// System.Web.UI.WebControls.PagedDataSource.cs
//
// Author: Duncan Mak (duncan@novell.com)
// Jackson Harper (jackson@ximian.com)
//
// Copyright (C) 2005 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.Collections;
using System.ComponentModel;
using System.Security.Permissions;
namespace System.Web.UI.WebControls{
// CAS - no inheritance demand required because the class is sealed
[AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class PagedDataSource : ICollection, IEnumerable, ITypedList
{
int page_size, current_page_index, virtual_count;
bool allow_paging, allow_custom_paging;
IEnumerable source;
#if NET_2_0
bool allow_server_paging;
#endif
public PagedDataSource ()
{
page_size = 10;
}
public bool AllowCustomPaging {
get { return allow_custom_paging; }
set {
allow_custom_paging = value;
#if NET_2_0
// AllowCustomPaging and AllowServerPaging are mutually exclusive
if (allow_custom_paging)
allow_server_paging = false;
#endif
}
}
public bool AllowPaging {
get { return allow_paging; }
set { allow_paging = value; }
}
public int Count {
get {
if (source == null)
return 0;
if (IsPagingEnabled) {
if (IsCustomPagingEnabled || !IsLastPage)
return page_size;
return DataSourceCount - FirstIndexInPage;
}
return DataSourceCount;
}
}
public int CurrentPageIndex {
get { return current_page_index; }
set { current_page_index = value; }
}
public IEnumerable DataSource {
get { return source; }
set { source = value; }
}
public int DataSourceCount {
get {
if (source == null)
return 0;
if (IsCustomPagingEnabled
#if NET_2_0
|| IsServerPagingEnabled
#endif
)
return virtual_count;
if (source is ICollection)
return ((ICollection) source).Count;
throw new HttpException ("The data source must implement ICollection");
}
}
public int FirstIndexInPage {
get {
if (!IsPagingEnabled || IsCustomPagingEnabled ||
#if NET_2_0
IsServerPagingEnabled ||
#endif
source == null)
return 0;
return current_page_index * page_size;
}
}
public bool IsCustomPagingEnabled {
get { return IsPagingEnabled && allow_custom_paging; }
}
#if NET_2_0
public bool IsServerPagingEnabled {
get { return IsPagingEnabled && allow_server_paging; }
}
#endif
public bool IsFirstPage {
get {
if (!allow_paging)
return true;
return current_page_index == 0;
}
}
public bool IsLastPage {
get {
if (!allow_paging || page_size == 0)
return true;
return (current_page_index == (PageCount - 1));
}
}
public bool IsPagingEnabled {
get { return (allow_paging && page_size != 0); }
}
public bool IsReadOnly {
get { return false; } // as documented
}
public bool IsSynchronized {
get { return false; } // as documented
}
public int PageCount {
get {
if (source == null)
return 0;
if (!IsPagingEnabled || DataSourceCount == 0 || page_size == 0)
return 1;
return (DataSourceCount + page_size - 1) / page_size;
}
}
public int PageSize {
get { return page_size; }
set { page_size = value; }
}
public object SyncRoot {
get { return this; }
}
public int VirtualCount {
get { return virtual_count; }
set { virtual_count = value; }
}
#if NET_2_0
public bool AllowServerPaging {
get {
return allow_server_paging;
}
set {
allow_server_paging = value;
// AllowCustomPaging and AllowServerPaging are mutually exclusive
if (allow_server_paging)
allow_custom_paging = false;
}
}
#endif
public void CopyTo (Array array, int index)
{
foreach (object o in source)
array.SetValue (o, index++);
}
public IEnumerator GetEnumerator ()
{
// IList goes first, as it implements ICollection
IList list = source as IList;
int first = 0;
int count;
int limit;
if (list != null) {
first = FirstIndexInPage;
count = ((ICollection) source).Count;
limit = ((first + page_size) > count) ? (count - first) : page_size;
return GetListEnum (list, first, first + limit);
}
ICollection col = source as ICollection;
if (col != null) {
first = FirstIndexInPage;
count = col.Count;
limit = ((first + page_size) > count) ? (count - first) : page_size;
return GetEnumeratorEnum (col.GetEnumerator (), first, first + page_size);
}
return source.GetEnumerator ();
}
public PropertyDescriptorCollection GetItemProperties (PropertyDescriptor [] list_accessors)
{
ITypedList typed = source as ITypedList;
if (typed == null)
return null;
return typed.GetItemProperties (list_accessors);
}
public string GetListName (PropertyDescriptor [] list_accessors)
{
return String.Empty; // as documented
}
IEnumerator GetListEnum (IList list, int start, int end)
{
if (!AllowPaging)
end = list.Count;
else if (start >= list.Count)
yield break;
for (int i = start; i < end; i++)
yield return list [i];
}
IEnumerator GetEnumeratorEnum (IEnumerator e, int start, int end)
{
for (int i = 0; i < start; i++)
e.MoveNext ();
for (int i = start; (!allow_paging || i < end) && e.MoveNext (); i++)
yield return e.Current;
}
}
}
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