Add support for XCB surfaces via xcffib [updated] #39

flacjacket · 2014-08-02T02:33:14Z

Adaptation of #37 addressing the concerns raised there. This adds cairocffi.xcb which allows for interfacing with XCB surfaces through cairo with the cairocffi.xcb.XCBSurface objects. There are also tests and docs for the new module. I couldn't think of a good way to verify the images that are rendered, but just left them to be if the tests run successfully.

I know the tests won't pass now, as the version of xcffib currently tagged on pypi isn't up to date. Once @tych0 takes care of that, the tests can be re-run and should pass (fingers crossed).

EDIT: all tests should pass now https://travis-ci.org/flacjacket/cairocffi/builds/31476403

flacjacket · 2014-08-06T18:47:56Z

Ping @SimonSapin
Tests are all passing, let me know if you'll be able to look at this

Add cairo-xcb.h functions to constants as cairocffi.constants._CAIRO_XCB_HEADERS

Create cairocffi.xcb module, which uses xcffib as a library to create XCBSurface objects

Add test cases for the new cairocffi.xcb module. Two test cases are for creating XCB surfaces on pixmap and window.

Add documentation for cairocffi.xcb module to sphinx docs

Installs xcffib for xcb support when running: pip install cairocffi[xcb]

When using XCB extensions you need to query the extension before making requests to it. (This is referred to in the XCB documentation as the "extension cache".) Older versions of cairo sometimes don't do this, so the first test will pass, but the second test will fail because cairo is caching request ids from the old connection (an example wth an xtrace is [1]). To work around this, we run each test in a separate process via --boxed, which forces cairo to ask XCB about the extensions for each test. [1]: http://paste.ubuntu.com/8320590/

flacjacket · 2014-09-11T23:47:30Z

@SimonSapin I've just updated this, between some work on this and on xcffib, this is now passing and robust, and we think is ready to merge. Let me know what you think about these changes as they stand, thanks.

SimonSapin · 2014-09-23T17:12:23Z

Released on PyPI in version 0.6, thanks!

flacjacket · 2014-09-23T17:55:47Z

I haven't taken an extensive look at testing against different cairo versions, I know it works fine on my machine with 1.12, but running in Ubuntu 12.04 with 1.10, I've seen the same problem as seen on Travis.

Thanks for getting this up!

SimonSapin · 2014-09-23T18:34:03Z

Yeah, all the XCB-related functions in cairo were added in 1.12.

tych0 · 2014-09-23T23:45:13Z

They've been around since at least 1.8 (that was the earliest I ever encountered them): http://cgit.freedesktop.org/cairo/tree/src/cairo-xcb-surface.c?h=1.8

I have no idea why the docs say 1.12, that seems wrong :). In any case, I haven't seen this bug on anything >= 1.13, although I haven't actually looked through the cairo source to see when they patched their implementation.

SimonSapin · 2014-09-24T08:17:30Z

Well, the error message seems pretty clear to me, the function is not in my build of 1.10.0: (And same with 1.8.2.)

$ tox -e py26-cairo-1.10.0
[...]
AttributeError: cairo_xcb_surface_create: "function 'cairo_xcb_surface_create' not found in library 'libcairo.so.2': ../cairo-1.10.0/lib/libcairo.so.2: undefined symbol: cairo_xcb_surface_create"

I built this cairo from cairo-1.10.0.tar.gz with ./configure && make on Archlinux x86_64

I do see these functions in the git tree as you point out, but for some reason the files are not included in the release tarballs.

SimonSapin · 2014-09-24T08:27:34Z

the files are not included in the release tarballs.

Now I’m confused. I’m not sure how I came to that conclusion 10 minutes ago. The files are there, but the ./configure script has an --enable-xcb option. Maybe it’s off by default before 1.12?

tych0 · 2014-09-24T12:50:08Z

I guess it depends on distro configuration, too. The debian/ubuntu packages
have had it on since 1.8 (viz. the tests pass on travis-ci with 1.10).

On Wed, Sep 24, 2014 at 3:27 AM, Simon Sapin notifications@github.com
wrote:

the files are not included in the release tarballs.

Now I’m confused. I’m not sure how I came to that conclusion 10 minutes
ago. The files are there, but the ./configure script has an --enable-xcb
option. Maybe it’s off by default before 1.12?

—
Reply to this email directly or view it on GitHub
#39 (comment).

........... Released on 2014-09-23. * `#39 <https://github.com/SimonSapin/cairocffi/pull/39>`_: Add :class:`xcb.XCBSurface`. * `#42 <https://github.com/SimonSapin/cairocffi/pull/42>`_: Add :class:`Win32PrintingSurface`.

whitelynx · 2017-04-07T04:01:04Z

I'm seeing a very similar issue on Arch Linux, with cairo 1.14.8-1 and cairocffi==0.8.0:

Traceback (most recent call last):
  File "xcffibaer", line 129, in <module>
    run()
  File "xcffibaer", line 104, in run
    surface = createWindow(conn, screens[screenIndex], visualType)
  File "xcffibaer", line 50, in createWindow
    surface = XCBSurface(conn, window, visualType, width, height)
  File "/home/whitelynx/Development/Personal/xcffibär/env/lib/python3.6/site-packages/cairocffi/xcb.py", line 37, in __init__
    p = cairo.cairo_xcb_surface_create(
AttributeError: cffi library 'libcairo.so.2' has no function, constant or global variable named 'cairo_xcb_surface_create'

The really weird thing is, according to /usr/include/cairo/cairo-features.h (from cairo 1.14.8-1), XCB support is enabled, which means that function should be there:

$ grep -r CAIRO_HAS_XCB_SURFACE /usr/include/cairo/
/usr/include/cairo/cairo-features.h:#define CAIRO_HAS_XCB_SURFACE 1
/usr/include/cairo/cairo-xcb.h:#if CAIRO_HAS_XCB_SURFACE
/usr/include/cairo/cairo-xcb.h:#else  /* CAIRO_HAS_XCB_SURFACE */
/usr/include/cairo/cairo-xcb.h:#endif /* CAIRO_HAS_XCB_SURFACE */
$ grep '#if CAIRO_HAS_XCB_SURFACE' /usr/include/cairo/cairo-xcb.h -A15
#if CAIRO_HAS_XCB_SURFACE

#include <xcb/xcb.h>
#include <xcb/render.h>

CAIRO_BEGIN_DECLS

cairo_public cairo_surface_t *
cairo_xcb_surface_create (xcb_connection_t	*connection,
			  xcb_drawable_t	 drawable,
			  xcb_visualtype_t	*visual,
			  int			 width,
			  int			 height);

cairo_public cairo_surface_t *
cairo_xcb_surface_create_for_bitmap (xcb_connection_t	*connection,

and the string even shows up in the .so:

$ strings /usr/lib/libcairo.so.2 | grep cairo_xcb_surface_create
cairo_xcb_surface_create
cairo_xcb_surface_create_for_bitmap
cairo_xcb_surface_create_with_xrender_format
_cairo_xcb_surface_create_similar

It seems like there's a mismatch between what cairocffi is trying to call, and what libcairo.so.2 is actually exporting, but I'm not sure how to debug that further... Should I open a new issue for this?

whitelynx · 2017-04-07T04:14:58Z

Also, just to clarify, I did install cairocffi with pip install cairocffi[xcb] as mentioned in the docs.

whitelynx · 2017-04-07T04:48:37Z

I managed to get it working using pip install cairocffi[xcb] -U --force-reinstall --no-binary cairocffi. Sadly, I don't think I can provide --no-binary cairocffi in a requirements.txt.

flacjacket · 2017-04-16T14:15:49Z

@whitelynx The way the XCB stuff works here currently, xcffib has to be installed before installing cairocffi in order for the XCB stuff to come in correctly. We have seen similar issues in qtile and have had to put in install-time checks that this AttributeError isn't being thrown.

whitelynx · 2017-04-21T14:34:32Z

Even separating cairocffi out into a separate requirements-2.txt and running pip install -r requirements-2.txt after installing everything else (including xcffib) doesn't solve this; the only way I've found to make it work so far is using --no-binary.

tych0 · 2017-04-21T15:11:09Z

I was just looking at this. I wonder if we can get away with copying and pasting the whole types definition from xcffib into cairocffi? We'd have to change it in both places when new structures were added, but given where XCB is at in its software life, perhaps that won't ever happen.

At least this way it wouldn't depend on what order things were installed in, which seems like it bites a lot of people today. Thoughts?

tych0 mentioned this pull request Aug 3, 2014

Add support for XCB surfaces via xcffib #37

Closed

flacjacket mentioned this pull request Aug 7, 2014

Use new cairocffi/xcb support tych0/qtile#13

Merged

flacjacket and others added 6 commits September 10, 2014 20:47

Add xcb information to mkconstants

722e05f

Add cairo-xcb.h functions to constants as cairocffi.constants._CAIRO_XCB_HEADERS

Add cairocffi.xcb

acf7287

Create cairocffi.xcb module, which uses xcffib as a library to create XCBSurface objects

Add xcb tests

aec3dd0

Add test cases for the new cairocffi.xcb module. Two test cases are for creating XCB surfaces on pixmap and window.

Add xcb documentation

9d99655

Add documentation for cairocffi.xcb module to sphinx docs

Add xcb install option

5f1dc60

Installs xcffib for xcb support when running: pip install cairocffi[xcb]

flacjacket force-pushed the xcb branch from a55035c to 132098d Compare September 11, 2014 23:38

SimonSapin merged commit 132098d into Kozea:master Sep 23, 2014

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Add support for XCB surfaces via xcffib [updated] #39

Add support for XCB surfaces via xcffib [updated] #39

flacjacket commented Aug 2, 2014

flacjacket commented Aug 6, 2014

flacjacket commented Sep 11, 2014

SimonSapin commented Sep 23, 2014

flacjacket commented Sep 23, 2014

SimonSapin commented Sep 23, 2014

tych0 commented Sep 23, 2014

SimonSapin commented Sep 24, 2014

SimonSapin commented Sep 24, 2014

tych0 commented Sep 24, 2014

whitelynx commented Apr 7, 2017

whitelynx commented Apr 7, 2017

whitelynx commented Apr 7, 2017

flacjacket commented Apr 16, 2017

whitelynx commented Apr 21, 2017

tych0 commented Apr 21, 2017

Add support for XCB surfaces via xcffib [updated] #39

Add support for XCB surfaces via xcffib [updated] #39

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flacjacket commented Aug 2, 2014

flacjacket commented Aug 6, 2014

flacjacket commented Sep 11, 2014

SimonSapin commented Sep 23, 2014

flacjacket commented Sep 23, 2014

SimonSapin commented Sep 23, 2014

tych0 commented Sep 23, 2014

SimonSapin commented Sep 24, 2014

SimonSapin commented Sep 24, 2014

tych0 commented Sep 24, 2014

whitelynx commented Apr 7, 2017

whitelynx commented Apr 7, 2017

whitelynx commented Apr 7, 2017

flacjacket commented Apr 16, 2017

whitelynx commented Apr 21, 2017

tych0 commented Apr 21, 2017