[california] Allow reducing duration of multi-day event: Bug #744147

[Jim Nelson <jnelson src gnome org>]

commit ba370f762bf4d66a9acbcb315d4eb0c357e6231b
Author: Jim Nelson <jim yorba org>
Date:   Wed Feb 11 17:58:54 2015 -0800

    Allow reducing duration of multi-day event: Bug #744147
    
    Time of day can be reduced but code didn't allow for date span
    duration to be reduced.  This provides for it.

 src/event-editor/event-editor-date-time-card.vala  |   25 ++++++++++++++++----
 .../event-editor-date-time-widget.vala             |   24 +++++++++++++++++++
 2 files changed, 44 insertions(+), 5 deletions(-)
---
diff --git a/src/event-editor/event-editor-date-time-card.vala 
b/src/event-editor/event-editor-date-time-card.vala
index c7882e0..ffd51c3 100644
--- a/src/event-editor/event-editor-date-time-card.vala
+++ b/src/event-editor/event-editor-date-time-card.vala
@@ -148,6 +148,9 @@ public class DateTimeCard : Gtk.Box, Toolkit.Card {
         
         all_day_checkbutton.active = (message.exact_time_span == null);
         
+        from_widget.user_modified = false;
+        to_widget.user_modified = false;
+        
         thaw_widget_notifications();
     }
     
@@ -207,16 +210,28 @@ public class DateTimeCard : Gtk.Box, Toolkit.Card {
     
     private void on_date_time_changed(DateTimeWidget source, DateTimeWidget other, int duration_adjustment) {
         // if From is pushed forward beyond To (or To pushed back before From), adjust the other
-        // widget to maintain the user's duration
+        // widget to maintain the user's duration ... to allow for spans to be reduced, don't auto
+        // adjust if the other was manually modified by the user (but at least make sure from is
+        // earlier than to)
         Calendar.ExactTime from_exact_time = from_widget.get_exact_time(Calendar.Timezone.local);
         Calendar.ExactTime to_exact_time = to_widget.get_exact_time(Calendar.Timezone.local);
         if (from_exact_time.compare_to(to_exact_time) >= 0) {
-            Calendar.ExactTime adjusted = source.get_exact_time(Calendar.Timezone.local)
-                .adjust_time(duration_adjustment, Calendar.TimeUnit.SECOND);
+            Calendar.ExactTime adjusted = source.get_exact_time(Calendar.Timezone.local);
+            if (!other.user_modified) {
+                // user hasn't touched the other widget, so maintain duration
+                adjusted = adjusted.adjust_time(duration_adjustment, Calendar.TimeUnit.SECOND);
+            }
+            
+            Calendar.Date new_other_date = new Calendar.Date.from_exact_time(adjusted);
+            Calendar.WallTime new_other_wall_time = adjusted.to_wall_time();
             
+            // to avoid signal cycles, freeze notifications and avoid property change notifications
+            // if new values are the same
             freeze_widget_notifications();
-            other.date = new Calendar.Date.from_exact_time(adjusted);
-            other.wall_time = adjusted.to_wall_time();
+            if (!other.date.equal_to(new_other_date))
+                other.date = new_other_date;
+            if (!other.wall_time.equal_to(new_other_wall_time))
+                other.wall_time = new_other_wall_time;
             thaw_widget_notifications();
         } else if (!source.in_time_edit) {
             // otherwise, this is the new duration to be maintained (but only adjust if not editing
diff --git a/src/event-editor/event-editor-date-time-widget.vala 
b/src/event-editor/event-editor-date-time-widget.vala
index 9849316..926206e 100644
--- a/src/event-editor/event-editor-date-time-widget.vala
+++ b/src/event-editor/event-editor-date-time-widget.vala
@@ -16,11 +16,15 @@ public class DateTimeWidget : Gtk.Box {
     public const string PROP_FLOOR = "floor";
     public const string PROP_CEILING = "ceiling";
     public const string PROP_OUT_OF_RANGE = "out-of-range";
+    public const string PROP_USER_MODIFIED = "user-modified";
     
     public bool enable_time { get; set; default = true; }
     
     public bool enable_date { get; set; default = true; }
     
+    /**
+     * Indicates one of the time-of-day controls have focus.
+     */
     public bool in_time_edit { get; protected set; default = false; }
     
     public Calendar.Date date { get; set; default = Calendar.System.today; }
@@ -37,6 +41,13 @@ public class DateTimeWidget : Gtk.Box {
      */
     public bool out_of_range { get; protected set; default = false; }
     
+    /**
+     * Set when the time or date is updated due to user manipulation of a widget.
+     *
+     * Can be reset any time by the owner of this widget.
+     */
+    public bool user_modified { get; set; default = false; }
+    
     [GtkChild]
     private Gtk.Calendar calendar;
     
@@ -167,22 +178,32 @@ public class DateTimeWidget : Gtk.Box {
         button_connector.clicked.connect(on_time_adjustment_clicked);
         
         calendar.day_selected.connect(on_calendar_day_selected);
+        calendar.day_selected.connect(on_user_modified);
         calendar.month_changed.connect(on_calendar_month_or_year_changed);
         calendar.next_year.connect(on_calendar_month_or_year_changed);
         calendar.prev_year.connect(on_calendar_month_or_year_changed);
         hour_entry.changed.connect(on_time_entry_changed);
+        hour_entry.changed.connect(on_user_modified);
         minutes_entry.changed.connect(on_time_entry_changed);
+        minutes_entry.changed.connect(on_user_modified);
     }
     
     private void disconnect_widget_signals() {
         button_connector.clicked.disconnect(on_time_adjustment_clicked);
         
         calendar.day_selected.disconnect(on_calendar_day_selected);
+        calendar.day_selected.disconnect(on_user_modified);
         calendar.month_changed.disconnect(on_calendar_month_or_year_changed);
         calendar.next_year.disconnect(on_calendar_month_or_year_changed);
         calendar.prev_year.disconnect(on_calendar_month_or_year_changed);
         hour_entry.changed.disconnect(on_time_entry_changed);
+        hour_entry.changed.disconnect(on_user_modified);
         minutes_entry.changed.disconnect(on_time_entry_changed);
+        minutes_entry.changed.disconnect(on_user_modified);
+    }
+    
+    private void on_user_modified() {
+        user_modified = true;
     }
     
     private bool on_time_adjustment_clicked(Toolkit.ButtonEvent details) {
@@ -224,6 +245,9 @@ public class DateTimeWidget : Gtk.Box {
             thaw_notify();
         }
         
+        // treat all valid changing events off the ButtonConnector as a user modification
+        on_user_modified();
+        
         return Toolkit.STOP;
     }