HtmlSelectionListAdapter.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / MIT / System / Web / UI / MobileControls / Adapters / HtmlSelectionListAdapter.cs / 1305376 / HtmlSelectionListAdapter.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

using System; 
using System.Globalization; 
using System.IO;
using System.Web; 
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.MobileControls;
using System.Collections.Specialized; 
using System.Diagnostics;
using System.Security.Permissions; 
 
#if COMPILING_FOR_SHIPPED_SOURCE
namespace System.Web.UI.MobileControls.ShippedAdapterSource 
#else
namespace System.Web.UI.MobileControls.Adapters
#endif
 
{
    /* 
     * HtmlSelectionListAdapter provides the html device functionality for SelectionList controls. 
     *
     * Copyright (c) 2000 Microsoft Corporation 
     */
    /// 
    [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)]
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    [Obsolete("The System.Web.Mobile.dll assembly has been deprecated and should no longer be used. For information about how to develop ASP.NET mobile applications, see http://go.microsoft.com/fwlink/?LinkId=157231.")]
    public class HtmlSelectionListAdapter : HtmlControlAdapter 
    { 
        /// 
        protected new SelectionList Control 
        {
            get
            {
                return (SelectionList)base.Control; 
            }
        } 
 
        /// 
        public override void OnInit(EventArgs e) 
        {
        }

        ///  
        public override void Render(HtmlMobileTextWriter writer)
        { 
            MobileListItemCollection items = Control.Items; 
            ListSelectType selectType = Control.SelectType;
 
            if (items.Count == 0 &&
                selectType != ListSelectType.ListBox &&
                selectType != ListSelectType.MultiSelectListBox)
            { 
                return;
            } 
 
            int selectedIndex = Control.SelectedIndex;
            String renderName; 
            if(Device.RequiresAttributeColonSubstitution)
            {
                renderName = Control.UniqueID.Replace(':', ',');
            } 
            else
            { 
                renderName = Control.UniqueID; 
            }
 
            switch(selectType)
            {
                case ListSelectType.DropDown:
                case ListSelectType.ListBox: 
                case ListSelectType.MultiSelectListBox:
 
                    if (items.Count == 0 && !Device.CanRenderEmptySelects) 
                    {
                        break; 
                    }

                    writer.EnterLayout(Style);
                    writer.WriteBeginTag("select"); 

                    if (selectType == ListSelectType.MultiSelectListBox) 
                    { 
                        writer.Write(" multiple");
                    } 

                    if (selectType == ListSelectType.ListBox || selectType == ListSelectType.MultiSelectListBox)
                    {
                        writer.WriteAttribute("size", Control.Rows.ToString(CultureInfo.InvariantCulture)); 
                    }
 
                    writer.WriteAttribute("name", renderName); 
                    writer.Write(">");
 
                    for(int itemIndex = 0; itemIndex < items.Count; itemIndex++)
                    {
                        MobileListItem item = items[itemIndex];
                        writer.WriteBeginTag("option"); 
                        WriteItemValueAttribute(writer, itemIndex, item.Value);
                        if (item.Selected && (Control.IsMultiSelect || itemIndex == selectedIndex)) 
                        { 
                            writer.Write(" selected>");
                        } 
                        else
                        {
                            writer.Write(">");
                        } 
                        writer.WriteEncodedText(item.Text);
                        writer.WriteLine(""); 
                    } 
                    writer.Write("");
 
                    if(Device.HidesRightAlignedMultiselectScrollbars &&
                        selectType == ListSelectType.MultiSelectListBox)
                    {
                        // nested if for perf 
                        if((Alignment)Style[Style.AlignmentKey, true] == Alignment.Right)
                        { 
                            writer.Write("    "); 
                        }
                    } 
                    writer.WriteLine("");

                    if (!Page.DesignMode)
                    { 
                        writer.ExitLayout(Style, Control.BreakAfter);
                    } 
                    else 
                    {
                        writer.ExitLayout(Style, false); 
                    }
                    break;

                case ListSelectType.Radio: 
                case ListSelectType.CheckBox:
 
                    String selectTypeString = 
                        (selectType == ListSelectType.Radio) ?
                        "radio" : 
                        "checkbox";
                    Alignment alignment = (Alignment)Style[Style.AlignmentKey, true];
                    if(!Device.Tables || alignment == Alignment.Left || alignment == Alignment.NotSet)
                    { 
                        writer.EnterStyle(Style);
                        bool breakAfter = false; 
                        for(int itemIndex = 0; itemIndex < items.Count; itemIndex++) 
                        {
                            if(breakAfter) 
                            {
                                writer.WriteBreak();
                            }
                            MobileListItem item = items[itemIndex]; 

                            writer.WriteBeginTag("input"); 
                            writer.WriteAttribute("type", selectTypeString); 
                            writer.WriteAttribute("name", renderName);
                            WriteItemValueAttribute(writer, itemIndex, item.Value); 
                            if (item.Selected &&
                                (Control.IsMultiSelect || itemIndex == selectedIndex) &&
                                Device.SupportsUncheck)
                            { 
                                writer.Write(" checked>");
                            } 
                            else 
                            {
                                writer.Write(">"); 
                            }
                            writer.WriteEncodedText(item.Text);
                            breakAfter = true;
                        } 
                        writer.ExitStyle(Style, Control.BreakAfter);
                    } 
                    else // Device supports tables and alignment is non default. 
                    {
                        Wrapping  wrapping  = (Wrapping) Style[Style.WrappingKey , true]; 
                        bool nowrap = (wrapping == Wrapping.NoWrap);

                        writer.EnterLayout(Style);
                        writer.WriteFullBeginTag("table"); 
                        writer.BeginStyleContext();
                        for(int itemIndex = 0; itemIndex < items.Count; itemIndex++) 
                        { 
                            MobileListItem item = items[itemIndex];
                            writer.WriteFullBeginTag("tr"); 
                            writer.WriteBeginTag("td");
                            if(nowrap)
                            {
                                writer.WriteAttribute("nowrap","true"); 
                            }
                            writer.Write(">"); 
 
                            writer.WriteBeginTag("input");
                            writer.WriteAttribute("type", selectTypeString); 
                            writer.WriteAttribute("name", renderName);
                            WriteItemValueAttribute(writer, itemIndex, item.Value);
                            if (item.Selected &&
                                (Control.IsMultiSelect || itemIndex == selectedIndex) && 
                                Device.SupportsUncheck)
                            { 
                                writer.Write(" checked>"); 
                            }
                            else 
                            {
                                writer.Write(">");
                            }
 
                            writer.MarkStyleContext();
                            writer.EnterFormat(Style); 
                            writer.WriteEncodedText(item.Text); 
                            writer.ExitFormat(Style);
                            writer.UnMarkStyleContext(); 
                            writer.WriteEndTag("td");
                            writer.WriteEndTag("tr");
                        }
                        writer.WriteEndTag("table"); 
                        writer.EndStyleContext();
                        writer.ExitFormat(Style, Control.BreakAfter); 
                    } 
                break;
            } 
        }

        // Parse the HTML posted data appropriately.
        ///  
        public override bool LoadPostData(String key,
                                          NameValueCollection data, 
                                          Object controlPrivateData, 
                                          out bool dataChanged)
        { 
            String[] selectedItems = data.GetValues(key);
            Debug.Assert (String.IsNullOrEmpty(Control.Form.Action),
                "Cross page post (!IsPostBack) assumed when Form.Action nonempty." +
                "LoadPostData should not have been be called."); 

            // If no post data is included, and the control is either not visible, or 
            // not on active form, this call should be ignored (the lack of post data 
            // is not due to there being no selection, but due to there being no
            // markup rendered that could generate the post data). 

            if (selectedItems == null &&
                    (!Control.Visible || Control.Form != Control.MobilePage.ActiveForm))
            { 
                dataChanged = false;
                return true; 
            } 

            // Case where nothing is selected. 
            if(selectedItems == null ||
               (selectedItems.Length == 1 && (selectedItems[0] != null && selectedItems[0].Length == 0)))
            {
                selectedItems = new String[]{}; 
            }
 
            int[] selectedItemIndices = new int[selectedItems.Length]; 

            // Note: controlPrivateData is selected indices from the viewstate. 
            int[] originalSelectedIndices = (int[])controlPrivateData;
            dataChanged = false;

            // If SelectType is DropDown && nothing was selected, select 
            // first elt.  (Non-mobile DropDown does same by getting SelectedIndex).
            if(Control.SelectType == ListSelectType.DropDown && 
               originalSelectedIndices.Length == 0 && 
               Control.Items.Count > 0)
            { 
                Control.Items[0].Selected = true;
                originalSelectedIndices = new int[]{0};
            }
 
            for(int i = 0; i < selectedItems.Length; i++)
            { 
                selectedItemIndices[i] = Int32.Parse(selectedItems[i], CultureInfo.InvariantCulture); 
            }
 
            // Do not assume posted selected indices are ascending.
            // We do know originalSelectedIndices are ascending.
            Array.Sort(selectedItemIndices);
 
            // Check whether selections have changed.
            if(selectedItemIndices.Length != originalSelectedIndices.Length) 
            { 
                dataChanged = true;
            } 
            else
            {
                for(int i = 0; i < selectedItems.Length; i++)
                { 
                    if(selectedItemIndices[i] != originalSelectedIndices[i])
                    { 
                        dataChanged = true; 
                    }
                } 
            }

            for (int i = 0; i < Control.Items.Count; i++)
            { 
                Control.Items[i].Selected = false;
            } 
 
            for(int i = 0; i < selectedItemIndices.Length; i++)
            { 
                Control.Items[selectedItemIndices[i]].Selected = true;
            }
            return true;
        } 

        private void WriteItemValueAttribute(HtmlTextWriter writer, int index, String value) 
        { 
            if (Page.DesignMode || String.IsNullOrEmpty(Control.Form.Action))
            { 
                writer.WriteAttribute("value", index.ToString(CultureInfo.InvariantCulture));
            }
            else
            { 
                writer.WriteAttribute("value", value, true /*encode*/);
            } 
        } 

        ///  
        protected override void RenderAsHiddenInputField(HtmlMobileTextWriter writer)
        {
            // Optimization - if viewstate is enabled for this control, and the
            // postback returns to this page, we just let it do the trick. 
            // One catch though - if the control is multiselect, it always
            // interprets return values, so we do need to write out. 
 
            if (Control.IsMultiSelect || Control.Form.Action.Length > 0 || !IsViewStateEnabled())
            { 
                String uniqueID = Control.UniqueID;
                MobileListItemCollection items = Control.Items;
                for (int i = 0; i < items.Count; i++)
                { 
                    if (items[i].Selected)
                    { 
                        writer.WriteHiddenField(uniqueID, i.ToString(CultureInfo.InvariantCulture)); 
                    }
                } 
            }
        }

        private bool IsViewStateEnabled() 
        {
            Control ctl = Control; 
            while (ctl != null) 
            {
                if (!ctl.EnableViewState) 
                {
                    return false;
                }
                ctl = ctl.Parent; 
            }
            return true; 
        } 
   }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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HtmlSelectionListAdapter.cs source code in C# .NET

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