Track operations fixes and other stuff.

[husamalhomsi]

Fixes #3592 and other stuff.

Before	After

Changes:
• Limit the ability of moving a track to its move grip.
• Clicking the move grip of a track doesn't hide the track's mute and options buttons.
• Clicking the move grip of a track changes the move grip's image to one with white squares instead of gray.
• Changed the cursor shape that shows when moving tracks to be vertical.
• Improved the position and padding of the gear image.
• Removed the trackop_c.png and trackop_h.png files and some of their related code in the style.css file of the default theme.

[gi0e5b06]

I can only approve (as I have made the same changes in my PR, including the TODO item).

[husamalhomsi]

Could you commit the fix for the TODO item here?

[gi0e5b06]

It's here: https://github.com/gi0e5b06/lmms/blob/master/src/core/Track.cpp
Moving is limited to the grip.
I don't remember if I changed something for the drag&drop. Anyway I think it should cover the whole area, the difference being made by the mimetype.

[gi0e5b06]

Also I like the lines 1876-1880: https://github.com/gi0e5b06/lmms/blob/86a54872b9d00fbfc338f1864a903bf4d690f962/src/core/Track.cpp#L1876

if( m_trackView->isMovingTrack() )
	{
		p.setPen(Qt::red);
		p.drawLine(r.x(),r.y(),r.x(),r.y()+r.height()-1);
	}

It draws a small red line on the left border when you're moving the track.

[husamalhomsi]

Edit: added a comparison.

I tested your suggestion.

Without line	With line

The line makes the grip look crammed with the white squares, and isn't enough alone.
I think the white squares on the grip are enough.

[tresf]

Note, this prevents the previous behavior of dragging a track by "any random empty part of the track label" behavior that had been working previously.

Since no one has made a UX argument against this, and it actually fixes the drag handle, merging. If you want the old way, you'll have to argue it back. From a UI perspective we really don't allow rearranging of items like this in any other part of the software except the pattern editors, which aren't UI input elements.

Although I personally prefer a "long hold, then drag" like most modern software uses, that should be filed as a new feature.

[PhysSong]

This breaks horizontal track resizing. I think this check should be moved to below.

[PhysSong]

To here.

[husamalhomsi]

Tested. Fixes the issue as expected.

[husamalhomsi]

Direct commit or PR?

[PhysSong]

Direct commit looks fine.

[husamalhomsi]

Done via e8debf9. 👍