maui-linux/Xamarin.Forms.Platform.WinRT.Phone/SearchBarRenderer.cs

using System;
using System.ComponentModel;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;

namespace Xamarin.Forms.Platform.WinRT
{
	public class SearchBarRenderer
		: ViewRenderer<SearchBar, SearchBox>
	{
		protected override void OnElementChanged (ElementChangedEventArgs<SearchBar> e)
		{
			if (e.NewElement != null) {
				if (Control == null) {
					SetNativeControl (new SearchBox ());
					Control.QuerySubmitted += OnQuerySubmitted;
					Control.QueryChanged += OnQueryChanged;
					Control.Loaded += (sender, args) => {
						_queryTextBox = Control.GetFirstDescendant<FormsTextBox> ();
						UpdateTextColor ();
						UpdatePlaceholderColor ();
					};
				}

				UpdateText ();
				UpdatePlaceholder ();
				UpdateFont ();
				UpdateAlignment ();
				UpdatePlaceholderColor ();
				UpdateTextColor ();
			}

			base.OnElementChanged (e);
		}

		protected override void OnElementPropertyChanged (object sender, PropertyChangedEventArgs e)
		{
			base.OnElementPropertyChanged (sender, e);

			if (e.PropertyName == SearchBar.TextProperty.PropertyName)
				UpdateText ();
			else if (e.PropertyName == SearchBar.PlaceholderProperty.PropertyName)
				UpdatePlaceholder ();
			else if (e.PropertyName == SearchBar.FontAttributesProperty.PropertyName)
				UpdateFont ();
			else if (e.PropertyName == SearchBar.FontFamilyProperty.PropertyName)
				UpdateFont ();
			else if (e.PropertyName == SearchBar.FontSizeProperty.PropertyName)
				UpdateFont ();
			else if (e.PropertyName == SearchBar.HorizontalTextAlignmentProperty.PropertyName)
				UpdateAlignment ();
			else if (e.PropertyName == SearchBar.PlaceholderColorProperty.PropertyName)
				UpdatePlaceholderColor ();
			else if (e.PropertyName == SearchBar.TextColorProperty.PropertyName)
				UpdateTextColor ();
		}

		bool _fontApplied;

		void OnQuerySubmitted (SearchBox sender, SearchBoxQuerySubmittedEventArgs e)
		{
			Element.OnSearchButtonPressed ();
		}

		void UpdatePlaceholder ()
		{
			Control.PlaceholderText = Element.Placeholder ?? string.Empty;
		}

		void UpdateFont ()
		{
			if (Control == null)
				return;

			var searchBar = Element;

			if (searchBar == null)
				return;

			bool searchBarIsDefault = searchBar.FontFamily == null && searchBar.FontSize == Device.GetNamedSize (NamedSize.Default, typeof (SearchBar), true) && searchBar.FontAttributes == FontAttributes.None;

			if (searchBarIsDefault && !_fontApplied)
				return;

			if (searchBarIsDefault) {
				Control.ClearValue (Windows.UI.Xaml.Controls.Control.FontStyleProperty);
				Control.ClearValue (Windows.UI.Xaml.Controls.Control.FontSizeProperty);
				Control.ClearValue (Windows.UI.Xaml.Controls.Control.FontFamilyProperty);
				Control.ClearValue (Windows.UI.Xaml.Controls.Control.FontWeightProperty);
				Control.ClearValue (Windows.UI.Xaml.Controls.Control.FontStretchProperty);
			} else {
				Control.ApplyFont (searchBar);
			}

			_fontApplied = true;
		}

		void OnQueryChanged (SearchBox sender, SearchBoxQueryChangedEventArgs e)
		{
			((IElementController) Element).SetValueFromRenderer (SearchBar.TextProperty, e.QueryText);
		}

		void UpdateText ()
		{
			Control.QueryText = Element.Text ?? string.Empty;
		}

		void UpdateAlignment ()
		{
			Control.HorizontalTextAlignment = Element.HorizontalTextAlignment;
		}

		void UpdateTextColor ()
		{
			if (_queryTextBox == null) {
				return;
			}

			var textColor = Element.TextColor;

			if (textColor.IsDefault)
			{
				if (_defaultTextColorBrush == null) {
					return;
				}

				_queryTextBox.Foreground = _defaultTextColorBrush;
			}

			_defaultTextColorBrush = _defaultTextColorBrush ?? _queryTextBox.Foreground;

			_queryTextBox.Foreground = textColor.ToBrush();
		}

		void UpdatePlaceholderColor ()
		{
			if (_queryTextBox == null) {
				return;
			}

			var placeholderColor = Element.PlaceholderColor;

			if (placeholderColor.IsDefault) {
				if (_defaultPlaceholderColorBrush == null) {
					return;
				}

				_queryTextBox.PlaceholderForegroundBrush = _defaultPlaceholderColorBrush;
			}

			_defaultPlaceholderColorBrush = _defaultPlaceholderColorBrush ?? _queryTextBox.PlaceholderForegroundBrush;

			_queryTextBox.PlaceholderForegroundBrush = placeholderColor.ToBrush ();
		}

		FormsTextBox _queryTextBox;
		Brush _defaultTextColorBrush;
		Brush _defaultPlaceholderColorBrush;
	}
}