Pushing missing changes

MediaBrowser.UI.Controls/ExtendedListBox.cs

@@ -0,0 +1,260 @@
+using System;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
+using System.Windows.Input;
+using System.Windows.Media;
+
+namespace MediaBrowser.UI.Controls
+{
+    /// <summary>
+    /// Extends the ListBox to provide auto-focus behavior when items are moused over
+    /// This also adds an ItemInvoked event that is fired when an item is clicked or invoked using the enter key
+    /// </summary>
+    public class ExtendedListBox : ListBox
+    {
+        /// <summary>
+        /// Fired when an item is clicked or invoked using the enter key
+        /// </summary>
+        public event EventHandler<ItemEventArgs<object>> ItemInvoked;
+
+        /// <summary>
+        /// Called when [item invoked].
+        /// </summary>
+        /// <param name="boundObject">The bound object.</param>
+        protected virtual void OnItemInvoked(object boundObject)
+        {
+            if (ItemInvoked != null)
+            {
+                ItemInvoked(this, new ItemEventArgs<object> { Argument = boundObject });
+            }
+        }
+
+        /// <summary>
+        /// The _auto focus
+        /// </summary>
+        private bool _autoFocus = true;
+        /// <summary>
+        /// Gets or sets a value indicating if the first list item should be auto-focused on load
+        /// </summary>
+        /// <value><c>true</c> if [auto focus]; otherwise, <c>false</c>.</value>
+        public bool AutoFocus
+        {
+            get { return _autoFocus; }
+            set
+            {
+                _autoFocus = value;
+            }
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ExtendedListBox" /> class.
+        /// </summary>
+        public ExtendedListBox()
+            : base()
+        {
+            ItemContainerGenerator.StatusChanged += ItemContainerGeneratorStatusChanged;
+        }
+
+        /// <summary>
+        /// The mouse down object
+        /// </summary>
+        private object mouseDownObject;
+
+        /// <summary>
+        /// Invoked when an unhandled <see cref="E:System.Windows.Input.Mouse.PreviewMouseDown" /> attached routed event reaches an element in its route that is derived from this class. Implement this method to add class handling for this event.
+        /// </summary>
+        /// <param name="e">The <see cref="T:System.Windows.Input.MouseButtonEventArgs" /> that contains the event data. The event data reports that one or more mouse buttons were pressed.</param>
+        protected override void OnPreviewMouseDown(MouseButtonEventArgs e)
+        {
+            base.OnPreviewMouseDown(e);
+
+            // Get the item that the mouse down event occurred on
+            mouseDownObject = GetBoundListItemObject((DependencyObject)e.OriginalSource);
+        }
+
+        /// <summary>
+        /// Invoked when an unhandled <see cref="E:System.Windows.UIElement.MouseLeftButtonUp" /> routed event reaches an element in its route that is derived from this class. Implement this method to add class handling for this event.
+        /// </summary>
+        /// <param name="e">The <see cref="T:System.Windows.Input.MouseButtonEventArgs" /> that contains the event data. The event data reports that the left mouse button was released.</param>
+        protected override void OnMouseLeftButtonUp(MouseButtonEventArgs e)
+        {
+            base.OnMouseLeftButtonUp(e);
+
+            // If the mouse up event occurred on the same item as the mousedown event, then fire ItemInvoked
+            if (mouseDownObject != null)
+            {
+                var boundObject = GetBoundListItemObject((DependencyObject)e.OriginalSource);
+
+                if (mouseDownObject == boundObject)
+                {
+                    mouseDownObject = null;
+                    OnItemInvoked(boundObject);
+                }
+            }
+        }
+
+        /// <summary>
+        /// The key down object
+        /// </summary>
+        private object keyDownObject;
+
+        /// <summary>
+        /// Responds to the <see cref="E:System.Windows.UIElement.KeyDown" /> event.
+        /// </summary>
+        /// <param name="e">Provides data for <see cref="T:System.Windows.Input.KeyEventArgs" />.</param>
+        protected override void OnKeyDown(KeyEventArgs e)
+        {
+            if (e.Key == Key.Enter)
+            {
+                if (!e.IsRepeat)
+                {
+                    // Get the item that the keydown event occurred on
+                    keyDownObject = GetBoundListItemObject((DependencyObject)e.OriginalSource);
+                }
+
+                e.Handled = true;
+            }
+
+            base.OnKeyDown(e);
+        }
+
+        /// <summary>
+        /// Invoked when an unhandled <see cref="E:System.Windows.Input.Keyboard.KeyUp" /> attached event reaches an element in its route that is derived from this class. Implement this method to add class handling for this event.
+        /// </summary>
+        /// <param name="e">The <see cref="T:System.Windows.Input.KeyEventArgs" /> that contains the event data.</param>
+        protected override void OnKeyUp(KeyEventArgs e)
+        {
+            base.OnKeyUp(e);
+
+            // Fire ItemInvoked when enter is pressed on an item
+            if (e.Key == Key.Enter)
+            {
+                if (!e.IsRepeat)
+                {
+                    // If the keyup event occurred on the same item as the keydown event, then fire ItemInvoked
+                    if (keyDownObject != null)
+                    {
+                        var boundObject = GetBoundListItemObject((DependencyObject)e.OriginalSource);
+
+                        if (keyDownObject == boundObject)
+                        {
+                            keyDownObject = null;
+                            OnItemInvoked(boundObject);
+                        }
+                    }
+                }
+
+                e.Handled = true;
+            }
+        }
+
+        /// <summary>
+        /// The _last mouse move point
+        /// </summary>
+        private Point? _lastMouseMovePoint;
+
+        /// <summary>
+        /// Handles OnMouseMove to auto-select the item that's being moused over
+        /// </summary>
+        /// <param name="e">Provides data for <see cref="T:System.Windows.Input.MouseEventArgs" />.</param>
+        protected override void OnMouseMove(MouseEventArgs e)
+        {
+            base.OnMouseMove(e);
+
+            var window = this.GetWindow();
+
+            // If the cursor is currently hidden, don't bother reacting to it
+            if (Cursor == Cursors.None || window.Cursor == Cursors.None)
+            {
+                return;
+            }
+
+            // Store the last position for comparison purposes
+            // Even if the mouse is not moving this event will fire as elements are showing and hiding
+            var pos = e.GetPosition(window);
+
+            if (!_lastMouseMovePoint.HasValue)
+            {
+                _lastMouseMovePoint = pos;
+                return;
+            }
+
+            if (pos == _lastMouseMovePoint)
+            {
+                return;
+            }
+
+            _lastMouseMovePoint = pos;
+
+            var dep = (DependencyObject)e.OriginalSource;
+
+            while ((dep != null) && !(dep is ListBoxItem))
+            {
+                dep = VisualTreeHelper.GetParent(dep);
+            }
+
+            if (dep != null)
+            {
+                var listBoxItem = dep as ListBoxItem;
+
+                if (!listBoxItem.IsFocused)
+                {
+                    listBoxItem.Focus();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Gets the datacontext for a given ListBoxItem
+        /// </summary>
+        /// <param name="dep">The dep.</param>
+        /// <returns>System.Object.</returns>
+        private object GetBoundListItemObject(DependencyObject dep)
+        {
+            while ((dep != null) && !(dep is ListBoxItem))
+            {
+                dep = VisualTreeHelper.GetParent(dep);
+            }
+
+            if (dep == null)
+            {
+                return null;
+            }
+
+            return ItemContainerGenerator.ItemFromContainer(dep);
+        }
+
+        /// <summary>
+        /// Autofocuses the first list item when the list is loaded
+        /// </summary>
+        /// <param name="sender">The sender.</param>
+        /// <param name="e">The <see cref="EventArgs" /> instance containing the event data.</param>
+        void ItemContainerGeneratorStatusChanged(object sender, EventArgs e)
+        {
+            if (ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated && AutoFocus)
+            {
+                Dispatcher.InvokeAsync(OnContainersGenerated);
+            }
+        }
+
+        /// <summary>
+        /// Called when [containers generated].
+        /// </summary>
+        void OnContainersGenerated()
+        {
+            var index = 0;
+
+            if (index >= 0)
+            {
+                var item = ItemContainerGenerator.ContainerFromIndex(index) as ListBoxItem;
+
+                if (item != null)
+                {
+                    item.Focus();
+                    ItemContainerGenerator.StatusChanged -= ItemContainerGeneratorStatusChanged;
+                }
+            }
+        }
+    }
+}