[PATCH wayland-protocols v3 1/7] xdg-shell: Turn xdg_surface into a generic base interface
Benoit Gschwind
gschwind at gnu-log.net
Wed Jun 8 14:45:28 UTC 2016
Hello Jonas,
On 08/06/2016 03:18, Jonas Ådahl wrote:
> On Wed, Jun 08, 2016 at 12:37:01AM +0200, Benoit Gschwind wrote:
>> Hello,
>>
>> This proposal look good, few optional comments following.
>>
>> On 26/05/2016 06:32, Jonas Ådahl wrote:
>>> Split out toplevel window like requests and events into a new interface
>>> called xdg_toplevel, and turn xdg_surface into a generic base interface
>>> which others extends.
>>>
>>> xdg_popup is changed to extend the xdg_surface.
>>>
>>> The configure event in xdg_surface was split up making
>>> xdg_surface.configure an event only carrying the serial number, while a
>>> new xdg_toplevel.configure event carries the other data previously sent
>>> via xdg_surface.configure. xdg_toplevel.configure is made to extend,
>>> via the latch-state mechanism, xdg_surface.configure and depends on
>>> that event to synchronize state.
>>>
>>> Other future xdg_surface based extensions are meant to also extend
>>> xdg_surface.configure for relevant window type dependend state
>>> synchronization.
>>>
>>> Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
>>> Signed-off-by: Mike Blumenkrantz <zmike at samsung.com>
>>> ---
>>>
>>> Changes since v2:
>>> - Grammar, typos and spelling fixes
>>> - Tried to clarify the latched state configure events sequence
>>> - Clarified window geometry constraints and semantics
>>>
>>>
>>> unstable/xdg-shell/xdg-shell-unstable-v6.xml | 275 ++++++++++++++++-----------
>>> 1 file changed, 165 insertions(+), 110 deletions(-)
>>>
>>> diff --git a/unstable/xdg-shell/xdg-shell-unstable-v6.xml b/unstable/xdg-shell/xdg-shell-unstable-v6.xml
>>> index ce57153..fa838f9 100644
>>> --- a/unstable/xdg-shell/xdg-shell-unstable-v6.xml
>>> +++ b/unstable/xdg-shell/xdg-shell-unstable-v6.xml
>>> @@ -54,11 +54,9 @@
>>>
>>> <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. A wl_surface can only be given an xdg_surface role
>>> - once. If get_xdg_surface is called with a wl_surface that already has
>>> - an active xdg_surface associated with it, or if it had any other role,
>>> - an error is raised.
>>> + This creates an xdg_surface for the given surface. While xdg_surface
>>> + itself is not a role, the corresponding surface may only be assigned
>>> + a role extending xdg_surface, such as xdg_toplevel or xdg_popup.
>>>
>>
>> I think the 3 line above are more confusing than useful and may be
>> replaced by the single sentence:
>> This creates an xdg_surface for the given surface.
>
> I think it helps describing the expectations here.
Then something like that:
xdg_surface are used as basis to define a role to a given surface, such
as xdg_toplevel or xdg_popup. It's also the basis of the management of
xdg's surfaces states.
>
>>
>>> See the documentation of xdg_surface for more details about what an
>>> xdg_surface is and how it is used.
>>> @@ -67,29 +65,6 @@
>>> <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. A wl_surface can only be given an xdg_popup role
>>> - once. If get_xdg_popup is called with a wl_surface that already has
>>> - an active xdg_popup associated with it, or if it had any other role,
>>> - an error is raised.
>>> -
>>> - This request must be used in response to some sort of user action
>>> - like a button press, key press, or touch down event.
>>> -
>>> - See the documentation of xdg_popup for more details about what an
>>> - xdg_popup is and how it is used.
>>> - </description>
>>> - <arg name="id" type="new_id" interface="zxdg_popup_v6"/>
>>> - <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
>>> @@ -117,13 +92,23 @@
>>> </interface>
>>>
>>> <interface name="zxdg_surface_v6" version="1">
>>> - <description summary="A desktop window">
>>> + <description summary="desktop user interface surface base interface">
>>> 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.
>>> + It provides a base set of functionality required to construct user
>>> + interface elements requiring management by the compositor, such as
>>> + toplevel windows, menus, etc. The types of functionality are split into
>>> + xdg_surface roles.
>>> +
>>> + Creating an xdg_surface does not set the role for a wl_surface. In order
>>> + to map an xdg_surface, create a role-specific object using, e.g.,
>>
>> In order to map an xdg_surface, the client must create a role-specific ...
>
> Sure.
>
>>
>>> + get_toplevel, get_popup. The wl_surface for any given xdg_surface can
>>> + have at most one role, and may not be assigned any role not based on
>>> + xdg_surface.
>>> +
>>> + A role must be assigned before any other requests are made to the
>>> + xdg_surface object.
>>>
>>> The client must call wl_surface.commit on the corresponding wl_surface
>>> for the xdg_surface state to take effect.
>>> @@ -133,12 +118,146 @@
>>> manipulate a buffer prior to the first xdg_surface.configure call must
>>> also be treated as errors.
>>>
>>> - For a surface to be mapped by the compositor the client must have
>>> - committed both an xdg_surface state and a buffer.
>>> + For a surface to be mapped by the compositor the client must have assigned
>>> + one of the xdg_surface based roles, it must have committed both the
>>> + xdg_surface state and the role dependent state, and it must have committed
>>> + a buffer.
>>
>> For a surface to be mapped by the compositor, the following conditions
>> must be met: (1) the client has assigned a xdg_surface based role to the
>> surface, (2) the client has set the xdg_surface state and the role
>> dependent state to the surface and (3) the client has committed a buffer
>> to the surface.
>
> Sure, that makes it a bit clearer.
>
>>
>>> + </description>
>>> +
>>> + <enum name="error">
>>> + <entry name="not_constructed" value="1"/>
>>> + <entry name="already_constructed" value="2"/>
>>> + </enum>
>>> +
>>> + <request name="destroy" type="destructor">
>>> + <description summary="destroy the xdg_surface">
>>> + Destroy the xdg_surface object. An xdg_surface must only be destroyed
>>> + after its role object has been destroyed.
>>> + </description>
>>> + </request>
>>> +
>>> + <request name="get_toplevel">
>>> + <description summary="assign the xdg_toplevel surface role">
>>> + This creates an xdg_toplevel object for the given xdg_surface and gives
>>> + the associated wl_surface the xdg_toplevel role.
>>> +
>>> + See the documentation of xdg_toplevel for more details about what an
>>> + xdg_toplevel is and how it is used.
>>> + </description>
>>> + <arg name="id" type="new_id" interface="zxdg_toplevel_v6"/>
>>> + </request>
>>> +
>>> + <request name="get_popup">
>>> + <description summary="assign the xdg_popup surface role">
>>> + This creates an xdg_popup object for the given xdg_surface and gives the
>>> + associated wl_surface the xdg_popup role.
>>> +
>>> + This request must be used in response to some sort of user action like a
>>> + button press, key press, or touch down event.
>>> +
>>> + See the documentation of xdg_popup for more details about what an
>>> + xdg_popup is and how it is used.
>>> + </description>
>>> + <arg name="id" type="new_id" interface="zxdg_popup_v6"/>
>>> + <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>
>>> +
>>> + <request name="set_window_geometry">
>>> + <description summary="set the new window geometry">
>>> + The window geometry of a surface 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, 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 is meant for extremely simple clients.
>>
>> This sentence was from the previous spec. but I would use :
>>
>> This defaults behavior is meant for simplest clients.
>>
>> maybe could be done in another patch.
>
> Yea, lets that would be better as a follow up.
>
>>
>>
>>> +
>>> + 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. Setting an invalid size
>>> + will raise an error. When applied, the effective window geometry will be
>>> + the set window geometry clamped to the bounding rectangle of the
>>> + combined geometry of the surface of the xdg_surface and the associated
>>> + subsurfaces.
>>> + </description>
>>> + <arg name="x" type="int"/>
>>> + <arg name="y" type="int"/>
>>> + <arg name="width" type="int"/>
>>> + <arg name="height" type="int"/>
>>> + </request>
>>> +
>>> + <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 an ack_configure request sometime before the commit
>>> + request, passing along the serial of the configure event.
>>> +
>>> + For instance, for toplevel surfaces 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.
>>> +
>>> + A client is not required to commit immediately after sending
>>> + an ack_configure request - it may even ack_configure several times
>>> + before its next surface commit.
>>> +
>>> + A client may send multiple ack_configure requests before committing, but
>>> + only the last request sent before a commit indicates which configure
>>> + event the client really is responding to.
>>> + </description>
>>> + <arg name="serial" type="uint" summary="the serial from the configure event"/>
>>> + </request>
>>> +
>>> + <event name="configure">
>>> + <description summary="suggest a surface change">
>>> + The configure event marks the end of a configure sequence. A configure
>>> + sequence is a set of zero or more events configuring the drawing of the
>>> + surface, finalized by this event.
>>
>> A configure sequence is a set of one or more events configuring the
>> state of the xdg_surface, including the final xdg_surface.configure event.
>
> Yes, that sounds better.
>
>>
>>> +
>>> + Where applicable, xdg_surface surface roles will during a configure
>>> + sequence extend this event as a latched state sent as events before the
>>> + xdg_surface.configure event. Such events should be considered to make up
>>> + a set of atomically applied configuration states, where the
>>> + xdg_surface.configure commits the accumulated state.
>>
>> I tried to figure out what the paragraph above explain. Here is my
>> rewording, If I'm wrong please correct myself and feel free to pick my
>> wording to improve this paragraph.
>>
>> The client must freeze the state of a window until a configure sequence
>> is completed. During the configure sequence the client accumulate state
>> changes. When and only when the client receive a xdg_surface.configure
>> event, the client can apply accumulated changes of the surface state.
>> During the configure sequence, a newer events override all previous
>> event of the same type.
>
> Yes, except I would assume a client wouldn't "freeze" anything, but
> would rather accumulate the changes in a "pending state" container
> similar to how the compositor handles surface state changes before
> wl_surface.commit.
>
>>
>>> +
>>> + Clients should arrange their surface for the new states, and then send
>>> + an 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="serial" type="uint" summary="serial of the configure event"/>
>>> + </event>
>>> + </interface>
>>> +
>>> + <interface name="zxdg_toplevel_v6" version="1">
>>> + <description summary="toplevel surface">
>>> + This interface defines an xdg_surface role which allows a surface to,
>>> + among other things, set window-like properties such as maximize,
>>> + fullscreen, and minimize, set application-specific metadata like title and
>>> + id, and well as trigger user interactive operations such as interactive
>>> + resize and move.
>>> </description>
>>>
>>> <request name="destroy" type="destructor">
>>> - <description summary="Destroy the xdg_surface">
>>> + <description summary="destroy the xdg_toplevel">
>>> 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.
>>> @@ -155,7 +274,7 @@
>>> "auxiliary" surfaces, so that the parent is raised when the dialog
>>> is raised.
>>> </description>
>>> - <arg name="parent" type="object" interface="zxdg_surface_v6" allow-null="true"/>
>>> + <arg name="parent" type="object" interface="zxdg_toplevel_v6" allow-null="true"/>
>>> </request>
>>>
>>> <request name="set_title">
>>> @@ -348,8 +467,10 @@
>>>
>>> <event name="configure">
>>> <description summary="suggest a surface change">
>>> - The configure event asks the client to resize its surface or to
>>> - change its state.
>>> + This configure event asks the client to resize its toplevel surface or
>>> + to change its state. It is not sent by itself but as a latched state
>>> + sent prior to the xdg_surface.configure event. See xdg_surface.configure
>>> + for details.
>>
>> This configure event asks the client to resize or to change states of
>> the client surface. This event is not applied immediately, see
>> xdg_surface.configure for details.
>
> Maybe "The configured state should not be applied immediately. See
> xdg_surface.configure for details."?
>
>>
>>>
>>> The width and height arguments specify a hint to the window
>>> about how its surface should be resized in window geometry
>>> @@ -364,81 +485,15 @@
>>> 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.
>>> + Clients must send an ack_configure in response to this event. See
>>> + xdg_surface.configure and xdg_surface.ack_configure for details.
>>> </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 an ack_configure request sometime 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.
>>> -
>>> - A client is not required to commit immediately after sending
>>> - an ack_configure request - it may even ack_configure several times
>>> - before its next surface commit.
>>> -
>>> - The compositor expects that the most recently received
>>> - ack_configure request at the time of a commit indicates which
>>> - configure event the client is responding to.
>>> - </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_max_size">
>>> <description summary="set the maximum size">
>>> Set a maximum size for the window.
>>> @@ -447,7 +502,7 @@
>>> not try to configure the window beyond this size.
>>>
>>> The width and height arguments are in window geometry coordinates.
>>> - See set_window_geometry.
>>> + See xdg_surface.set_window_geometry.
>>>
>>> Values set in this way are double-buffered. They will get applied
>>> on the next commit.
>>> @@ -488,7 +543,7 @@
>>> not try to configure the window below this size.
>>>
>>> The width and height arguments are in window geometry coordinates.
>>> - See set_window_geometry.
>>> + See xdg_surface.set_window_geometry.
>>>
>>> Values set in this way are double-buffered. They will get applied
>>> on the next commit.
>>> @@ -631,7 +686,7 @@
>>> their own is clicked should dismiss the popup using the destroy
>>> request.
>>>
>>> - The parent surface must have either an xdg_surface or xdg_popup
>>> + The parent surface must have either the xdg_toplevel or xdg_popup surface
>>> role.
>>>
>>> Specifying an xdg_popup for the parent means that the popups are
>>> @@ -653,7 +708,7 @@
>>> 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.
>>> + xdg_surface.get_popup.
>>>
>>> The client must call wl_surface.commit on the corresponding wl_surface
>>> for the xdg_popup state to take effect.
>>>
>>
>> Best regards
>
> Thanks for taking a look
>
>
> Jonas
>
>> --
>> Benoit Gschwind
>>
Best regards
--
Benoit Gschwind
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