[PATCH] ui: add new config flag for interface selection

[Yuya Nishihara]

On Tue, 22 Dec 2015 21:30:11 -0800, Laurent Charignon wrote:
> # HG changeset patch
> # User Laurent Charignon <lcharignon at fb.com>
> # Date 1450848537 28800
> #      Tue Dec 22 21:28:57 2015 -0800
> # Node ID 3e4f77c0bd16c78f2de991b483325eef1dc6f3fb
> # Parent  fe376159a58d9b3d748b669ac011b0eed0346fea
> ui: add new config flag for interface selection
> 
> This patch introduces a new config flag ui.interface to select the interface
> for interactive commands. It currently only applies to chunks selection.
> The config can be overridden on a per feature basis with the flag
> ui.interface.<feature>.
> 
> diff --git a/mercurial/help/config.txt b/mercurial/help/config.txt
> --- a/mercurial/help/config.txt
> +++ b/mercurial/help/config.txt
> @@ -1500,6 +1500,17 @@
>  ``interactive``
>      Allow to prompt the user. (default: True)
>  
> +``interface``
> +    Select the default interface for interactive features (default: text).
> +    Possible values are 'text' and 'curses'.
> +
> +``interface.chunkselector``
> +    Select the interface for chunkselection.
> +    Possible values are 'text' and 'crecord'.
> +    This config overrides the interface specified by ui.interface.
> +    If ui.interface and ui.interface.chunkselector aren't set, we use the text
> +    interface.

I prefer new section rather than putting everything under pseudo 'ui.interface.'
sub section. For example,

  [interactive-ui]
  default = text
  chunkselector = curses

And we have to remove all of them if HGPLAIN is specified.

> diff --git a/mercurial/ui.py b/mercurial/ui.py
> --- a/mercurial/ui.py
> +++ b/mercurial/ui.py
> @@ -696,6 +696,53 @@
>              return False
>          return util.isatty(fh)
>  
> +    def interface(self, feature):
> +        '''what interface to use for interactive console features?
> +
> +        The interface is controlled by the value of `ui.interface` but also by
> +        the value of feature-specific configuration. For example:
> +        ui.interface.histedit = text
> +        ui.interface.chunkselector = crecord
> +
> +        Means that the default interfaces for commands is curses, the
> +        interface for histedit is text and the interface for selecting chunk
> +        is crecord (a curses interface).
> +
> +        Consider the following exemple:
> +        ui.interface = curses
> +        ui.interface.histedit = text
> +
> +        Then histedit will use the text interface and chunkselector will use
> +        the default curses interface (crecord at the moment).
> +        '''
> +
> +        alloweddefaultinterfaces = ("text", "curses")
> +        defaultfeaturesinterfaces = {
> +            "chunkselector": {
> +                "text": "text",
> +                "curses": "crecord"
> +            }
> +        }
> +
> +        # Default interface
> +        defaultinterface = "text"
> +        i = self.config("ui", "interface", None)
> +        if i is not None:
> +            if i not in alloweddefaultinterfaces:
> +                raise error.Abort(("Unknown interface requested %s") % i)

_("unknown interface requested %s")

> +            else:
> +                defaultinterface = i
> +
> +        # Feature-specific interface
> +        if feature not in ("chunkselector"):

("chunkselector",)

> +            raise error.Abort(("Unknown feature requested %s") % feature)

Unknown "feature" is an implementation bug. Perhaps it should raise ValueError
or something.