A patch using select2 to implement this feature. I made tiny modifications to the select2 css file so that dropdown's are about the same height as they are without this patch.
http://ivaynberg.github.io/select2/

The patch is against 2.2.3 but a version that is also patched with zbx extras and the snmp builder, however only 3 zabbix files contain 1 or 2 extra lines, so it shouldn't really matter to apply it.

You also have to put these files in styles/ :

select2.png
select2-spinner.gif
select2x2.png

They can be found in this archive:
https://github.com/ivaynberg/select2/archive/3.4.6.tar.gz

Screenshot of the result.

ps.: The Attach Screenshot button redirects me to an oracle page hence the use of Attach Files.

It looks a little better if you add this to the bottom of select2.css:

 
.select2-container  {
    border: none;
}

.header_r .select2-container {
    margin-top: -3px;
}

.item-list-row .select2-container {
    margin-top: 6px;
}

.select2-result-label {
    line-height: 1.1em;
}

(2014-04-25 these fixes have been included in the patch currently attached to the issue)

+1
That would be an easy and nice improvement to the frontend when dealing with a large number of items.

Thanks, but I think it's best to use the vote system on the right side of the issue in the people section, so that it turns up in queries for popular issues. Given the huge impact on usability on bigger installations (we have by now over 1000 graphs on some hosts) and the availability of a patch with almost no code changes to the actual zabbix code it looks to me like a nice candidate for addition to standard zabbix.

There's still a little issue, select2 also kicks in when selecting applications for a new item but that doesn't work particularly well. I'll see if how I can fix that.

Fix for this issue, but disabled for multiselect boxes as it didn't work for those and was not very usefull anyway.
Basically multiselect can be disabled from the constructor of ccombobox.

Patch against vanilla 2.2.4.

The version I have just added is a patch against 2.2.4 as part of the RPM. It shows how little has to change in the actual zabbix code.

Interesting idea!

Two things that possibly could be improved:

• combo-box entries may wrap
• in pop-ups selection isn't visible

Fixed style.css so that selected value in drop down is visible for popups.

Marc, what exactly do you mean with 'Combo-box entries may wrap'?
If I have a very long graph name it is shown in the drop-down selection list on 2 lines so that it's entirely readable but that's expected behavior, works fine and is probably not what you're hinting at.
I do notice that when you select such very long graph name, the widget is shown on a second line, but this behavior is the same without select2 as seen in the attached screenshots. I don't think it's necessarily bad either.

image that shows combo box moves to second line both with and without select2

patch including all modified code

Files to be stored in styles/ folder.

Works fine as far as I can tell, but it is also present in some places where I would rather not have it. It doesn't really make sense on dropdowns with fixed content, e. g. severity on Monitoring/Maps.

For whatever reason it appears to be missing for "Host" on the following Configuration/Hosts entities: Graphs, Web, Triggers, Applications. I applied the patch on a 2.2.0 though, so that may cause it.

Updated version of select2 to 3.5.0 and extracted custom css (specific for zabbix) from the original select2.css file into an additional one (select2-zabbix.css) to make it possible to upgrade without having to rebase the original select2 css file everytime.

Volker, disabling it for fixed content dropdowns could be done, I have updated the CComboBox class constructor with an option $autocomplete that defaults to true, but could be set false for small dropdowns (and must be set to false for the current multiselect comboboxes.) However I am undecided if should be disabled for small comboboxes, while the feature is not required there I think the interface looks cleaner if all comboboxes have the same styling.
I hadn't noticed the missing functionality on the Configuration/Hosts entities yet. I'll have a look if I can see what's going on there.

v3 version of the patch fixes the problem where the multiselect didn't work if there are multiple html elements with the same id (hostid) on the page.

Just played around with select2 again.
What about setting 'minimumResultForSearch' to a reasonable value (e.g. 10) to prevent auto-search for small combo-boxes?

I don't know, I prefer to have the same look for all combo-boxes. While the search isn't required for small comboboxes it doesn't hurt either and it looks a little sloppy if not all combo-boxes have the same look.

That's the point.
When using the mentioned setting the look keeps the same. Just the auto-search functionality (input field) is disabled, respectively hidden:

Aah, I agree. I thought you were suggesting to add an option to zabbix that would disable calling select2 for small combo-boxes. I see now that select2 has an option to just remove the search box which does make sense.

Btw, adding ~15 17 pixels to the element width in resolveContainerWidth() of select2.js seems to prevent cutting/wrapping of values.
Don't know whether there is a less hackish way to achieve the same.

Some combo-boxes get display:inline set what leads to combo-boxes with maximum width. E.g. on item edit.
To prevent this I changed 'inline' to 'inline-block' in CViewSwitcher class (for objDisplay its default case).

Another thing I chaged was the border-radius. Setting this to 0px looks a bit more similar to the origin combo-boxes.

Yet another thing I changed was left text aligning for current selection/chosen text.

The patch in connection with iexplore 9 makes no fun when having ~1.5k elements. It's very laggy - not that I care though...

Hi,
this is almost exactly what I am looking for. Will this work on 2.4.4? And if yes how do I install this - sorry I am new to zabbix so I have no idea how to do it.

Thanks in advance

Yes it will work, but it will need some changes. I have it running on a modified version of zabbix 2.4.3 (various patches applied.) I'll try to make an updated patch for the latest stable release within 2 weeks, if I can find the time.

Thank you for reply. That sound awesome. This sort of functionality is must for us since we frequently search graphs by name. I am looking forward for updated patch.

Thanks again

Hi.
anything new regarding the patch?

Sorry, I haven't found the time due to other projects I'm working on. I will eventually make a new patch (if nobody else does it) but it will take at least a few more weeks.
Maybe have a look at the patch file in a text editor, the contents of the zip file,... and it might already be obvious to you how to make the required changes.

Hi,
have you managed to look into it?

This should work, although I haven't tested it yet.

Installation procedure pretty much goes like this:
copy the files select2.png select2-spinner.gif select2x2.png to /usr/share/zabbix/styles
copy the .patch file to your home directory

And then:
cd /usr/share
tar cvzf ~/zabbix-backup.tar.gz zabbix
cd /usr/share/zabbix
patch -p3 < ~/zabbix-2.4.6-zbxnext-2185.patch

In case something goes wrong you should be able to recover with
cd /usr/share
tar xvzf ~/zabbix-backup.tar.gz

Hi,
thanks for patch, but unfortunately it is not working for me. Is there something else that needs to be done except procedure that you described?

No, could you try to see what the javascript console in your browser says?

I get no errors. Only these two warnings:
Use of Mutation Events is deprecated. Use MutationObserver instead. telify.js:962:0
Use of getPreventDefault() is deprecated. Use defaultPrevented instead. jsLoader.php:4979:0

Any idea where is the problem?

There's no telify.js in my installation, I have no idea where you got it, but I don't think it came from zabbix or my patch.

And is this patch working for you fine?

Yes. Have you looked in your server log files?

Ok so after setting up new test machine I can see it is working. I guess in my production machine/real test machine it is not working because I installed Zabbix-Extras which are somewhat broken in their own regards.
I cant even say how happy I am to get this working, because this was major hold back for us to start replacing Nagios + Cacti with Zabbix. Hope this gets integrated into core soon.

This would be a very nice additions to installations with larger number of hosts/groups. And also make selecting much easier.
Select2 is very good, and could even improve how it looks when you have nested groups:
https://www.sitepoint.com/13-jquery-selectboxdrop-down-plugins/

Select2 is now in version 4.0.3, so I would say it is very mature and should be safe to include as it supports most browsers.
https://github.com/select2/select2/releases

I just attached a patch that can be applied to 3.0.4, if ever you were to consider this.

For those interested: Because this does not get merged in the product and I no longer wanted to patch each release I have solved this problem in the browser instead: https://github.com/jankeirse/zabbix-select2-dropdowns 

Tested with zabbix 4.0.5. Advantage: far easier to deploy than patching the server. Should be largely version independent. Disadvantage: every zabbix user that wants it has to install it in the browser of their choice. 

I believe it is pretty much resolved in the latest 5.x. We introduced autocomplete controls (instead of long drop-downs) across all UI.