I found a perfect implementation of a clickable image at:
forums.limesurvey.org/forum/can-i-do-thi...-heatmap-integration

provided by tPartner.

However, I would like to keep the coordinates of all mouse clicks. How can this be achieved? What should be changed in the code?
I am using LimeSurvey version [url=https://localhost/index.php/admin/index#modalSystemInformation]3.28.2+220308[/url].
 

Modify the code in this question theme - github.com/tpartner/LimeSurvey-Image-Interest-Points-3x

I am currently using a modified version of the JavaScript code earlier provided by tPartner. See the file attached. It works well, except  that the coordinates that are obtained differ per device (desktop, smartphone) and screen shape/size. Is there a way to get a kind of absolute coordinates that are not affected by the device or screen shape/size?

 

This is wonderful.
I am using LimeSurvey Community Edition Versie 3.28.36+221102 on Xubuntu 20.04.
I copied the \interestPoints folder to /var/www/html/limesurvey/themes/question.
I created a multiple-short-text question.
Under Question theme I can choose from 'Standard' and 'inputondemand'.
But alas, 'interestPoints' does not show up there.
Do I need to do anything special in order to get 'interestPoint' to become available?

Hm,
shouldn't it be in upload/themes/question?
 
 

There is no folder 'question' in: /var/www/html/limesurvey/upload/themes.
So I created the folder myself and copied the folder interestPoints/ in it.
But the theme is still not found by LimeSurvey.

Can you give a screenshot of the complete directory path to the config.xml file in interestPoints.

The complete path is:
/var/www/html/limesurvey/themes/question/interestPoints

When figuring this out I found that the folder interestPoints and its subfolders were not readable. I changed this with 'sudo chmod a+r+x ...', and subsequently 'Interest Points' showed up in LimeSurvey. Your task brought me on the right track, thanks!

How can I set "AJAX mode" to "No"?
In the survey I went to the theme options, then in the right screen I choose 'simple options' and choose 'no' at 'inherit everything'. Then you get a lot more options, but there is no option for 'AJAX mode'. I could also not find that option under 'advanced options'.
 

In later 3.x versions, this is not necessary, AJAX mode was removed.

I added three subquestions for sign, coordinates and comment. It looks like in the attached screenshot, for each of them is an input field.
If I click on the map, nothing happens. Do I have to do anything special in addition?
 

Look for JavaScript errors in the console.