[glom] Disables the Open button next to ID fields if the field is empty.

[Murray Cumming <murrayc src gnome org>]

commit 4cbeb70ae5acdd9e7772e3dc30ddbcb9a99df1d2
Author: Murray Cumming <murrayc murrayc com>
Date:   Sun May 10 17:19:48 2009 +0200

    Disables the Open button next to ID fields if the field is empty.
    
    * glom/utility_widgets/datawidget.[h|cc]:
    Added private update_go_to_details_button_sensitivity() method and
    called it whenever the value is changed by the user or set via
    set_value(). Fixes bug #565023.
---
 ChangeLog                          |    9 +++++++++
 glom/utility_widgets/datawidget.cc |   25 +++++++++++++++++++++----
 glom/utility_widgets/datawidget.h  |    5 +++++
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 5c66131..5e40619 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2009-05-10  Murray Cumming  <murrayc murrayc-x61>
+
+	Disables the Open button next to ID fields if the field is empty.
+
+	* glom/utility_widgets/datawidget.[h|cc]: 
+	Added private update_go_to_details_button_sensitivity() method and 
+	called it whenever the value is changed by the user or set via 
+	set_value(). Fixes bug #565023.
+
 2009-05-07  Murray Cumming  <murrayc murrayc-x61>
 
 	Allow non-network-shared connections when using IPv6.
diff --git a/glom/utility_widgets/datawidget.cc b/glom/utility_widgets/datawidget.cc
index ee285bb..111f496 100644
--- a/glom/utility_widgets/datawidget.cc
+++ b/glom/utility_widgets/datawidget.cc
@@ -46,6 +46,8 @@ DataWidget::DataWidget(Field::glom_field_type glom_type, const Glib::ustring& ti
 */
 
 DataWidget::DataWidget(const sharedptr<LayoutItem_Field>& field, const Glib::ustring& table_name, const Document* document)
+:  m_child(0),
+   m_button_go_to_details(0)
 {
   const Field::glom_field_type glom_type = field->get_glom_type();
   set_layout_item(field, table_name);
@@ -240,10 +242,10 @@ DataWidget::DataWidget(const sharedptr<LayoutItem_Field>& field, const Glib::ust
     if((field_used_in_relationship_to_one || field_is_related_primary_key) && hbox_parent)
     {
       //Add a button for related record navigation:
-      Gtk::Button* button_go_to_details = Gtk::manage(new Gtk::Button(Gtk::Stock::OPEN));
-      button_go_to_details->set_tooltip_text(_("Open the record identified by this ID, in the other table."));
-      hbox_parent->pack_start(*button_go_to_details);
-      button_go_to_details->signal_clicked().connect(sigc::mem_fun(*this, &DataWidget::on_button_open_details));
+      m_button_go_to_details = Gtk::manage(new Gtk::Button(Gtk::Stock::OPEN));
+      m_button_go_to_details->set_tooltip_text(_("Open the record identified by this ID, in the other table."));
+      hbox_parent->pack_start(*m_button_go_to_details);
+      m_button_go_to_details->signal_clicked().connect(sigc::mem_fun(*this, &DataWidget::on_button_open_details));
 
       //Add a button to make it easier to choose an ID for this field.
       //Don't add this for simple related primary key fields, because they 
@@ -276,6 +278,7 @@ DataWidget::~DataWidget()
 void DataWidget::on_widget_edited()
 {
   m_signal_edited.emit(get_value());
+  update_go_to_details_button_sensitivity();
 }
 
 DataWidget::type_signal_edited DataWidget::signal_edited()
@@ -307,6 +310,20 @@ void DataWidget::set_value(const Gnome::Gda::Value& value)
       checkbutton->set_active( bValue );
     }
   }
+
+  update_go_to_details_button_sensitivity();
+}
+
+void DataWidget::update_go_to_details_button_sensitivity()
+{
+  //If there is a Go-To-Details "Open" button, only enable it if there is 
+  //an ID:
+  if(m_button_go_to_details)
+  {
+    const Gnome::Gda::Value value = get_value();
+    const bool enabled = !Conversions::value_is_empty(value);
+    m_button_go_to_details->set_sensitive(enabled);
+  }
 }
 
 Gnome::Gda::Value DataWidget::get_value() const
diff --git a/glom/utility_widgets/datawidget.h b/glom/utility_widgets/datawidget.h
index 6e6cfc7..27be179 100644
--- a/glom/utility_widgets/datawidget.h
+++ b/glom/utility_widgets/datawidget.h
@@ -113,11 +113,16 @@ private:
    */
   bool offer_related_record_id_find(Gnome::Gda::Value& chosen_id);
 
+private:
+  void update_go_to_details_button_sensitivity();
+
+protected:
   type_signal_edited m_signal_edited;
   type_signal_open_details_requested m_signal_open_details_requested;
 
   Gtk::Label m_label;
   Gtk::Widget* m_child;
+  Gtk::Button* m_button_go_to_details;
 };
 
 } //namespace Glom