Index: VerpakkingsDefinitie/UI/GebruikerScherm.dfm
===================================================================
diff -u
--- VerpakkingsDefinitie/UI/GebruikerScherm.dfm	(revision 0)
+++ VerpakkingsDefinitie/UI/GebruikerScherm.dfm	(revision 555)
@@ -0,0 +1,57 @@
+object FormGebruiker: TFormGebruiker
+  Left = 0
+  Top = 0
+  BorderStyle = bsNone
+  Caption = 'FormGebruiker'
+  ClientHeight = 40
+  ClientWidth = 584
+  Color = 1513421
+  Font.Charset = DEFAULT_CHARSET
+  Font.Color = clWindowText
+  Font.Height = -11
+  Font.Name = 'Tahoma'
+  Font.Style = []
+  OldCreateOrder = False
+  OnCreate = FormCreate
+  OnDestroy = FormDestroy
+  DesignSize = (
+    584
+    40)
+  PixelsPerInch = 96
+  TextHeight = 13
+  object LabelGebruikersnaam: TLabel
+    Left = 8
+    Top = 8
+    Width = 134
+    Height = 19
+    Caption = 'Gebruikersnaam'
+    Font.Charset = DEFAULT_CHARSET
+    Font.Color = clWhite
+    Font.Height = -16
+    Font.Name = 'Tahoma'
+    Font.Style = [fsBold]
+    ParentFont = False
+  end
+  object PanelLogIn: TPanel
+    Left = 484
+    Top = 4
+    Width = 92
+    Height = 28
+    Anchors = [akTop, akRight]
+    BevelEdges = []
+    BevelOuter = bvSpace
+    BiDiMode = bdLeftToRight
+    Caption = 'LOG UIT'
+    Font.Charset = DEFAULT_CHARSET
+    Font.Color = clWhite
+    Font.Height = -11
+    Font.Name = 'Tahoma'
+    Font.Style = [fsBold]
+    ParentBiDiMode = False
+    ParentFont = False
+    TabOrder = 0
+    OnClick = PanelLogInClick
+    OnMouseDown = PanelLogInMouseDown
+    OnMouseUp = PanelLogInMouseUp
+  end
+end
Index: VerpakkingsDefinitie/VerpakkingsDefinitie.dproj
===================================================================
diff -u -r553 -r555
--- VerpakkingsDefinitie/VerpakkingsDefinitie.dproj	(.../VerpakkingsDefinitie.dproj)	(revision 553)
+++ VerpakkingsDefinitie/VerpakkingsDefinitie.dproj	(.../VerpakkingsDefinitie.dproj)	(revision 555)
@@ -70,6 +70,9 @@
 			<DCC_RemoteDebug>true</DCC_RemoteDebug>
 		</PropertyGroup>
 		<PropertyGroup Condition="'$(Cfg_1_Win32)'!=''">
+			<BCC_DebugLineNumbers>true</BCC_DebugLineNumbers>
+			<BCC_SourceDebuggingOn>true</BCC_SourceDebuggingOn>
+			<ILINK_FullDebugInfo>true</ILINK_FullDebugInfo>
 			<VerInfo_IncludeVerInfo>true</VerInfo_IncludeVerInfo>
 			<VerInfo_Locale>1033</VerInfo_Locale>
 			<DCC_RemoteDebug>false</DCC_RemoteDebug>
@@ -98,6 +101,11 @@
 				<Form>FormZoekProducten</Form>
 			</DCCReference>
 			<DCCReference Include="UI\Util.pas"/>
+			<DCCReference Include="UI\GebruikerScherm.pas">
+				<Form>FormGebruiker</Form>
+				<FormType>dfm</FormType>
+			</DCCReference>
+			<DCCReference Include="UI\ObserverPattern.pas"/>
 			<BuildConfiguration Include="Release">
 				<Key>Cfg_2</Key>
 				<CfgParent>Base</CfgParent>
Index: VerpakkingsDefinitie/Main.pas
===================================================================
diff -u -r554 -r555
--- VerpakkingsDefinitie/Main.pas	(.../Main.pas)	(revision 554)
+++ VerpakkingsDefinitie/Main.pas	(.../Main.pas)	(revision 555)
@@ -1,7 +1,7 @@
 unit Main;
 
 interface
-
+ { TODO -cnavigatie : NavigeerNaar in interface zetten ter abstractie voor subschermen }
 uses
   Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
   System.Classes, Vcl.Graphics,
@@ -35,7 +35,7 @@
 implementation
 
 uses
-  Subscherm, LogInScherm, ZoekProductenScherm;
+  Subscherm, LogInScherm, ZoekProductenScherm, GebruikerScherm;
 
 {$R *.dfm}
 
@@ -67,7 +67,6 @@
   Application.ProcessMessages; // Interrupts the execution of an application so that it can process the message queue.
 
   // Volgende subscherm laden in panel
-  { TODO -cNavigatie : Huidige schermen verwijderen (indien nodig) met Controls property }
 
   // PanelMain behouden we altijd, the children can be free.
   for i := 0 to PanelMain.ControlCount - 1 do
@@ -84,7 +83,7 @@
         // Schermen op GridPanel plaatsen
         // PlaatsControlOpGrid(GridPanel; Control; RowI; ColI; (opt) RowSpan; (opt)ColSpan);
         // Gebruikersgegevens scherm bovenaan.
-        NieuweGridControl := TFormLogin.Create(GridPanel, Self, FAppContext, FAgent);
+        NieuweGridControl := TFormGebruiker.Create(GridPanel, Self, FAppContext, FAppContext.UserServerServiceContext, FAgent);
         PlaatsControlOpGrid(GridPanel, NieuweGridControl, 0, 0, 1, 2);
         // Zoekscherm daaronder links
         NieuweGridControl := TFormZoekProducten.Create(GridPanel, Self, FAppContext);
Index: VerpakkingsDefinitie/UI/GebruikerScherm.pas
===================================================================
diff -u
--- VerpakkingsDefinitie/UI/GebruikerScherm.pas	(revision 0)
+++ VerpakkingsDefinitie/UI/GebruikerScherm.pas	(revision 555)
@@ -0,0 +1,81 @@
+unit GebruikerScherm;
+
+interface
+
+uses
+  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
+  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls,
+  ObserverPattern,
+  Agent, Main, ApplicationContext, Subscherm;
+
+type
+  TFormGebruiker = class(TFormSubscherm)
+    LabelGebruikersnaam: TLabel;
+    PanelLogIn: TPanel;
+    procedure FormCreate(Sender: TObject);
+    procedure FormDestroy(Sender: TObject);
+    procedure PanelLogInMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
+    procedure PanelLogInMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
+    procedure PanelLogInClick(Sender: TObject);
+  private
+    FGebruikerSubject: TSubject;
+    FGebruikerSubjectObserver: TSubjectObserver;
+    FUserAgent: TAgent;
+    procedure UpdateGui(Sender: TObject);
+  public
+    Constructor Create(AOwner: TComponent; Navigator: TFormMain; ApplicationContext: TApplicationContext;
+      GebruikerSubject: TSubject; UserAgent: TAgent);
+  end;
+
+implementation
+
+{$R *.dfm}
+
+constructor TFormGebruiker.Create(AOwner: TComponent; Navigator: TFormMain; ApplicationContext: TApplicationContext;
+  GebruikerSubject: TSubject; UserAgent: TAgent);
+begin
+  inherited Create(AOwner, Navigator, ApplicationContext);
+  self.FGebruikerSubject := GebruikerSubject;
+  self.FGebruikerSubjectObserver := TSubjectObserver.Create(self);
+  self.FGebruikerSubjectObserver.OnChange := UpdateGui;
+  self.FUserAgent := UserAgent;
+end;
+
+procedure TFormGebruiker.FormCreate(Sender: TObject);
+begin
+  FGebruikerSubject.RegisterObserver(FGebruikerSubjectObserver);
+end;
+
+procedure TFormGebruiker.FormDestroy(Sender: TObject);
+begin
+  FGebruikerSubject.UnregisterObserver(FGebruikerSubjectObserver);
+end;
+
+procedure TFormGebruiker.UpdateGui(Sender: TObject);
+begin
+  // Update with data from ApplicationContext
+  LabelGebruikersnaam.Caption := self.ApplicationContext.UserServerServiceContext.GebruikersNaam;
+end;
+
+// Indrukken van button simuleren op panel: http://www.festra.com/wwwboard/messages/1006.html
+procedure TFormGebruiker.PanelLogInClick(Sender: TObject);
+begin
+  try
+    FUserAgent.GebruikerAfmelden(self.ApplicationContext.UserServerServiceContext);
+  finally
+    // Als logout mislukt, gewoon naar inlog scherm gaan. De gebruiker kan dan opnieuw inloggen.
+     self.Navigator.NavigeerNaar(Main.NAVLOGIN);
+  end;
+end;
+
+procedure TFormGebruiker.PanelLogInMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
+begin
+  (Sender as TPanel).BevelOuter := bvLowered;
+end;
+
+procedure TFormGebruiker.PanelLogInMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
+begin
+  (Sender as TPanel).BevelOuter := bvRaised;
+end;
+
+end.
Index: VerpakkingsDefinitie/UI/Subscherm.pas
===================================================================
diff -u -r552 -r555
--- VerpakkingsDefinitie/UI/Subscherm.pas	(.../Subscherm.pas)	(revision 552)
+++ VerpakkingsDefinitie/UI/Subscherm.pas	(.../Subscherm.pas)	(revision 555)
@@ -17,7 +17,7 @@
     FApplicationContext: TApplicationContext;
   protected
     property Navigator: TFormMain Read FNavigator write FNavigator;
-    property ApplicationContextObj: TApplicationContext Read FApplicationContext write FApplicationContext;
+    property ApplicationContext: TApplicationContext Read FApplicationContext write FApplicationContext;
   public
     Constructor Create(AOwner: TComponent; Navigator: TFormMain; ApplicationContext: TApplicationContext); overload;
   end;
@@ -29,7 +29,7 @@
   inherited Create(AOwner);
 
   Self.Navigator := Navigator;
-  Self.ApplicationContextObj := ApplicationContext;
+  Self.ApplicationContext := ApplicationContext;
 
   BorderStyle := bsNone; // Subschermen hebben geen border
 end;
Index: VerpakkingsDefinitie/ApplicationContext.pas
===================================================================
diff -u -r551 -r555
--- VerpakkingsDefinitie/ApplicationContext.pas	(.../ApplicationContext.pas)	(revision 551)
+++ VerpakkingsDefinitie/ApplicationContext.pas	(.../ApplicationContext.pas)	(revision 555)
@@ -7,11 +7,14 @@
 
 interface
 
+uses
+  ObserverPattern;
+
 // SUB CONTEXTS: klassen die overeenkomen met bepaalde sub-context (bv. alles gerelateerd met authenticatie).
 
 // - UserServerService
 type
-  TUserServerServiceContext = class
+  TUserServerServiceContext = class(TSubject)
   private
     FSessionKey: string;
     FGebruikersNaam: string;
@@ -20,6 +23,7 @@
     FErrorMessage: string;
     FInternalErrorMessage: string;
   public
+    procedure Changed();
     property SessionKey: string read FSessionKey write FSessionKey;
     property GebruikersNaam: string read FGebruikersNaam write FGebruikersNaam;
     property IsOK: Boolean read FIsOK write FIsOK;
@@ -31,14 +35,19 @@
   // Application context bevat alle sub-contexts
   TApplicationContext = class
   private
-      FUserServerServiceContext: TUserServerServiceContext;
+    FUserServerServiceContext: TUserServerServiceContext;
   public
     constructor Create();
     property UserServerServiceContext: TUserServerServiceContext read FUserServerServiceContext write FUserServerServiceContext;
   end;
 
 implementation
 
+procedure TUserServerServiceContext.Changed();
+begin
+  self.Change();
+end;
+
 constructor TApplicationContext.Create();
 begin
   FUserServerServiceContext := TUserServerServiceContext.Create();
Index: VerpakkingsDefinitie/VerpakkingsDefinitie.dpr
===================================================================
diff -u -r553 -r555
--- VerpakkingsDefinitie/VerpakkingsDefinitie.dpr	(.../VerpakkingsDefinitie.dpr)	(revision 553)
+++ VerpakkingsDefinitie/VerpakkingsDefinitie.dpr	(.../VerpakkingsDefinitie.dpr)	(revision 555)
@@ -9,7 +9,9 @@
   Subscherm in 'UI\Subscherm.pas',
   UserServerService in 'WS\UserServerService.pas',
   ZoekProductenScherm in 'UI\ZoekProductenScherm.pas' {FormZoekProducten},
-  Util in 'UI\Util.pas';
+  Util in 'UI\Util.pas',
+  GebruikerScherm in 'UI\GebruikerScherm.pas' {FormGebruiker},
+  ObserverPattern in 'UI\ObserverPattern.pas';
 
 {$R *.res}
 
Index: VerpakkingsDefinitie/UI/ObserverPattern.pas
===================================================================
diff -u
--- VerpakkingsDefinitie/UI/ObserverPattern.pas	(revision 0)
+++ VerpakkingsDefinitie/UI/ObserverPattern.pas	(revision 555)
@@ -0,0 +1,83 @@
+// Based on: https://sourcemaking.com/design_patterns/observer/delphi
+unit ObserverPattern;
+
+interface
+
+uses
+  System.Classes;
+
+type
+  TSubjectObserver = class(TComponent)
+  private
+    FEnabled: Boolean;
+    FOnChange: TNotifyEvent;
+  protected
+    procedure Change;
+  public
+    constructor Create(AOwner: TComponent);
+  published
+    property Enabled: Boolean read FEnabled write FEnabled;
+    property OnChange: TNotifyEvent read FOnChange write FOnChange;
+  end;
+
+  TSubject = class(TObject)
+  private
+    FObservers: TList;
+  protected
+    procedure Change; // Call this method to dispatch change
+  public
+    constructor Create();
+    procedure RegisterObserver(Observer: TSubjectObserver);
+    procedure UnregisterObserver(Observer: TSubjectObserver);
+  end;
+
+implementation
+
+constructor TSubjectObserver.Create(AOwner: TComponent);
+begin
+  inherited Create(AOwner);
+  self.FEnabled := True;
+end;
+
+procedure TSubjectObserver.Change;
+begin
+  if Assigned(FOnChange) then
+    FOnChange(self);
+end;
+
+constructor TSubject.Create();
+begin
+  inherited Create();
+  FObservers := TList.Create();
+end;
+
+procedure TSubject.Change;
+var
+  Obs: TSubjectObserver;
+  I: Integer;
+begin
+  for I := 0 to FObservers.Count - 1 do
+  begin
+    Obs := FObservers[I];
+    if Obs.Enabled then
+      Obs.Change;
+  end;
+end;
+
+procedure TSubject.RegisterObserver(Observer: TSubjectObserver);
+begin
+  if FObservers.IndexOf(Observer) = -1 then
+  begin
+    FObservers.Add(Observer);
+    // Update nieuwe observer
+    if Observer.Enabled then
+      Observer.Change;
+  end;
+end;
+
+procedure TSubject.UnregisterObserver(Observer: TSubjectObserver);
+begin
+  FObservers.Remove(Observer);
+end;
+
+end.
Index: VerpakkingsDefinitie/UI/LogInScherm.pas
===================================================================
diff -u -r552 -r555
--- VerpakkingsDefinitie/UI/LogInScherm.pas	(.../LogInScherm.pas)	(revision 552)
+++ VerpakkingsDefinitie/UI/LogInScherm.pas	(.../LogInScherm.pas)	(revision 555)
@@ -28,7 +28,6 @@
     procedure Login();
   public
     Constructor Create(AOwner: TComponent; Navigator: TFormMain; ApplicationContext: TApplicationContext; Agent: TAgent);
-      overload;
   end;
 
 implementation
@@ -96,19 +95,19 @@
 var
   ErrorMessage: string;
 begin
-  FAgent.GebruikerAanmelden(EditGebruikersnaam.Text, EditWachtwoord.Text, ApplicationContextObj.UserServerServiceContext);
+  FAgent.GebruikerAanmelden(EditGebruikersnaam.Text, EditWachtwoord.Text, ApplicationContext.UserServerServiceContext);
 
-  if ApplicationContextObj.UserServerServiceContext.IsOK then
+  if ApplicationContext.UserServerServiceContext.IsOK then
   begin
     (self.Navigator as TFormMain).NavigeerNaar(Main.NAVZOEKPRODUCTEN);
   end
   else
   begin
     // Login gefaald
-    ErrorMessage := ApplicationContextObj.UserServerServiceContext.ErrorMessage;
-    if ApplicationContextObj.UserServerServiceContext.InternalErrorMessage <> '' then
+    ErrorMessage := ApplicationContext.UserServerServiceContext.ErrorMessage;
+    if ApplicationContext.UserServerServiceContext.InternalErrorMessage <> '' then
     begin
-      ErrorMessage := ErrorMessage + sLineBreak + ApplicationContextObj.UserServerServiceContext.InternalErrorMessage;
+      ErrorMessage := ErrorMessage + sLineBreak + ApplicationContext.UserServerServiceContext.InternalErrorMessage;
     end;
 
     if MessageDlg(ErrorMessage, TMsgDlgType.mtInformation, [mbRetry, mbCancel], 0, mbCancel) = mrRetry then
Index: VerpakkingsDefinitie/UI/LogInScherm.dfm
===================================================================
diff -u -r554 -r555
--- VerpakkingsDefinitie/UI/LogInScherm.dfm	(.../LogInScherm.dfm)	(revision 554)
+++ VerpakkingsDefinitie/UI/LogInScherm.dfm	(.../LogInScherm.dfm)	(revision 555)
@@ -72,7 +72,6 @@
     Anchors = [akTop]
     TabOrder = 0
     OnChange = EditGebruikersnaamChange
-    ExplicitLeft = 19
   end
   object EditWachtwoord: TEdit
     Left = 23
@@ -81,7 +80,6 @@
     Height = 21
     Anchors = [akTop]
     TabOrder = 1
-    ExplicitLeft = 19
   end
   object PanelLogIn: TPanel
     Left = 57
@@ -104,6 +102,5 @@
     OnClick = PanelLogInClick
     OnMouseDown = PanelLogInMouseDown
     OnMouseUp = PanelLogInMouseUp
-    ExplicitLeft = 53
   end
 end
Index: VerpakkingsDefinitie/UI/ZoekProductenScherm.dfm
===================================================================
diff -u -r554 -r555
--- VerpakkingsDefinitie/UI/ZoekProductenScherm.dfm	(.../ZoekProductenScherm.dfm)	(revision 554)
+++ VerpakkingsDefinitie/UI/ZoekProductenScherm.dfm	(.../ZoekProductenScherm.dfm)	(revision 555)
@@ -32,12 +32,8 @@
     Font.Style = []
     ParentFont = False
     TabOrder = 0
-    ExplicitWidth = 839
-    ExplicitHeight = 625
     object TabSheetKortTekst: TTabSheet
       Caption = 'Kort tekst'
-      ExplicitWidth = 831
-      ExplicitHeight = 597
       object Label1: TLabel
         Left = 3
         Top = 16
Index: VerpakkingsDefinitie/Main.dfm
===================================================================
diff -u -r554 -r555
--- VerpakkingsDefinitie/Main.dfm	(.../Main.dfm)	(revision 554)
+++ VerpakkingsDefinitie/Main.dfm	(.../Main.dfm)	(revision 555)
@@ -29,7 +29,5 @@
     ParentShowHint = False
     ShowHint = True
     TabOrder = 0
-    ExplicitWidth = 497
-    ExplicitHeight = 441
   end
 end
Index: VerpakkingsDefinitie/WS/Agent.pas
===================================================================
diff -u -r552 -r555
--- VerpakkingsDefinitie/WS/Agent.pas	(.../Agent.pas)	(revision 552)
+++ VerpakkingsDefinitie/WS/Agent.pas	(.../Agent.pas)	(revision 555)
@@ -3,7 +3,7 @@
 interface
 
 uses SysUtils,
-  ApplicationContext, UserServerService;
+  ObserverPattern, ApplicationContext, UserServerService;
 
 // Resource strings are stored as resources and linked into the executable or
 // library so that they can be modified without recompiling the program.
@@ -78,6 +78,8 @@
 
   UserServerServiceContext.SessionKey := pxLogInObj.SessionKey;
   UserServerServiceContext.GebruikersNaam := pxLogInObj.GebruikersNaam;
+
+  UserServerServiceContext.Changed();
 end;
 
 procedure TAgent.RegistreerMislukteLogin(UserServerServiceContext: TUserServerServiceContext; pxStatusObj: pxStatus);
@@ -89,6 +91,8 @@
   UserServerServiceContext.IsOK := pxStatusObj.IsOK;
   UserServerServiceContext.ErrorMessage := pxStatusObj.Message_;
   UserServerServiceContext.InternalErrorMessage := pxStatusObj.InternalMessage;
+
+  UserServerServiceContext.Changed();
 end;
 
 procedure TAgent.GebruikerAfmelden(UserServerServiceContext: TUserServerServiceContext);
@@ -133,13 +137,17 @@
   UserServerServiceContext.InternalErrorMessage := '';
   UserServerServiceContext.SessionKey := '';
   UserServerServiceContext.GebruikersNaam := '';
+
+  UserServerServiceContext.Changed();
 end;
 
 procedure TAgent.RegistreerMislukteLogout(UserServerServiceContext: TUserServerServiceContext; pxStatusObj: pxStatus);
 begin
   UserServerServiceContext.IsOK := pxStatusObj.IsOK;
   UserServerServiceContext.ErrorMessage := pxStatusObj.Message_;
   UserServerServiceContext.InternalErrorMessage := pxStatusObj.InternalMessage;
+
+  UserServerServiceContext.Changed();
 end;
 
 end.