maui-linux/Xamarin.Forms.Platform.WinR.../TabbedPageRenderer.cs

369 строки
8.5 KiB
C#

using System;
using System.Collections.Specialized;
using System.ComponentModel;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Automation;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;
using Xamarin.Forms.Internals;
using WGrid = Windows.UI.Xaml.Controls.Grid;
namespace Xamarin.Forms.Platform.WinRT
{
internal class TabbedPagePresenter : Windows.UI.Xaml.Controls.ContentPresenter
{
public TabbedPagePresenter()
{
SizeChanged += (s, e) =>
{
if (ActualWidth > 0 && ActualHeight > 0)
{
var tab = ((Page)DataContext);
((IPageController)tab.RealParent).ContainerArea = new Rectangle(0, 0, ActualWidth, ActualHeight);
}
};
}
}
public class TabbedPageRenderer
: IVisualElementRenderer, ITitleProvider
{
const string TabBarHeaderTextBlockName = "TabbedPageHeaderTextBlock";
const string TabBarHeaderGridName = "TabbedPageHeaderGrid";
Color _barBackgroundColor;
Color _barTextColor;
bool _disposed;
VisualElementTracker<Page, Pivot> _tracker;
bool _showTitle;
ITitleProvider TitleProvider => this;
IPageController PageController => Element as IPageController;
public event EventHandler<VisualElementChangedEventArgs> ElementChanged;
public FrameworkElement ContainerElement
{
get { return Control; }
}
VisualElement IVisualElementRenderer.Element
{
get { return Element; }
}
public FormsPivot Control
{
get;
private set;
}
public TabbedPage Element
{
get;
private set;
}
public void SetElement(VisualElement element)
{
if (element != null && !(element is TabbedPage))
throw new ArgumentException("Element must be a TabbedPage", "element");
TabbedPage oldElement = Element;
Element = (TabbedPage)element;
if (oldElement != null)
{
oldElement.PropertyChanged -= OnElementPropertyChanged;
((INotifyCollectionChanged)oldElement.Children).CollectionChanged -= OnPagesChanged;
}
if (element != null)
{
if (Control == null)
{
Control = new FormsPivot
{
Style = (Windows.UI.Xaml.Style)Windows.UI.Xaml.Application.Current.Resources["TabbedPageStyle"],
ItemTemplate = (Windows.UI.Xaml.DataTemplate)Windows.UI.Xaml.Application.Current.Resources["TabbedPage"]
};
Control.SelectionChanged += OnSelectionChanged;
Tracker = new BackgroundTracker<Pivot>(Windows.UI.Xaml.Controls.Control.BackgroundProperty)
{
Element = (Page)element,
Control = Control,
Container = Control
};
Control.Loaded += OnLoaded;
Control.Unloaded += OnUnloaded;
}
Control.DataContext = Element;
OnPagesChanged(Element.Children, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
UpdateCurrentPage();
((INotifyCollectionChanged)Element.Children).CollectionChanged += OnPagesChanged;
element.PropertyChanged += OnElementPropertyChanged;
if (!string.IsNullOrEmpty(element.AutomationId))
Control.SetValue(AutomationProperties.AutomationIdProperty, element.AutomationId);
}
OnElementChanged(new VisualElementChangedEventArgs(oldElement, element));
}
public SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint)
{
var constraint = new Windows.Foundation.Size(widthConstraint, heightConstraint);
var oldWidth = Control.Width;
var oldHeight = Control.Height;
Control.Height = double.NaN;
Control.Width = double.NaN;
Control.Measure(constraint);
var result = new Size(Math.Ceiling(Control.DesiredSize.Width), Math.Ceiling(Control.DesiredSize.Height));
Control.Width = oldWidth;
Control.Height = oldHeight;
return new SizeRequest(result);
}
public void Dispose()
{
Dispose(true);
}
protected virtual void Dispose(bool disposing)
{
if (!disposing || _disposed)
return;
_disposed = true;
PageController?.SendDisappearing();
SetElement(null);
Tracker = null;
}
protected VisualElementTracker<Page, Pivot> Tracker
{
get
{
return _tracker;
}
set
{
if (_tracker == value)
return;
if (_tracker != null)
{
_tracker.Dispose();
/*this.tracker.Updated -= OnTrackerUpdated;*/
}
_tracker = value;
/*if (this.tracker != null)
this.tracker.Updated += OnTrackerUpdated;*/
}
}
bool ITitleProvider.ShowTitle
{
get
{
return _showTitle;
}
set
{
if (_showTitle == value)
return;
_showTitle = value;
Control.TitleVisibility = _showTitle ? Visibility.Visible : Visibility.Collapsed;
}
}
string ITitleProvider.Title
{
get
{
return (string)Control?.Title;
}
set
{
if (Control != null)
Control.Title = value;
}
}
Brush ITitleProvider.BarBackgroundBrush
{
set
{
Control.ToolbarBackground = value;
}
}
Brush ITitleProvider.BarForegroundBrush
{
set
{
Control.ToolbarForeground = value;
}
}
protected virtual void OnElementChanged(VisualElementChangedEventArgs e)
{
var changed = ElementChanged;
if (changed != null)
changed(this, e);
}
void OnPagesChanged(object sender, NotifyCollectionChangedEventArgs e)
{
e.Apply(Element.Children, Control.Items);
// Potential performance issue, UpdateLayout () is called for every page change
Control.UpdateLayout();
}
void OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (Element == null)
return;
Page page = (e.AddedItems.Count > 0) ? (Page)e.AddedItems[0] : null;
Element.CurrentPage = page;
}
void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == nameof(TabbedPage.CurrentPage))
{
UpdateCurrentPage();
UpdateBarTextColor();
UpdateBarBackgroundColor();
}
else if (e.PropertyName == TabbedPage.BarTextColorProperty.PropertyName)
UpdateBarTextColor();
else if (e.PropertyName == TabbedPage.BarBackgroundColorProperty.PropertyName)
UpdateBarBackgroundColor();
}
void UpdateCurrentPage()
{
Page page = Element.CurrentPage;
UpdateTitle(page);
if (page == null)
return;
Control.SelectedItem = page;
}
void OnLoaded(object sender, RoutedEventArgs args)
{
PageController?.SendAppearing();
UpdateBarTextColor();
UpdateBarBackgroundColor();
}
void OnUnloaded(object sender, RoutedEventArgs args)
{
PageController?.SendDisappearing();
}
void OnTrackerUpdated(object sender, EventArgs e)
{
}
Brush GetBarBackgroundBrush()
{
object defaultColor = Windows.UI.Xaml.Application.Current.Resources["AppBarBackgroundThemeBrush"];
if (Element.BarBackgroundColor.IsDefault && defaultColor != null)
return (Brush)defaultColor;
return Element.BarBackgroundColor.ToBrush();
}
Brush GetBarForegroundBrush()
{
object defaultColor = Windows.UI.Xaml.Application.Current.Resources["AppBarItemForegroundThemeBrush"];
if (Element.BarTextColor.IsDefault && defaultColor != null)
return (Brush)defaultColor;
return Element.BarTextColor.ToBrush();
}
void UpdateBarBackgroundColor()
{
if (Element == null) return;
var barBackgroundColor = Element.BarBackgroundColor;
if (barBackgroundColor == _barBackgroundColor) return;
_barBackgroundColor = barBackgroundColor;
var controlToolbarBackground = Control.ToolbarBackground;
if (controlToolbarBackground == null && barBackgroundColor.IsDefault) return;
var brush = GetBarBackgroundBrush();
if (brush == controlToolbarBackground) return;
TitleProvider.BarBackgroundBrush = brush;
foreach (WGrid tabBarGrid in Control.GetDescendantsByName<WGrid>(TabBarHeaderGridName))
{
tabBarGrid.Background = brush;
}
}
void UpdateBarTextColor()
{
if (Element == null) return;
var barTextColor = Element.BarTextColor;
if (barTextColor == _barTextColor) return;
_barTextColor = barTextColor;
var controlToolbarForeground = Control.ToolbarForeground;
if (controlToolbarForeground == null && barTextColor.IsDefault) return;
var brush = GetBarForegroundBrush();
if (brush == controlToolbarForeground) return;
TitleProvider.BarForegroundBrush = brush;
foreach (TextBlock tabBarTextBlock in Control.GetDescendantsByName<TextBlock>(TabBarHeaderTextBlockName))
{
tabBarTextBlock.Foreground = brush;
}
}
void UpdateTitle(Page child)
{
Control.ClearValue(Pivot.TitleProperty);
if (child == null)
return;
var renderer = Platform.GetRenderer(child);
var navigationRenderer = renderer as NavigationPageRenderer;
if (navigationRenderer != null)
{
Control.Title = navigationRenderer.Title;
}
else
{
TitleProvider.ShowTitle = false;
}
}
}
}