prs/prs.mobile/comal.timesheets/CustomControls/Pages/MultiSelectPage.xaml.cs

using comal.timesheets.Data_Classes;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace comal.timesheets
{
    public delegate void MultiSelctPageSaved(IEnumerable<MultiSelectPageViewItem> items, int colnumber, string columnname);

    [XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class MultiSelectPage : ContentPage
    {
        public event MultiSelctPageSaved OnPageSaved;
        List<string> Options = new List<string>();
        int Columnnumber;
        string ColumnName;
        ObservableCollection<MultiSelectPageViewItem> Items = new ObservableCollection<MultiSelectPageViewItem>();

        public MultiSelectPage(List<string> options, string title = "Select Options")
        {
            Setup(options, title);
            listView.ItemsSource = Items;
        }

        public MultiSelectPage(List<string> options, List<DataGridFilter> filters, int columnnumber, string columnname)
        {
            Setup(options, columnname);
            foreach (var filter in filters)
            {
                var item = Items.FirstOrDefault(x => x.Value == filter.Value);
                item.Selected = true;
            }
            ColumnName = columnname;
            Columnnumber = columnnumber;
            listView.ItemsSource = Items;
        }
        private void Setup(List<string> options, string title)
        {
            InitializeComponent();
            titleLbl.Text = title;
            NavigationPage.SetHasBackButton(this, false);
            Options = options;
            foreach (var option in Options)
                Items.Add(new MultiSelectPageViewItem { Value = option });
        }

        private void SearchEnt_Changed(object sender, EventArgs e)
        {
            string s = searchEnt.Text;
            listView.ItemsSource = Items.Where(
                x => x.Value.Contains(s) || x.Value.Contains(s.ToUpper()) || x.Value.Contains(s.ToLower())
                || x.Value.Contains(SearchUtils.UpperCaseFirst(s)) || x.Value.Contains(SearchUtils.LowerCaseFirst(s)) || x.Value.Contains(SearchUtils.UpperCaseSecond(s))
                );
        }

        private void CancelBtn_Clicked(object sender, EventArgs e)
        {
            Navigation.PopAsync();
        }

        private void SaveBtn_Clicked(object sender, EventArgs e)
        {
            OnPageSaved(Items.Where(x => x.Selected == true), Columnnumber, ColumnName) ;
            Navigation.PopAsync();
        }

        private void Item_Tapped(object sender, EventArgs e)
        {
            var selecteditem = listView.SelectedItem as MultiSelectPageViewItem;
            var item = Items.FirstOrDefault(x => x.Value == selecteditem.Value);
            item.Selected = item.Selected == true ? false : true;
        }

        private void SelectAll_Clicked(object sender, EventArgs e)
        {
            foreach (var item in Items)            
                item.Selected = true;           
        }

        private void ClearAll_Clicked(object sender, EventArgs e)
        {
            foreach (var item in Items)
                item.Selected = false;
        }
    }

    public class MultiSelectPageViewItem : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        private bool selected;
        public string Value { get; set; }
        public bool Selected
        {
            get => selected;
            set 
            {
                selected = value;
                OnPropertyChanged("Selected");
            }
        }
        public MultiSelectPageViewItem()
        {
            Value = "";
            Selected = false;
        }
        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}