Here is a weird one… a while ago I created a graphic file which has several components including some sliders…. they all work fine.

If I go to add a slider… it can't be seen, and I have to click to move it to the foreground. It looks fine…

(Click to enlarge)

but if I run the program, it cannot be seen… like it does not exist.

(Click to enlarge)

If I copy an existing slider, it works just fine.

If I change into a slider box… it runs fine… change it into a slider… nope… gone… invisible.

If I create a new graphic project and drop in a slider… same thing.

What is going on???

Jerry

I have no answer but they are beautiful dials man!  8-)

 Seems all okay here.

My guess is it's a GTK theme bug.

Did you try with QT?

There are too many questions to formulate an answer.

What gtk toolkit controls theme do you use? (try changing it)

Is an Arrangement set on the panel?

Are you using latest gambas?

I thought it was because I had used a different style… so I tried QT (didn't like that one) and I tried the GTK styles… I'm certain I originally wrote it in plain Graphics.
My version on the Raspberry Pi is fine… so I guess I'll try reloading GAMBAS and see if that works.

thatbruce : If you need dials for something let me know… I have a whole thread on here somewhere where I was addressing that. I used to draw the dial, then lay the pointer over it… using math to get the angle. Then I got lazy… I Create the dial, then use an animation program to generate 100 frames as PNG images with reflections, shadows, etc. Then I create an imagebox and drop in the gauge0000.png and as you change the value it goes to gauge0100.png and looks great. I can drop a textbox in the appropriate spot to get the RPM, Temperature, whatever… works well.

I'll do a video on my channel and drop a ZIP file for you to play with if there is an interest.

These are experiments for my Wind Tunnel project:
(The video starts about 5 minutes in at the GAMBAS part.)

Jerry

Askjerry said

Then I got lazy… I Create the dial, then use an animation program to generate 100 frames as PNG images with reflections, shadows, etc. Then I create an imagebox and drop in the gauge0000.png and as you change the value it goes to gauge0100.png and looks great.

KIS (Keep It Simple), I love your creativity…  

 One way to find 'lost' components on your form is to switch to hierarchy view.
You can then select the component from the list and see where it is as the sizing guides appear even if the component is buried behind something else.
If you still can't see it, check the X/Y locations. Wouldn't be the first time I've lost something because it's at X = 10 Y = -10,000.

When you drop and drag a component to the form in the GUI, ensure that the parent container is selected first.
If you have a parent container with an transparent background then you 'think' you dropped the component on container but the parent form was selected and you dropped it on the main body. I's so easy to do.

In your specific case, I do think it is a bug of some sort but at least using the process above, you can prove to yourself that the component is on the correct parent /location.

That's just it… it is exactly where it is supposed to be.

If I go to create a new slider, it is automatically set to the back… I have to move it to the front. I upgraded and did a sudo apt-get install gambas3 so it now has version 3.18.0 which is the latest on the distro for BOOKWORM. As I stated before… on both my Raspberry Pi 3B+ and my Raspberry Pi 400, there are no issues. (However I think they are running the QT version if I remember correctly.)

On this machine… the desktop… only the slider seems to be affected. If I change it into a sliderbox it works just fine.

Set as sliderbox…

(Click to enlarge)

Set as slider…

(Click to enlarge)

Strange huh?

By the way… this is the entire program to use this method of creating a gauge… the rest is just generating the images and putting them into a folder within the project.


The multiplier in the line:  Gauge1_Text.Text = Format(Gauge1_Scroll.value * 0.14, "00.00") & " KPH"
Is because there are 250 steps to get to the max value of 35kph. (35 / 250 = 0.14) This sets the proper text.

I'll make a generic gauge and get it uploaded somewhere if you guys want to play with one.

NOTE: After the upgrade… the original program no longer works… it comes up a "read only" which means I would need to re-create all the elements, then paste the code into a mew project.

Jerry

3.18.0 Fails but 3.15.3 works just fine… no issues at all.

I really wish I could uninstall 3.18.0 and throttle back to 3.15.1 because as far as I'm concerned… it was perfect.

I'll probably see if I can save the project on a thumbdrive then clone the Pi 400 NMVe with the working version, and use that on the Wind Tunnel project.

I can't believe they haven't updated the software… or am i the only person on the planet with the issue?

It fails on the Pi B3+ and on my PC Running Linux… both have 3.18.0 installed. 

I have 100% confirmed that the older version of GAMBAS3 ( V 3.15.2 ) that exists on my Raspberry Pi 400 is the ONLY machine where the sliders work properly.

That machine is running with a 256 GB NMVe as the hard drive instead of an SD card. I may still have the original 64 GB microSD… I have to look for it. If I do, I could install that into the Raspberry Pi B3+ that I am using for the Wind Tunnel, and have it run a fully functional version of the software. But the other issue… is HOW do I get a copy of the software off the current microSD card? I tried opening the Wind Tunnel project then saving it from GAMBAS onto a thumbdrive… it looks like it is there, but then I put that drive into the Raspberry Pi 400… and I cannot see it.

GAMBAS has a horrible habbit of locking up the directory where you can't just copy, paste, cut, or otherwise change anyting in the project folder… at least on the two Rasberry Pi machines. On the Linux PC, I can do whatever I want aparently. Why does it have to screw with the drive on the Pi devices??? So damned fustrating!!!

Is there a way to tell the Pi B3+ to remove the current GAMBAS3 and replace it with the 3.15.2 version?

It's either that… or I may need to duplicate the Pi 400 drive… which means another NMVe to match the capacity… overkill for this project… but I have been working on this Wind Tunnel going on 3 years now… I REALLY do not want to have to sart over…

Seriosly… am I the ONLY person where the sliders don't work? On multiple machines?

Anyone??? 

Askjerry said

Seriosly… am I the ONLY person where the sliders don't work? On multiple machines?

Anyone??? 

From “Post #12,781”, November 2nd 2025, 5:27 PM

I have no problems with any sliders on any of my programs so yes, sorry it's just you.

I have had issues in the past from sliders being too thin.
A slider will not render if it's too small.
previously it caused warnings on some toolkits if the sliders were too small and rendered, so the fix was to not allow them to render below a certain size.

So my guess would be yours are too thin, Make them wider.

and if yr going to update gambas why not update it to the latest 3.21 not 3.18 that is 2 years old?

actually it sounds like you may have a layout problem, like the sliders are disappearing behind a panel or something.

Post a sample project with a form that has this problem and i will see if i can figure out the issue.

Bruce, you are correct.

If I drag a slider from the menu and drop it on a form, I see the dotted line where it is, but no slider, and running it… it is totally invisible.

If however I widen it up a bit… then it is normal. I had not thought about a rendering issue. I just created a QT graphics version and tried that… worked fine.

I just created a GTK graphics program… and again… invisible… until I made it wider.

Problem now resolved! Thanks Bruce… I wish I had known about that sooner… now I can get back to the rest of my programming… it's a fully automated Wind Tunnel… load cells for the vertical and horizontal loads of the wing, servo controlled angle of attack, PWM controlled turbine speed. I just got some of the PICO 2040 and 2053 series modules to experiment with… I'm going to have the Raspberry Pi query the module (serial) and have it read the TACH on the turbine, and read the pressure sensor on the PITOT tube to return RPM and wind speed so that I can log all the data. The sliders were pivitol for fan speed adjustment, servo positioning and trim, etc.

I really appciate your help!
Jerry