diff options
Diffstat (limited to 'Xamarin.Forms.Platform.WinRT.Tablet/TabbedPageRenderer.cs')
| -rw-r--r-- | Xamarin.Forms.Platform.WinRT.Tablet/TabbedPageRenderer.cs | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.WinRT.Tablet/TabbedPageRenderer.cs b/Xamarin.Forms.Platform.WinRT.Tablet/TabbedPageRenderer.cs new file mode 100644 index 00000000..33923a49 --- /dev/null +++ b/Xamarin.Forms.Platform.WinRT.Tablet/TabbedPageRenderer.cs @@ -0,0 +1,236 @@ +using System; +using System.Collections.Specialized; +using System.ComponentModel; +using Windows.UI.Xaml; +using Windows.UI.Xaml.Controls; +using Windows.UI.Xaml.Media.Animation; + +namespace Xamarin.Forms.Platform.WinRT +{ + public class TabbedPageRenderer + : IVisualElementRenderer + { + Canvas _canvas; + + bool _disposed; + TabsControl _tabs; + VisualElementTracker<Page, Canvas> _tracker; + + public TabbedPage Page + { + get { return (TabbedPage)Element; } + } + + protected VisualElementTracker<Page, Canvas> Tracker + { + get { return _tracker; } + set + { + if (_tracker == value) + return; + + if (_tracker != null) + _tracker.Dispose(); + + _tracker = value; + } + } + + public event EventHandler<VisualElementChangedEventArgs> ElementChanged; + + public FrameworkElement ContainerElement + { + get { return _canvas; } + } + + public VisualElement Element { get; private set; } + + public void SetElement(VisualElement element) + { + if (element != null && !(element is TabbedPage)) + throw new ArgumentException("Element must be a TabbedPage", "element"); + + var oldElement = Page; + Element = element; + + if (oldElement != null) + { + oldElement.PropertyChanged -= OnElementPropertyChanged; + ((INotifyCollectionChanged)oldElement.Children).CollectionChanged -= OnPagesChanged; + } + + if (element != null) + { + if (_tracker == null) + { + _tabs = new TabsControl(); + + _canvas = new Canvas(); + + _canvas.ChildrenTransitions = new TransitionCollection + { + new EntranceThemeTransition() + }; + + Tracker = new BackgroundTracker<Canvas>(Panel.BackgroundProperty) + { + Element = (Page)element, + Control = _canvas, + Container = _canvas + }; + + _canvas.Loaded += OnLoaded; + _canvas.Unloaded += OnUnloaded; + } + + _tabs.DataContext = element; + + OnPagesChanged(Page.Children, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset)); + UpdateCurrentPage(); + + ((INotifyCollectionChanged)Page.Children).CollectionChanged += OnPagesChanged; + element.PropertyChanged += OnElementPropertyChanged; + } + + OnElementChanged(new VisualElementChangedEventArgs(oldElement, element)); + } + + public SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint) + { + if (_canvas.Children.Count == 0) + return new SizeRequest(); + + var constraint = new Windows.Foundation.Size(widthConstraint, heightConstraint); + var child = (FrameworkElement)_canvas.Children[0]; + + var oldWidth = child.Width; + var oldHeight = child.Height; + + child.Height = double.NaN; + child.Width = double.NaN; + + child.Measure(constraint); + var result = new Size(Math.Ceiling(child.DesiredSize.Width), Math.Ceiling(child.DesiredSize.Height)); + + child.Width = oldWidth; + child.Height = oldHeight; + + return new SizeRequest(result); + } + + public void Dispose() + { + Dispose(true); + } + + protected virtual void Dispose(bool disposing) + { + if (!disposing || _disposed) + return; + + _disposed = true; + SetElement(null); + Tracker = null; + } + + protected virtual void OnElementChanged(VisualElementChangedEventArgs e) + { + var changed = ElementChanged; + if (changed != null) + changed(this, e); + } + + void OnPagesChanged(object sender, NotifyCollectionChangedEventArgs e) + { + e.Apply(Page.Children, _tabs.Items); + } + + internal void OnTabSelected(Page tab) + { + CloseTabs(); + Page.CurrentPage = tab; + } + + void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e) + { + if (e.PropertyName == "CurrentPage") + UpdateCurrentPage(); + } + + void UpdateCurrentPage() + { + var renderer = Page.CurrentPage.GetOrCreateRenderer(); + _canvas.Children.Clear(); + + if (renderer != null) + _canvas.Children.Add(renderer.ContainerElement); + } + + void OnLoaded(object sender, RoutedEventArgs args) + { + if (Page == null) + return; + + ShowTabs(); + Page.SendAppearing(); + } + + Windows.UI.Xaml.Controls.Page GetTopPage() + { + var frame = Window.Current.Content as Windows.UI.Xaml.Controls.Frame; + if (frame == null) + return null; + + return frame.Content as Windows.UI.Xaml.Controls.Page; + } + + AppBar GetOrCreateAppBar() + { + var npage = GetTopPage(); + if (npage == null) + return null; + + if (npage.TopAppBar == null) + npage.TopAppBar = new AppBar(); + + return npage.TopAppBar; + } + + void ShowTabs() + { + var bar = GetOrCreateAppBar(); + if (bar != null) + bar.Content = _tabs; + } + + void CloseTabs() + { + var page = GetTopPage(); + if (page == null) + return; + + if (page.TopAppBar != null) + page.TopAppBar.IsOpen = false; + } + + void RemoveTabs() + { + var page = GetTopPage(); + if (page == null) + return; + + // Explicitly unparent this.tabs so we can reuse + if (page.TopAppBar != null) + page.TopAppBar.Content = null; + + page.TopAppBar = null; + } + + void OnUnloaded(object sender, RoutedEventArgs args) + { + RemoveTabs(); + if (Page != null) + Page.SendDisappearing(); + } + } +}
\ No newline at end of file |