CoolTerm for Linux feedback: Autoscroll

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DavidH
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Joined: Tue Jan 12, 2016 3:18 am

CoolTerm for Linux feedback: Autoscroll

Post by DavidH »

Dear Mr. Meier,

Thank you for CoolTerm, for giving it away for free, and for making a Linux version. Out of the dozen-or-so terminal emulators I've tried, CoolTerm is the only one with which I've been able to successfully connect to my serial device. It also appears the only one that allows me to connect with the RTS and DTR flags off from the start, so, again, thank you!

That said, under Linux Mint, the Autoscroll feature in version 1.45 (the only one I've tried) has an Autoscroll bug that causes some outrageously annoying behavior that I'll explain as best I can:

Let's assume the window can fit ~9.7 lines of output (this appears to be the minimum size I can set the CoolTerm window to). With Autoscroll active, and as long as the window isn't full, everything behaves as expected.

However, when the first thing on line 10 is printed (which is when a vertical scrollbar appears), the window doesn't scroll, so line 10 is only partially visible (hence ~9.7).

When the next thing is printed, the window scrolls to the bottom, revealing the bottom-most line in full.
When the next thing is printed, the window scrolls to the top.
When the next thing is printed, the window scrolls to the bottom again.

The window will then keep alternating between scrolling to the top and scrolling to the bottom for each new message that is printed, and the scroll bar will follow. At first, I thought this was related to newlines, but it's not - a message can contain 0 newlines or several, and the behavior will be the same.

This probably doesn't happen on other platforms than mine, or you would have heard about it, but it does on mine, and it gives me a headache :( I depend on CoolTerm (or an alternative, which, as I mentioned, I'm unable to find) in my work, and wish to help in any way I can to solve this problem.
DavidH
Posts: 6
Joined: Tue Jan 12, 2016 3:18 am

Re: CoolTerm for Linux feedback: Autoscroll

Post by DavidH »

Turns out the same thing happens in Ubuntu 15.04 as well.

I've also checked on both Windows and Mac, and there, Autoscroll works well. And if it didn't, I'm sure you would know about it already, I just wanted to see for myself :)
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roger
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Re: CoolTerm for Linux feedback: Autoscroll

Post by roger »

Hi David,

thanks for your post. I only have limited access to Linux for testing, but I will try and see if I can replicate what you're seeing. For the most part, I'm at the mercy of the controls that the OS provides. The autoscroll feature is a built-in feature of the text control I'm using to display text. Mac and Windows seem to be supporting this well. If it doesn't behave the same in Linux, I may have to code this manually. I'll see what I can do. Stay tuned.

Roger
DavidH
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Joined: Tue Jan 12, 2016 3:18 am

Re: CoolTerm for Linux feedback: Autoscroll

Post by DavidH »

Thanks for the reply.
I only have limited access to Linux for testing
I can completey understand that you don't want to spend all your time maintaining your software on three different platforms (especially since "Linux" can mean just about anything), but I have to ask: Are you familiar with virtual machines? Using e.g. VirtualBox (which is free) you can install e.g. Ubuntu (also free, and arguably one of the most common forms of Linux) inside your OSX/Windows, without messing with your original OS and having to dual-boot or any such thing. This would probably make things easier for you, especially for testing things like GUIs. If you need any help getting started, just ask.
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roger
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Re: CoolTerm for Linux feedback: Autoscroll

Post by roger »

Yes, virtual machines using VirtualBox is basically all I have at my disposal for testing. I have been able to verify GUI improvements I made that way. I have Ubuntu, CentOS, and Mint running as virtual machines. This works for simple stuff like testing GUI and making sure that CoolTerm even starts, which has been a pain since it requires libraries that are not installed on 64-bit systems by default. I have been able to get it running on all three distributions, though. Verifying actual serial port functionality in a virtual machine is a bit different, and I haven't delved into getting that working yet. Linux is a currently a moving target with the IDE I'm using to develop CoolTerm, and everytime the IDE is updated, I most likely will have to go through the exercise with the missing libraries again, which is why I dread testing with Linux. Compared to the Mac and Windows user base, the Linux user base is extremely tiny. I therefore need to focus mostly on getting Mac and Windows working properly. However, and since I'm somewhat of a beginner with regard to Linux, I do appreciate feedback from advanced Linux users such as yourself as it allows me to look at specific issues that have been reported as not working rather than trying to verify everything each time I compile a new binary. So, please keep the feedback coming.

Roger
DavidH
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Joined: Tue Jan 12, 2016 3:18 am

Re: CoolTerm for Linux feedback: Autoscroll

Post by DavidH »

I'm not a terribly advanced Linux user, to be honest :)
Yes, virtual machines using VirtualBox is basically all I have at my disposal for testing.
They should be all you need, as long as you stay away from OpenGL. That's my experience, at least!
Verifying actual serial port functionality in a virtual machine is a bit different, and I haven't delved into getting that working yet
Well, for what it's worth, I've been using CoolTerm inside a virtual machine to connect to a serial device over USB, and have had no problems (except the GUI and autoscroll things). Like I mentioned in the first post, virtual machine or not, CoolTerm is the only thing I've been able to use to connect to my device at all.
I therefore need to focus mostly on getting Mac and Windows working properly.
I totally understand. Thanks for even bothering making a Linux port! It's just too bad it has this autoscroll bug, because it makes it so much more difficult (and annoying) to use. It falls on the finish line, so to speak.

I wonder if it's a bug in the library you're using, or if maybe there's some flag somewhere that needs to be set for it to work properly in Linux, but that can be left alone on the other systems. I can't imagine you would have to make your own text box just to get this working, there has to be an easier way. Perhaps you could make a much smaller/simpler application that only outputs some text in a box, that reproduces this behavior (scroll bug in Linux, but not Windows/OSX) that you could demonstrate to the Xojo developers, along with its source code (without having to reveal any of the CoolTerm source code), and maybe they can help figure out what's wrong?
DavidH
Posts: 6
Joined: Tue Jan 12, 2016 3:18 am

Re: CoolTerm for Linux feedback: Autoscroll

Post by DavidH »

Looks like this was fixed in 1.4.6. Thanks!
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