[Merged] PR #4361: Add tooltip to f(x) when there is no expression

[chennes]

PR 4361

This PR comes from a suggestion by @luzpaz on Gitter, so there hasn't been any discussion of it here, as far as I am aware. There were several different ways this could have been implemented, so if you have any thoughts we can discuss it here.

At first it seemed very innocuous: just adding a tooltip to the little f(x) symbol where you click to access the formula. The old behavior was that there was no tooltip if there was no expression, and the expression itself as the tooltip if there was. This PR adds a tooltip ("Enter an expression...") when there is no expression, and adds "Expression: " to the beginning of the tip when there is one (that was suggested by @kisolre).

I say "at first" because it turns out that the code for displaying that symbol and handling the tooltip is duplicated in five different classes spread out over three files. I could not bring myself to hardcode those strings in everyplace they would be needed, considering that it's very possible that the wording will be changed either now or in the future. So instead I added a new function to the ExpressionLabel class that encapsulates the new behavior. Unfortunately, doing so means I had to litter the code with dynamic casts, because we are storing a QLabel*, not an ExpressionLabel*.

I think once we begin the 0.20 development cycle I'd like to revisit this and do some refactoring to eliminate all the duplicated code, and the dynamic casts, but I don't want to do that just to implement this otherwise very simple feature.

[Kunda1]

Thanks @chennes!

pinged by pinger macro

@realthunder does this PR conflict with your pending expression PR code at all?

[chrisb]

Shouldn't this better be left completely out of 0.19?

[chennes]

Shouldn't this then be left completely out of 0.19?

Yes, probably, I didn't read about the feature freeze until after I submitted the PR. My bad, sorry!

[Kunda1]

Not necessarily as this gray-area since it's part of the documentation of FC.

[realthunder]

Yes, probably, I didn't read about the feature freeze until after I submitted the PR. My bad, sorry!

I kind of implemented similar feature in my branch recently. Maybe you can take a look (main commit here, and there are a few follow ups). Most of handling of that icon is integrated into ExpressionLabel.

expr-editor2.gif (183.72 KiB) Viewed 5686 times

[chennes]

Most of handling of that icon is integrated into ExpressionLabel.

That's great, I think that was the long-term answer: I was just trying to put together a quick low-impact PR. But since I've missed the feature freeze anyway it probably doesn't matter anymore.

[chrisb]

I prefer the way of showing the expression in the value: no need to hover with the mouse, and more than one expression visible at a time.