Added ability to change color palettes

[Seanny123]

Added a modal dialogue to choose between a variety of palettes

I meant to make this a self-contained commit, but because it plays a lot with legends and whatnot, it contains #565 and #567

[Seanny123]

@tcstewar @jgosmann if any of you are in the reviewing mood, start here

[Seanny123]

Nvm, in my efforts to rebase, I accidentally lost some code.

[Seanny123]

Ready for review again if someone is feeling ambitious/bored.

[Seanny123]

Current issues:

• Palette selection should show the palette to the right of the choice

[tcstewar]

???? Why not just do

info = dict(uid=id(self), label=self.label, 
                   n_lines=self.n_lines, synapse=0,
                   legend_labels=self.def_legend_labels)

and get rid of this whole override thing?

[Seanny123]

Because the behaviour of javascript_config is to override everything with the defaults. It doesn't look to see if the defaults have been set to anything else. Is that it's intended behaviour or should the code be changed?

[tcstewar]

I don't think I understand... all javascript_config does is go through the config entry for the item and just into a json output:

        for attr in self.config._clsparams.params:
            cfg[attr] = getattr(self.config, attr)
        return json.dumps(cfg)

what do you mean by overriding everything with the defaults?

[Seanny123]

I'll break it down why it over-writes by going through the above code with the example of legend_labels being set in dict argument to ["A", "B", "C"].

cfg is the dict I've passed in as an argument. The for-loop takes values from the default config, which is self.config._clsparams and adds it to cfg. The default config contains legend_labels = [], so when the for-loop runs, regardless of what the value that cfg has for legend_labels, it will be over-written by the default config. That is why ["A","B","C"] will be over-written to []. Does that make sense now?

[Seanny123]

It's basically equivalent to running this code:

cfg = dict(label="pants", n_lines=4, legend_labels=["A", "B", "C"])

default_conf = dict(min=-1, max=1, legend_labels=[])

for attr in default_conf.keys():
    cfg[attr] = default_conf[attr]
print(cfg)

[bjkomer]

I'm seeing the basal ganglia plots disappear when making a change in the editor, they might not be getting saved properly in the config.