Archive for the ‘open source’ Category


Improvements for visually impaired people

In Bluefish,Gnome,gtk+,open source,Programming on April 29, 2012 by oli4444

Last week I received an email if Bluefish could be improved for people with a visual impairment. I never occurred to me that there would be people with limited vision wanting to use Bluefish. The most requested features in the email were:

  1. Zoom in/out with ctrl+ / ctrl-
  2. Maximum screen estate
  3. Better cursor visibility

The first feature was easy. Bluefish  already has zoom with ctrl-mousewheel, so I added the accelerators (it turned out that the requester was not aware of this feature).

For the second feature I created an option that automatically hides all menu bars, status bars and toolbars on fullscreen (F11). It displays them again if you hit F11 again. This way basically every bit of the screen is used by the editor itself. The only issue I found is when LXDE is used. LXDE has bound F11 to the window-manager fullscreen, so the application fullscreen never gets called. I moved my code to the configure event handler, where I can detect both the internal fullscreen as well as a window manager fullscreen.

The third feature was the hardest bit. With some help from IRC I managed to make the cursor-aspect-ratio user defined.

In gtk2 it looks like this:

style "bluefish-cursor" {GtkWidget::cursor-aspect-ratio = %f }
class "GtkTextView" style "bluefish-cursor"

which is loaded with gtk_rc_parse_string()

In gtk3it is slightly nicer:

GtkTextView {-GtkWidget-cursor-aspect-ratio: %f;}

which is loaded with gtk_css_provider_load_from_data() and gtk_style_context_add_provider()

Next to a bigger cursor I made a setting to highlight the cursor position: it paints a differently coloured background on the character left and right of the cursor. I connected that to the mark-set insert-text and delete-range signals, the last two with g_signal_connect_after() to get the new location of the cursor and not the old location.

This code does have quite a performance impact: scrolling with the arrow keys is significantly slower with this option enabled. I used this code:

     gtk_text_buffer_get_bounds(btv->buffer, &it1, &it2);
     gtk_text_buffer_remove_tag(btv->buffer, btv->cursortag, &it1, &it2);
     it1 = *location;
     it2 = it1;
     gtk_text_buffer_apply_tag(btv->buffer, btv->cursortag, &it1, &it2);

What this code causes is an update the internal structure of the GtkTextBuffer (probably something like a balanced tree) that keeps track where each tag starts and stops – for every cursor move. After rethinking this I remembered this is much easier done in the expose event!

get the coordinates with gtk_text_view_get_iter_location(), convert them with gtk_text_view_buffer_to_window_coords() and paint with cairo_rectangle() and cairo_fill():

   gtk_text_buffer_get_iter_at_mark(buffer, &it, gtk_text_buffer_get_insert(buffer));
   gtk_text_view_buffer_to_window_coords(view, GTK_TEXT_WINDOW_TEXT
            , itrect.x, itrect.y, &x2, &y2);
   cairo_rectangle(cr, (gfloat)x2-width, (gfloat)y2, (gfloat)(width*2 )
            , (gfloat)itrect.height);

The result is visible below. So now it is test time!


Bluefish 2.2.2 released

In Bluefish,open source on March 8, 2012 by oli4444

Bluefish 2.2.2 is largely a bug fix release with some very minor new features. A regression in the search functionality was fixed, that caused a segfault if a document with search results was closed. Multiple replace with search results directly next to each other corrupting the text was also fixed. The broken cursor positioning that ruined the Zencoding plugin was also fixed. On the multiplatform front: on Windows handling of the profile directory with non-ascii characters was fixed and on MacOSX image browsing in the image dialog was fixed. Two GTK-3 related bugs where fixed: the CSS dialog was unusable on GTK-3 and the right margin indicator was positioned wrong. Next to the major fixes several small memory leaks where fixed. Next to the bug fixes some small improvements where made. Startup is slightly faster using more threads during startup and improving the document recovery. The annoying scrolling of the side bar filebrowser in ‘treeview’ mode was fixed, descriptions of language options where fixed, and some menu strings, some HTML5 options where improved, accelerators and shortcut keys got improved and translations got better. The new features: duplicate line and delete line, and the Catalan translation.

Download it from


Debugging a reference count bug

In Bluefish,gtk+,open source,Programming,Ubuntu on February 5, 2012 by oli4444 Tagged:

Last days I have been debugging some weird reports. They all show the same characteristics:

  • the users are on Ubuntu 11.10
  • they use bluefish compiled against gtk 3.2 (so not the bluefish package that is provided by Ubuntu, but a newer one)
  • in the Bluefish run the sort function of a GtkTreeModelSort is called after the GtkTreeModelSort should have been finalized and free’ed.

First I used gobject-list.c from to see all refs and unrefs on all GtkTreeModelSort objects in Bluefish (luckily there is only 1 used in Bluefish).This showed that there was indeed a GtkTreeModelSort with lots of references left after it should have been finalized. I tried the same thing on Fedora 16 (also gtk-3.2), but it can only be reproduced on Ubuntu 11.10.I tried to get backtraces with gobject-list (which uses libunwind for that) but those backtraces turned out to be useless.

Luckily I received some help on IRC #gtk+ from Company and alex. The first idea was to use systemtap, but since there is no useful kernel for systemtap available for Ubuntu I had to use something more low tech suggested by Company:  I set a breakpoint on gtk_tree_model_sort_new to retrieve the pointer of the GtkTreeModelSort. Once I got that pointer I could set a breakpoint on g_object_ref and g_object_unref with a condition on this pointer. Then I created an automatic backtrace on each breakpoint:

break g_object_ref if object == 0x123123123

I configured gdb to log everrything to a file, and did a bluefish run. This resulted in a 2.1 Mb logfile with backtraces. This log also showed there were more refs than unrefs.

In this logfile there were a lot of similar backtraces, with an identical function doing a ref and an unref. I wrote a short python script to parse the backtraces and skip all ‘valid pairs’

After this step I had only 15 backtraces left. And from these backtraces the leaking references were easily identified.

Because I was unsure if this is a Ubuntu specific bug or a generic gtk bug the resulting bugreport can be found both at and at

Now I am wondering if this approach would work for any reference count leaking problem. I guess the most difficult issue is to find the value of the pointer that is leaking if you have many objects of the same type.. Any suggestions how to do this?


Happy new year: Bluefish 2.2.1 released!

In Bluefish,open source on January 3, 2012 by oli4444

Bluefish 2.2.1 is mostly a bug fix release, but it has one major new feature: Zencoding support (which requires python). The bug fixes include a fix to build on Gtk+-2.22, many translations are better up-to-date, a fix for PCRE regular expression searching, several layout fixes for Gtk+-3.2, several obscure segfault fixes, a fix for autocompletion of variables in PHP, <img> dialog fixes, some memory-leak fixes and othere minor fixes.

Download Bluefish here, or check the how to install Bluefish page on our wiki.


The (too large) minimum width of a GtkEntry in Gtk+-3.2

In Bluefish,Gnome,open source,Programming on December 14, 2011 by oli4444

Bluefish has a side-pane in it’s main interface, which is implemented using a GtkHPaned widget. Users may drag the handle to increase or decrease the side pane. Now lets see what happens if the user makes the sidebar smaller than the widgets in there. I created a mini example application that works with both Gtk+-2 and Gtk+-3. There is a GtkEntry in the left sidebar, and a GtkTextView on the right. This is a screenshot with Gtk+-2:

Initial view of the example application

Now see what happens if you drag the handle to the left in Gtk+-2:

Gtk+-2 making the widget smallerThe widget now becomes smaller, and it is cropped on the right side, which looks natural.

Now see what happens if you drag the handle to the left in Gtk+-3.2:

What it looks like inb Gtk+-3.2The widget is cropped from the left side, which has the content, which looks awful. Also there is a huge empty space after the “Hello World” because the GtkEntry minimum width is very large.

My suggestions for improvement:

  • decrease the minimum width of the GtkEntry to 30 pixels or so
  • when cropping widgets, crop from the right if the widget is on the left side of the handle, crop from the left if the widget is on the right side of the handle. That suggests that the user drags the handle as a layer on top over the widget which feels much more natural.

b.t.w. GtkEntry is not the only widget that has a too-large minimum width. In Bluefish we also use libgucharmap, and the gucharmap widget forces an even wider sidebar in Gtk+-3.2.


GtkTable and GtkLabel with wrap on Gtk+-3, and trying to stay compatible with Gtk+-2…

In Bluefish,Gnome,open source,Programming on November 30, 2011 by oli4444

Bluefish has several dialogs that use a GtkLabel with wrap enabled inside a GtkTable. Since the width-for-height changes in Gtk+-3.2 these GtkLabel’s take an enormous amount of vertical space. If this launchpad bug is correct it will use enough vertical space to put every word on a new line.

The suggestion in that bugreport is to switch to GtkGrid. This is a good suggestion, but is has a drawback. In Gtk+-2 there is no way to set widget specifc expand properties in a GtkGrid (in a GtkTable this is done with gtk_table_attach()). In Gtk+-3 new properties have been added to GtkWidget to control whether a widget may expand or not. We (Bluefish developers) try to remain compatible with Gtk+-2 at the moment. So what to do? GtkGrid may solve our problem in Gtk+-3 but causes problems in Gtk+-2, and GtkTable solves our problem in Gtk+-2 but causes problems in Gtk+-3 ?

Luckily I found a workaround:


This fixes the problem with a GtkLabel with wrap in a GtkTable in Gtk+-3.2. So for the moment we stick with GtkTable with this workaround.


Bluefish 2.2.0 released

In Bluefish,Gnome,Gnome shell,open source on November 27, 2011 by oli4444

Bluefish 2.2.0 is a new major release and the start for the 2.2 series. Under the hood Bluefish 2.2.0 has a massive number of changes: Bluefish now works with gtk-3 (gtk-2 is still supported), and the syntax scanner had a major overhaul to make it faster, which is especially noticeable when working on large files.

Another big change in Bluefish 2.2.0 is the new search and replace function. It has been completely redesigned: the simple search function is now integrated in the main window, and the new function supports both search and replace in files on disk (next to already opened documents). Other new features include a toggle comment function that is context-aware (add <!– –> comments in html code, use // comments in javascript code, /* */ in php code, etc. even if all of these languages are in a single file) and a select block feature that automatically selects the current context block and can be used multiple times to select the parent blocks. Another new feature of the syntax recognition is the autocompletion of user-defined functions, and a jump function that will bring you immediately the the definition of a function.

Next to all the new features many existing features have been improved and polished. Furthermore support for new languages has been added, such as Google Go, D, Vala and Ada.

I created an introduction movie using the built in screen recording option of the gnome 3 shell, which has no sound recording. I recorded my voice with audacity and tried to merge them both with pitivi. Pitivi just hanged at rendering 98% no matter what I tried. Then I switched to openshot, which crashed a few times but it did render my video. Unfortunatelythe result was bigger than the original video and sound files, with worse video quality. Anyway, you can see the result on youtube:

p.s. the 2.2.1 release of Bluefish will have a zen-coding plugin!


Bluefish, Ubuntu or Gtk bug?

In Bluefish,Gnome,open source,Programming,Ubuntu on October 25, 2011 by oli4444

There is a weird widget scaling issue happening with Bluefish compiled on Ubuntu 11.10 with gtk-3.2.0 that I don’t see on the same Ubuntu 11.10 with Bluefish compiled with gtk-2.24.6 nor on Fedora 15 compiled with Bluefish compiled with either gtk-3.0.12 or gtk-2.24.4.

Bluefish has a GtkHPaned widget to show a sidebar (by default on the left). Inside that sidebar is a GtkNotebook, and inside that notebook is a GtkComboBox. The text string in the GtkComboBox sometimes becomes quite long. Normally this string is just shortened by gtk as can be seen below (the string is file:///home/olivier etc. etc.):

On Ubuntu 11.10 with gtk-3.2, however, this string defines the GtkComboBox minimum width, and if you try to move the GtkHPaned handle to the left it makes all of the contents inside the GtkHPaned move to the left, outside the window border (watch the left side of the GtkNoteBook, see that one of the tabs is moved outside the window? See that the contents of the GtkTreeView are moved outside the window?):

In this example there is a long string in the active entry of the GtkComboBox, but if there is a short string active and a long string only in the popup menu, the issue still appears. So the minimum width is defined by the longest string in the GtkListModel.

In the documentation I cannot find if a GtkComboBox should shrink smaller than the text that is possibly in the popup menu. But I do know that this has never been a problem before on any gtk version up to gtk-3.0 (but Fedora 16 is not yet released, so my only Gtk-3.2 box has Ubuntu 11.10), so I’m wondering if the bug is in Bluefish, Ubuntu or Gtk?

Update 1: I can reproduce this on Fedora 16 beta, so this is not an Ubuntu issue, it is either Gtk-3.2 or Bluefish

Update 2: thanks to the comment from Benjamin Otte I fixed part of the issue by setting the ellipsize property to the GtkComboBox text renderer. However it is still not really back to normal nice behavior. The GtkComboBox furthermore has weird/buggy behavior if ellipsize is disabled. If there used to be a long string in the model, but that string is gone, it still wants a very big width. I think at least this bit is buggy.


After 5 year a new release for Directoryassistant

In Gnome,Linux desktop,open source on October 10, 2011 by oli4444

After ~5 years without a release, I released Directoryassistant 2.1. Directory Assistant is a small application for managing addresses and contact information in a LDAP address book. I originally wrote it because I organized my addresses in an ldap store so I could use them in different programs, but my girlfriend did not, so we always had incomplete or out-of-sync information. Nowadays we have the same addressbook on all our computers and smartphones in our household.

Directoryassistant 2.1 is just a minor feature enhancement release. I guess the next version will be major again because right now it still uses gtk+-2 and python-gtk2, so the next thing to do would be gtk+-3 compatibility and python with GObject-Introspection.


Next Bluefish version, 2.0.4 or 2.2.0 ?

In Bluefish,open source,Programming on October 1, 2011 by oli4444

I’m wondering which version number we should give to the next Bluefish release. Are the changes just minor, so should we use 2.0.4, or are the changes big enough to justify a 2.2.0 version number?

On the surface the changes are not very dramatic. Several new features, such as “select block” (<shift><ctrl><b>) which will select the syntax block that the cursor is in (use multiple times to get one of the the parent blocks), the block stack is displayed on the statusbar (for example “{ { /*” if you are in a comment that is in a loop in a function), and a completely rewritten search and replace engine. It can now search (and replace) recursively trough files, do both backward and forward searches, and gives more options for the regular expression searches. The quickbar feature has been removed because it turned out to be difficult to port to gtkuimanager. Perhaps it will be added again if there is a lot of demand for that.

However, under the hood there are massive changes. All of the menu and toolbar code and their calbacks have been rewritten to use GtkUIManager. The code now compiles with gtk+-3. The syntax highlighting engine has been changed a lot. The internal syntax caching structures have been rewitten, and all the code that handles that. Almost 30 commit on bftextview2_scanner.c for example, a 30k diff on a 60k file.

So from a developer point of view, 2.2.0 is justified. But from a user point of view, this should be just 2.0.4.


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