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//------------------------------------------------------------------------------
// <copyright file="Container.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.ComponentModel {
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Security.Permissions;
/// <devdoc>
/// <para>
/// Encapsulates
/// zero or more components.
/// </para>
/// </devdoc>
[HostProtection(SharedState = true)]
public class Container : IContainer
{
private ISite[] sites;
private int siteCount;
private ComponentCollection components;
private ContainerFilterService filter;
private bool checkedFilter;
private object syncObj = new Object();
~Container() {
Dispose(false);
}
// Adds a component to the container.
/// <devdoc>
/// <para>
/// Adds the specified component to the <see cref='System.ComponentModel.Container'/>
/// . The component is unnamed.
/// </para>
/// </devdoc>
public virtual void Add(IComponent component) {
Add(component, null);
}
// Adds a component to the container.
/// <devdoc>
/// <para>
/// Adds the specified component to the <see cref='System.ComponentModel.Container'/> and assigns a name to
/// it.
/// </para>
/// </devdoc>
public virtual void Add(IComponent component, String name) {
lock (syncObj) {
if (component == null) {
return;
}
ISite site = component.Site;
if (site != null && site.Container == this) {
return;
}
if (sites == null) {
sites = new ISite[4];
}
else {
// Validate that new components
// have either a null name or a unique one.
//
ValidateName(component, name);
if (sites.Length == siteCount) {
ISite[] newSites = new ISite[siteCount * 2];
Array.Copy(sites, 0, newSites, 0, siteCount);
sites = newSites;
}
}
if (site != null) {
site.Container.Remove(component);
}
ISite newSite = CreateSite(component, name);
sites[siteCount++] = newSite;
component.Site = newSite;
components = null;
}
}
// Creates a site for the component within the container.
/// <devdoc>
/// <para>Creates a Site <see cref='System.ComponentModel.ISite'/> for the given <see cref='System.ComponentModel.IComponent'/>
/// and assigns the given name to the site.</para>
/// </devdoc>
protected virtual ISite CreateSite(IComponent component, string name) {
return new Site(component, this, name);
}
// Disposes of the container. A call to the Dispose method indicates that
// the user of the container has no further need for it.
//
// The implementation of Dispose must:
//
// (1) Remove any references the container is holding to other components.
// This is typically accomplished by assigning null to any fields that
// contain references to other components.
//
// (2) Release any system resources that are associated with the container,
// such as file handles, window handles, or database connections.
//
// (3) Dispose of child components by calling the Dispose method of each.
//
// Ideally, a call to Dispose will revert a container to the state it was
// in immediately after it was created. However, this is not a requirement.
// Following a call to its Dispose method, a container is permitted to raise
// exceptions for operations that cannot meaningfully be performed.
//
/// <devdoc>
/// <para>
/// Disposes of the <see cref='System.ComponentModel.Container'/>
/// .
/// </para>
/// </devdoc>
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing) {
if (disposing) {
lock (syncObj) {
while (siteCount > 0) {
ISite site = sites[--siteCount];
site.Component.Site = null;
site.Component.Dispose();
}
sites = null;
components = null;
}
}
}
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
protected virtual object GetService(Type service) {
return((service == typeof(IContainer)) ? this : null);
}
// The components in the container.
/// <devdoc>
/// <para>
/// Gets all the components in the <see cref='System.ComponentModel.Container'/>
/// .
/// </para>
/// </devdoc>
public virtual ComponentCollection Components {
get {
lock (syncObj) {
if (components == null) {
IComponent[] result = new IComponent[siteCount];
for (int i = 0; i < siteCount; i++) {
result[i] = sites[i].Component;
}
components = new ComponentCollection(result);
// At each component add, if we don't yet have a filter, look for one.
// Components may add filters.
if (filter == null && checkedFilter) {
checkedFilter = false;
}
}
if (!checkedFilter) {
filter = GetService(typeof(ContainerFilterService)) as ContainerFilterService;
checkedFilter = true;
}
if (filter != null) {
ComponentCollection filteredComponents = filter.FilterComponents(components);
Debug.Assert(filteredComponents != null, "Incorrect ContainerFilterService implementation.");
if (filteredComponents != null) {
components = filteredComponents;
}
}
return components;
}
}
}
// Removes a component from the container.
/// <devdoc>
/// <para>
/// Removes a component from the <see cref='System.ComponentModel.Container'/>
/// .
/// </para>
/// </devdoc>
public virtual void Remove(IComponent component) {
Remove(component, false);
}
private void Remove(IComponent component, bool preserveSite) {
lock (syncObj) {
if (component == null)
return;
ISite site = component.Site;
if (site == null || site.Container != this)
return;
if (!preserveSite)
component.Site = null;
for (int i = 0; i < siteCount; i++) {
if (sites[i] == site) {
siteCount--;
Array.Copy(sites, i + 1, sites, i, siteCount - i);
sites[siteCount] = null;
components = null;
break;
}
}
}
}
protected void RemoveWithoutUnsiting(IComponent component) {
Remove(component, true);
}
/// <devdoc>
/// Validates that the given name is valid for a component. The default implementation
/// verifies that name is either null or unique compared to the names of other
/// components in the container.
/// </devdoc>
protected virtual void ValidateName(IComponent component, string name) {
if (component == null) {
throw new ArgumentNullException("component");
}
if (name != null) {
for (int i = 0; i < Math.Min(siteCount,sites.Length); i++) {
ISite s = sites[ i ];
if (s != null && s.Name != null
&& string.Equals(s.Name, name, StringComparison.OrdinalIgnoreCase)
&& s.Component != component) {
InheritanceAttribute inheritanceAttribute = (InheritanceAttribute)TypeDescriptor.GetAttributes(s.Component)[typeof(InheritanceAttribute)];
if(inheritanceAttribute.InheritanceLevel != InheritanceLevel.InheritedReadOnly) {
throw new ArgumentException(SR.GetString(SR.DuplicateComponentName, name));
}
}
}
}
}
private class Site : ISite
{
private IComponent component;
private Container container;
private String name;
internal Site(IComponent component, Container container, String name) {
this.component = component;
this.container = container;
this.name = name;
}
// The component sited by this component site.
public IComponent Component {
get {
return component;
}
}
// The container in which the component is sited.
public IContainer Container {
get {
return container;
}
}
public Object GetService(Type service) {
return((service == typeof(ISite)) ? this : container.GetService(service));
}
// Indicates whether the component is in design mode.
public bool DesignMode {
get {
return false;
}
}
// The name of the component.
//
public String Name
{
get { return name;}
set {
if (value == null || name == null || !value.Equals(name)) {
//
container.ValidateName(component, value);
name = value;
}
}
}
}
}
}
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