[california/wip/725783-time] Make up/down widgets sensitive according to their valid states

[Jim Nelson <jnelson src gnome org>]

commit c94a14d979154f0cf43f8a223d1af67e70959da7
Author: Jim Nelson <jim yorba org>
Date:   Tue Aug 5 16:59:33 2014 -0700

    Make up/down widgets sensitive according to their valid states

 src/host/host-date-time-widget.vala |   79 ++++++++++++++++++++++++++--------
 1 files changed, 60 insertions(+), 19 deletions(-)
---
diff --git a/src/host/host-date-time-widget.vala b/src/host/host-date-time-widget.vala
index d715964..03f772f 100644
--- a/src/host/host-date-time-widget.vala
+++ b/src/host/host-date-time-widget.vala
@@ -32,7 +32,7 @@ public class DateTimeWidget : Gtk.Box {
      * Indicates if the widgets are filled-in with invalid values or is valid but out of the range
      * of { link floor} and/or { link ceiling}.
      */
-    public bool out_of_range { get; private set; default = false; }
+    public bool out_of_range { get; protected set; default = false; }
     
     [GtkChild]
     private Gtk.Calendar calendar;
@@ -81,20 +81,43 @@ public class DateTimeWidget : Gtk.Box {
         numeric_filter.connect_to(hour_entry);
         numeric_filter.connect_to(minutes_entry);
         
-        // use signal handlers to initialize widgets
-        on_date_changed();
-        on_wall_time_changed();
-        
-        connect_property_signals();
-        connect_widget_signals();
-        
         // specifically-enabled sensitivities
         bind_bool_to_time_controls(PROP_ENABLE_TIME, iterate<Gtk.Widget>(
             hour_up, hour_down, minutes_up, minutes_down, meridiem_up, meridiem_down,
             hour_entry, colon_label, minutes_entry, meridiem_label));
         
+        // set sensitivities for up/down widgets
+        foreach (Gtk.Widget widget in
+            iterate<Gtk.Widget>(hour_up, hour_down, minutes_up, minutes_down, meridiem_up, meridiem_down)) {
+            bind_property(PROP_DATE, widget, "sensitive", BindingFlags.SYNC_CREATE,
+                transform_adjustment_widget_to_sensitive);
+            bind_property(PROP_WALL_TIME, widget, "sensitive", BindingFlags.SYNC_CREATE,
+                transform_adjustment_widget_to_sensitive);
+            bind_property(PROP_FLOOR, widget, "sensitive", BindingFlags.SYNC_CREATE,
+                transform_adjustment_widget_to_sensitive);
+            bind_property(PROP_CEILING, widget, "sensitive", BindingFlags.SYNC_CREATE,
+                transform_adjustment_widget_to_sensitive);
+        }
+        
+        // update out_of_range when its dependencies change
+        bind_property(PROP_DATE, this, PROP_OUT_OF_RANGE, BindingFlags.SYNC_CREATE,
+            transform_to_out_of_range);
+        bind_property(PROP_WALL_TIME, this, PROP_OUT_OF_RANGE, BindingFlags.SYNC_CREATE,
+            transform_to_out_of_range);
+        bind_property(PROP_FLOOR, this, PROP_OUT_OF_RANGE, BindingFlags.SYNC_CREATE,
+            transform_to_out_of_range);
+        bind_property(PROP_CEILING, this, PROP_OUT_OF_RANGE, BindingFlags.SYNC_CREATE,
+            transform_to_out_of_range);
+        
         bind_bool_to_time_controls(PROP_ENABLE_DATE, iterate<Gtk.Widget>(calendar));
         
+        // use signal handlers to initialize widgets
+        on_date_changed();
+        on_wall_time_changed();
+        
+        connect_property_signals();
+        connect_widget_signals();
+        
         // honor 24-hour time
         Calendar.System.instance.is_24hr_changed.connect(system_24hr_changed);
         system_24hr_changed();
@@ -115,6 +138,25 @@ public class DateTimeWidget : Gtk.Box {
             bind_property(property, time_widget, "sensitive", BindingFlags.SYNC_CREATE);
     }
     
+    // Determine if the up/down adjustments should be sensitive (if they're next value is valid)
+    private bool transform_adjustment_widget_to_sensitive(Binding binding, Value source_value,
+        ref Value target_value) {
+        int amount;
+        Calendar.TimeUnit time_unit;
+        if (!adjust_time_controls((Gtk.Widget) binding.target, out amount, out time_unit))
+            return false;
+        
+        target_value = is_valid_date_time(date, wall_time.adjust(amount, time_unit, null));
+        
+        return true;
+    }
+    
+    private bool transform_to_out_of_range(Binding binding, Value source_value, ref Value target_value) {
+        target_value = is_valid_date_time(date, wall_time);
+        
+        return true;
+    }
+    
     private void connect_property_signals() {
         notify[PROP_DATE].connect(on_date_changed);
         notify[PROP_WALL_TIME].connect(on_wall_time_changed);
@@ -153,7 +195,7 @@ public class DateTimeWidget : Gtk.Box {
         
         int amount;
         Calendar.TimeUnit time_unit;
-        if (!adjust_time_controls(details, out amount, out time_unit))
+        if (!adjust_time_controls(details.widget, out amount, out time_unit))
             return Toolkit.PROPAGATE;
         
         // use free_adjust() to adjust each unit individually without affecting others
@@ -167,23 +209,23 @@ public class DateTimeWidget : Gtk.Box {
         return Toolkit.STOP;
     }
     
-    private bool adjust_time_controls(Toolkit.ButtonEvent details, out int amount, out Calendar.TimeUnit 
time_unit) {
-        if (details.widget == hour_up) {
+    private bool adjust_time_controls(Gtk.Widget widget, out int amount, out Calendar.TimeUnit time_unit) {
+        if (widget == hour_up) {
             amount = 1;
             time_unit = Calendar.TimeUnit.HOUR;
-        } else if (details.widget == hour_down) {
+        } else if (widget == hour_down) {
             amount = -1;
             time_unit = Calendar.TimeUnit.HOUR;
-        } else if (details.widget == minutes_up) {
+        } else if (widget == minutes_up) {
             amount = 5;
             time_unit = Calendar.TimeUnit.MINUTE;
-        } else if (details.widget == minutes_down) {
+        } else if (widget == minutes_down) {
             amount = -5;
             time_unit = Calendar.TimeUnit.MINUTE;
-        } else if (details.widget == meridiem_up) {
+        } else if (widget == meridiem_up) {
             amount = 12;
             time_unit = Calendar.TimeUnit.HOUR;
-        } else if (details.widget == meridiem_down) {
+        } else if (widget == meridiem_down) {
             amount = -12;
             time_unit = Calendar.TimeUnit.HOUR;
         } else {
@@ -276,10 +318,9 @@ public class DateTimeWidget : Gtk.Box {
         
         disconnect_property_signals();
         
-        freeze_notify();
         out_of_range = !valid;
-        wall_time = new_wall_time;
-        thaw_notify();
+        if (valid)
+            wall_time = new_wall_time;
         
         connect_property_signals();
     }