ShellChromeGallery.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Maui;
using Microsoft.Maui.Controls;
using Microsoft.Maui.Graphics;

namespace Maui.Controls.Sample.Pages.ShellGalleries
{
	public partial class ShellChromeGallery
	{
		AppShell? AppShell => Application.Current!.MainPage as AppShell;

		public ShellChromeGallery()
		{
			InitializeComponent();

			flyoutBehavior.ItemsSource = Enum.GetNames(typeof(FlyoutBehavior));
			flyoutBehavior.SelectedIndexChanged += OnFlyoutBehaviorSelectedIndexChanged;

			flyoutHeaderBehavior.ItemsSource = Enum.GetNames(typeof(FlyoutHeaderBehavior));
			flyoutHeaderBehavior.SelectedIndexChanged += OnFlyoutHeaderBehaviorSelectedIndexChanged;

			if (AppShell != null)
			{
				flyoutBehavior.SelectedIndex = (int)AppShell.FlyoutBehavior;
				flyoutHeaderBehavior.SelectedIndex = (int)AppShell.FlyoutHeaderBehavior;
				AppShell.FlyoutBackdrop = SolidColorBrush.Pink;
			}
			else
			{
				flyoutBehavior.SelectedIndex = 1;
				flyoutHeaderBehavior.SelectedIndex = 0;
			}
		}
		protected override void OnNavigatedTo(NavigatedToEventArgs args)
		{
			base.OnNavigatedTo(args);
			popToRoot.IsVisible = Navigation.NavigationStack.Count > 1;
		}

		async void OnPushPage(object sender, EventArgs e)
		{
			await Navigation.PushAsync(new ShellChromeGallery());
		}

		async void OnPopPage(object sender, EventArgs e)
		{
			if (Navigation.NavigationStack.Count > 1)
				await Navigation.PopAsync();
		}

		async void OnPopToRoot(object sender, EventArgs e)
		{
			await Navigation.PopToRootAsync();
		}



		void OnFlyoutHeaderBehaviorSelectedIndexChanged(object? sender, EventArgs e)
		{
			AppShell!.FlyoutHeaderBehavior = (FlyoutHeaderBehavior)flyoutHeaderBehavior.SelectedIndex;
		}

		void OnFlyoutBehaviorSelectedIndexChanged(object? sender, EventArgs e)
		{
			AppShell!.FlyoutBehavior = (FlyoutBehavior)flyoutBehavior.SelectedIndex;
		}

		protected override void OnAppearing()
		{
			AppShell!.FlyoutBehavior = (FlyoutBehavior)flyoutBehavior.SelectedIndex;
			AppShell!.FlyoutHeaderBehavior = (FlyoutHeaderBehavior)flyoutHeaderBehavior.SelectedIndex;
		}

		void OnToggleFlyoutIsPresented(object sender, EventArgs e)
		{
			AppShell!.FlyoutIsPresented = !AppShell!.FlyoutIsPresented;
		}
		
		void OnToggleFlyoutBackgroundColor(object sender, EventArgs e)
		{
			AppShell!.RemoveBinding(Shell.FlyoutBackgroundProperty);
			if (AppShell.FlyoutBackground.IsEmpty ||
				AppShell.FlyoutBackground == SolidColorBrush.Purple)
			{
				AppShell.FlyoutBackground = SolidColorBrush.Black;
			}
			else if (AppShell.FlyoutBackground == SolidColorBrush.Black)
			{
				AppShell.FlyoutBackground = SolidColorBrush.Purple;
			}
			else
			{
				AppShell.FlyoutBackground = SolidColorBrush.Purple;
			}

			flyoutBackgroundColor.Background = AppShell.FlyoutBackground;
		}

		void OnToggleNavBarIsVisible(object sender, EventArgs e)
		{
			Shell.SetNavBarIsVisible(this, !Shell.GetNavBarIsVisible(this));
		}

		void OnToggleBackButtonIsVisible(object sender, EventArgs e)
		{
			var backButtonBehavior = Shell.GetBackButtonBehavior(this) ?? new BackButtonBehavior();
			backButtonBehavior.IsVisible = !backButtonBehavior.IsVisible;
			Shell.SetBackButtonBehavior(this, backButtonBehavior);
		}

		void OnToggleSearchHandler(object sender, EventArgs e)
		{
			var searchHandler = Shell.GetSearchHandler(this);
			if (searchHandler != null)
				RemoveSearchHandler();
			else
				AddSearchHandler("text here");
		}

		void OnToggleTabBar(object sender, EventArgs e)
		{
			Shell.SetTabBarIsVisible(this, !Shell.GetTabBarIsVisible(this));
		}

		void OnToggleTabBarTitleColor(object sender, EventArgs e)
		{
			var random = new Random();
			Shell.SetTabBarTitleColor(Shell.Current.CurrentItem, Color.FromRgb(random.Next(0, 255), random.Next(0, 255), random.Next(0, 255)));
		}

		void OnToggleTabBarUnselectedColor(object sender, EventArgs e)
		{
			var random = new Random();
			Shell.SetTabBarUnselectedColor(Shell.Current.CurrentItem, Color.FromRgb(random.Next(0, 255), random.Next(0, 255), random.Next(0, 255)));
		}

		void OnToggleTabBarForegroundColor(object sender, EventArgs e)
		{
			var random = new Random();
			Shell.SetTabBarForegroundColor(Shell.Current.CurrentItem, Color.FromRgb(random.Next(0, 255), random.Next(0, 255), random.Next(0, 255)));
		}

		protected void AddSearchHandler(string placeholder)
		{
			var searchHandler = new CustomSearchHandler();

			searchHandler.ShowsResults = true;

			searchHandler.ClearIconName = "Clear";
			searchHandler.ClearIconHelpText = "Clears the search field text";

			searchHandler.ClearPlaceholderName = "Voice Search";
			searchHandler.ClearPlaceholderHelpText = "Start voice search";

			searchHandler.QueryIconName = "Search";
			searchHandler.QueryIconHelpText = "Press to search app";

			searchHandler.Placeholder = placeholder;

			searchHandler.ClearPlaceholderEnabled = true;
			searchHandler.ClearPlaceholderIcon = "mic.png";

			Shell.SetSearchHandler(this, searchHandler);
		}

		protected void RemoveSearchHandler()
		{
			ClearValue(Shell.SearchHandlerProperty);
		}
	}

	internal class CustomSearchHandler : SearchHandler
	{
		protected async override void OnQueryChanged(string oldValue, string newValue)
		{
			base.OnQueryChanged(oldValue, newValue);

			if (string.IsNullOrEmpty(newValue))
			{
				ItemsSource = null;
			}
			else
			{
				List<string> results = new List<string>();
				results.Add(newValue + "initial");

				ItemsSource = results;

				await Task.Delay(2000);

				results = new List<string>();

				for (int i = 0; i < 10; i++)
				{
					results.Add(newValue + i);
				}

				ItemsSource = results;
			}
		}
	}
}