Re: [[TIG][PATCH] 1/3] Add log_select function to find commit from context in log view

[Jonas Fonseca <fonseca@diku.dk>]

On Fri, Aug 2, 2013 at 8:23 PM, Kumar Appaiah <a.kumar@alumni.iitm.ac.in> wrote:
> This commit introduces and uses the log_select function to find the
> correct commit in the unsplit log view. In the log view, if one
> scrolls down across a commit line, the current commit (as displayed in
> the status bar) gets updated, but not so when scrolling upward across
> a commit. The log_select function handles this scenario to to the

s/to to/to do/

> ``right thing''. In addition, it introduces the log_state structure as
> the private entry of the log view to hold a flag that decides whether
> to re-evaluate the current commit based on scrolling.
>
> Signed-off-by: Kumar Appaiah <a.kumar@alumni.iitm.ac.in>
> ---
>  tig.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/tig.c b/tig.c
> index 72f132a..dd4b0f4 100644
> --- a/tig.c
> +++ b/tig.c
> @@ -4384,6 +4384,33 @@ pager_select(struct view *view, struct line *line)
>         }
>  }
>
> +struct log_state {
> +       bool update_commit_ref;
> +};
> +
> +static void
> +log_select(struct view *view, struct line *line)
> +{
> +       struct log_state *state = (struct log_state *) view->private;
> +
> +       if (state->update_commit_ref && line->lineno > 1) {
> +               /* We need to recalculate the previous commit,
> +                  since the user has likely scrolled up. */

I'd prefer that state->update_commit_ref is given another name so it
won't be necessary to have these comments everywhere the field is
used, for example recalculate_commit_context. The comment could be
moved to the declaration in struct log_state to explain its use.

Multi-line comments should start with '*' for each additonal line, e.g.

  /* bla bla
   * bla bla */

> +               const struct line *commit_line = find_prev_line_by_type(view, line, LINE_COMMIT);
> +
> +               if (commit_line)
> +                       string_copy_rev(view->ref, (char *) (commit_line->data + STRING_SIZE("commit ")));

You mentioned elsewhere that this looked funny, and I guess you are
right. I will extract this into a utility method so you can simply
call: string_copy_rev_from_line(view->ref, commit_line); ...

> +       }
> +       if (line->type == LINE_COMMIT) {
> +               char *text = (char *)line->data + STRING_SIZE("commit ");
> +
> +               if (!view_has_flags(view, VIEW_NO_REF))
> +                       string_copy_rev(view->ref, text);

... and: string_copy_rev_from_line(view->ref, line);

> +       }
> +       string_copy_rev(ref_commit, view->ref);
> +       state->update_commit_ref = FALSE;
> +}
> +
>  static bool
>  pager_open(struct view *view, enum open_flags flags)
>  {
> @@ -4427,11 +4454,30 @@ log_open(struct view *view, enum open_flags flags)
>  static enum request
>  log_request(struct view *view, enum request request, struct line *line)
>  {
> +       struct log_state *state = (struct log_state *) view->private;

There's no need to cast view->private here.

> +
>         switch (request) {
>         case REQ_REFRESH:
>                 load_refs();
>                 refresh_view(view);
>                 return REQ_NONE;
> +
> +       case REQ_MOVE_UP:
> +       case REQ_PREVIOUS:
> +               if (line->type == LINE_COMMIT && line->lineno > 1) {
> +                       /* We are at a commit, and heading upward. We
> +                          force log_select to find the previous
> +                          commit above, from the context. */

Please delete this comment.

> +                       state->update_commit_ref = TRUE;
> +               }
> +               return pager_request(view, request, line);

There's not really any reason to call pager_request here, since it
only handles REQ_ENTER.

> +
> +       case REQ_MOVE_PAGE_UP:
> +       case REQ_MOVE_PAGE_DOWN:
> +               /* We need to figure out the right commit again. */

Please delete this this comment.

> +               state->update_commit_ref = TRUE;
> +               return pager_request(view, request, line);

Calling pager_request again.

> +
>         default:
>                 return pager_request(view, request, line);
>         }
> @@ -4441,13 +4487,13 @@ static struct view_ops log_ops = {
>         "line",
>         { "log" },
>         VIEW_ADD_PAGER_REFS | VIEW_OPEN_DIFF | VIEW_SEND_CHILD_ENTER | VIEW_NO_PARENT_NAV,
> -       0,
> +       sizeof(struct log_state),
>         log_open,
>         pager_read,
>         pager_draw,
>         log_request,
>         pager_grep,
> -       pager_select,
> +       log_select,
>  };
>
>  struct diff_state {
> --
> 1.8.3.2
>

-- 
Jonas Fonseca