/// <summary>
/// Sets the parent of the specified <paramref name="child"/> to this container
/// </summary>
/// <remarks>
/// This is used by container authors to set the parent of a child before it is added to the underlying platform control.
///
/// The <paramref name="assign"/> parameter should call the handler method to add the child to the parent.
/// </remarks>
/// <returns><c>true</c>, if parent was set, <c>false</c> otherwise.</returns>
/// <param name="child">Child to set the parent</param>
/// <param name="assign">Method to assign the child to the handler</param>
/// <param name="previousChild">Previous child that the new child is replacing.</param>
protected void SetParent(Control child, Action assign = null, Control previousChild = null)
{
bool triggerPrevious = false;
if (previousChild != null && !ReferenceEquals(previousChild.VisualParent, null) && (!ReferenceEquals(previousChild, child) || !ReferenceEquals(child.VisualParent, this)))
{
#if DEBUG
if (!ReferenceEquals(previousChild.VisualParent, this))
{
throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, "The child control is not a child of this container. Ensure you only remove children that you own."));
}
#endif
if (previousChild.Loaded)
{
previousChild.TriggerUnLoad(EventArgs.Empty);
}
previousChild.VisualParent = null;
triggerPrevious = true;
}
if (child != null && !ReferenceEquals(child.VisualParent, this))
{
// Detach so parent can remove from controls collection if necessary.
// prevents UnLoad from being called more than once when containers think a control is still a child
// no-op if there is no parent (handled in detach)
child.Detach();
if (child.LogicalParent == null)
{
child.LogicalParent = this;
}
child.VisualParent = this;
if (Loaded && !child.Loaded)
{
using (child.Platform.Context)
{
child.TriggerPreLoad(EventArgs.Empty);
child.TriggerLoad(EventArgs.Empty);
child.TriggerDataContextChanged(EventArgs.Empty);
if (assign != null)
{
assign();
}
child.TriggerLoadComplete(EventArgs.Empty);
}
if (triggerPrevious)
{
previousChild.TriggerDataContextChanged(EventArgs.Empty);
}
return;
}
}
if (assign != null)
{
assign();
}
if (triggerPrevious)
{
previousChild.TriggerDataContextChanged(EventArgs.Empty);
}
}
/// <summary>
/// Removes the child control from the logical parent of this container.
/// </summary>
/// <remarks>
/// This should be used from containers that use other Eto controls to layout its children but should not be part
/// of the logical heirarchy.
/// </remarks>
/// <seealso cref="SetLogicalParent"/>
/// <param name="child">Child to remove from this container as the logical parent.</param>
protected void RemoveLogicalParent(Control child)
{
if (child == null)
{
return;
}
if (!ReferenceEquals(child.LogicalParent, this))
{
throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, "The child control is not a logical child of this container. Ensure you only remove children that you own."));
}
child.Detach();
child.LogicalParent = null;
}
/// <summary>
/// Sets the parent of the specified <paramref name="child"/> to this container
/// </summary>
/// <remarks>
/// This is used by container authors to set the parent of a child before it is added to the underlying platform control.
///
/// If this returns <c>true</c>, you should call <see cref="Control.OnLoadComplete"/> after the control has been added
/// to the underlying platform control.
/// </remarks>
/// <returns><c>true</c>, if parent was set, <c>false</c> otherwise.</returns>
/// <param name="child">Child to set the parent</param>
protected bool SetParent(Control child)
{
if (child != null && !ReferenceEquals(child.Parent, this))
{
// Detach so parent can remove from controls collection if necessary.
// prevents UnLoad from being called more than once when containers think a control is still a child
// no-op if there is no parent (handled in detach)
child.Detach();
child.Parent = this;
if (Loaded && !child.Loaded)
{
child.OnPreLoad(EventArgs.Empty);
child.OnLoad(EventArgs.Empty);
child.OnDataContextChanged(EventArgs.Empty);
return(true);
}
}
return(false);
}
/// <summary>
/// Sets the parent of the specified <paramref name="child"/> to this container
/// </summary>
/// <remarks>
/// This is used by container authors to set the parent of a child before it is added to the underlying platform control.
///
/// If this returns <c>true</c>, you should call <see cref="Control.OnLoadComplete"/> after the control has been added
/// to the underlying platform control.
/// </remarks>
/// <returns><c>true</c>, if parent was set, <c>false</c> otherwise.</returns>
/// <param name="child">Child to set the parent</param>
protected bool SetParent(Control child)
{
if (child != null && !ReferenceEquals(child.Parent, this))
{
// Detach so parent can remove from controls collection if necessary.
// prevents UnLoad from being called more than once when containers think a control is still a child
// no-op if there is no parent (handled in detach)
child.Detach();
child.Parent = this;
if (Loaded && !child.Loaded)
{
child.OnPreLoad(EventArgs.Empty);
child.OnLoad(EventArgs.Empty);
child.OnDataContextChanged(EventArgs.Empty);
return true;
}
}
return false;
}
/// <summary>
/// Sets the parent of the specified <paramref name="child"/> to this container
/// </summary>
/// <remarks>
/// This is used by container authors to set the parent of a child before it is added to the underlying platform control.
///
/// The <paramref name="assign"/> parameter should call the handler method to add the child to the parent.
/// </remarks>
/// <returns><c>true</c>, if parent was set, <c>false</c> otherwise.</returns>
/// <param name="child">Child to set the parent</param>
/// <param name="assign">Method to assign the child to the handler</param>
/// <param name="previousChild">Previous child that the new child is replacing.</param>
protected void SetParent(Control child, Action assign, Control previousChild = null)
{
bool triggerPrevious = false;
if (previousChild != null && !ReferenceEquals(previousChild.Parent, null) && (!ReferenceEquals(previousChild, child) || !ReferenceEquals(child.Parent, this)))
{
#if DEBUG
if (!ReferenceEquals(previousChild.Parent, this))
throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, "The child control is not a child of this container. Ensure you only remove children that you own."));
#endif
if (previousChild.Loaded)
{
previousChild.TriggerUnLoad(EventArgs.Empty);
}
previousChild.Parent = null;
triggerPrevious = true;
}
if (child != null && !ReferenceEquals(child.Parent, this))
{
// Detach so parent can remove from controls collection if necessary.
// prevents UnLoad from being called more than once when containers think a control is still a child
// no-op if there is no parent (handled in detach)
child.Detach();
child.Parent = this;
if (Loaded && !child.Loaded)
{
using (child.Platform.Context)
{
child.TriggerPreLoad(EventArgs.Empty);
child.TriggerLoad(EventArgs.Empty);
child.TriggerDataContextChanged(EventArgs.Empty);
assign();
child.TriggerLoadComplete(EventArgs.Empty);
}
if (triggerPrevious)
previousChild.TriggerDataContextChanged(EventArgs.Empty);
return;
}
}
assign();
if (triggerPrevious)
previousChild.TriggerDataContextChanged(EventArgs.Empty);
}