private bool DeleteElement(SvgElement element, bool deleteFromParent)
{
if (element == null)
{
return(false);
}
var parent = element.GetParent();
if (parent == null)
{
// root node cannot be delete!
ErrorMessage = "root node cannot be delete!";
return(false);
}
// set the Next reference of the previous
if (element.GetPrevious() != null)
{
element.GetPrevious().SetNext(element.GetNext());
}
// set the Previous reference of the next
if (element.GetNext() != null)
{
element.GetNext().SetPrevious(element.GetPrevious());
}
// check if the element is the first child
// the deleteFromParent flag is used to avoid deleting
// all parent-child relationship. This is used in the Cut
// operation where the subtree can be pasted
if (deleteFromParent)
{
if (IsFirstChild(element))
{
// set the Child reference of the parent to the next
element.GetParent().SetChild(element.GetNext());
}
}
// delete its children
var child = element.GetChild();
while (child != null)
{
DeleteElement(child, false);
child = child.GetNext();
}
// delete the element from the colloection
svgDocumentElements.Remove(element.GetInternalId());
return(true);
}
/// <summary>
/// It moves the element before its current previous sibling.
/// </summary>
/// <param name="element">Element to be moved.</param>
/// <returns>
/// true if the operation succeeded.
/// </returns>
public bool ElementPositionUp(SvgElement element)
{
var parent = element.GetParent();
if (parent == null)
{
ErrorMessage = "Root node cannot be moved";
return(false);
}
if (IsFirstChild(element))
{
ErrorMessage = "Element is already at the first position";
return(false);
}
var next = element.GetNext();
var previous = element.GetPrevious();
SvgElement previous2 = null;
element.SetNext(null);
element.SetPrevious(null);
// fix Next
if (next != null)
{
next.SetPrevious(previous);
}
// fix Previous
if (previous != null)
{
previous.SetNext(next);
previous2 = previous.GetPrevious();
previous.SetPrevious(element);
// check if the Previous is the first child
if (IsFirstChild(previous))
{
// if yes the moved element has to became the new first child
if (previous.GetParent() != null)
{
previous.GetParent().SetChild(element);
}
}
}
// fix Previous/Previous
if (previous2 != null)
{
previous2.SetNext(element);
}
// fix Element
element.SetNext(previous);
element.SetPrevious(previous2);
return(true);
}
/// <summary>
/// It moves the element after its current next sibling.
/// </summary>
/// <param name="element">Element to be moved.</param>
/// <returns>
/// true if the operation succeeded.
/// </returns>
public bool ElementPositionDown(SvgElement element)
{
var parent = element.GetParent();
if (parent == null)
{
ErrorMessage = "Root node cannot be moved";
return(false);
}
if (IsLastSibling(element))
{
ErrorMessage = "Element is already at the last sibling position";
return(false);
}
var next = element.GetNext();
SvgElement next2 = null;
var previous = element.GetPrevious();
// fix Next
if (next != null)
{
next.SetPrevious(element.GetPrevious());
next2 = next.GetNext();
next.SetNext(element);
}
// fix Previous
if (previous != null)
{
previous.SetNext(next);
}
// fix Element
if (IsFirstChild(element))
{
parent.SetChild(next);
}
element.SetPrevious(next);
element.SetNext(next2);
if (next2 != null)
{
next2.SetPrevious(element);
}
return(true);
}
/// <summary>
/// It moves the element one level up in the tree hierarchy.
/// </summary>
/// <param name="element">Element to be moved.</param>
/// <returns>
/// true if the operation succeeded.
/// </returns>
public bool ElementLevelUp(SvgElement element)
{
var parent = element.GetParent();
if (parent == null)
{
ErrorMessage = "Root node cannot be moved";
return(false);
}
if (parent.GetParent() == null)
{
ErrorMessage = "An element cannot be moved up to the root";
return(false);
}
var next = element.GetNext();
// the first child of the parent became the next
parent.SetChild(next);
if (next != null)
{
next.SetPrevious(null);
}
// get the last sibling of the parent
var last = GetLastSibling(parent);
if (last != null)
{
last.SetNext(element);
}
element.SetParent(parent.GetParent());
element.SetPrevious(last);
element.SetNext(null);
return(true);
}
private bool DeleteElement(SvgElement element, bool deleteFromParent)
{
if ( element == null )
{
return false;
}
var parent = element.GetParent();
if ( parent == null )
{
// root node cannot be delete!
ErrorMessage = "root node cannot be delete!";
return false;
}
// set the Next reference of the previous
if ( element.GetPrevious() != null )
{
element.GetPrevious().SetNext(element.GetNext());
}
// set the Previous reference of the next
if ( element.GetNext() != null )
{
element.GetNext().SetPrevious(element.GetPrevious());
}
// check if the element is the first child
// the deleteFromParent flag is used to avoid deleting
// all parent-child relationship. This is used in the Cut
// operation where the subtree can be pasted
if ( deleteFromParent )
{
if ( IsFirstChild(element) )
{
// set the Child reference of the parent to the next
element.GetParent().SetChild(element.GetNext());
}
}
// delete its children
var child = element.GetChild();
while ( child != null )
{
DeleteElement(child, false);
child = child.GetNext();
}
// delete the element from the colloection
svgDocumentElements.Remove(element.GetInternalId());
return true;
}
/// <summary>
/// It moves the element before its current previous sibling.
/// </summary>
/// <param name="element">Element to be moved.</param>
/// <returns>
/// true if the operation succeeded.
/// </returns>
public bool ElementPositionUp(SvgElement element)
{
var parent = element.GetParent();
if ( parent == null )
{
ErrorMessage = "Root node cannot be moved";
return false;
}
if ( IsFirstChild(element) )
{
ErrorMessage = "Element is already at the first position";
return false;
}
var next = element.GetNext();
var previous = element.GetPrevious();
SvgElement previous2 = null;
element.SetNext(null);
element.SetPrevious(null);
// fix Next
if ( next != null )
{
next.SetPrevious(previous);
}
// fix Previous
if ( previous != null )
{
previous.SetNext(next);
previous2 = previous.GetPrevious();
previous.SetPrevious(element);
// check if the Previous is the first child
if ( IsFirstChild(previous) )
{
// if yes the moved element has to became the new first child
if ( previous.GetParent() != null )
{
previous.GetParent().SetChild(element);
}
}
}
// fix Previous/Previous
if ( previous2 != null )
{
previous2.SetNext(element);
}
// fix Element
element.SetNext(previous);
element.SetPrevious(previous2);
return true;
}
/// <summary>
/// It moves the element after its current next sibling.
/// </summary>
/// <param name="element">Element to be moved.</param>
/// <returns>
/// true if the operation succeeded.
/// </returns>
public bool ElementPositionDown(SvgElement element)
{
var parent = element.GetParent();
if ( parent == null )
{
ErrorMessage = "Root node cannot be moved";
return false;
}
if ( IsLastSibling(element) )
{
ErrorMessage = "Element is already at the last sibling position";
return false;
}
var next = element.GetNext();
SvgElement next2 = null;
var previous = element.GetPrevious();
// fix Next
if ( next != null )
{
next.SetPrevious(element.GetPrevious());
next2 = next.GetNext();
next.SetNext(element);
}
// fix Previous
if ( previous != null )
{
previous.SetNext(next);
}
// fix Element
if ( IsFirstChild(element) )
{
parent.SetChild(next);
}
element.SetPrevious(next);
element.SetNext(next2);
if ( next2 != null )
{
next2.SetPrevious(element);
}
return true;
}
/// <summary>
/// It moves the element one level up in the tree hierarchy.
/// </summary>
/// <param name="element">Element to be moved.</param>
/// <returns>
/// true if the operation succeeded.
/// </returns>
public bool ElementLevelUp(SvgElement element)
{
var parent = element.GetParent();
if ( parent == null )
{
ErrorMessage = "Root node cannot be moved";
return false;
}
if ( parent.GetParent() == null )
{
ErrorMessage = "An element cannot be moved up to the root";
return false;
}
var next = element.GetNext();
// the first child of the parent became the next
parent.SetChild(next);
if ( next != null )
{
next.SetPrevious(null);
}
// get the last sibling of the parent
var last = GetLastSibling(parent);
if ( last != null )
{
last.SetNext(element);
}
element.SetParent(parent.GetParent());
element.SetPrevious(last);
element.SetNext(null);
return true;
}
