diff options
Diffstat (limited to 'MediaBrowser.UI.Controls/ExtendedListBox.cs')
| -rw-r--r-- | MediaBrowser.UI.Controls/ExtendedListBox.cs | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/MediaBrowser.UI.Controls/ExtendedListBox.cs b/MediaBrowser.UI.Controls/ExtendedListBox.cs new file mode 100644 index 000000000..fb6738939 --- /dev/null +++ b/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; + } + } + } + } +} |