xdg-shell: Clarify the meaning of app ID and give example

[platform/upstream/weston.git] / protocol / xdg-shell.xml

<?xml version="1.0" encoding="UTF-8"?>
<protocol name="xdg_shell">

  <copyright>
    Copyright © 2008-2013 Kristian Høgsberg
    Copyright © 2013      Rafael Antognolli
    Copyright © 2013      Jasper St. Pierre
    Copyright © 2010-2013 Intel Corporation

    Permission to use, copy, modify, distribute, and sell this
    software and its documentation for any purpose is hereby granted
    without fee, provided that the above copyright notice appear in
    all copies and that both that copyright notice and this permission
    notice appear in supporting documentation, and that the name of
    the copyright holders not be used in advertising or publicity
    pertaining to distribution of the software without specific,
    written prior permission.  The copyright holders make no
    representations about the suitability of this software for any
    purpose.  It is provided "as is" without express or implied
    warranty.

    THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
    SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
    FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
    SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
    AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
    THIS SOFTWARE.
  </copyright>

  <interface name="xdg_shell" version="1">
    <description summary="create desktop-style surfaces">
      xdg_shell allows clients to turn a wl_surface into a "real window"
      which can be dragged, resized, stacked, and moved around by the
      user. Everything about this interface is suited towards traditional
      desktop environments.
    </description>

    <enum name="version">
      <description summary="latest protocol version">
        The 'current' member of this enum gives the version of the
        protocol.  Implementations can compare this to the version
        they implement using static_assert to ensure the protocol and
        implementation versions match.
      </description>
      <entry name="current" value="5" summary="Always the latest version"/>
    </enum>

    <enum name="error">
      <entry name="role" value="0" summary="given wl_surface has another role"/>
      <entry name="defunct_surfaces" value="1" summary="xdg_shell was destroyed before children"/>
      <entry name="not_the_topmost_popup" value="2" summary="the client tried to map or destroy a non-topmost popup"/>
      <entry name="invalid_popup_parent" value="3" summary="the client specified an invalid popup parent surface"/>
    </enum>

    <request name="destroy" type="destructor">
      <description summary="destroy xdg_shell">
        Destroy this xdg_shell object.

        Destroying a bound xdg_shell object while there are surfaces
        still alive created by this xdg_shell object instance is illegal
        and will result in a protocol error.
      </description>
    </request>

    <request name="use_unstable_version">
      <description summary="enable use of this unstable version">
        Negotiate the unstable version of the interface.  This
        mechanism is in place to ensure client and server agree on the
        unstable versions of the protocol that they speak or exit
        cleanly if they don't agree.  This request will go away once
        the xdg-shell protocol is stable.
      </description>
      <arg name="version" type="int"/>
    </request>

    <request name="get_xdg_surface">
      <description summary="create a shell surface from a surface">
        This creates an xdg_surface for the given surface and gives it the
        xdg_surface role. See the documentation of xdg_surface for more details.
      </description>
      <arg name="id" type="new_id" interface="xdg_surface"/>
      <arg name="surface" type="object" interface="wl_surface"/>
    </request>

    <request name="get_xdg_popup">
      <description summary="create a popup for a surface">
        This creates an xdg_popup for the given surface and gives it the
        xdg_popup role. See the documentation of xdg_popup for more details.

        This request must be used in response to some sort of user action
        like a button press, key press, or touch down event.
      </description>
      <arg name="id" type="new_id" interface="xdg_popup"/>
      <arg name="surface" type="object" interface="wl_surface"/>
      <arg name="parent" type="object" interface="wl_surface"/>
      <arg name="seat" type="object" interface="wl_seat" summary="the wl_seat of the user event"/>
      <arg name="serial" type="uint" summary="the serial of the user event"/>
      <arg name="x" type="int"/>
      <arg name="y" type="int"/>
    </request>

    <event name="ping">
      <description summary="check if the client is alive">
        The ping event asks the client if it's still alive. Pass the
        serial specified in the event back to the compositor by sending
        a "pong" request back with the specified serial.

        Compositors can use this to determine if the client is still
        alive. It's unspecified what will happen if the client doesn't
        respond to the ping request, or in what timeframe. Clients should
        try to respond in a reasonable amount of time.
      </description>
      <arg name="serial" type="uint" summary="pass this to the pong request"/>
    </event>

    <request name="pong">
      <description summary="respond to a ping event">
        A client must respond to a ping event with a pong request or
        the client may be deemed unresponsive.
      </description>
      <arg name="serial" type="uint" summary="serial of the ping event"/>
    </request>
  </interface>

  <interface name="xdg_surface" version="1">
    <description summary="A desktop window">
      An interface that may be implemented by a wl_surface, for
      implementations that provide a desktop-style user interface.

      It provides requests to treat surfaces like windows, allowing to set
      properties like maximized, fullscreen, minimized, and to move and resize
      them, and associate metadata like title and app id.

      The client must call wl_surface.commit on the corresponding wl_surface
      for the xdg_surface state to take effect. Prior to committing the new
      state, it can set up initial configuration, such as maximizing or setting
      a window geometry.

      Even without attaching a buffer the compositor must respond to initial
      committed configuration, for instance sending a configure event with
      expected window geometry if the client maximized its surface during
      initialization.

      For a surface to be mapped by the compositor the client must have
      committed both an xdg_surface state and a buffer.
    </description>

    <request name="destroy" type="destructor">
      <description summary="Destroy the xdg_surface">
        Unmap and destroy the window. The window will be effectively
        hidden from the user's point of view, and all state like
        maximization, fullscreen, and so on, will be lost.
      </description>
    </request>

    <request name="set_parent">
      <description summary="set the parent of this surface">
        Set the "parent" of this surface. This window should be stacked
        above a parent. The parent surface must be mapped as long as this
        surface is mapped.

        Parent windows should be set on dialogs, toolboxes, or other
        "auxiliary" surfaces, so that the parent is raised when the dialog
        is raised.
      </description>
      <arg name="parent" type="object" interface="xdg_surface" allow-null="true"/>
    </request>

    <request name="set_title">
      <description summary="set surface title">
        Set a short title for the surface.

        This string may be used to identify the surface in a task bar,
        window list, or other user interface elements provided by the
        compositor.

        The string must be encoded in UTF-8.
      </description>
      <arg name="title" type="string"/>
    </request>

    <request name="set_app_id">
      <description summary="set application ID">
        Set an application identifier for the surface.

        The app ID identifies the general class of applications to which
        the surface belongs. The compositor can use this to group multiple
        surfaces together, or to determine how to launch a new application.

        For D-Bus activatable applications, the app ID is used as the D-Bus
        service name.

        The compositor shell will try to group application surfaces together
        by their app ID.  As a best practice, it is suggested to select app
        ID's that match the basename of the application's .desktop file.
        For example, "org.freedesktop.FooViewer" where the .desktop file is
        "org.freedesktop.FooViewer.desktop".

        See the desktop-entry specification [0] for more details on
        application identifiers and how they relate to well-known D-Bus
        names and .desktop files.

        [0] http://standards.freedesktop.org/desktop-entry-spec/
      </description>
      <arg name="app_id" type="string"/>
    </request>

    <request name="show_window_menu">
      <description summary="show the window menu">
        Clients implementing client-side decorations might want to show
        a context menu when right-clicking on the decorations, giving the
        user a menu that they can use to maximize or minimize the window.

        This request asks the compositor to pop up such a window menu at
        the given position, relative to the local surface coordinates of
        the parent surface. There are no guarantees as to what menu items
        the window menu contains.

        This request must be used in response to some sort of user action
        like a button press, key press, or touch down event.
      </description>

      <arg name="seat" type="object" interface="wl_seat" summary="the wl_seat of the user event"/>
      <arg name="serial" type="uint" summary="the serial of the user event"/>
      <arg name="x" type="int" summary="the x position to pop up the window menu at"/>
      <arg name="y" type="int" summary="the y position to pop up the window menu at"/>
    </request>

    <request name="move">
      <description summary="start an interactive move">
        Start an interactive, user-driven move of the surface.

        This request must be used in response to some sort of user action
        like a button press, key press, or touch down event.

        The server may ignore move requests depending on the state of
        the surface (e.g. fullscreen or maximized).
      </description>
      <arg name="seat" type="object" interface="wl_seat" summary="the wl_seat of the user event"/>
      <arg name="serial" type="uint" summary="the serial of the user event"/>
    </request>

    <enum name="resize_edge">
      <description summary="edge values for resizing">
        These values are used to indicate which edge of a surface
        is being dragged in a resize operation. The server may
        use this information to adapt its behavior, e.g. choose
        an appropriate cursor image.
      </description>
      <entry name="none" value="0"/>
      <entry name="top" value="1"/>
      <entry name="bottom" value="2"/>
      <entry name="left" value="4"/>
      <entry name="top_left" value="5"/>
      <entry name="bottom_left" value="6"/>
      <entry name="right" value="8"/>
      <entry name="top_right" value="9"/>
      <entry name="bottom_right" value="10"/>
    </enum>

    <request name="resize">
      <description summary="start an interactive resize">
        Start a user-driven, interactive resize of the surface.

        This request must be used in response to some sort of user action
        like a button press, key press, or touch down event.

        The server may ignore resize requests depending on the state of
        the surface (e.g. fullscreen or maximized).
      </description>
      <arg name="seat" type="object" interface="wl_seat" summary="the wl_seat of the user event"/>
      <arg name="serial" type="uint" summary="the serial of the user event"/>
      <arg name="edges" type="uint" summary="which edge or corner is being dragged"/>
    </request>

    <enum name="state">
      <description summary="types of state on the surface">
        The different state values used on the surface. This is designed for
        state values like maximized, fullscreen. It is paired with the
        configure event to ensure that both the client and the compositor
        setting the state can be synchronized.

        States set in this way are double-buffered. They will get applied on
        the next commit.

        Desktop environments may extend this enum by taking up a range of
        values and documenting the range they chose in this description.
        They are not required to document the values for the range that they
        chose. Ideally, any good extensions from a desktop environment should
        make its way into standardization into this enum.

        The current reserved ranges are:

        0x0000 - 0x0FFF: xdg-shell core values, documented below.
        0x1000 - 0x1FFF: GNOME
      </description>
      <entry name="maximized" value="1" summary="the surface is maximized">
        The surface is maximized. The window geometry specified in the configure
        event must be obeyed by the client.
      </entry>
      <entry name="fullscreen" value="2" summary="the surface is fullscreen">
        The surface is fullscreen. The window geometry specified in the configure
        event must be obeyed by the client.
      </entry>
      <entry name="resizing" value="3">
        The surface is being resized. The window geometry specified in the
        configure event is a maximum; the client cannot resize beyond it.
        Clients that have aspect ratio or cell sizing configuration can use
        a smaller size, however.
      </entry>
      <entry name="activated" value="4">
        Client window decorations should be painted as if the window is
        active. Do not assume this means that the window actually has
        keyboard or pointer focus.
      </entry>
    </enum>

    <event name="configure">
      <description summary="suggest a surface change">
        The configure event asks the client to resize its surface or to
        change its state.

        The width and height arguments specify a hint to the window
        about how its surface should be resized in window geometry
        coordinates. See set_window_geometry.

        If the width or height arguments are zero, it means the client
        should decide its own window dimension. This may happen when the
        compositor need to configure the state of the surface but doesn't
        have any information about any previous or expected dimension.

        The states listed in the event specify how the width/height
        arguments should be interpreted, and possibly how it should be
        drawn.

        Clients should arrange their surface for the new size and
        states, and then send a ack_configure request with the serial
        sent in this configure event at some point before committing
        the new surface.

        If the client receives multiple configure events before it
        can respond to one, it is free to discard all but the last
        event it received.
      </description>

      <arg name="width" type="int"/>
      <arg name="height" type="int"/>
      <arg name="states" type="array"/>
      <arg name="serial" type="uint"/>
    </event>

    <request name="ack_configure">
      <description summary="ack a configure event">
        When a configure event is received, if a client commits the
        surface in response to the configure event, then the client
        must make a ack_configure request before the commit request,
        passing along the serial of the configure event.

        For instance, the compositor might use this information to move
        a surface to the top left only when the client has drawn itself
        for the maximized or fullscreen state.

        If the client receives multiple configure events before it
        can respond to one, it only has to ack the last configure event.
      </description>
      <arg name="serial" type="uint" summary="the serial from the configure event"/>
    </request>

    <request name="set_window_geometry">
      <description summary="set the new window geometry">
        The window geometry of a window is its "visible bounds" from the
        user's perspective. Client-side decorations often have invisible
        portions like drop-shadows which should be ignored for the
        purposes of aligning, placing and constraining windows.

        The window geometry is double buffered, and will be applied at the
        time wl_surface.commit of the corresponding wl_surface is called.

        Once the window geometry of the surface is set once, it is not
        possible to unset it, and it will remain the same until
        set_window_geometry is called again, even if a new subsurface or
        buffer is attached.

        If never set, the value is the full bounds of the surface,
        including any subsurfaces. This updates dynamically on every
        commit. This unset mode is meant for extremely simple clients.

        If responding to a configure event, the window geometry in here
        must respect the sizing negotiations specified by the states in
        the configure event.

        The arguments are given in the surface local coordinate space of
        the wl_surface associated with this xdg_surface.

        The width and height must be greater than zero.
      </description>
      <arg name="x" type="int"/>
      <arg name="y" type="int"/>
      <arg name="width" type="int"/>
      <arg name="height" type="int"/>
    </request>

    <request name="set_maximized" />
    <request name="unset_maximized" />

    <request name="set_fullscreen">
      <description summary="set the window as fullscreen on a monitor">
        Make the surface fullscreen.

        You can specify an output that you would prefer to be fullscreen.
        If this value is NULL, it's up to the compositor to choose which
        display will be used to map this surface.

        If the surface doesn't cover the whole output, the compositor will
        position the surface in the center of the output and compensate with
        black borders filling the rest of the output.
      </description>
      <arg name="output" type="object" interface="wl_output" allow-null="true"/>
    </request>
    <request name="unset_fullscreen" />

    <request name="set_minimized">
      <description summary="set the window as minimized">
        Request that the compositor minimize your surface. There is no
        way to know if the surface is currently minimized, nor is there
        any way to unset minimization on this surface.

        If you are looking to throttle redrawing when minimized, please
        instead use the wl_surface.frame event for this, as this will
        also work with live previews on windows in Alt-Tab, Expose or
        similar compositor features.
      </description>
    </request>

    <event name="close">
      <description summary="surface wants to be closed">
        The close event is sent by the compositor when the user
        wants the surface to be closed. This should be equivalent to
        the user clicking the close button in client-side decorations,
        if your application has any...

        This is only a request that the user intends to close your
        window. The client may choose to ignore this request, or show
        a dialog to ask the user to save their data...
      </description>
    </event>
  </interface>

  <interface name="xdg_popup" version="1">
    <description summary="short-lived, popup surfaces for menus">
      A popup surface is a short-lived, temporary surface that can be
      used to implement menus. It takes an explicit grab on the surface
      that will be dismissed when the user dismisses the popup. This can
      be done by the user clicking outside the surface, using the keyboard,
      or even locking the screen through closing the lid or a timeout.

      When the popup is dismissed, a popup_done event will be sent out,
      and at the same time the surface will be unmapped. The xdg_popup
      object is now inert and cannot be reactivated, so clients should
      destroy it. Explicitly destroying the xdg_popup object will also
      dismiss the popup and unmap the surface.

      Clients will receive events for all their surfaces during this
      grab (which is an "owner-events" grab in X11 parlance). This is
      done so that users can navigate through submenus and other
      "nested" popup windows without having to dismiss the topmost
      popup.

      Clients that want to dismiss the popup when another surface of
      their own is clicked should dismiss the popup using the destroy
      request.

      The parent surface must have either an xdg_surface or xdg_popup
      role.

      Specifying an xdg_popup for the parent means that the popups are
      nested, with this popup now being the topmost popup. Nested
      popups must be destroyed in the reverse order they were created
      in, e.g. the only popup you are allowed to destroy at all times
      is the topmost one.

      If there is an existing popup when creating a new popup, the
      parent must be the current topmost popup.

      A parent surface must be mapped before the new popup is mapped.

      When compositors choose to dismiss a popup, they will likely
      dismiss every nested popup as well. When a compositor dismisses
      popups, it will follow the same dismissing order as required
      from the client.

      The x and y arguments passed when creating the popup object specify
      where the top left of the popup should be placed, relative to the
      local surface coordinates of the parent surface. See
      xdg_shell.get_xdg_popup.

      The client must call wl_surface.commit on the corresponding wl_surface
      for the xdg_popup state to take effect.

      For a surface to be mapped by the compositor the client must have
      committed both the xdg_popup state and a buffer.
    </description>

    <request name="destroy" type="destructor">
      <description summary="remove xdg_popup interface">
        This destroys the popup. Explicitly destroying the xdg_popup
        object will also dismiss the popup, and unmap the surface.

        If this xdg_popup is not the "topmost" popup, a protocol error
        will be sent.
      </description>
    </request>

    <event name="popup_done">
      <description summary="popup interaction is done">
        The popup_done event is sent out when a popup is dismissed by the
        compositor. The client should destroy the xdg_popup object at this
        point.
      </description>
    </event>

  </interface>
</protocol>