Handle not rendered properly if border-width = 0

[Peter Hurley]

When rendering handles (unico-draw.c: unico-draw-handle), if the current style context has border-width = 0, the handle is not rendered properly. This happens because the line-width is style-matched to "border-width" in unico_get_line_width(), which in turn, means that some of the lines are not stroked and the geometry calculations are off.

When rendering handles, often the border-width will be set to 0 so that the entire background will be wiped to the correct pattern (without leaving a border artifact - this happens on oneiric with gnome-panel and the Radiance theme). The same problem exists when rendering separators as well.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gtk3-engines-unico 1.0.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-15.25-generic 3.0.13
Uname: Linux 3.0.0-15-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Tue Jan 24 00:03:26 2012
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gtk3-engines-unico
UpgradeStatus: No upgrade log present (probably fresh install)

[Peter Hurley (phurley)]

I added a simple patch for selecting the max of either the existing line-width or 1.

Another approach would be register a new style property ('-unico-line-width'?) and use that value instead of 'border-width'.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "02_fix_handle_rendering_for_border_width_0" of this bug report has been identified as being a patch. The ubuntu-reviewers team has been subscribed to the bug report so that they can review the patch. In the event that this is in fact not a patch you can resolve this situation by removing the tag 'patch' from the bug report and editing the attachment so that it is not flagged as a patch. Additionally, if you are member of the ubuntu-reviewers team please also unsubscribe the team from this bug report.

[This is an automated message performed by a Launchpad user owned by Brian Murray. Please contact him regarding any issues with the action taken in this bug report.]

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Vadim Rutkovsky (roignac)]

This also affects gnome-sushi - see discussion at https://bugzilla.gnome.org/show_bug.cgi?id=670500

[Andrea Cimitan (cimi)]

It's a bug in light-themes.

[Peter Hurley (phurley)]

@Andrea,

Would you please include a link to the relevant Launchpad light-themes bug and include an explanation of *why* you think this is a light-themes bug?

As I explained in the OP, if the border-width is 0, the handle is not drawn correctly. Are you saying that, by-design, a handle cannot be rendered correctly within a style context where the border-width = 0?

[Andrea Cimitan (cimi)]

It's a light-themes bug because you need to add a special case for sushi and add the lines to not draw outer stroke and inner stroke.
There are cases where border-width is 0 but you still want a shadow or an inner stroke, example is the combobox with an entry. So it's done in this way in unico but just needs tweaks on the theme side.

[Peter Hurley (phurley)]

I think if you re-read the OP bug description, you'll realize this bug (and report) has nothing to do with the bug in sushi.

The problem described here is a bug in the unico engine when rendering handles and separators.

[Andrea Cimitan (cimi)]

It's not a bug in unico, but in light-themes. Please don't change the status

[Andrea Cimitan (cimi)]

Anyway, I will have a look in unico to see if I can add an user case for similar issues.

[Peter Hurley (phurley)]

I have a attached a screenshot of *bug #920832* which shows *the handle* being rendered incorrectly in the gnome-panel.

[Peter Hurley (phurley)]

I have attached a screenshot of the correctly rendered *handle* after the unico engine patch I already supplied in comment #2.

As you can see, this bug has *NOTHING* to do with *bug 937141*.

Please un-duplicate bug 937141, and reset the correct status for this bug to 'New' for the unico engine and remove the light-themes status.

[Dmitry Shachnev (mitya57)]

I have to agree with Peter, it's actually a Unico bug and the patch fixes it. Also, this needs to be applied before you release light-themes with my branch merged :)

[Andrea Cimitan (cimi)]

Well, the patch is wrong cause border-width can be bigger than 1. Also, I still think this is not a bug in unico cause you can simply can add a special style class if needed.
In any case, test against unico trunk.
I won't fix this in unico at the moment, as I don't consider it a bug

[Peter Hurley (phurley)]

Ok, I agree -- the patch is wrong. The real bug here is that unico should not be using the border-width style to style interior render elements. In the comment that included the patch, I noted that a more appropriate fix might be to register a new style property instead.

This is *not* fixable from outside unico.

[Peter Hurley (phurley)]

@Andrea,

I don't understand what you meant by "you can simply can add a special style class if needed."

I have attached a standalone testcase which demonstrates the bug. The testcase is a toplevel window which contains a single widget -- a subclassed EventBox that renders a handle centered within the window. Please note that the only drawing in this testcase -- including the background -- is done by GtkRenderHandle *which is rendered by the unico engine*.

The testcase styles the widget with a css fragment defined in main() as faux_theme.

Feel free to "add a special style class" to the faux_theme definition so that the testcase output matches the reference image which I will also attach.

[Andrea Cimitan (cimi)]

if you set a border-width of 0, why you should have a handle? :\

[Peter Hurley (phurley)]

That question is totally irrelevant. The purpose of a themeing engine is customize the look of standard elements, not to oversee the UI design of applications.

This is becoming absurd and farcical -- the title of this bug is "Handle not rendered properly if border-width = 0" and your 5th comment on this bug is "if you set a border-width of 0, why you should have a handle?" after twice insisting this is a light-themes bug and telling me not to change the bug status ?????

[Andrea Cimitan (cimi)]

I don't render anything if border-width is 0. If you want a 1px handle, set border-width to 1.

[Andrea Cimitan (cimi)]

And yes, no artifacts will be rendered with unico trunk if border-width is 1, as I intentionally adjust the background. Check trunk

[Daniel van Vugt (vanvugt)]

I don't think Ubuntu has "handles" any more. Does it?