Because of Christmas I make a little wish.
Am I the only one who is terribly annoyed about the size-changing of caja list-windows at opening a directory? I would like to just switch that off. A fixed size of two windows side by side would be perfect for me.
I also miss the 2 color rows as it was at 16.04 with gtk2. It was much easier to handle than on a blank background.
Merry Christmas to you all and thank you very much for the wonderful work you do with Mate!
Tatanka
Hello there. I have written code for Caja in the past and am thus fairly familiar with the code of Caja. On top of that, I have done public and private work on GTK. As such, I can probably implement both of your wishes.
Your second wish is fairly clear to me: I don't need further explanation of that one, as I also miss the "zebra stripes", as they were called.
But as for the first feature request, I do not understand. When I resize a Caja window, the new size becomes the default, and any future Caja windows I open will be sized the same as the Caja window I adjusted. This means that I can resize a window to fill half of the screen, and Caja will open up with that window size from then on, until I resize the window again. Are you saying that you'd like to set Caja's default window size, and then "lock" the default window size so that Caja always, from then on, defaults to a window that fills half the screen?
If you can communicate your wish clearly to me, I can implement it for you.
Merry Christmas.
Hello Gordon. Thanks for trying to help me!
I'm not a native speaker so first I did not find the right term.
What I mean is the panes. Mostly I open a second pane with F3. First both of them have the same size, but when I open a folder, the horizontal size changes and it switches with about every folder change. Whatsoever I have to set it back manually. I would appreciate if you could find a solution to this issue and also for the "zebras".
Thanks a lot in advance!
Okay, now I think I understand what bug you are describing. Once opening up the two-paned view using F3, initially the two panes are an equal width:
However, once you start navigating folders in one or both of the panes, sometimes the panes will resize unexpectedly:
But if you then drag the separator between the panes, and manually resize the panes so that they are (roughly) equal in size again, all of a sudden the unexpected resizing doesn't happen after that:
How odd.
If that's the problem that you're talking about, I have a hunch I know what's causing it, and I'll do my best to provide you with fixes for the behavior. I think both can be fixed quickly.
Thanks for pointing these bugs out; I am a quality assurance tester for Ubuntu MATE, which means I try to find bugs and fix them, but I rarely use Caja's two-pane layout, so I was blind to that bug.
Best wishes.
Exactly, that's what I mean. Annoying, isn't it? I would appreciate if you can find a solution. By the way, there's another issue annoying me when I move or copy a file from one pane to the other with the mouse:
When I hold it over a folder for more than 1 second the folder pops up automaticly. So when I search for the destination of the file too long I have a long list in that pane with expanded folders. Very disturbing also to close them all again! May be there is a chance to switch that off?
Dear Gordon, I always read your fine contributions all over this forum and I appreciate them very much. Thank you for all your work for Mate and the community!
I missed that too, but reunited with them since switching to a Qt desktop - that is, until I use a GTK app or GTK file picker! 
I look after a set of community GTK3 patches known as gtk3-classic. We don't have a patch for the alternating rows but if @gordon is interested, this could be a place to re-implement it!
It's currently only packaged for Arch Linux, but if there's demand, I'll have another stab at packaging for Ubuntu MATE.
Merry Christmas @tatanka.
I did not see your comment about the expanding folders until just now, so I haven't patched that yet. But I got the extra pane to work correctly in very little time -- and I even got the zebra stripes to work, though it took me until 03:00 A.M on the 24th to get that to work. No problem, though. It was well worth the lost sleep! 
In advance, I also regret not being able to provide you with pre-built packages that have these bugfixes / feature additions. I wanted to, but I don't know what version of Ubuntu MATE you are using, so I don't know what versions of Caja and GTK+ to compile for you.
However, I have two patches to the source code of these programs -- one for Caja and one for GTK+. The former, if you apply it to Caja and then build Caja, will rectify the extra pane bug, and also adds code so that the extra pane to be open by default, if you like. The latter patch, when applied to GTK+, will add code to help enable zebra stripes -- but in order to actually show the zebra stripes, you need an additional file. Use the terminal commands:
mkdir -p ~/.config/gtk-3.0
pluma ~/.config/gtk-3.0/gtk.css
This will create a file that enables you to apply your own style preferences to your applications. I added the following code to that file to give me zebra stripes -- in Caja only:
.caja-notebook treeview.even:not(:selected)
{
background-color: shade(@theme_base_color, .9);
}
.caja-notebook treeview.sorted.odd:not(:selected)
{
background-color: shade(@theme_base_color, .9);
}
.caja-notebook treeview.sorted.even:not(:selected)
{
background-color: shade(@theme_base_color, .81);
}
Feel free to change the shade(...) statements to colors of your liking. I wish there were an easier way to do the zebra striping; but since my patch has not circulated the Internet very much yet, popular themes do not have zebra stripe-drawing code yet, so for the time being, we will have to define our own zebra stripe styles.
Okay, that was a whole lot of stuff to throw at you all at once. Let me break this down for you:
Download my patches to a folder in your home directory. The two patches you will need are located at:
Build the caja package from source code, patching in my first patch and only my first patch above. I have written detailed instructions for how to build packages from source, at: How to modify and rebuild a package for Ubuntu MATE (or Ubuntu, or Debian).
Now build the libgtk-3-0 package, patching it using my second patch and only my second patch, using the same instructions I linked to above. (But replace any instances of caja with libgtk-3-0 or similar.)
Create a file under your home directory, at ~/.config/gtk-3.0/gtk.css, that contains style rules for the zebra stripes. An example that worked for me with the TraditionalOk theme is given far above.
You now have two choices: You can log out and log back in, or you can run:
caja --quit
Either way, your open Caja windows will be closed. When you have done either, lo and behold, if everything worked, you should now have a user interface that looks something like this:
Again, sorry I couldn't build the packages for you, and sorry I haven't implemented the third feature request yet, but I hope I have not let you down too much! If things do go wrong, perhaps with the compilation, don't be afraid to reach out to me again; I probably can help with that too.
Happy Holidays from Gord. I hope to hear back from you soon.
Gordon, you are great! It takes my breath. Now you gave me a lot to learn and to do - and I love it! It will take some time for me to accomplish and I will let you know about. Thank you very much!
Patch one worked wonderful and caja runs smoothly.
The building of #2 always stops with a fatal error:
make[2]: Verzeichnis „BUILD01/gtk+3.0-3.24.20/debian/build/deb“ wird verlassen
dh_auto_test: error: cd debian/build/deb && make -j4 check VERBOSE=1 -k check -j1 returned exit code 2
make[1]: *** [debian/rules:209: override_dh_auto_test] Fehler 25
make[1]: Verzeichnis „BUILD01/gtk+3.0-3.24.20“ wird verlassen
make: *** [debian/rules:135: binary] Fehler 2
dpkg-buildpackage: Fehler: Unterprozess debian/rules binary lieferte Exitstatus 2
debuild: fatal error at line 1182:
My System is Ubuntu 20.04.3 Mate 1.26.0 Kernel Linux 5.4.0-91-generic x86_64 libgtk-3-0 3.24.20
Maybe this is of interest: sudo apt build-dep libgtk-3-0 --> source "gtk+3.0" is chosen instead of libgtk-3-0
Whatever the problem may be, it appears not to be particular to my patch; it appears the code compiled just fine, but the "test suite" failed to run.
Unfortunately, I can't deduce much more than that from the output that you showed me. Can you scan up a few more lines and copy more of the build log -- perhaps at least 25 more lines above, or as many as you can get if there are fewer than 25 lines above? That would be great if you could do that. I think we can make this work if you show me more of the output.
Thanks for not getting discouraged by the lack of success of the second compilation! I'm looking forward to seeing more of the build output.
No reason to get discouraged - I'm a tinkerer 
At the moment Caja doesn't work any more. I think you are right that the testsuite failed. I startet a new patch and send you here the last few lines of 850 with FAIL:
FAIL
GTester: last random seed: R02Scda9c8cc829b7f1e7bfb7e5789fb14b0
(pid=427488)
/home/rw/BUILD01/gtk+3.0-3.24.20/testsuite/reftests/window-height-for-width.ui:
** (gtk-reftest:427488): WARNING **: 14:50:40.054: atk-bridge: Couldn't listen on dbus server: In D-Bus address, character '+' should have been escaped
FAIL
GTester: last random seed: R02S064f6fb8680616a6216e03debb94f301
(pid=427505)
/home/rw/BUILD01/gtk+3.0-3.24.20/testsuite/reftests/window-show-contents-on-map.ui:
** (gtk-reftest:427505): WARNING **: 14:50:40.302: atk-bridge: Couldn't listen on dbus server: In D-Bus address, character '+' should have been escaped
FAIL
GTester: last random seed: R02S0afa753eeb7bd04f350220c7c2d704ae
(pid=427522)
FAIL: gtk-reftest
make[6]: *** [Makefile:1741: test-cwd] Fehler 1
make[6]: Das Ziel „check-local“ wurde wegen Fehlern nicht aktualisiert.
make[6]: Verzeichnis „/home/rw/BUILD01/gtk+3.0-3.24.20/debian/build/deb/testsuite/reftests“ wird verlassen
make[5]: *** [Makefile:1569: check-am] Fehler 2
make[5]: Verzeichnis „/home/rw/BUILD01/gtk+3.0-3.24.20/debian/build/deb/testsuite/reftests“ wird verlassen
make[4]: *** [Makefile:1571: check] Fehler 2
make[4]: Verzeichnis „/home/rw/BUILD01/gtk+3.0-3.24.20/debian/build/deb/testsuite/reftests“ wird verlassen
Making check in tools
make[4]: Verzeichnis „/home/rw/BUILD01/gtk+3.0-3.24.20/debian/build/deb/testsuite/tools“ wird betreten
make check-local
make[5]: Verzeichnis „/home/rw/BUILD01/gtk+3.0-3.24.20/debian/build/deb/testsuite/tools“ wird betreten
** (gtester:427547): WARNING **: 14:50:40.556: Deprecated: Since GLib 2.62, gtester and gtester-report are deprecated. Port to TAP.
Yesterday, after reinstalling a systembackup I installed patch#1 again and Caja worked as it should be. Starting my computer today Caja again is not working.
I also installed UM 20.10 on a new HD. Both patches worked and Caja was running smoothly! Seems to me I better upgrade... 
NO! Today the same problem. Caja not working. 
So even Caja won't start?? Wow. Did I really botch things up that bad?
Is there anything related to Caja in your ~/.xsession-errors file:
grep -i 'caja' ~/.xsession-errors
Also look in:
journalctl | grep -i caja
The latter might contain more details if Caja "segfaulted" or otherwise crashed.
I had neither problem with 21.04, 21.10, Debian Bookworm, or my Gentoo installation. That's a pity that it doesn't work for you. 
Hope this helps. 
at fully patched caja UM 20.10:
error if I try to open:
Dec 28 20:12:45 rw-desktop kernel: [ 348.755102] traps: caja[1967] trap int3 ip:7fd6f305166f sp:7ffd12d7f8f0 error:0 in libglib-2.0.so.0.6800.4[7fd6f3012000+8d000]
.xsession-errors
(caja:2654): Gtk-WARNING **: 12:17:15.823: Failed to register client: GDBus.Error:org.gnome.SessionManager.AlreadyRegistered: Unable to register client
(caja:2654): GLib-GIO-ERROR **: 12:17:22.136: Settings schema 'org.mate.caja.window-state' does not contain a key named 'start-with-extra-pane'
(caja:3910): Gtk-WARNING **: 12:17:26.822: Failed to register client: GDBus.Error:org.gnome.SessionManager.AlreadyRegistered: Unable to register client
(caja:3910): GLib-GIO-ERROR **: 12:17:29.123: Settings schema 'org.mate.caja.window-state' does not contain a key named 'start-with-extra-pane'
(caja:3952): Gtk-WARNING **: 12:17:29.332: Failed to register client: GDBus.Error:org.gnome.SessionManager.AlreadyRegistered: Unable to register client
(caja:3952): GLib-GIO-ERROR **: 12:17:31.924: Settings schema 'org.mate.caja.window-state' does not contain a key named 'start-with-extra-pane'
(caja:4563): Gtk-WARNING **: 12:17:35.842: Failed to register client: GDBus.Error:org.gnome.SessionManager.AlreadyRegistered: Unable to register client
(caja:4563): GLib-GIO-ERROR **: 12:17:37.053: Settings schema 'org.mate.caja.window-state' does not contain a key named 'start-with-extra-pane'
(caja:4753): Gtk-WARNING **: 12:17:37.319: Failed to register client: GDBus.Error:org.gnome.SessionManager.AlreadyRegistered: Unable to register client
rw@rw-desktop:~$ journalctl --since=yesterday | grep -i caja
Dez 27 11:34:26 rw-desktop dbus-daemon[1647]: [session uid=1000 pid=1647] Activating via systemd: service name='org.freedesktop.portal.Desktop' unit='xdg-desktop-portal.service' requested by ':1.26' (uid=1000 pid=1955 comm="/usr/bin/caja " label="unconfined")
Dez 27 11:49:29 rw-desktop polkitd(authority=local)[928]: Operator of unix-session:c2 successfully authenticated as unix-user:rw to gain ONE-SHOT authorization for action com.ubuntu.pkexec.gdebi.gtk for unix-process:1955:1524 [/usr/bin/caja] (owned by unix-user:rw)
Dez 27 11:53:56 rw-desktop polkitd(authority=local)[928]: Operator of unix-session:c2 successfully authenticated as unix-user:rw to gain ONE-SHOT authorization for action com.ubuntu.pkexec.gdebi.gtk for unix-process:1955:1524 [/usr/bin/caja] (owned by unix-user:rw)
Dez 27 12:17:15 rw-desktop dbus-daemon[2114]: [session uid=1000 pid=2114] Activating via systemd: service name='org.freedesktop.portal.Desktop' unit='xdg-desktop-portal.service' requested by ':1.26' (uid=1000 pid=2654 comm="/usr/bin/caja " label="unconfined")
Dez 27 12:17:22 rw-desktop kernel: traps: caja[2654] trap int3 ip:7f729651666f sp:7ffe97d7d570 error:0 in libglib-2.0.so.0.6800.4[7f72964d7000+8d000]
Dez 27 12:17:29 rw-desktop kernel: traps: caja[3910] trap int3 ip:7fba8a27666f sp:7ffdeadce1a0 error:0 in libglib-2.0.so.0.6800.4[7fba8a237000+8d000]
Dez 27 12:17:31 rw-desktop kernel: traps: caja[3952] trap int3 ip:7f031e99166f sp:7ffde62e69c0 error:0 in libglib-2.0.so.0.6800.4[7f031e952000+8d000]
Dez 27 12:17:37 rw-desktop kernel: traps: caja[4563] trap int3 ip:7fa7877fc66f sp:7ffff740f670 error:0 in libglib-2.0.so.0.6800.4[7fa7877bd000+8d000]
Dez 27 12:17:45 rw-desktop whoopsie-upload-all[3947]: Collecting info for /var/crash/_usr_bin_caja.1000.crash...
Dez 27 12:17:45 rw-desktop whoopsie-upload-all[3947]: Marking /var/crash/_usr_bin_caja.1000.crash for whoopsie upload
Dez 27 12:17:45 rw-desktop whoopsie[1300]: [12:17:45] Parsing /var/crash/_usr_bin_caja.1000.crash.
Dez 27 12:17:45 rw-desktop whoopsie[1300]: [12:17:45] Uploading /var/crash/_usr_bin_caja.1000.crash.
Dez 27 12:17:45 rw-desktop whoopsie-upload-all[5181]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 27 12:17:45 rw-desktop whoopsie-upload-all[5184]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 27 12:17:45 rw-desktop whoopsie-upload-all[5186]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 27 12:17:45 rw-desktop whoopsie-upload-all[5188]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 27 12:17:45 rw-desktop whoopsie-upload-all[5190]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 28 11:02:13 rw-desktop whoopsie[1430]: [11:02:13] Parsing /var/crash/_usr_bin_caja.1000.crash.
Dez 28 11:02:13 rw-desktop whoopsie[1430]: [11:02:13] Uploading /var/crash/_usr_bin_caja.1000.crash.
Dez 28 11:02:13 rw-desktop whoopsie-upload-all[1431]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 28 11:02:13 rw-desktop whoopsie-upload-all[1633]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 28 11:02:13 rw-desktop whoopsie-upload-all[1635]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 28 11:02:13 rw-desktop whoopsie-upload-all[1637]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 28 11:02:13 rw-desktop whoopsie-upload-all[1639]: /var/crash/_usr_bin_caja.1000.crash already marked for upload, skipping
Dez 28 11:02:46 rw-desktop dbus-daemon[1729]: [session uid=1000 pid=1729] Activating via systemd: service name='org.freedesktop.portal.Desktop' unit='xdg-desktop-portal.service' requested by ':1.23' (uid=1000 pid=2050 comm="/usr/bin/caja " label="unconfined")
Dez 28 11:03:23 rw-desktop kernel: traps: caja[2050] trap int3 ip:7fa4e48ac66f sp:7ffe6b785870 error:0 in libglib-2.0.so.0.6800.4[7fa4e486d000+8d000]
Dez 28 11:03:53 rw-desktop kernel: traps: caja[2474] trap int3 ip:7f31758a066f sp:7ffc21a70240 error:0 in libglib-2.0.so.0.6800.4[7f3175861000+8d000]
At the end of the build process, multiple package files (files that end in *.deb) should have been created. Did you install all of them? Because if you do not, and you just install the caja package, there is another package (caja-common) that you built that also needs to be installed. That caja-common package contains the preferences data for Caja, and if it's not installed, Caja will probably crash mysteriously.
Sorry. I know that wasn't obvious; I'll update my guide so that point is clearer.
Thank you for your patience, dear Gordon!
No, the guide is very clear. Yesterday following your great guidance I installed with ../*.deb. It worked well also after restart. Today the same - Caja not working. You are right, caja common was missing! I now installed it again (?) by running the debs. Now caja works - I hope also after restart.
Still patch #2 makes no deb files. But maybe it was also about missing caja common? I will also try now again to make it.
Made another build process with patch#2. No package.
This is a list of the first fails:
touch testsuite/reftests/button-wrapping.ui.known_fail
touch testsuite/reftests/cellrenderer-pixbuf-stock-rtl.ui.known_fail
touch testsuite/reftests/flipping-icons.ui.known_fail
touch testsuite/reftests/label-sizing.ui.known_fail
touch testsuite/reftests/label-wrap-justify.ui.known_fail
touch testsuite/reftests/quit-mnemonic.ui.known_fail
touch testsuite/reftests/symbolic-icon-translucent-color.ui.known_fail
touch testsuite/reftests/window-height-for-width.ui.known_fail
TEST: display... (pid=315085)
display-im6.q16: unable to open image `--quiet': Datei oder Verzeichnis nicht gefunden @ error/blob.c/OpenBlob/2874.
display-im6.q16: no decode delegate for this image format `' @ error/constitute.c/ReadImage/560.
display-im6.q16: unable to open image `--keep-going': Datei oder Verzeichnis nicht gefunden @ error/blob.c/OpenBlob/2874.
display-im6.q16: no decode delegate for this image format `' @ error/constitute.c/ReadImage/560.
display-im6.q16: unrecognized option `-m=quick' @ error/display.c/DisplayImageCommand/1414.
FAIL: display
ubprocess:
** (gtester:315178): CRITICAL **: 12:46:44.773: test_log_msg: assertion 'testcase_open == 0' failed
OK
/tests/cellview-new: OK
/tests/cellview-new-with-context: OK
/tests/cellview-object-new: OK
/tests/cellview-subclass0: OK
/tests/cellview-subclass1: OK
/tests/cellview-subclass2: OK
/tests/cellview-subclass3: /tests/cellview-subclass3/subprocess:
** (gtester:315178): CRITICAL **: 12:46:44.826: test_log_msg: assertion 'testcase_open == 0' failed
OK
/tests/column-new: OK
/tests/column-new-with-area: OK
/tests/column-object-new: OK
/tests/column-subclass0: OK
/tests/column-subclass1: OK
/tests/column-subclass2: OK
/tests/column-subclass3: /tests/column-subclass3/subprocess:
** (gtester:315178): CRITICAL **: 12:46:44.882: test_log_msg: assertion 'testcase_open == 0' failed
OK
/tests/completion-new: OK
/tests/completion-new-with-area: OK
/tests/completion-object-new: OK
/tests/completion-subclass0: OK
/tests/completion-subclass1: OK
/tests/completion-subclass2: OK
/tests/completion-subclass3: /tests/completion-subclass3/subprocess:
** (gtester:315178): CRITICAL **: 12:46:44.944: test_log_msg: assertion 'testcase_open == 0' failed
OK
** (/home/rw/BUILD01/gtk+3.0-3.24.20/debian/build/deb/testsuite/gtk/.libs/defaultvalue:315370): WARNING **: 12:46:48.655: atk-bridge: Couldn't listen on dbus server: In D-Bus address, character '+' should have been escaped
cleaning up pid 315384
FAIL: defaultvalue
TEST: gtkmenu... (pid=315477)
/gmenu/bind:
** (/home/rw/BUILD01/gtk+3.0-3.24.20/debian/build/deb/testsuite/gtk/.libs/gtkmenu:315477): WARNING **: 12:46:49.414: atk-bridge: Couldn't listen on dbus server: In D-Bus address, character '+' should have been escaped
FAIL
GTester: last random seed: R02S0ab77029c49508d75cd194f3a129d642
(pid=315492)
FAIL: gtkmenu
TEST: icontheme... (pid=315506)
/icontheme/basics: OK
/icontheme/lookup-order: OK
/icontheme/generic-fallback: OK
/icontheme/force-symbolic: OK
/icontheme/force-regular: OK
/icontheme/rtl: OK
/icontheme/symbolic-single-size: OK
/icontheme/svg-size: OK
/icontheme/size: OK
/icontheme/builtin: OK
/icontheme/list: OK
/icontheme/async:
** (/home/rw/BUILD01/gtk+3.0-3.24.20/debian/build/deb/testsuite/gtk/.libs/icontheme:315506): WARNING **: 12:46:49.757: atk-bridge: Couldn't listen on dbus server: In D-Bus address, character '+' should have been escaped
FAIL
GTester: last random seed: R02S5b00891a9c181893d02638149ad31966
(pid=315524)
/icontheme/inherit: OK
/icontheme/nonsquare-symbolic: OK
FAIL: icontheme
Very strange. Again made both patches under UM 20.10 and Caja works flawlessly! Why not in 20.04? I wish I had more background knowlege like you.
I also tried the 20.10 debs in 20.04 but there are unfulfilled dependencies.
Really strange stuff happening here!
Though, I will note that Ubuntu MATE 21.10 has MATE 1.26 officially, whereas Ubuntu MATE 20.10 needs the Fresh MATE PPA installed in order to get MATE 1.26. Maybe every time a system update is done, your patched version of some (but not all) of the Caja packages are getting removed? I dunno. It doesn't make sense.
Maybe I'll see if I can convince somebody in the Debian / Ubuntu MATE project to apply my patch to Caja 1.26 officially in 21.10, or maybe I can convince @Wimpy to apply the patch to the Fresh MATE PPA. This is supposed to be a bugfix, and I have submitted it "upstream" to the developers of Caja themselves now:
Reasonably decision for me: update to UM 20.10. So we have brought it to full success! All works smoothly. Patch #1 I had to do twice, because Mate did what you supposed: Caja-common gir1.2-caja gir1.2-caja-2.0 libcaja-extension-dev libcaja-extension1 where immediatly "updated".
Thank you so much, dear Gordon! I want to express my gratitude - any idea?
Anything new about the folder opening issue?
I was waiting to deal with the folder opening issue until we figured out what was wrong with the other patches, but now that that's taken care of, I can start work on the folder opening issue.