Re: [PATCH] [PATCH] git-gui: Add hotkeys to set widget focus

[Pratyush Yadav <me@yadavpratyush.com>]

On 02/09/19 09:42PM, Bert Wesarg wrote:
> On Sun, Sep 1, 2019 at 9:37 PM Birger Skogeng Pedersen
> <birger.sp@gmail.com> wrote:
> >
> > The user cannot change focus between the list of files, the diff view and
> > the commit message widgets without using the mouse (clicking either of
> > the four widgets).
> >
> > With this patch, the user may set ui focus to the previously selected path
> > in either the "Unstaged Changes" or "Staged Changes" widgets, using
> > CTRL/CMD+1 or CTRL/CMD+2.
> >
> > The user may also set the ui focus to the diff view widget with
> > CTRL/CMD+3, or to the commit message widget with CTRL/CMD+4.
> >
> > This enables the user to select/unselect files, view the diff and create a
> > commit in git-gui using keyboard-only.
> >
> > Signed-off-by: Birger Skogeng Pedersen <birger.sp@gmail.com>
> > ---
> >  git-gui.sh | 35 ++++++++++++++++++++++++++++++++++-
> >  1 file changed, 34 insertions(+), 1 deletion(-)
> >
> > diff --git a/git-gui.sh b/git-gui.sh
> > index 5bc21b8..ce620f1 100755
> > --- a/git-gui.sh
> > +++ b/git-gui.sh
> > @@ -2495,7 +2495,7 @@ proc force_first_diff {after} {
> >
> >  proc toggle_or_diff {mode w args} {
> >         global file_states file_lists current_diff_path ui_index ui_workdir
> > -       global last_clicked selected_paths
> > +       global last_clicked selected_paths file_lists_last_clicked
> >
> >         if {$mode eq "click"} {
> >                 foreach {x y} $args break
> > @@ -2527,6 +2527,8 @@ proc toggle_or_diff {mode w args} {
> >         $ui_index tag remove in_sel 0.0 end
> >         $ui_workdir tag remove in_sel 0.0 end
> >
> > +       set file_lists_last_clicked($w) $lno
> 
> So we only remember the lno in the widget, that could mean, that we
> select the wrong file after a rescan, which shifted the previous path
> one down. Can we remember the pathname instead, and try to find this
> again in the file list?
 
I raised a similar concern. Birger's response was that it is not a 
trivial change for him, and he needs help with it. So I decided to keep 
it like it is.

But now I thought about it a bit more, and I don't think it should be 
too difficult. A quick look tells me that $file_lists should be a sorted 
list with unique entries (git-gui.sh::display_file_helper{}), so it 
shouldn't be too difficult to find a given path. display_file_helper 
does:

  set lno [lsearch -sorted -exact $file_lists($w) $path]

which should also be what we want.

I have a quick-and-dirty fix for it. Haven't tested it too well, but it 
seems to work for some basic things like removing a file and refreshing, 
and then selecting focus again. Do give it a spin. I'll send the patch 
in reply to this email.

> > +
> >         # Determine the state of the file
> >         if {[info exists file_states($path)]} {
> >                 set state [lindex $file_states($path) 0]
> > @@ -2640,6 +2642,29 @@ proc show_less_context {} {
> >         }
> >  }
> >
> > +proc select_path_in {widget} {
> 
> can we name it 'focus_and_select_path_in', as the main job ob this
> function is to focus the widget. It makes also the 'bind' command
> below more readily, because than all bind commands start with 'focus'.

Ah, I was kind of uneasy with the function name, but couldn't come up 
with a good one. This sounds all right. Another suggestion that I'd put 
out: "focus_widget". As you said, focusing a widget is the main job of 
this function. Selecting paths is secondary. IMO it should be fine to 
not have "select_path_in" in the function name because you select the 
path in the process of focusing on widget.
 
> > +       global file_lists last_clicked selected_paths ui_workdir
> 
> ui_workdir not referenced in this function

Nice catch.

> > +       global file_lists_last_clicked
> > +
> > +       set _list_length [llength $file_lists($widget)]
> > +       if {$_list_length > 0} {
> > +
> > +               set _index $file_lists_last_clicked($widget)
> 
> I have the impression that variables starting with '_' are mainly used
> as read-only global variables, see the list at line 158, and not that
> often as temporal local variables.
> 
> > +               if {$_index eq {}} {
> > +                       set _index 1
> > +               } elseif {$_index > $_list_length} {
> > +                       set _index $_list_length
> > +               }
> > +
> > +               focus $widget
> > +               set last_clicked [list $widget $_index]
> > +               set path [lindex $file_lists($widget) [expr $_index - 1]]
> > +               array unset selected_paths
> > +               set selected_paths($path) 1
> > +               show_diff $path $widget
> > +       }
> > +}
> > +
> >  ######################################################################
> >  ##
> >  ## ui construction
> > @@ -3852,6 +3877,14 @@ foreach i [list $ui_index $ui_workdir] {
> >  }
> >  unset i
> >
> > +bind . <$M1B-Key-1> {select_path_in $::ui_workdir}
> > +bind . <$M1B-Key-2> {select_path_in $::ui_index}
> > +bind . <$M1B-Key-3> {focus $::ui_diff}
> > +bind . <$M1B-Key-4> {focus $::ui_comm}
> 
> I would like to bring up a proposal: AFAICS, more or less all CTRL
> bindings have a menu entry. But it does not make sense to have a menu
> entry for these bindings. And I think we could add more bindings for
> keyboard-afine users. Thus I would like to propose to use ALT as the
> modifier for these bindings, which would give us a nice binding
> classification.
> 
> How about that?
 
FWIW, I agree with this. To add to this, it would also somewhat match 
with bindings in other programs. For example, in Firefox you can choose 
tabs 0-9 with Alt+0-9. In gnome-terminal, you can also choose tabs with 
Alt+0-9. AFAIK Chrome does this too.

My one concern is, does an Alt key exist on Mac (AFAIK it does, but I 
want to be sure)? I don't think we have any existing bindings with Alt, 
so will they work well with Macs?

-- 
Regards,
Pratyush Yadav