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//------------------------------------------------------------------------------
// <copyright file="ControlCollection.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.UI {
using System.Runtime.InteropServices;
using System;
using System.Collections;
using System.Security.Permissions;
/// <devdoc>
/// <para>
/// The <see langword='ControlCollection'/> class provides a
/// collection container that enables a control to maintain a
/// list of its child controls.
///
/// For performance reasons, this is internally strongly typed. Most implementation is copied from
/// ArrayList.cs
/// </para>
/// </devdoc>
public class ControlCollection : ICollection {
private Control _owner;
private Control[] _controls;
private int _size;
private int _version;
private string _readOnlyErrorMsg = null;
private int _defaultCapacity = 5;
private int _growthFactor = 4;
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public ControlCollection(Control owner) {
if (owner == null) {
throw new ArgumentNullException("owner");
}
_owner = owner;
}
internal ControlCollection(Control owner, int defaultCapacity, int growthFactor) {
if (owner == null) {
throw new ArgumentNullException("owner");
}
_owner = owner;
_defaultCapacity = defaultCapacity;
_growthFactor = growthFactor;
}
/*
* Adds a child control to this control.
*/
/// <devdoc>
/// <para>Adds the specified <see cref='System.Web.UI.Control'/> object
/// to the collection. The new control is logically added to the end of an ordinal
/// index array.</para>
/// </devdoc>
public virtual void Add(Control child) {
// Note: duplication of code with AddAt is deliberate for performance reasons. This is the more common form of the call.
// Check arguments
if (child == null)
throw new ArgumentNullException("child");
if (_readOnlyErrorMsg != null) {
throw new HttpException(SR.GetString(_readOnlyErrorMsg ));
}
// Make sure we have room
if (_controls == null) {
_controls = new Control[_defaultCapacity];
}
else if (_size >= _controls.Length) {
Control[] newArray = new Control[_controls.Length * _growthFactor ];
Array.Copy(_controls, newArray, _controls.Length);
_controls = newArray;
}
// Add the control
int index = _size;
_controls[index] = child;
_size++;
_version++;
// Notify Owner
_owner.AddedControl(child, index);
}
/*
* Adds a child control to this control at a certain index
*/
/// <devdoc>
/// <para>Adds the specified <see cref='System.Web.UI.Control'/> object to the collection. The new control is added
/// to the array at the specified index location.</para>
/// </devdoc>
public virtual void AddAt(int index, Control child) {
// For compatability, we must support this.
if (index == -1) {
Add(child);
return;
}
// Check Arguments
if (child == null) {
throw new ArgumentNullException("child");
}
if (index < 0 || index > _size) {
throw new ArgumentOutOfRangeException("index");
}
if (_readOnlyErrorMsg != null) {
throw new HttpException(SR.GetString(_readOnlyErrorMsg ));
}
// Make sure we have room
if (_controls == null) {
_controls = new Control[_defaultCapacity];
}
else if (_size >= _controls.Length) {
//expand
Control[] newArray = new Control[_controls.Length * _growthFactor ];
//copy precedents
Array.Copy(_controls, newArray, index);
//insert
newArray[index] = child;
//copy antecedents
Array.Copy(_controls, index, newArray, index+1, _size - index);
_controls = newArray;
}
// Insert the control
else if (index < _size) {
Array.Copy(_controls, index, _controls, index + 1, _size - index);
}
_controls[index] = child;
_size++;
_version++;
_owner.AddedControl(child, index);
}
/// <devdoc>
/// <para>
/// Removes all controls in the collection.
/// </para>
/// </devdoc>
public virtual void Clear() {
if (_controls != null) {
// ASURT 123965: This used to call RemoveAt(0), which was an n^2 operation. Removing from the end of the array now.
for (int i = _size - 1; i >= 0; i--) {
RemoveAt(i);
}
if (_owner is INamingContainer)
_owner.ClearNamingContainer();
}
}
/// <devdoc>
/// <para>
/// Indicates whether the collection contains a specific object
/// </para>
/// </devdoc>
public virtual bool Contains(Control c) {
if (_controls == null || c == null)
return false;
for (int i = 0; i < _size; i++) {
if (Object.ReferenceEquals(c, _controls[i])) {
return true;
}
}
return false;
}
/*
* Retrieves the number of child controls.
*/
/// <devdoc>
/// <para>
/// Gets the number of child controls in the collection.
/// </para>
/// </devdoc>
public virtual int Count {
get {
return _size;
}
}
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
protected Control Owner {
get {
return _owner;
}
}
/// <devdoc>
/// <para>
/// Returns the index of a specified <see cref='System.Web.UI.Control'/>
/// object
/// in the collection.
/// </para>
/// </devdoc>
public virtual int IndexOf(Control value) {
if (_controls == null)
return -1;
return Array.IndexOf(_controls, value, 0, _size);
}
/// <devdoc>
/// <para>
/// Returns an enumerator of all controls in the collection.
/// </para>
/// </devdoc>
public virtual IEnumerator GetEnumerator() {
return new ControlCollectionEnumerator(this);
}
/// <devdoc>
/// <para>Copies the specified child control to a location in the collection.</para>
/// </devdoc>
public virtual void CopyTo(Array array, int index) {
if (_controls == null)
return;
if ((array != null) && (array.Rank != 1))
throw new HttpException(SR.GetString(SR.InvalidArgumentValue, "array"));
Array.Copy(_controls, 0, array, index, _size);
}
/// <devdoc>
/// <para>Gets the parent control of the control collection.</para>
/// </devdoc>
public Object SyncRoot {
get { return this;}
}
/// <devdoc>
/// <para>Gets a value indicating whether the collection is read-only.</para>
/// </devdoc>
public bool IsReadOnly {
get { return (_readOnlyErrorMsg != null); }
}
// Setting an error message makes the control collection read only. If the user tries to modify
// the collection, we look up the error message in the resources and throw an exception.
// Set errorMsg to null to make the collection not read only.
internal string SetCollectionReadOnly(string errorMsg) {
string olderror = _readOnlyErrorMsg;
_readOnlyErrorMsg = errorMsg;
return olderror;
}
/// <devdoc>
/// <para> Gets a value indicating whether the collection
/// is synchronized.</para>
/// </devdoc>
public bool IsSynchronized {
get { return false;}
}
/// <devdoc>
/// <para>
/// Gets a reference to an ordinal-indexed control in the collection.
/// </para>
/// </devdoc>
virtual public Control this[int index]
{
get {
if (index < 0 || index >= _size) {
throw new ArgumentOutOfRangeException("index");
}
return _controls[index];
}
}
/// <devdoc>
/// <para>
/// Removes the specified child control from the collection.
/// </para>
/// </devdoc>
public virtual void RemoveAt(int index) {
if (_readOnlyErrorMsg != null) {
throw new HttpException(SR.GetString(_readOnlyErrorMsg ));
}
Control child = this[index];
_size--;
if (index < _size) {
Array.Copy(_controls, index + 1, _controls, index, _size - index);
}
_controls[_size] = null;
_version++;
_owner.RemovedControl(child);
}
/// <devdoc>
/// <para>
/// Removes the specified
/// child control object from the collection.
/// </para>
/// </devdoc>
public virtual void Remove(Control value) {
int index = IndexOf(value);
if (index >=0)
RemoveAt(index);
}
// This is a copy of the ArrayListEnumeratorSimple in ArrayList.cs
private class ControlCollectionEnumerator : IEnumerator
{
private ControlCollection list;
private int index;
private int version;
private Control currentElement;
internal ControlCollectionEnumerator(ControlCollection list) {
this.list = list;
this.index = -1;
version = list._version;
}
public bool MoveNext() {
if (index < (list.Count-1)) {
if (version != list._version) {
throw new InvalidOperationException(SR.GetString(SR.ListEnumVersionMismatch));
}
index++;
currentElement = list[index];
return true;
}
else
index = list.Count;
return false;
}
object IEnumerator.Current {
get {
return Current;
}
}
public Control Current {
get {
if (index == -1)
throw new InvalidOperationException(SR.GetString(SR.ListEnumCurrentOutOfRange));
if (index >= list.Count)
throw new InvalidOperationException(SR.GetString(SR.ListEnumCurrentOutOfRange));
return currentElement;
}
}
public void Reset() {
if (version != list._version)
throw new InvalidOperationException(SR.GetString(SR.ListEnumVersionMismatch));
currentElement = null;
index = -1;
}
}
}
}
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