public bool RequestFocus(global::Android.Views.View control, Func <bool> baseRequestFocus)
{
IViewParent ancestor = control.Parent;
var previousFocusability = DescendantFocusability.BlockDescendants;
ConditionalFocusLayout cfl = null;
// Work our way up through the tree until we find a ConditionalFocusLayout
while (ancestor is ViewGroup)
{
cfl = ancestor as ConditionalFocusLayout;
if (cfl != null)
{
previousFocusability = cfl.DescendantFocusability;
// Toggle DescendantFocusability to allow this control to get focus
cfl.DescendantFocusability = DescendantFocusability.AfterDescendants;
break;
}
ancestor = ancestor.Parent;
}
// Call the original RequestFocus implementation for the View
bool result = baseRequestFocus();
if (cfl != null)
{
// Toggle descendantfocusability back to whatever it was
cfl.DescendantFocusability = previousFocusability;
}
return(result);
}
void DisposeOfConditionalFocusLayout(ConditionalFocusLayout layout)
{
var renderedView = layout?.GetChildAt(0);
var element = (renderedView as INativeElementView)?.Element;
var view = (element as ViewCell)?.View;
if (view != null)
{
var renderer = AppCompat.Platform.GetRenderer(view);
if (renderer == renderedView)
{
element.ClearValue(AppCompat.Platform.RendererProperty);
}
renderer?.Dispose();
renderer = null;
}
renderedView?.Dispose();
renderedView = null;
}
void UpdateSeparatorVisibility(Cell cell, bool cellIsBeingReused, bool isHeader, bool nextCellIsHeader, bool isSeparatorVisible, ConditionalFocusLayout layout, out AView bline)
{
bline = null;
if (cellIsBeingReused && layout.ChildCount > 1)
{
layout.RemoveViewAt(1);
}
var makeBline = isSeparatorVisible || isHeader && isSeparatorVisible && !nextCellIsHeader;
if (makeBline)
{
bline = new AView(_context)
{
LayoutParameters = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, 1)
};
layout.AddView(bline);
}
else if (layout.ChildCount > 1)
{
layout.RemoveViewAt(1);
}
}
public override AView GetView(int position, AView convertView, ViewGroup parent)
{
Cell cell = null;
Performance.Start(out string reference);
ListViewCachingStrategy cachingStrategy = Controller.CachingStrategy;
var nextCellIsHeader = false;
if (cachingStrategy == ListViewCachingStrategy.RetainElement || convertView == null)
{
if (_listView.IsGroupingEnabled)
{
List <Cell> cells = GetCellsFromPosition(position, 2);
if (cells.Count > 0)
{
cell = cells[0];
}
if (cells.Count == 2)
{
nextCellIsHeader = cells[1].GetIsGroupHeader <ItemsView <Cell>, Cell>();
}
}
if (cell == null)
{
cell = GetCellForPosition(position);
if (cell == null)
{
Performance.Stop(reference);
return(new AView(_context));
}
}
}
var cellIsBeingReused = false;
var layout = convertView as ConditionalFocusLayout;
if (layout != null)
{
cellIsBeingReused = true;
convertView = layout.GetChildAt(0);
}
else
{
layout = new ConditionalFocusLayout(_context)
{
Orientation = Orientation.Vertical
};
_layoutsCreated.Add(layout);
}
if (((cachingStrategy & ListViewCachingStrategy.RecycleElement) != 0) && convertView != null)
{
var boxedCell = convertView as INativeElementView;
if (boxedCell == null)
{
throw new InvalidOperationException($"View for cell must implement {nameof(INativeElementView)} to enable recycling.");
}
cell = (Cell)boxedCell.Element;
#pragma warning disable CS0618 // Type or member is obsolete
// The Platform property is no longer necessary, but we have to set it because some third-party
// library might still be retrieving it and using it
cell.Platform = _listView.Platform;
#pragma warning restore CS0618 // Type or member is obsolete
ICellController cellController = cell;
cellController.SendDisappearing();
int row = position;
var group = 0;
var templatedItems = TemplatedItemsView.TemplatedItems;
if (_listView.IsGroupingEnabled)
{
group = templatedItems.GetGroupIndexFromGlobal(position, out row);
}
var templatedList = templatedItems.GetGroup(group);
if (_listView.IsGroupingEnabled)
{
if (row == 0)
{
templatedList.UpdateHeader(cell, group);
}
else
{
templatedList.UpdateContent(cell, row - 1);
}
}
else
{
templatedList.UpdateContent(cell, row);
}
cellController.SendAppearing();
if (cell.BindingContext == ActionModeObject)
{
ActionModeContext = cell;
ContextView = layout;
}
if (ReferenceEquals(_listView.SelectedItem, cell.BindingContext))
{
Select(_listView.IsGroupingEnabled ? row - 1 : row, layout);
}
else if (cell.BindingContext == ActionModeObject)
{
SetSelectedBackground(layout, true);
}
else
{
UnsetSelectedBackground(layout);
}
Performance.Stop(reference);
return(layout);
}
AView view = CellFactory.GetCell(cell, convertView, parent, _context, _listView);
Performance.Start(reference, "AddView");
if (cellIsBeingReused)
{
if (convertView != view)
{
layout.RemoveViewAt(0);
layout.AddView(view, 0);
}
}
else
{
layout.AddView(view, 0);
}
Performance.Stop(reference, "AddView");
bool isHeader = cell.GetIsGroupHeader <ItemsView <Cell>, Cell>();
AView bline;
bool isSeparatorVisible = _listView.SeparatorVisibility == SeparatorVisibility.Default;
if (isSeparatorVisible)
{
UpdateSeparatorVisibility(cell, cellIsBeingReused, isHeader, nextCellIsHeader, isSeparatorVisible, layout, out bline);
UpdateSeparatorColor(isHeader, bline);
}
else if (layout.ChildCount > 1)
{
layout.RemoveViewAt(1);
}
if ((bool)cell.GetValue(IsSelectedProperty))
{
Select(position, layout);
}
else
{
UnsetSelectedBackground(layout);
}
layout.ApplyTouchListenersToSpecialCells(cell);
Performance.Stop(reference);
return(layout);
}
public override AView GetView(int position, AView convertView, ViewGroup parent)
{
bool isHeader, nextIsHeader;
Cell item = GetCellForPosition(position, out isHeader, out nextIsHeader);
if (item == null)
{
return(new AView(Context));
}
var makeBline = true;
var layout = convertView as ConditionalFocusLayout;
if (layout != null)
{
makeBline = false;
convertView = layout.GetChildAt(0);
}
else
{
layout = new ConditionalFocusLayout(Context)
{
Orientation = Orientation.Vertical
}
};
AView aview = CellFactory.GetCell(item, convertView, parent, Context, _view);
if (!makeBline)
{
if (convertView != aview)
{
layout.RemoveViewAt(0);
layout.AddView(aview, 0);
}
}
else
{
layout.AddView(aview, 0);
}
AView bline;
if (makeBline)
{
bline = new AView(Context)
{
LayoutParameters = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, 1)
};
layout.AddView(bline);
}
else
{
bline = layout.GetChildAt(1);
}
if (isHeader)
{
bline.SetBackgroundColor(Color.Accent.ToAndroid());
}
else if (nextIsHeader)
{
bline.SetBackgroundColor(global::Android.Graphics.Color.Transparent);
}
else
{
using (var value = new TypedValue())
{
int id = global::Android.Resource.Drawable.DividerHorizontalDark;
if (Context.Theme.ResolveAttribute(global::Android.Resource.Attribute.ListDivider, value, true))
{
id = value.ResourceId;
}
else if (Context.Theme.ResolveAttribute(global::Android.Resource.Attribute.Divider, value, true))
{
id = value.ResourceId;
}
bline.SetBackgroundResource(id);
}
}
layout.ApplyTouchListenersToSpecialCells(item);
if (_restoreFocus == item)
{
if (!aview.HasFocus)
{
aview.RequestFocus();
}
_restoreFocus = null;
}
else if (aview.HasFocus)
{
aview.ClearFocus();
}
return(layout);
}
