How do we "Fit()" the terminal when terminal is initially hidden?

[TomzBench]

It would be helpful to know how the fit addon works, Because I am having trouble getting the terminal to size correctly when the terminal is initially loaded with display: none. The terminal exists in my UI as part of a tabbed pane, which is not rendered on initial view. However, a user can click the terminal tab and the terminal will enter the view.

On the initial view of the terminal tab, the terminal overflows the height significantly. However, tabbing away and back again will then render correctly. Im not sure why that happens. I also use ReactResizable component and can resize the terminal. This part works great however, because I can use onResize events to fit() the terminal.

So my only problem is when the terminal loads initially in a hidden state, it seems to be unable to detect the heights correctly. So knowing how the fitaddon works a bit could help me figure out the best way to load my terminal into view. I am doing my best to try and call fit() when the terminal is tabbed into view but this has not been successful so far.

The docs on the fit addon are very light, it could be helpful to go over some gotchas or limitations in the fit Addon

[jerch]

You can find the addon code here: https://github.com/xtermjs/xterm.js/blob/master/addons/xterm-addon-fit/src/FitAddon.ts

[TomzBench]

Thanks.

My initially hidden terminal has 0 for dimensions from the _renderService. But after a tab navigation puts the terminal in view I call fit again. At this moment, the parentElements height is appropriately calculated. But the _renderService still claims 0 dimensions and so fit returns undefined when initially loaded into view. dims seems correct the second time around however and so re-navigating back works like normal..

[TomzBench]

I can get it to work when i call resize with some arbitrary values and then call fit.

To make this more sensible, i gave my React Terminal component an imperative handle with a method called unhide. which will internally will resize and then fit, so not to call resize every time, and only when not hidden.

Not sure if this could be a bug in the fitAddon, which does not handle uninitialized cols/rows correctly. I think instead of returning undefined when the rows/cols are unknown, you can resize and then fit