// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Diagnostics;
using System.Linq;
using ICSharpCode.AvalonEdit.Document;
namespace ICSharpCode.AvalonEdit.Xml
{
/// <summary>
/// Abstact base class for all types that can contain child nodes
/// </summary>
public abstract class AXmlContainer: AXmlObject
{
/// <summary>
/// Children of the node. It is read-only.
/// Note that is has CollectionChanged event.
/// </summary>
public AXmlObjectCollection<AXmlObject> Children { get; private set; }
/// <summary> Create new container </summary>
protected AXmlContainer()
{
this.Children = new AXmlObjectCollection<AXmlObject>();
}
#region Helpper methods
ObservableCollection<AXmlElement> elements;
/// <summary> Gets direcly nested elements (non-recursive) </summary>
public ObservableCollection<AXmlElement> Elements {
get {
if (elements == null) {
elements = new FilteredCollection<AXmlElement, AXmlObjectCollection<AXmlObject>>(this.Children);
}
return elements;
}
}
internal AXmlObject FirstChild {
get {
return this.Children[0];
}
}
internal AXmlObject LastChild {
get {
return this.Children[this.Children.Count - 1];
}
}
#endregion
/// <inheritdoc/>
public override IEnumerable<AXmlObject> GetSelfAndAllChildren()
{
return (new AXmlObject[] { this }).Flatten(
delegate(AXmlObject i) {
AXmlContainer container = i as AXmlContainer;
if (container != null)
return container.Children;
else
return null;
}
);
}
/// <summary>
/// Gets a child fully containg the given offset.
/// Goes recursively down the tree.
/// Specail case if at the end of attribute or text
/// </summary>
public AXmlObject GetChildAtOffset(int offset)
{
foreach(AXmlObject child in this.Children) {
if ((child is AXmlAttribute || child is AXmlText) && offset == child.EndOffset) return child;
if (child.StartOffset < offset && offset < child.EndOffset) {
AXmlContainer container = child as AXmlContainer;
if (container != null) {
return container.GetChildAtOffset(offset);
} else {
return child;
}
}
}
return this; // No childs at offset
}
// Only these four methods should be used to modify the collection
/// <summary> To be used exlucively by the parser </summary>
internal void AddChild(AXmlObject item)
{
// Childs can be only added to newly parsed items
Assert(this.Parent == null, "I have to be new");
Assert(item.IsCached, "Added item must be in cache");
// Do not set parent pointer
this.Children.InsertItemAt(this.Children.Count, item);
}
/// <summary> To be used exlucively by the parser </summary>
internal void AddChildren(IEnumerable<AXmlObject> items)
{
// Childs can be only added to newly parsed items
Assert(this.Parent == null, "I have to be new");
// Do not set parent pointer
this.Children.InsertItemsAt(this.Children.Count, items.ToList());
}
/// <summary>
/// To be used exclusively by the children update algorithm.
/// Insert child and keep links consistent.
/// </summary>
void InsertChild(int index, AXmlObject item)
{
AXmlParser.Log("Inserting {0} at index {1}", item, index);
Assert(this.Document != null, "Can not insert to dangling object");
Assert(item.Parent != this, "Can not own item twice");
SetParentPointersInTree(item);
this.Children.InsertItemAt(index, item);
this.Document.OnObjectInserted(index, item);
}
/// <summary> Recursively fix all parent pointer in a tree </summary>
/// <remarks>
/// Cache constraint:
/// If cached item has parent set, then the whole subtree must be consistent and document set
/// </remarks>
void SetParentPointersInTree(AXmlObject item)
{
// All items come from the parser cache
if (item.Parent == null) {
// Dangling object - either a new parser object or removed tree (still cached)
item.Parent = this;
item.Document = this.Document;
AXmlContainer container = item as AXmlContainer;
if (container != null) {
foreach(AXmlObject child in container.Children) {
container.SetParentPointersInTree(child);
}
}
} else if (item.Parent == this) {
// If node is attached and then deattached, it will have null parent pointer
// but valid subtree - so its children will alredy have correct parent pointer
// like in this case
// item.DebugCheckConsistency(false);
// Rest of the tree is consistent - do not recurse
} else {
// From cache & parent set => consitent subtree
// item.DebugCheckConsistency(false);
// The parent (or any futher parents) can not be part of parsed document
// becuase otherwise this item would be included twice => safe to change parents
// Maintain cache constraint by setting parents to null
foreach(AXmlObject ancest in item.GetAncestors().ToList()) {
ancest.Parent = null;
}
item.Parent = this;
// Rest of the tree is consistent - do not recurse
}
}
/// <summary>
/// To be used exclusively by the children update algorithm.
/// Remove child, set parent to null and notify the document
/// </summary>
void RemoveChild(int index)
{
AXmlObject removed = this.Children[index];
AXmlParser.Log("Removing {0} at index {1}", removed, index);
// Stop tracking if the object can not be used again
if (!removed.IsCached)
this.Document.Parser.TrackedSegments.RemoveParsedObject(removed);
// Null parent pointer
Assert(removed.Parent == this, "Inconsistent child");
removed.Parent = null;
this.Children.RemoveItemAt(index);
this.Document.OnObjectRemoved(index, removed);
}
/// <summary> Verify that the subtree is consistent. Only in debug build. </summary>
/// <remarks> Parent pointers might be null or pointing somewhere else in parse tree </remarks>
internal override void DebugCheckConsistency(bool checkParentPointers)
{
base.DebugCheckConsistency(checkParentPointers);
AXmlObject prevChild = null;
int myStartOffset = this.StartOffset;
int myEndOffset = this.EndOffset;
foreach(AXmlObject child in this.Children) {
Assert(child.Length != 0, "Empty child");
if (checkParentPointers) {
Assert(child.Parent != null, "Null parent reference");
Assert(child.Parent == this, "Inccorect parent reference");
}
if (this.Document != null) {
Assert(child.Document != null, "Child has null document");
Assert(child.Document == this.Document, "Child is in different document");
}
if (this.IsCached)
Assert(child.IsCached, "Child not in cache");
Assert(myStartOffset <= child.StartOffset && child.EndOffset <= myEndOffset, "Child not within parent text range");
if (prevChild != null)
Assert(prevChild.EndOffset <= child.StartOffset, "Overlaping childs");
child.DebugCheckConsistency(checkParentPointers);
prevChild = child;
}
}
/// <remarks>
/// Note the the method is not called recuively.
/// Only the helper methods are recursive.
/// </remarks>
internal void UpdateTreeFrom(AXmlContainer srcContainer)
{
this.StartOffset = srcContainer.StartOffset; // Force the update
this.UpdateDataFrom(srcContainer);
RemoveChildrenNotIn(srcContainer.Children);
InsertAndUpdateChildrenFrom(srcContainer.Children);
}
void RemoveChildrenNotIn(IList<AXmlObject> srcList)
{
Dictionary<int, AXmlObject> srcChildren = srcList.ToDictionary(i => i.StartOffset);
for(int i = 0; i < this.Children.Count;) {
AXmlObject child = this.Children[i];
AXmlObject srcChild;
if (srcChildren.TryGetValue(child.StartOffset, out srcChild) && child.CanUpdateDataFrom(srcChild)) {
// Keep only one item with given offset (we might have several due to deletion)
srcChildren.Remove(child.StartOffset);
// If contaner that needs updating
AXmlContainer childAsContainer = child as AXmlContainer;
if (childAsContainer != null && child.LastUpdatedFrom != srcChild)
childAsContainer.RemoveChildrenNotIn(((AXmlContainer)srcChild).Children);
i++;
} else {
RemoveChild(i);
}
}
}
void InsertAndUpdateChildrenFrom(IList<AXmlObject> srcList)
{
for(int i = 0; i < srcList.Count; i++) {
// End of our list?
if (i == this.Children.Count) {
InsertChild(i, srcList[i]);
continue;
}
AXmlObject child = this.Children[i];
AXmlObject srcChild = srcList[i];
if (child.CanUpdateDataFrom(srcChild)) { // includes offset test
// Does it need updating?
if (child.LastUpdatedFrom != srcChild) {
child.UpdateDataFrom(srcChild);
AXmlContainer childAsContainer = child as AXmlContainer;
if (childAsContainer != null)
childAsContainer.InsertAndUpdateChildrenFrom(((AXmlContainer)srcChild).Children);
}
} else {
InsertChild(i, srcChild);
}
}
Assert(this.Children.Count == srcList.Count, "List lengths differ after update");
}
}
}