 2 | +<!-- |
| 3 | + Copyright Red Hat |
| 4 | +
|
| 5 | + SPDX-License-Identifier: LGPL-2.1-or-later |
| 6 | +
|
| 7 | + This library is free software; you can redistribute it and/or |
| 8 | + modify it under the terms of the GNU Lesser General Public |
| 9 | + License as published by the Free Software Foundation; either |
| 10 | + version 2.1 of the License, or (at your option) any later version. |
| 11 | +
|
| 12 | + This library is distributed in the hope that it will be useful, |
| 13 | + but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | + Lesser General Public License for more details. |
| 16 | +
|
| 17 | + You should have received a copy of the GNU Lesser General Public |
| 18 | + License along with this library. If not, see <http://www.gnu.org/licenses/>. |
| 19 | +--> |
| 20 | + |
| 21 | +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd"> |
| 22 | + <!-- |
| 23 | + org.freedesktop.portal.SaveRestore: |
| 24 | + @short_description: Portal for coordinating app state save and restore |
| 25 | +
|
| 26 | + The SaveRestore interface allows the session to coordinate with applications |
| 27 | + to implement a session-wide state save/restore feature. Apps that can save |
| 28 | + their state to disk should register with this portal. In exchange, the system |
| 29 | + may restore session state after the session ends (i.e. after a reboot). |
| 30 | + It is not a portal in the strict sense, since it does not involve user |
| 31 | + interaction. Applications are expected to use this interface indirectly, |
| 32 | + via integration with their UI toolkit. |
| 33 | +
|
| 34 | + This documentation describes version 1 of this interface. |
| 35 | + --> |
| 36 | + <interface name="org.freedesktop.portal.SaveRestore"> |
| 37 | + <!-- |
| 38 | + Register: |
| 39 | + @options: Vardict with optional further information |
| 40 | + @session_handle: Object path for the created :ref:`org.freedesktop.portal.Session` object |
| 41 | + @registration: Vardict directing the app how to restore its state |
| 42 | +
|
| 43 | + Registers this app with the save/restore API. If the user logs out while |
| 44 | + the app is registered, the system will remember that this app was running |
| 45 | + and can relaunch it on next log-in. The app can then register itself again |
| 46 | + on next startup to be notified of what state (if any) it should restore. |
| 47 | +
|
| 48 | + During a clean shutdown, the app should close the created session using |
| 49 | + :ref:`org.freedesktop.portal.Session.Close`. If the app disconnects from |
| 50 | + the bus without closing the session first, the system will consider the |
| 51 | + shutdown unclean and will report this to the app on its next startup. |
| 52 | +
|
| 53 | + Supported keys in the @options vardict include: |
| 54 | +
|
| 55 | + * ``session_handle_token`` (``s``) |
| 56 | +
|
| 57 | + A string that will be used as the last element of the session handle. Must be a valid |
| 58 | + object path element. See the :ref:`org.freedesktop.portal.Session` documentation for |
| 59 | + more information about the session handle. |
| 60 | +
|
| 61 | + Supported keys in the @registration vardict include: |
| 62 | +
|
| 63 | + * ``instance-id`` (``s``) |
| 64 | +
|
| 65 | + A short alphanumeric string that identifies different instances of a |
| 66 | + multi-instance app. This allows multi-instance apps to keep the state |
| 67 | + of each instance separated. Single-instance apps should use this as |
| 68 | + well, because the system will return different identifiers when running |
| 69 | + different graphical sessions. For instance: if a user switches between |
| 70 | + GNOME and KDE regularly, even single-instance apps will need to save |
| 71 | + and load their state under different instance IDs. |
| 72 | +
|
| 73 | + * ``restore-reason`` (``u``) |
| 74 | +
|
| 75 | + Tells the app which state it needs to restore. Supported values: |
| 76 | +
|
| 77 | + - ``PRISTINE``: 0. The app should not attempt to restore any state. |
| 78 | +
|
| 79 | + - ``LAUNCH``: 1. This is a normal launch, so the app should restore |
| 80 | + some state (i.e. previous window size and position, default view on |
| 81 | + the home page) but it shouldn't attempt a full state restore. The |
| 82 | + exception is apps that have a preference that allows the user to |
| 83 | + decide if the app should always save and restore its state: if the |
| 84 | + user opts into this behavior, then it's permissible for the app to |
| 85 | + treat ``LAUNCH`` as equivalent to ``RESTORE``. |
| 86 | +
|
| 87 | + - ``RECOVER``: 2. This is the first launch after the app unexpectedly |
| 88 | + disconnected from the bus. The app should try to restore as much |
| 89 | + state as it can, but it should be careful to avoid crash loops. Apps |
| 90 | + can handle this by prompting users before attempting to restore state, |
| 91 | + or by strategically throwing away some state. For instance: a web |
| 92 | + browser may choose to restore open tabs but not restore the web |
| 93 | + content inside of each tab, instead showing a placeholder page and |
| 94 | + prompting the user to reload the tab. To support this feature |
| 95 | + properly, apps should periodically save their state while taking care |
| 96 | + to avoid unnecessary I/O. For instance: apps can flush their state |
| 97 | + to disk every 15 seconds, but only while the app is focused. |
| 98 | +
|
| 99 | + - ``RESTORE``: 3. The app should attempt to restore as much state as |
| 100 | + possible. |
| 101 | +
|
| 102 | + * ``discard-instance-ids`` (``as``) |
| 103 | +
|
| 104 | + A list of instance IDs (as above) that the system is done with and will |
| 105 | + no longer return to the app. The app should clean up any state it has |
| 106 | + associated with these IDs, and then report completion via |
| 107 | + :ref:`org.freedesktop.portal.SaveRestore.DiscardInstanceIdsResponse`. |
| 108 | + --> |
| 109 | + <method name="Register"> |
| 110 | + <annotation name="org.qtproject.QtDBus.QtTypeName.In0" value="QVariantMap"/> |
| 111 | + <arg type="a{sv}" name="options" direction="in"/> |
| 112 | + <arg type="o" name="session_handle" direction="out"/> |
| 113 | + <annotation name="org.qtproject.QtDBus.QtTypeName.Out1" value="QVariantMap"/> |
| 114 | + <arg type="a{sv}" name="registration" direction="out"/> |
| 115 | + </method> |
| 116 | + |
| 117 | + <!-- |
| 118 | + DiscardedInstanceIds: |
| 119 | + @session_handle: Object path for the :ref:`org.freedesktop.portal.Session` object |
| 120 | + @instance_ids: List of instance IDs the application discarded |
| 121 | +
|
| 122 | + Confirms that the caller has discarded the instance IDs, as requested by |
| 123 | + the ``discard-instance-ids`` value returned by |
| 124 | + :ref:`org.freedesktop.portal.SaveRestore.Register`. The system will finish |
| 125 | + discarding its internal tracking of the instance IDs once this is called. |
| 126 | + --> |
| 127 | + <method name="DiscardedInstanceIds"> |
| 128 | + <arg type="o" name="session_handle" direction="in"/> |
| 129 | + <arg type="as" name="instance_ids" direction="in"/> |
| 130 | + </method> |
| 131 | + |
| 132 | + <!-- |
| 133 | + SaveHint: |
| 134 | + @session_handle: Object path for the :ref:`org.freedesktop.portal.Session` object |
| 135 | +
|
| 136 | + The SaveHint signal is sent to an app whenever the system thinks it |
| 137 | + would be a good moment for the app to save its state. In response, apps |
| 138 | + should immediately save their state and then respond with |
| 139 | + :ref:`org.freedesktop.portal.SaveRestore.SaveHintResponse`. |
| 140 | +
|
| 141 | + Note that apps should not be using this signal as the only reason to |
| 142 | + save their state. This signal will be emitted relatively rarely. Each |
| 143 | + app should periodically save its own state at moments where it makes |
| 144 | + sense for the app. |
| 145 | + --> |
| 146 | + <signal name="SaveHint"> |
| 147 | + <arg type="o" name="session_handle" direction="out"/> |
| 148 | + </signal> |
| 149 | + |
| 150 | + <!-- |
| 151 | + SaveHintResponse: |
| 152 | + @session_handle: Object path for the :ref:`org.freedesktop.portal.Session` object |
| 153 | +
|
| 154 | + Acknowledges that the caller received the :ref:`org.freedesktop.portal.SaveRestore::SaveHint` |
| 155 | + signal. This method should be called within 3 seconds of receiving the signal. |
| 156 | + --> |
| 157 | + <method name="SaveHintResponse"> |
| 158 | + <arg type="o" name="session_handle" direction="in"/> |
| 159 | + </method> |
| 160 | + |
| 161 | + <!-- |
| 162 | + Quit: |
| 163 | + @session_handle: Object path for the :ref:`org.freedesktop.portal.Session` object |
| 164 | +
|
| 165 | + The Quit signal is sent to an app whenever the system decides to |
| 166 | + terminate the app to free up system resources (i.e. memory). The app |
| 167 | + should immediately save its state to disk and then exit cleanly, within |
| 168 | + 3 seconds of receiving this signal. The app may be transparently restarted |
| 169 | + by the system at a later date. |
| 170 | + --> |
| 171 | + <signal name="Quit"> |
| 172 | + <arg type="o" name="session_handle" direction="out"/> |
| 173 | + </signal> |
| 174 | + |
| 175 | + <property name="version" type="u" access="read"/> |
| 176 | + </interface> |
| 177 | +</node> |
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