Derive selected day from selected item

Previously, with only one day visible at a time, the appointments panel
displayed the details of the day selected in the calendar (slctd_day);
information required for operations on items (day_items) can often be
derived from the selected day. The items available are derived from the
selected day. In particular, the selected item is derived from the
selected day.

With multiple days in the APP panel, the relation between selected day
(in the calendar) and the selected item (in the APP panel) has, in a
way, been turned around. The selected item may now be moved between days
without explicitly changing the selected day. Implicitly it is changed
when the target day of a move is unavailable.

This commit draws the full consequence: the selected day in the calendar
is always (set to) the day of the selected item in the APP panel.

The static variable 'struct date slctd_day' lives in ui_calendar.c and
is accessible through various public functions. To these are added
ui_calendar_set_slctd_day() which sets slctd_day directly.

The selected day retains its significance for load of the day vector (in
day_store_items()): the range of loaded days begins with the selected
day.  Movements (up/down) in the APP panel will change the selected day
as the selected item moves among the already loaded days. Only when the
target of a movement is unreachable, will further days be loaded. On the
other hand, if the same range of days must be reloaded because of a
changed item, the selected item - and with it the selected day - must be
reset to the first day item (see do_storage()).

Movements in the calendar (generic-next-day, etc.) are not affected and
behave as previously, i.e. they will cause a range of days to be loaded
with the selected day as the first and the selected item as the first of
the selected day.

Signed-off-by: Lars Henriksen <LarsHenriksen@get2net.dk>
Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/calcurse.h b/src/calcurse.h
index 3429ee2..f14b0bb 100644
--- a/src/calcurse.h
+++ b/src/calcurse.h
@@ -781,6 +781,7 @@ unsigned ui_calendar_week_begins_on_monday(void);
 void ui_calendar_store_current_date(struct date *);
 void ui_calendar_init_slctd_day(void);
 struct date *ui_calendar_get_slctd_day(void);
+void ui_calendar_set_slctd_day(struct date);
 void ui_calendar_monthly_view_cache_set_invalid(void);
 void ui_calendar_update_panel(void);
 void ui_calendar_goto_today(void);
@@ -825,7 +826,7 @@ void day_write_stdout(time_t, const char *, const char *, const char *,
 void day_popup_item(struct day_item *);
 int day_check_if_item(struct date);
 unsigned day_chk_busy_slices(struct date, int, int *);
-struct day_item *day_cut_item(time_t, int);
+struct day_item *day_cut_item(int);
 int day_paste_item(struct day_item *, time_t);
 struct day_item *day_get_item(int);
 unsigned day_item_count(int);
@@ -1176,6 +1177,7 @@ int get_item_hour(time_t);
 int get_item_min(time_t);
 struct tm date2tm(struct date, unsigned, unsigned);
 time_t date2sec(struct date, unsigned, unsigned);
+struct date sec2date(time_t);
 time_t utcdate2sec(struct date, unsigned, unsigned);
 int date_cmp(struct date *, struct date *);
 int date_cmp_day(time_t, time_t);