Core wayland protocol
- - generate pointer_focus (and drag focus) on raise/lower, move
- windows, all kinds of changes in surface stacking.
+ - Maybe try to make remote wayland actually happen, to see if there
+ is something in the protocol/architecture that makes it harder than
+ it should be.
- - glyph cache
+ICCCM
- - dnd, figure out large object transfer: through wayland protocol or
- pass an fd through the compositor to the other client and let them
- sort it out?
-
- - DnD issues:
-
- How to roboustly handle failing drag, ie the case where an
- application gets a button event, tries to activate a drag, but when
- the server gets the drag request, the button has already been
- released and the grab is no longer active. What's the concern:
-
- - Application may set a drag cursor that doesn't revert back,
- since a failed drag doesn't result in a pointer_focus event to
- give focus back to the surface. We could just do that: if the
- pointer_focus is the same surface as we tried to start a grab
- for, just remove and give back pointer_focus.
-
- Alternatively, set drag cursors only in response to drag events,
- like drag focus. But drag_focus and drag_motion are sent to the
- drag target, so the source surface won't always get those. We
- may also end up setting the cursor after the drag ends, but in
- this case the drag started and ended and we'll get a
- pointer_focus event, which will make the application reset the
- pointer image. Could introduce a drag start event that
- indicates that the drag active.
-
- How to handle drop decline (accept with type=NULL)
-
- - Targets must send a NULL type in accept if they don't accept a
- drop at the drag_focus/drag_motion position. Root window will
- send a NULL type or x-wayland/root-something type if the source
- offers that.
-
- Races between pointer motion, ending the drag, the target sending
- accept request and the source receiving the target event.
-
- - We've sent a drag focus or motion event to the source, but
- haven't received an accept request corresponding to that event
- and now the button is release. The compositor could wait for
- the source to reply to outstanding focus/motion events before
- sending the finish event to the source. Or we could send the
- finish event through the source so that it needs to reply to the
- finish event too. Either way, the state of the drag blocks on
- the client. What if we drag to a client that doesn't doo dnd?
-
- How do we animate the drag icon back to the drag origin in case of
- a failed drag?
-
- How to handle surfaces from clients that don't know about dnd or
- don't care? Maybe the dnd object should have a
- dnd.register_surface() method so clients can opt-in the surfaces
- that will participate in dnd. Or just assume client is not
- participating until we receive an accept request.
-
- May need to look at all offer events before we can decide which one
- to go with. Problem is, we don't know when we've seen that last
- offer event.
-
- - copy-n-paste, store data in server (only one mime-type available)
- or do X style (content mime-type negotiation, but data goes away
- when client quits).
-
- - Optional pointer images.
-
- - Discard buffer, as in "wayland discarded your buffer, it's no
- longer visible, you can stop updating it now.", reattach, as in "oh
- hey, I'm about to show your buffer that I threw away, what was it
- again?". for wayland system compositor vt switcing, for example,
- to be able to throw away the surfaces in the session we're
- switching away from. for minimized windows that we don't want live
- thumb nails for. etc.
+ - mime-type guidelines for data_source (ie, both dnd and selection):
+ recommended types for text or images, types that a clipboard
+ manager must support, mime-types must be listed in preferred order
- - Initial placement of surfaces. Guess we can do, 1)
- surface-relative (menus), 2) pointer-relative (tooltips and
- right-click menus) or 3) server-decides (all other top-levels).
+ - we need a "no kb focus please" mechanism. Or should this be
+ implicit in a specific surface type?
- - When a surface is the size of the screen and on top, we can set the
- scanout buffer to that surface directly. Like compiz unredirect
- top-level window feature. Except it won't have any protocol state
- side-effects and the client that owns the surface won't know. We
- lose control of updates. Should work well for X server root window
- under wayland. Should be possible for yuv overlays as well.
+EWMH
- - what about cursors then? maybe use hw cursors if the cursor
- satisfies hw limitations (64x64, only one cursor), switch to
- composited cursors if not.
+ - configure should provide dx_left, dx_right, dy_top, dy_bottom, or
+ dx, dy, width and height.
- - clients needs to allocate the surface to be suitable for
- scanout, which they can do whenever they go fullscreen.
+ - move to workspace, keep on top, on all workspaces, minimize etc
+ requests for implementing client side window menu? or just make a
+ "show window menu" request to let the compositor display and manage
+ a popup window?
- - multihead, screen geometry and crtc layout protocol, hotplug
+ - window move and resize functionality for kb and touch.
- - input device discovery, hotplug
+ - Protocol for specifying title bar rectangle (for moving
+ unresponsive apps). Rectangle for close button, so we can popup
+ force-close dialog if application doesn't respond to ping event
+ when user clicks there. We could use the region mechanism here
+ too.
- - Advertise axes as part of the discovery, use something like
- "org.wayland.input.x" to identify the axes.
+ - popup placement protocol logic.
- - keyboard state, layout events at connect time and when it
- changes, keyboard leds
+ - subsurface mechanism. we need this for cases where we would use an
+ X subwindow for gl or video other different visual type.
- - relative events
+EGL/gbm
- - multi touch?
+ - Land Robert Braggs EGL extensions: frame age, swap with damage
- - synaptics, 3-button emulation, scim
+ - Make it possible to share buffers from compositor to clients.
+ Tricky part here is how to indicate to EGL on the server side that
+ it should make an EGLImage available to a client. We'll need a
+ "create a wl_buffer for this EGLImage for this client" kind of
+ entry point.
- - Figure out if we need the batch/commit scheme and what to do
- instead. Since dropping the "copy" request, we have a race between
- copy from back to front and reporting damage. "copy" did this
- atomically, but copy is a rendering operation (wayland doesn't do
- rendering) and requires synchronization between server and client
- before client can reuse backbuffer.
+ - Protocol for arbitrating access to scanout buffers (physically
+ contiguous memory). When a client goes fullscreen (or ideally as
+ the compositor starts the animation that will make it fullscreen)
+ we send a "give up your scanout buffer" to the current fullscreen
+ client (if any) and when the client acks that we send a "try to
+ allocate a scanout buffer now" event to the fullscreen-to-be
+ client.
- The race condition happens when a client copies new content into
- its window and then, before the client reports the damage, the
- compositor then does a partial repaint (triggered by another
- client) that only pulls in part of the repainted area. It's only a
- one-frame glitch, as the client will submit the damage and the
- compositor will repaint the damaged area next frame. And ideally
- clients should do all rendering as early in the frame as possible
- to avoid this race.
- - auth; We need to generate a random socket name and advertise that
- on dbus along with a connection cookie. Something like a method
- that returns the socket name and a connection cookie. The
- connection cookie is just another random string that the client
- must pass to the wayland server to become authenticated. The
- Wayland server generates the cookie on demand when the dbus method
- is called and expires it after 5s or so.
+Misc
- - or just pass the fd over dbus
+ - glyph cache
+
+ - Needs a mechanism to pass buffers to client.
+
+ buffer = drm.create_buffer(); /* buffer with stuff in it */
- - drm bo access control, authentication, flink_to
+ cache.upload(buffer, x, y, width, height, int hash)
- - Range protocol may not be sufficient... if a server cycles through
- 2^32 object IDs we don't have a way to handle wrapping. And since
- we hand out a range of 256 IDs to each new clients, we're just
- talking about 2^24 clients. That's 31 years with a new client
- every minute... Maybe just use bigger ranges, then it's feasible
- to track and garbage collect them when a client dies.
+ drm.buffer: id, name, stride etc /* event to announce cache buffer */
- - Add protocol to let applications specify the effective/logical
- surface rectangle, that is, the edge of the window, ignoring drop
- shadows and other padding. The compositor needs this for snapping
- and constraining window motion. Also, maybe communicate the opaque
- region of the window (or just a conservative, simple estimate), to
- let the compositor reduce overdraw.
+ cache.image: hash, buffer, x, y, stride /* event to announce
+ * location in cache */
+
+ cache.reject: hash /* no upload for you! */
+
+ cache.retire: buffer /* cache has stopped using buffer, please
+ * reupload whatever you had in that buffer */
+
+ - A "please suspend" event from the compositor, to indicate to an
+ application that it's no longer visible/active. Or maybe discard
+ buffer, as in "wayland discarded your buffer, it's no longer
+ visible, you can stop updating it now.", reattach, as in "oh hey,
+ I'm about to show your buffer that I threw away, what was it
+ again?". for wayland system compositor vt switcing, for example,
+ to be able to throw away the surfaces in the session we're
+ switching away from. for minimized windows that we don't want live
+ thumb nails for. etc.
- - multi gpu, needs queue and seqno to wait on in requests
Clients and ports
- port gtk+
- - eek, so much X legacy stuff there...
-
- draw window decorations in gtkwindow.c
- - start from alexl's client-side-windows branch
-
- Details about pointer grabs. wayland doesn't have active grabs,
menus will behave subtly different. Under X, clicking a menu
open grabs the pointer and clicking outside the window pops down
the menu and swallows the click. without active grabs we can't
swallow the click. I'm sure there much more...
- - Port Qt? There's already talk about this on the list.
-
- - X on Wayland
-
- - move most of the code from xf86-video-intel into a Xorg wayland
- module.
+ - dnd, copy-paste
- - don't ask KMS for available output and modes, use the info from
- the wayland server. then stop mooching off of drmmode.c.
+ - Investigate DirectFB on Wayland (or is that Wayland on DirectFB?)
- - map multiple wayland input devices to MPX in Xorg.
+ - SDL port, bnf has work in progress here:
+ http://cgit.freedesktop.org/~bnf/sdl-wayland/
- - rootless; avoid allocating and setting the front buffer, draw
- window decorations in the X server (!), how to map input?
- - gnome-shell as a wayland session compositor
+Ideas
- - runs as a client of the wayland session compositor, uses
- clutter+egl on wayland
+ - A wayland settings protocol to tell clients about themes (icons,
+ cursors, widget themes), fonts details (family, hinting
+ preferences) etc. Just send all settings at connect time, send
+ updates when a setting change. Getting a little close to gconf
+ here, but could be pretty simple:
- - talks to an Xorg server as the compositing and window manager
- for that server and renders the output to a wayland surface.
- the Xorg server should be modified to take input from the system
- compositor through gnome-shell, but not allocate a front buffer.
+ interface "settings":
+ event int_value(string name, int value)
+ event string_value(string name, string value)
- - make gnome-shell itself a nested wayland server and allow native
- wayland clients to connect and can native wayland windows with
- the windows from the X server.
+ but maybe it's better to just require that clients get that from
+ somewhere else (gconf/dbus).
- - qemu as a wayland client; session surface as X case
- - qemu has too simple acceleration, so a Wayland backend like the
- SDL/VNC ones it has now is trivial.
+Crazy ideas
- - paravirt: forward wayland screen info as mmio, expose gem ioctls as mmio
+ - AF_WAYLAND - A new socket type. Eliminate compositor context
+ switch by making kernel understand enough of wayland that it can
+ forward input events as wayland events and do page flipping in
+ response to surface_attach requests:
- - mapping vmem is tricky, should try to only use ioctl (pwrite+pread)
+ - ioctl(wayland_fd, "surface_attach to object 5 should do a kms page
+ flip on ctrc 2");
- - not useful for Windows without a windows paravirt driver.
+ - what about multiple crtcs? what about frame event for other
+ clients?
- - two approaches: 1) do a toplevel qemu window, or 2) expose a
- wayland server in the guest that forwards to the host wayland
- server, ie a "remote" compositor, but with the gem buffers
- shared. could do a wl_connection directly on mmio memory, with
- head and tail pointers. use an alloc_head register to indicate
- desired data to write, if it overwrites tail, block guest. just
- a socket would be easier.
+ - forward these input devices to the client
- - moblin as a wayland compositor
+ - "scancode 124 pressed or released with scan codes 18,22 and 30
+ held down gives control back to userspace wayland.
- - clutter as a wayland compositors
+ - what about maintaining cursor position? what about pointer
+ acceleration? maybe this only works in "client cursor mode",
+ where wayland hides the cursor and only sends relative events?
+ Solves the composited cursor problem. How does X show its
+ cursor then?
- - argh, mutter
+ - Probably not worth it.
projects / profile / ivi / wayland.git / blobdiff