1149171 - Adding new toolbar buttons requires adding new prefs

Status: NEW

(DevTools :: Framework, defect)

Description

[Patrick Brosset <:pbro>]

If you want to create a new toolbar button in the devtools, you have to go through the following steps:

- create a new gcli command,
- flag your command as buttonId and buttonClass,
- create an icon for the button
- whitelist your command in toolbox.js : ToolboxButtons
- update pref devtools.toolbox.toolbarSpec to also contain the command to be executed
- *AND* create a new pref in firefox.js. For instance:

pref("devtools.command-button-mycommand.enabled", false);

The pref is ultimately used to persist the state of the toolbar button (whether it's visible in the toolbar by default or not).

Storing this in a pref is fine, but it looks like an implementation detail, and asking to create a new pref for it is bad, especially when the button is hidden by default.

The pref is used here:
https://dxr.mozilla.org/mozilla-central/source/browser/devtools/framework/toolbox.js#806

Which later does `Services.prefs.getBoolPref(pref)`.

Right now, not defining the pref will make this call fail with NS_ERROR_UNEXPECTED.

The proposal is to try/catch the getBoolPref call to avoid having to define a new pref for new toolbar buttons.
The toolbox framework should just create it itself when/if it needs to store the state of the button.

Comment 1

[Brian Grinstead [:bgrins]]

(In reply to Patrick Brosset [:pbrosset] [:patrick] from comment #0)
> The proposal is to try/catch the getBoolPref call to avoid having to define
> a new pref for new toolbar buttons.
> The toolbox framework should just create it itself when/if it needs to store
> the state of the button.

Seems reasonable to me.  Also, I notice here that in this part visibilityswitch is defaulting to true if not defined: https://dxr.mozilla.org/mozilla-central/source/browser/devtools/framework/toolbox.js#820.  I think it should be defaulting to false instead.