[PATCH wayland-protocols 00/11] Declaring xdg-shell stable

[Yong Bakos]

Hi Jonas,
Regarding renaming,

> On May 24, 2017, at 2:35 AM, Jonas Ådahl <jadahl at gmail.com> wrote:
> 
> Hi,
> 
> I think it is time to take the next step regarding xdg_shell: declaring it
> stable. The current unstable version (xdg_shell unstable v6) has been
> implemented in multiple code bases, used by multiple desktop environments for
> quite some time, and I think this proves it is time to take the next step.
> 
> While it has indeed been implemented and used, there has been various issues
> raised regarding the protocol, but I believe all of these qualify as minor
> enough not requiring a new unstable release.
> 
> I'll go through them here in this E-mail, but please do read the actual commits
> for the actual change.
> 
> 1) Renaming the main global interface
> 
> It is not possible to just strip the unstable protocol prefix/postfix of the
> global interface name, so it had to be renamed. The reason for this is that up
> until the unstable version 6, the global interface name of the protocol was
> simply "xdg_shell". This means that without clever version hackery, we can not
> make the it discoverable that this is indeed the new stable interface and not
> an old unstable one.
> 
> The new name has been discussion previously on #wayland, and at one point Pekka
> came up with "xdg_wm_base" as xdg_shell really is about the window management
> basics. I chose this name for this patch series, but it is not set in stone.
> Other suggestions include "wp_shell", "wp_desktop_shell", "xdg_desktop_shell".

Since this is a general shell interface, and not "desktop" specific, I humbly
suggest "wp_shell" and also replacing occurrences of "window" to "surface"
within descriptions.

I do not mean to shed naming here, and forgive my ignorance as I haven't been
following the discussion on #wayland.

yong


> 
> 2) The anchor rectangle of a xdg_positioner may now be empty
> 
> If one wants to position a menu against corner of a pixel and have it flip in
> any direction, this was not possible due to the requirement that a anchor
> rectangle of a xdg_positioner had to be non-empty. Allowing an empty anchor
> rectangle fixes this without any down sides.
> 
> 3) More forgiving managing of stacking relationships
> 
> The set_parent request of xdg_toplevel was specified to require unmapping the
> parent before the child. This was poorly enforced in various implementations,
> and making it an error will have serious consequences when the relationship
> crosses client boundaries, as is possible using xdg_foreign (used by
> xdg-desktop-portal, i.e. sandboxed clients using portals). Make things a bit
> more forgiving, while at the same time more predictable. For example, unmapping
> a parent that itself has a parent, will turn its children children of its own
> parent.
> 
> 4) Allowing external protocols to define popup parent relationships
> 
> To use xdg_popup for things such as a window menu implemented in westons
> desktop shell client, we must allow passing null as a parent, relying on some
> external protocol for setting up this relationship. Allowing this also makes it
> possible to extend xdg_foreign with foreign popup menus in case this is ever
> needed.
> 
> 5) Define behaviour when attaching a null buffer to a surface
> 
> The behaviour of attaching a null buffer was previously undefined. Some
> compositors just didn't render the surface, some assumed it was invalid
> behaviour and sent an error. In short, the now defined behavior depends on the
> role; it'll either permanently unmap the surface (xdg_popup), or unmap it and
> reset all attributes as if the xdg_surface and role objects was just created
> (xdg_toplevel). See corresponding patch (xdg-shell: clarify map/unmap wording)
> for details.
> 
> 6) Misc minor changes/clarification/rewording
> 
> Other changes are best read in the actual patches, but just to make things more
> complete, they include some rewording of the documentation of the global
> interface, clarification of maintaining window positions in relation to window
> management changes and terminology corrections. The maintainers listed in the
> README has also changed to be me and Mike Blumenkrantz.
> 
> 
> So these are the changes that should provide us on a good base shell protocol.
> If we can agree on making this, we can later start adding more extensions, both
> externally (as separate protocols) or inside xdg_shell (as global interfaces,
> or new requests/events). There are already plans and ideas of additions that
> has been discussed at various places, but I believe we should not try to
> introduce any new features to the base protocol before having something we can
> rely on for backward compatibility.
> 
> So in other words, proposing to make xdg_shell stable does not mean it defines
> everything that needs to be defined; it means that it defines the bare minimum
> a compositor must implement to support clients that use xdg_shell in a way that
> can be extended in the future. If there is something missing for implementing a
> certain feature, that is expected; if there is something that makes extending
> the protocol to implement a certain feature impossible, that should be fixed.
> 
> 
> Jonas
> 
> 
> 
> Jonas Ådahl (10):
>  Add xdg-shell to stable/
>  xdg-shell: Rename interfaces
>  xdg-shell: Update copyright notices
>  xdg-shell: Reword the xdg_wm_base introduction
>  xdg-shell/positioner: Allow empty anchor_rect
>  xdg-shell: Replace 'monitor' with 'output'
>  xdg-shell/surface: Add note about window position and geometry
>  xdg-shell/toplevel: Clarify xdg_toplevel.set_parent(null)
>  xdg-shell/toplevel: Chain multiple parent-child relationships
>  xdg-shell/popup: Allow custom parent by passing null as parent
> 
> Mike Blumenkrantz (1):
>  xdg-shell: clarify map/unmap wording
> 
> stable/xdg-shell/README        |    5 +
> stable/xdg-shell/xdg-shell.xml | 1080 ++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 1085 insertions(+)
> create mode 100644 stable/xdg-shell/README
> create mode 100644 stable/xdg-shell/xdg-shell.xml
> 
> -- 
> 2.13.0
> 
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