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using System;
using System.Collections;
using System.Collections.Specialized;
using System.Diagnostics;
using MonoTouch.Foundation;
using MonoTouch.UIKit;
namespace Praeclarum.UI
{
[Register ("ObservableTableViewController")]
public class ObservableTableViewController : UITableViewController
{
public UITableViewRowAnimation AddAnimation { get; set; }
public UITableViewRowAnimation DeleteAnimation { get; set; }
object dataSource;
IList list;
INotifyCollectionChanged notifier;
System.Threading.Thread mainThread;
bool loadedView = false;
public object DataSource {
get {
return dataSource;
}
set {
if (dataSource == value)
return;
if (notifier != null) {
notifier.CollectionChanged -= HandleCollectionChanged;
}
dataSource = value;
list = value as IList;
notifier = value as INotifyCollectionChanged;
if (notifier != null) {
notifier.CollectionChanged += HandleCollectionChanged;
}
if (loadedView) {
TableView.ReloadData ();
}
}
}
public ObservableTableViewController ()
: base (UITableViewStyle.Plain)
{
Initialize ();
}
public ObservableTableViewController (UITableViewStyle withStyle)
: base (withStyle)
{
Initialize ();
}
void Initialize ()
{
mainThread = System.Threading.Thread.CurrentThread;
AddAnimation = UITableViewRowAnimation.Automatic;
DeleteAnimation = UITableViewRowAnimation.Automatic;
}
public override void ViewDidLoad ()
{
base.ViewDidLoad ();
TableView.Source = CreateSource ();
loadedView = true;
}
protected virtual ObservableTableSource CreateSource ()
{
return new ObservableTableSource (this);
}
protected virtual UITableViewCell CreateCell (NSString reuseId)
{
return new UITableViewCell (UITableViewCellStyle.Default, reuseId);
}
protected virtual void BindCell (UITableViewCell cell, object item, NSIndexPath indexPath)
{
cell.TextLabel.Text = item.ToString ();
}
protected virtual void OnRowSelected (object item, NSIndexPath indexPath)
{
}
void HandleCollectionChanged (object sender, NotifyCollectionChangedEventArgs e)
{
if (!loadedView)
return;
NSAction act = () => {
if (e.Action == NotifyCollectionChangedAction.Reset) {
TableView.ReloadData ();
}
if (e.Action == NotifyCollectionChangedAction.Add) {
var count = e.NewItems.Count;
var paths = new NSIndexPath[count];
for (var i = 0; i < count; i++) {
paths [i] = NSIndexPath.FromRowSection (e.NewStartingIndex + i, 0);
}
TableView.InsertRows (paths, AddAnimation);
} else if (e.Action == NotifyCollectionChangedAction.Remove) {
var count = e.OldItems.Count;
var paths = new NSIndexPath[count];
for (var i = 0; i < count; i++) {
paths [i] = NSIndexPath.FromRowSection (e.OldStartingIndex + i, 0);
}
TableView.DeleteRows (paths, DeleteAnimation);
}
};
var isMainThread = System.Threading.Thread.CurrentThread == mainThread;
if (isMainThread) {
act ();
} else {
NSOperationQueue.MainQueue.AddOperation (act);
NSOperationQueue.MainQueue.WaitUntilAllOperationsAreFinished ();
}
}
protected class ObservableTableSource : UITableViewSource
{
readonly ObservableTableViewController controller;
static readonly NSString reuseId = new NSString ("C");
public ObservableTableSource (ObservableTableViewController controller)
{
this.controller = controller;
}
public override void RowSelected (UITableView tableView, NSIndexPath indexPath)
{
var item = controller.list != null ? controller.list [indexPath.Row] : null;
try {
controller.OnRowSelected (item, indexPath);
} catch (Exception ex) {
Debug.WriteLine (ex);
}
}
public override int NumberOfSections (UITableView tableView)
{
return 1;
}
public override int RowsInSection (UITableView tableview, int section)
{
var coll = controller.list;
return coll != null ? coll.Count : 0;
}
public override UITableViewCell GetCell (UITableView tableView, NSIndexPath indexPath)
{
var cell = tableView.DequeueReusableCell (reuseId) ??
controller.CreateCell (reuseId);
try {
var coll = controller.list;
if (coll != null) {
var obj = coll[indexPath.Row];
controller.BindCell (cell, obj, indexPath);
}
return cell;
}
catch (Exception ex) {
Debug.WriteLine (ex);
}
return cell;
}
}
}
}
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