Merge pull request #10 from Standaard-boos/Navigation

Make navigation MVVM compliant

Author: BastogneBas

View/MainMenuData.cs

@@ -4,12 +4,14 @@
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:View"
+        xmlns:vm="clr-namespace:ViewModel;assembly=ViewModel"
+        xmlns:vmc="clr-namespace:ViewModel.Commands;assembly=ViewModel"
         mc:Ignorable="d"
-        Title="MainWindow" Height="450" Width="800">
+        Title="Stugether" Height="450" Width="800">
+    <Window.DataContext>
+        <vm:MainPageViewModel/>
+    </Window.DataContext>
     <DockPanel LastChildFill="True">
-        <DockPanel.DataContext>
-            <local:MainMenuData/>
-        </DockPanel.DataContext>
         <StackPanel DockPanel.Dock="Left" Width="100">
             <Grid Height="{Binding ActualHeight, ElementName=tbContentTitle, Mode=OneWay}">
                 <Grid.ColumnDefinitions>
@@ -28,12 +30,12 @@
                 </ItemsControl.ItemsPanel>
                 <ItemsControl.ItemTemplate>
                     <ItemContainerTemplate>
-                        <local:MainWindowNavigationItem Content="{Binding Title}" Page="{Binding Page}" ExtraNavigationInformation="{Binding ExtraInformation}" Click="MainWindowNavigationItem_Click"/>
+                        <local:MainWindowNavigationItem Content="{Binding Title}" Page="{Binding Page}" ExtraNavigationInformation="{Binding ExtraInformation}" Command="{Binding Path=DataContext.NavigateButtonCommand, RelativeSource={RelativeSource AncestorType=Window},Mode=Default}" CommandParameter="{Binding Mode=OneWay}"/>
                     </ItemContainerTemplate>
                 </ItemsControl.ItemTemplate>
             </ItemsControl>
         </StackPanel>
-        <TextBlock x:Name="tbContentTitle" DockPanel.Dock="Top" Text="Title" FontSize="22" FontWeight="Bold"/>
-        <Frame x:Name="frContent" NavigationUIVisibility="Hidden" Navigated="frContent_Navigated"/>
+        <TextBlock x:Name="tbContentTitle" DockPanel.Dock="Top" FontSize="22" FontWeight="Bold" Text="{Binding Title}"/>
+        <Frame x:Name="frContent" NavigationUIVisibility="Hidden" Navigated="frContent_Navigated" Source="{Binding CurrentVisiblePage}" />
     </DockPanel>
 </Window>

View/MainWindow.xaml

@@ -14,26 +14,9 @@ public partial class MainWindow : Window
         public MainWindow()
         {
             InitializeComponent();
-            SSHConnection.InitializeSsh(); // Not MVVM, this needs to be moved somewhere soon
+            SSHConnection.InitializeSsh(); // TODO: Not MVVM, this needs to be moved somewhere soon
         }
 
-        private void Button_Click(object sender, RoutedEventArgs e)
-        {
-            AuthenticationWindow authenticationWindow = new AuthenticationWindow();
-            authenticationWindow.Show();
-        }
-
-        /// <summary>
-        /// Occurs when a navigation item is clicked to navigate to its page
-        /// </summary>
-        /// <param name="sender">The source of the event.</param>
-        /// <param name="e">The event data.</param>
-        private void MainWindowNavigationItem_Click(object sender, RoutedEventArgs e)
-        {
-            MainWindowNavigationItem mwniSender = (MainWindowNavigationItem)sender;
-            tbContentTitle.Text = (string)mwniSender.Content;
-            frContent.Navigate(mwniSender.Page);
-        }
 
         /// <summary>
         /// Occurs when the back/forward buttons are clicked

View/MainWindow.xaml.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Windows.Input;
+
+namespace ViewModel.Commands
+{
+    /// <summary>
+    /// Handles the click events of the main menu buttons
+    /// </summary>
+    public class NavigateButtonCommand : ICommand
+    {
+        /// <summary>
+        /// The viewmodel modified by this command
+        /// </summary>
+        public MainPageViewModel VM { get; set; }
+
+        /// <summary>
+        /// Creates a new NavigateButtonCommand
+        /// </summary>
+        /// <param name="vm">The viewmodel modified by this command</param>
+        public NavigateButtonCommand(MainPageViewModel vm)
+        {
+            VM = vm;
+        }
+
+        /// <summary>
+        /// Defines the method that determines whether the command can execute in its current state.
+        /// </summary>
+        /// <param name="parameter">This value can be null, because it is not used.</param>
+        /// <returns>true if this command can be executed; otherwise, false.</returns>
+        public bool CanExecute(object parameter) => VM.MainNavigationItems.Count > 0;
+
+        /// <summary>
+        /// Updates the viewmodel with the given information.
+        /// </summary>
+        /// <param name="parameter">The String or MainMenuNavigationItemData containing information about information where to navigate to</param>
+        public void Execute(object parameter)
+        {
+            if (parameter.GetType() == typeof(string))
+            {
+                VM.CurrentVisiblePage = (string)parameter;
+                VM.Title = "StudentMatcher";
+            }
+            else if (parameter.GetType() == typeof(MainPageViewModel.MainMenuNavigationItemData))
+            {
+                var data = (MainPageViewModel.MainMenuNavigationItemData)parameter;
+                VM.CurrentVisiblePage = data.Page;
+                VM.Title = data.Title;
+            }
+            else
+            {
+                throw new InvalidOperationException("Accepts only strings");
+            }
+        }
+
+        /// <summary>
+        /// Occurs when changes occur that affect whether or not the command should execute.
+        /// </summary>
+        public event EventHandler CanExecuteChanged;
+    }
+}

ViewModel/Commands/NavigateButtonCommand.cs

@@ -0,0 +1,125 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Text;
+using ViewModel.Commands;
+//using System.Windows.Controls;
+
+namespace ViewModel
+{
+    /// <summary>
+    /// ViewModel for MainPage
+    /// </summary>
+    public class MainPageViewModel : INotifyPropertyChanged
+    {
+        #region Properties
+        /// <summary>
+        /// Collection of pages for the main navigation menu
+        /// </summary>
+        public ObservableCollection<MainMenuNavigationItemData> MainNavigationItems { get; } = new ObservableCollection<MainMenuNavigationItemData>()
+        {
+            new MainMenuNavigationItemData("Profile", "ProfilePage.xaml", null)
+        };
+
+
+        private string currentVisiblePage;
+        /// <summary>
+        /// Page that is currently visible on the frame
+        /// </summary>
+        public string CurrentVisiblePage
+        {
+            get
+            {
+                return currentVisiblePage;
+            }
+            set
+            {
+                currentVisiblePage = value;
+                OnPropertyChanged("CurrentVisiblePage");
+            }
+        }
+
+        private string title;
+        /// <summary>
+        /// Title shown on top of the page
+        /// </summary>
+        public string Title
+        {
+            get
+            {
+                return title;
+            }
+            set
+            {
+                title = value;
+                OnPropertyChanged("Title");
+            }
+        }
+
+        /// <summary>
+        /// Handles the click events of the main menu buttons
+        /// </summary>
+        public NavigateButtonCommand NavigateButtonCommand { get; set; }
+        #endregion
+
+        #region constructor
+        /// <summary>
+        /// Creates a new viewmodel for MainPage
+        /// </summary>
+        public MainPageViewModel()
+        {
+            NavigateButtonCommand = new NavigateButtonCommand(this);
+        }
+        #endregion
+
+        #region MainMenuNavigationItemData
+        /// <summary>
+        /// The data for a menu item on the main navigation menu
+        /// </summary>
+        public struct MainMenuNavigationItemData
+        {
+            /// <summary>
+            /// Creates an item of data for the main navigation menu
+            /// </summary>
+            /// <param name="title">The title of the page shown on the top of the main page</param>
+            /// <param name="page">The page to be navigated to</param>
+            /// <param name="extraInformation">Optional extra information to be given when navigating</param>
+            public MainMenuNavigationItemData(string title, string page, object extraInformation)
+            {
+                Title = title;
+                Page = page;
+                ExtraInformation = extraInformation;
+            }
+
+            /// <summary>
+            /// The title of the page shown on the top of the main page
+            /// </summary>
+            public string Title { get; set; }
+            /// <summary>
+            /// The page to be navigated to
+            /// </summary>
+            public string Page { get; set; }
+            /// <summary>
+            /// Optional extra information to be given when navigating
+            /// </summary>
+            public object ExtraInformation { get; set; }
+        }
+        #endregion
+
+        #region Property change notification
+        /// <summary>
+        /// Occurs when a property value changes.
+        /// </summary>
+        public event PropertyChangedEventHandler PropertyChanged;
+        /// <summary>
+        /// Triggers the PropertyChanged event
+        /// </summary>
+        /// <param name="propertyName">The property which is changed</param>
+        private void OnPropertyChanged(string propertyName)
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
+        #endregion
+    }
+}