/// <summary>
/// Creates the <see cref="Panel"/> when <see cref="ApplyTemplate"/> is called for the first
/// time.
/// </summary>
protected virtual void CreatePanel()
{
Panel = ItemsPanel.Build();
Panel.SetValue(TemplatedParentProperty, TemplatedParent);
LogicalChildren.Clear();
VisualChildren.Clear();
LogicalChildren.Add(Panel);
VisualChildren.Add(Panel);
_createdPanel = true;
INotifyCollectionChanged incc = Items as INotifyCollectionChanged;
if (incc != null)
{
incc.CollectionChanged += ItemsCollectionChanged;
}
ItemsChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
/// <summary>
/// Creates the <see cref="Panel"/> when <see cref="ApplyTemplate"/> is called for the first
/// time.
/// </summary>
private void CreatePanel()
{
Panel = ItemsPanel.Build();
Panel.SetValue(TemplatedParentProperty, TemplatedParent);
LogicalChildren.Clear();
VisualChildren.Clear();
LogicalChildren.Add(Panel);
VisualChildren.Add(Panel);
_createdPanel = true;
if (!IsHosted && _itemsSubscription == null && Items is INotifyCollectionChanged incc)
{
_itemsSubscription = incc.WeakSubscribe(ItemsCollectionChanged);
}
PanelCreated(Panel);
ItemsChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
/// <summary>
/// Called when the <see cref="Children"/> collection changes.
/// </summary>
/// <param name="sender">The event sender.</param>
/// <param name="e">The event args.</param>
protected virtual void ChildrenChanged(object sender, NotifyCollectionChangedEventArgs e)
{
List <Control> controls;
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
controls = e.NewItems.OfType <Control>().ToList();
LogicalChildren.InsertRange(e.NewStartingIndex, controls);
VisualChildren.InsertRange(e.NewStartingIndex, e.NewItems.OfType <Visual>());
break;
case NotifyCollectionChangedAction.Move:
LogicalChildren.MoveRange(e.OldStartingIndex, e.OldItems.Count, e.NewStartingIndex);
VisualChildren.MoveRange(e.OldStartingIndex, e.OldItems.Count, e.NewStartingIndex);
break;
case NotifyCollectionChangedAction.Remove:
controls = e.OldItems.OfType <Control>().ToList();
LogicalChildren.RemoveAll(controls);
VisualChildren.RemoveAll(e.OldItems.OfType <Visual>());
break;
case NotifyCollectionChangedAction.Replace:
for (var i = 0; i < e.OldItems.Count; ++i)
{
var index = i + e.OldStartingIndex;
var child = (IControl)e.NewItems[i];
LogicalChildren[index] = child;
VisualChildren[index] = child;
}
break;
case NotifyCollectionChangedAction.Reset:
throw new NotSupportedException();
}
InvalidateMeasure();
}
/// <summary>
/// Creates the <see cref="Panel"/> when <see cref="ApplyTemplate"/> is called for the first
/// time.
/// </summary>
private void CreatePanel()
{
Panel = ItemsPanel.Build();
Panel.SetValue(TemplatedParentProperty, TemplatedParent);
if (!Panel.IsSet(KeyboardNavigation.DirectionalNavigationProperty))
{
KeyboardNavigation.SetDirectionalNavigation(
(InputElement)Panel,
KeyboardNavigationMode.Contained);
}
LogicalChildren.Clear();
VisualChildren.Clear();
LogicalChildren.Add(Panel);
VisualChildren.Add(Panel);
KeyboardNavigation.SetTabNavigation(
(InputElement)Panel,
KeyboardNavigation.GetTabNavigation(this));
_createdPanel = true;
CreateItemsAndListenForChanges(Items);
}
protected virtual void LayoutChildren(double x, double y, double width, double height)
{
var area = new Rectangle(x, y, width, height);
Rectangle originalArea = area;
if (_containerAreaSet)
{
area = ContainerArea;
area.X += Padding.Left;
area.Y += Padding.Right;
area.Width -= Padding.HorizontalThickness;
area.Height -= Padding.VerticalThickness;
area.Width = Math.Max(0, area.Width);
area.Height = Math.Max(0, area.Height);
}
List <Element> elements = LogicalChildren.ToList();
foreach (Element element in elements)
{
var child = element as VisualElement;
if (child == null)
{
continue;
}
var page = child as Page;
if (page != null && page.IgnoresContainerArea)
{
Maui.Controls.Layout.LayoutChildIntoBoundingRegion(child, originalArea);
}
else
{
Maui.Controls.Layout.LayoutChildIntoBoundingRegion(child, area);
}
}
}
/// <summary>
/// Updates the <see cref="Child"/> control based on the control's <see cref="Content"/>.
/// </summary>
/// <remarks>
/// Usually the <see cref="Child"/> control is created automatically when
/// <see cref="ApplyTemplate"/> is called; however for this to happen, the control needs to
/// be attached to a logical tree (if the control is not attached to the logical tree, it
/// is reasonable to expect that the DataTemplates needed for the child are not yet
/// available). This method forces the <see cref="Child"/> control's creation at any point,
/// and is particularly useful in unit tests.
/// </remarks>
public void UpdateChild()
{
var content = Content;
var oldChild = Child;
var newChild = content as IControl;
if (content != null && newChild == null)
{
// We have content and it isn't a control, so first try to recycle the existing
// child control to display the new data by querying if the template that created
// the child can recycle items and that it also matches the new data.
if (oldChild != null &&
_dataTemplate != null &&
_dataTemplate.SupportsRecycling &&
_dataTemplate.Match(content))
{
newChild = oldChild;
}
else
{
// We couldn't recycle an existing control so find a data template for the data
// and use it to create a control.
_dataTemplate = this.FindDataTemplate(content, ContentTemplate) ?? FuncDataTemplate.Default;
newChild = _dataTemplate.Build(content);
// Try to give the new control its own name scope.
var controlResult = newChild as Control;
if (controlResult != null)
{
NameScope.SetNameScope(controlResult, new NameScope());
}
}
}
else
{
_dataTemplate = null;
}
// Remove the old child if we're not recycling it.
if (oldChild != null && newChild != oldChild)
{
VisualChildren.Remove(oldChild);
}
// Set the DataContext if the data isn't a control.
if (!(content is IControl))
{
DataContext = content;
}
// Update the Child.
if (newChild == null)
{
Child = null;
}
else if (newChild != oldChild)
{
((ISetInheritanceParent)newChild).SetParent(this);
Child = newChild;
if (oldChild?.Parent == this)
{
LogicalChildren.Remove(oldChild);
}
if (newChild.Parent == null)
{
var templatedLogicalParent = TemplatedParent as ILogical;
if (templatedLogicalParent != null)
{
((ISetLogicalParent)newChild).SetParent(templatedLogicalParent);
}
else
{
LogicalChildren.Add(newChild);
}
}
VisualChildren.Add(newChild);
}
_createdChild = true;
}
internal bool IsTopMost(Window window)
{
int index = LogicalChildren.IndexOf(window);
return(index >= 0 && index == LogicalChildren.Count - 1);
}
protected override Size ArrangeOverride(Size finalSize)
{
int firstRow = Cells.GetInitialRow();
foreach (var cell in Cells.GetVisibleCells())
{
double width = AccumulatedColumnWidths[cell.Column.Index + 1] -
AccumulatedColumnWidths[cell.Column.Index] - GridControl.VerticalLinesThickness;
cell.Arrange(new Rect(AccumulatedColumnWidths[cell.Column.Index],
AccumulatedRowHeights[cell.Row - firstRow],
width, cell.DesiredSize.Height));
}
UpdateGridLines();
ScrollBar.Arrange(new Rect(finalSize.Width - ScrollBar.Width, 0.0, ScrollBar.Width, finalSize.Height));
return(finalSize);
void UpdateGridLines()
{
int lastAccumulatedColumnWidthsIndex = AccumulatedColumnWidths.Count - 1;
while (ColumnLines.Count > lastAccumulatedColumnWidthsIndex)
{
var columnLine = ColumnLines[ColumnLines.Count - 1];
ColumnLines.Remove(columnLine);
LogicalChildren.Remove(columnLine);
VisualChildren.Remove(columnLine);
}
while (lastAccumulatedColumnWidthsIndex > ColumnLines.Count)
{
Line columnLine = new Line();
columnLine.Stroke = GridControl.VerticalLinesBrush;
columnLine.StrokeThickness = GridControl.VerticalLinesThickness;
ColumnLines.Add(columnLine);
LogicalChildren.Add(columnLine);
VisualChildren.Add(columnLine);
}
int lastAccumulatedRowHeightsIndex = AccumulatedRowHeights.Count(rh => !Double.IsNaN(rh)) - 1;
while (RowLines.Count > lastAccumulatedRowHeightsIndex)
{
var rowLine = RowLines[RowLines.Count - 1];
RowLines.Remove(rowLine);
LogicalChildren.Remove(rowLine);
VisualChildren.Remove(rowLine);
}
while (lastAccumulatedRowHeightsIndex > RowLines.Count)
{
Line rowLine = new Line();
rowLine.Stroke = GridControl.HorizontalLinesBrush;
rowLine.StrokeThickness = GridControl.HorizontalLinesThickness;
RowLines.Add(rowLine);
LogicalChildren.Add(rowLine);
VisualChildren.Add(rowLine);
}
for (int i = 0; i < RowLines.Count; i++)
{
double y = AccumulatedRowHeights[i + 1] - GridControl.HorizontalLinesThickness / 2.0;
RowLines[i].StartPoint = new Point(0.0, y);
RowLines[i].EndPoint = new Point(AccumulatedColumnWidths[lastAccumulatedColumnWidthsIndex], y);
}
for (int i = 0; i < ColumnLines.Count; i++)
{
double x = AccumulatedColumnWidths[i + 1] - GridControl.VerticalLinesThickness / 2.0;
ColumnLines[i].StartPoint = new Point(x, 0.0);
ColumnLines[i].EndPoint = new Point(x, AccumulatedRowHeights[lastAccumulatedRowHeightsIndex]);
}
foreach (var line in RowLines.Concat(ColumnLines))
{
line.InvalidateMeasure();
line.Measure(Size.Infinity);
}
}
}
