diff options
Diffstat (limited to 'Xamarin.Forms.Platform.WinRT/VisualElementPackager.cs')
| -rw-r--r-- | Xamarin.Forms.Platform.WinRT/VisualElementPackager.cs | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.WinRT/VisualElementPackager.cs b/Xamarin.Forms.Platform.WinRT/VisualElementPackager.cs new file mode 100644 index 00000000..1c4036e0 --- /dev/null +++ b/Xamarin.Forms.Platform.WinRT/VisualElementPackager.cs @@ -0,0 +1,147 @@ +using System; +using System.Collections.ObjectModel; +using Windows.UI.Xaml.Controls; + +#if WINDOWS_UWP + +namespace Xamarin.Forms.Platform.UWP +#else + +namespace Xamarin.Forms.Platform.WinRT +#endif +{ + public class VisualElementPackager : IDisposable + { + readonly int _column; + readonly int _columnSpan; + + readonly Panel _panel; + readonly IVisualElementRenderer _renderer; + readonly int _row; + readonly int _rowSpan; + bool _disposed; + bool _isLoaded; + + public VisualElementPackager(IVisualElementRenderer renderer) + { + if (renderer == null) + throw new ArgumentNullException("renderer"); + + _renderer = renderer; + + _panel = renderer.ContainerElement as Panel; + if (_panel == null) + throw new ArgumentException("Renderer's container element must be a Panel"); + } + + public VisualElementPackager(IVisualElementRenderer renderer, int row = 0, int rowSpan = 0, int column = 0, int columnSpan = 0) : this(renderer) + { + _row = row; + _rowSpan = rowSpan; + _column = column; + _columnSpan = columnSpan; + } + + public void Dispose() + { + if (_disposed) + return; + + _disposed = true; + + VisualElement element = _renderer.Element; + if (element != null) + { + element.ChildAdded -= OnChildAdded; + element.ChildRemoved -= OnChildRemoved; + } + } + + public void Load() + { + if (_isLoaded) + return; + + _isLoaded = true; + _renderer.Element.ChildAdded += OnChildAdded; + _renderer.Element.ChildRemoved += OnChildRemoved; + + ReadOnlyCollection<Element> children = _renderer.Element.LogicalChildren; + for (var i = 0; i < children.Count; i++) + { + OnChildAdded(_renderer.Element, new ElementEventArgs(children[i])); + } + } + + void EnsureZIndex() + { + if (_renderer.Element.LogicalChildren.Count == 0) + return; + + for (var z = 0; z < _renderer.Element.LogicalChildren.Count; z++) + { + var child = _renderer.Element.LogicalChildren[z] as VisualElement; + if (child == null) + continue; + + IVisualElementRenderer childRenderer = Platform.GetRenderer(child); + + if (childRenderer == null) + { + continue; + } + + Canvas.SetZIndex(childRenderer.ContainerElement, z + 1); + } + } + + void OnChildAdded(object sender, ElementEventArgs e) + { + var view = e.Element as VisualElement; + + if (view == null) + return; + + IVisualElementRenderer childRenderer = Platform.CreateRenderer(view); + Platform.SetRenderer(view, childRenderer); + + if (_row > 0) + Windows.UI.Xaml.Controls.Grid.SetRow(childRenderer.ContainerElement, _row); + if (_rowSpan > 0) + Windows.UI.Xaml.Controls.Grid.SetRowSpan(childRenderer.ContainerElement, _rowSpan); + if (_column > 0) + Windows.UI.Xaml.Controls.Grid.SetColumn(childRenderer.ContainerElement, _column); + if (_columnSpan > 0) + Windows.UI.Xaml.Controls.Grid.SetColumnSpan(childRenderer.ContainerElement, _columnSpan); + + _panel.Children.Add(childRenderer.ContainerElement); + + EnsureZIndex(); + } + + void OnChildRemoved(object sender, ElementEventArgs e) + { + var view = e.Element as VisualElement; + + if (view == null) + return; + + IVisualElementRenderer childRenderer = Platform.GetRenderer(view); + if (childRenderer != null) + { + if (_row > 0) + childRenderer.ContainerElement.ClearValue(Windows.UI.Xaml.Controls.Grid.RowProperty); + if (_rowSpan > 0) + childRenderer.ContainerElement.ClearValue(Windows.UI.Xaml.Controls.Grid.RowSpanProperty); + if (_column > 0) + childRenderer.ContainerElement.ClearValue(Windows.UI.Xaml.Controls.Grid.ColumnProperty); + if (_columnSpan > 0) + childRenderer.ContainerElement.ClearValue(Windows.UI.Xaml.Controls.Grid.ColumnSpanProperty); + + _panel.Children.Remove(childRenderer.ContainerElement); + + view.Cleanup(); + } + } + } +}
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