can't set background color for terminal

[cdepillabout]

@LSLeary implemented the ability to set the colors for the terminal in #28.

However, it looks like there is a problem with setting the background color of the terminal. He's not sure whether this is a problem in his own code, or gi-vte, or the VTE library itself.

[cdepillabout]

After doing a little investigation into this, we don't think that it is a problem with the Termonad code, or the gi-vte library (since it is a relatively thin wrapper), but instead with the VTE library.

It would be a good idea to testing this out with the latest version of the VTE library and seeing if it still doesn't work. This should be relatively easy using nix.

If it is still broken, then we should create an issue on the VTE repo reporting it and asking what to do here.

In the meantime, the documentation for Termonad.Config should be updated to show that the background can actually be set by passing Nothing for the background argument in order to use the very first element of the palette array as the background color.

[dakotaclemenceplaza]

Hi, it seems nobody is working on this as well as well as on #73. I've looked into this code

  terminalSetColors vteTerm Nothing Nothing . Just
    =<< traverse toRGBA (paletteToList . palette $ colourConf)
  -- PR #28 / issue #29: Setting the background colour is broken in gi-vte or VTE.  If
  -- this next line is called, then you are no longer able to set the
  -- background color using the palette.
  -- terminalSetColorBackground vteTerm =<< toRGBA (backgroundColour colourConf)
  terminalSetColorForeground vteTerm =<< toRGBA (foregroundColour colourConf)

The problem seems to be that even if you don't specify backgroundColor in your config it just sets the colour from default config which happens to be black. If you put terminalSetColorBackground before terminalSetColors then you can use palette because it will overwrite background color. Isn't it just the matter of order? terminalSetColorForeground works the same way. You have three different ways to specify color for background - default, specific and through the palette and the last one overwrites everything.

[cdepillabout]

@dakotaclemenceplaza Thanks a lot for looking into this.

How would you recommend fixing it? Just switching the order to terminalSetColors and terminalSetColorBackground/terminalSetColorForeground? Or maybe you're saying that you can either use terminalSetColors OR terminalSetColorBackground, but using both doesn't work?

Would you be able to send a PR fixing this? (And hopefully updating the datatype and documenation on ColourConfig as needed?)

[dakotaclemenceplaza]

I'm not sure yet how exactly to make it better, at the very least the point is to use default config only if there are no others. I'll try to think about it more and then fix it.

[dakotaclemenceplaza]

I sent the PR.
The bug was even more subtle. My first goal was to add transparency so I was adding some code that eventually helped me to catch it. In addition to the order, when you set background color you create newZeroRGBA which has alpha and defaults to 0 meaning that color becomes completely transparent and non-visible, but at the same time transparency wasn't working and it just resulted in a black background. At least I think it was that.