Normalize guides rotation angles to positive values

[prkos]

Several users noticed inconsistencies in angle values being positive or negative. The numbers are correct technically, as you can calculate the angle from X axis clockwise or anti-clockwise. But from the usability perspective this can be a bit confusing and not convenient if you need to calculate in your head or take more steps to get to the desired value format.

The sign seems to depend on the pointer position when releasing the guide after rotation. If the pointer is above the guide origin the number is positive, if below the origin the sign is negative.

For example, a new guide is created at 45°. It is rotated clockwise by grabbing it at the top right and dragging downwards until it locks at -45°, and the guide settings are showing -45°. If the guide is then rotated by 180° by dragging from bottom right to top left, the angle is showing 135°.

It seems that the quadrants acceptable for angle values are first, second and fourth. But it might be more usable if only the first and second quadrants are considered and the angle is always displayed as a positive value. The value would always show 135° and never -45° in the above example.

One other usability comment: the angle value shown in the statusbar is being rounded to a whole number, which can give false confidence that snapping was correct when it wasn't.

[LucaDC (lucadc)]

Hi prkos,
I often use negative angles when drawing symmetric shapes, like +20° and -20° so the I-II quadrant convention (as you call it) would be inconvenient for me. This is only an example to say that the solution to the problem is not straightforward as the different conventions are all useful.
Also, one may prefer to see the III quadrant going from 180° to 270° rather than from -180° to -90° (and the IV from 270 to 359.9999...); or even have a clockwise positive going...
IMHO this is not really a point on general usability because it depends too much on what kind of drawings you're making and on the way you're used to think angles. You may have heard complaints about perceived inconsistencies but consider that users that don't find inconsistencies usually don't speak.

The only effective way I see to solve this issue could be to add an option on how angles should be displayed, giving some predefined choices (there are not so many, I think). Otherwise, the current implementation (that considers the point you drag in four quadrants ranging from -180° to 180°) seems the more natural and accurate to me.

Or maybe another simpler solution could be to add a button in the guides dialog to rotate the guide by 180° (ranging from -180° to 180°) so one could quickly adjust the displayed angle value to the preferred quadrant and convention.

+1 to have fractional digits (at least 1 or 2) shown in the status bar but I'd open a new report for this to give its own traceability (but first check if it already exists because I have some reminiscence).