SlicerT: improve mouse pointer logic with related visual enhancement

[dirk-de-bugger]

Hello,

I provide this patch in hope of it being usefull.

The loop in SlicerT's SlicerTWaveform::updateClosest currently picks the last slice point in range of the mouse pointer. This change makes it pick the closest one. Since (as fr as I observed) the list is sorted the loop can be exited if the distance starts to get bigger again.

I also find it hard to see the difference between light gray and white I also changed the highlight color to a more distinct one. (I need to figure out how to detect when the mouse leaves the area to clear the highlight.)

Please excuse any indentation issues. I made more changes (currently for my own benefit) and created this branch/PR with the Github online editor.

Regards,
Dirk

[qnebra]

Color change looks good and have more contrast than previous color, despite worries of author it properly clears to default.

Regardless changes in workflow, I don't have issues and slices at cursor centre are higlighted, not those on right edge of cursor. So, it fixes minor annoyance with SlicerT, got better colors.

So, approved after functional review. Will leave code review to someone with better understanding of code.

[RoxasKH]

Can we have a screenshot? Just for reference
Looking at the code i'm assuming the bar gets yellow when selecting a slice marker

Honestly in the design i made at that time i didn't even know there was a marker selected state

[qnebra]

Can we have a screenshot? Just for reference Looking at the code i'm assuming the bar gets yellow when selecting a slice marker

It is red. QColor use RGB values, judging from code and highlighted line being red in test.

[dirk-de-bugger]

Thank you for considering my change.
This is what it looks like:

[RoxasKH]

Can we have a screenshot? Just for reference Looking at the code i'm assuming the bar gets yellow when selecting a slice marker

It is red. QColor use RGB values, judging from code and highlighted line being red in test.

My bad, i meant red, i misread it as 255, 255, 0 someway. That red is quite a strong color (just like any "ms paint" color) and out of LMMS palette (mentioned here #3534). Not that the purple tones i used in SlicerT are, but it might be a good idea to tone it down a bit, while maintaning a good contrast, or find some other color that fits.

Examples of a slightly toned down red or orange. I've tried shades of green/blue too but they just don't match well and yellow is definitely too bright so the intuition here is right.

Red	Orange

Honestly speaking tho, it's the first time i think i see a selected marker state on a slicer. I believe usually the slice is the subject of selection, i'm wondering what's the need for the last indicator that has been touched to be recognizable.

[RoxasKH]

Thank you for considering my change. This is what it looks like:

Whoops, thanks a lot for the screenshot, i was writing my answer while you posted yours, so i missed it, i appreciate it

[dirk-de-bugger]

I made the red a little darker
static QColor s_sliceHighlightColor = QColor(200, 50, 50);
and added handling of the leaveEvent, so to remove the highlight when the mouse pointer leaves the waveform area:

Bildschirmaufnahme.2025-02-22.221929.mp4

Should I add the changes to my branch of this PR or create a new PR?

void SlicerTWaveform::leaveEvent(QEvent *event)
{
    m_closestObject = UIObjects::Nothing;
    m_closestSlice = -1;
    updateCursor();
    drawSeeker();
    drawEditor();
    update();
}

[qnebra]

Or just add as new commit, then maybe change pull request name to something more general but still about changes in SlicerT.
I don't know, something like maybe
"SlicerT: visual fixes, mouse pointer logic changes"