Snap to curve in OMEdit plot

[Per Östlund]

At the moment OMEdit shows the time and value at the mouse cursor when in plotting mode. It would be nice if it allowed the cursor to snap to a curve, so that the user can see the exact value of a variable at a certain point in time.

The feature should be togglable by the user so that it can be turned on and off as needed. It could work so that when it's on and the user moves his cursor close to one of the plotted curves a symbol is displayed on the corresponding time-point on the curve, and the variable name, time and value is displayed in a label attached to the symbol instead of the cursor. When the user moves the cursor sufficiently far away from the curve it unsnaps again. Some care needs to be taken when multiple curves are close to each other, possibly by keeping track of which curve the user is currently following and keeping to that curve until the cursor moves far enough away from that curve.

[anonymous]

Another important missing feature of OMEDIT plot windows is a way to understand which curve belongs to which output file, in case curves from different files are displayed in the same plot window.

I know that adding the file name to each curve would make the curve names too long. Therefore my proposal is to display the full name, including the file name, only when the mouse hovers on the curve name. In Qt, if the curve name is a label widget this is straightforward.
When the mouse cursor is elsewhere, to display only the names that are displayed now is ok.

[Adeel Asghar]

Done in ffd8bcc/OMPlot.

[Christoph <buchner@…>]

Great implementation, thanks! Works well from some short tests.

[Andrea Bartolini]

In case of overlapped curves only the name of the first curve is shown in the label.
If different groups of overlapped curves are present in the same graph, it is difficult to identify which curves are in a group.
To help to identify overlapped curves in a group, all the names of the overlapped curves in the same group should be shown in the label.

OMEdit 1.12.0~dev-309-g2230a75
Connected to OpenModelica 1.12.0~dev-789-g42b0038
sysop: Ubuntu 16.04

[Francesco Casella]

Rescheduled to 1.14.0 after 1.13.0 releasee

[Adeel Asghar]

Fixed in 8eee160/OpenModelica.