* Bugfix in TDynamicComboBoxView mediator class.

* A few other minor changes to mediators
* Extended the tiOPF demo 21 even further, showing more features of MGM implementation.

2 files changed, 16 insertions, 6 deletions

diff --git a/extras/tiopf/gui/tiListMediators.pas b/extras/tiopf/gui/tiListMediators.pas
index 5aca05d7..f00fa56d 100644
--- a/extras/tiopf/gui/tiListMediators.pas
+++ b/extras/tiopf/gui/tiListMediators.pas
@@ -33,9 +33,10 @@ type
     procedure SetSelectedObject(const AValue: TtiObject);override;
     procedure CreateColumns; override;
     procedure DoCreateItemMediator(AData: TtiObject; ARowIdx : Integer); override;
-    Function  GetGuiControl : TComponent; override;
-    Procedure SetGuiControl (Const AValue : TComponent); override;
+    function  GetGuiControl : TComponent; override;
+    procedure SetGuiControl (Const AValue : TComponent); override;
     procedure SetupGUIandObject; override;
+    procedure ClearList; override;
     procedure RebuildList; override;
   public
     constructor CreateCustom(AModel: TtiObjectList; AView: TfpgListView; ADisplayNames: string; AIsObserving: Boolean = True); overload;
@@ -43,7 +44,7 @@ type
     class function ComponentClass: TClass; override;
     Constructor Create; override;
     Destructor Destroy; override;
-    procedure HandleSelectionChanged; override;
+    procedure HandleSelectionChanged; {override;}
   published
     property    View: TfpgListView read FView Write SetView;
   end;
@@ -131,7 +132,7 @@ type
     destructor Destroy; override;
     class function CompositeMediator: Boolean; override;
     class function ComponentClass: TClass; override;
-    procedure HandleSelectionChanged; override;
+    procedure HandleSelectionChanged; {override;}
     property View: TfpgListBox read FView;
   end;
 
@@ -234,6 +235,11 @@ begin
 //  FView.ScrollBars        := ssAutoBoth;
 end;
 
+procedure TListViewMediator.ClearList;
+begin
+  View.Items.Clear;
+end;
+
 procedure TListViewMediator.RebuildList;
 begin
   MediatorList.Clear;
diff --git a/extras/tiopf/gui/tiMediators.pas b/extras/tiopf/gui/tiMediators.pas
index 828a5eb8..2825c1f4 100644
--- a/extras/tiopf/gui/tiMediators.pas
+++ b/extras/tiopf/gui/tiMediators.pas
@@ -508,8 +508,10 @@ end;
 
 procedure TMediatorDynamicComboBoxView.SetListObject(const AValue: TtiObjectList);
 begin
-  Inherited;
+  inherited;
   InternalListRefresh;
+  if Assigned(ValueList) then
+    EditControl.Enabled := ValueList.Count > 0;
 end;
 
 procedure TMediatorDynamicComboBoxView.InternalListRefresh;
@@ -565,7 +567,9 @@ begin
   if UseInternalOnChange then
     EditControl.OnChange := @DoOnChange; // default OnChange event handler
 
-  EditControl.Enabled   := (ValueList.Count > 0);
+  {$Note As far as I can see, ValueList is always going to be nil here! - Graeme }
+  if ValueList <> nil then
+    EditControl.Enabled := (ValueList.Count > 0);
 end;
 
 procedure TMediatorDynamicComboBoxView.DoGuiToObject;