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using System;
using System.ComponentModel;
using Android.Content;
using Android.Views;
using Android.Widget;
using AView = Android.Views.View;
using Object = Java.Lang.Object;
using Xamarin.Forms.Internals;
namespace Xamarin.Forms.Platform.Android
{
public class CellRenderer : IRegisterable
{
static readonly PropertyChangedEventHandler PropertyChangedHandler = OnGlobalCellPropertyChanged;
static readonly BindableProperty RendererProperty = BindableProperty.CreateAttached("Renderer", typeof(CellRenderer), typeof(Cell), null);
EventHandler _onForceUpdateSizeRequested;
public View ParentView { get; set; }
protected Cell Cell { get; set; }
public AView GetCell(Cell item, AView convertView, ViewGroup parent, Context context)
{
Performance.Start();
Cell = item;
Cell.PropertyChanged -= PropertyChangedHandler;
SetRenderer(Cell, this);
if (convertView != null)
{
Object tag = convertView.Tag;
CellRenderer renderer = (tag as RendererHolder)?.Renderer;
Cell oldCell = renderer?.Cell;
if (oldCell != null)
{
((ICellController)oldCell).SendDisappearing();
if (Cell != oldCell)
{
SetRenderer(oldCell, null);
}
}
}
AView view = GetCellCore(item, convertView, parent, context);
WireUpForceUpdateSizeRequested(item, view);
var holder = view.Tag as RendererHolder;
if (holder == null)
view.Tag = new RendererHolder(this);
else
holder.Renderer = this;
Cell.PropertyChanged += PropertyChangedHandler;
((ICellController)Cell).SendAppearing();
Performance.Stop();
return view;
}
protected virtual AView GetCellCore(Cell item, AView convertView, ViewGroup parent, Context context)
{
Performance.Start();
LayoutInflater inflater = LayoutInflater.FromContext(context);
const int type = global::Android.Resource.Layout.SimpleListItem1;
AView view = inflater.Inflate(type, null);
var textView = view.FindViewById<TextView>(global::Android.Resource.Id.Text1);
textView.Text = item.ToString();
textView.SetBackgroundColor(global::Android.Graphics.Color.Transparent);
view.SetBackgroundColor(global::Android.Graphics.Color.Black);
Performance.Stop();
return view;
}
protected virtual void OnCellPropertyChanged(object sender, PropertyChangedEventArgs e)
{
}
protected void WireUpForceUpdateSizeRequested(Cell cell, AView nativeCell)
{
ICellController cellController = cell;
cellController.ForceUpdateSizeRequested -= _onForceUpdateSizeRequested;
_onForceUpdateSizeRequested = (sender, e) =>
{
// RenderHeight may not be changed, but that's okay, since we
// don't actually use the height argument in the OnMeasure override.
nativeCell.Measure(nativeCell.Width, (int)cell.RenderHeight);
nativeCell.SetMinimumHeight(nativeCell.MeasuredHeight);
nativeCell.SetMinimumWidth(nativeCell.MeasuredWidth);
};
cellController.ForceUpdateSizeRequested += _onForceUpdateSizeRequested;
}
internal static CellRenderer GetRenderer(BindableObject cell)
{
return (CellRenderer)cell.GetValue(RendererProperty);
}
internal static void SetRenderer(BindableObject cell, CellRenderer renderer)
{
cell.SetValue(RendererProperty, renderer);
}
static void OnGlobalCellPropertyChanged(object sender, PropertyChangedEventArgs e)
{
var cell = (Cell)sender;
CellRenderer renderer = GetRenderer(cell);
if (renderer == null)
{
cell.PropertyChanged -= PropertyChangedHandler;
return;
}
renderer.OnCellPropertyChanged(sender, e);
}
class RendererHolder : Object
{
readonly WeakReference<CellRenderer> _rendererRef;
public RendererHolder(CellRenderer renderer)
{
_rendererRef = new WeakReference<CellRenderer>(renderer);
}
public CellRenderer Renderer
{
get
{
CellRenderer renderer;
return _rendererRef.TryGetTarget(out renderer) ? renderer : null;
}
set { _rendererRef.SetTarget(value); }
}
}
}
}
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