ChtmlTextWriter.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / xsp / System / Web / UI / ChtmlTextWriter.cs / 1 / ChtmlTextWriter.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

// ChtmlTextWriter.cs 
// 

namespace System.Web.UI { 
    using System;
    using System.Collections;
    using System.Collections.Specialized;
    using System.IO; 
    using System.Text;
    using System.Web.UI.WebControls; 
    using System.Web.Util; 
    using System.Globalization;
    using System.Security.Permissions; 


    /// 
    ///    [To be supplied.] 
    /// 
    [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    public class ChtmlTextWriter : Html32TextWriter {
        private Hashtable _recognizedAttributes = new Hashtable(StringComparer.CurrentCultureIgnoreCase); 
        private Hashtable _suppressedAttributes = new Hashtable(StringComparer.CurrentCultureIgnoreCase);
        private Hashtable _globalSuppressedAttributes = new Hashtable(StringComparer.CurrentCultureIgnoreCase);

 
        public ChtmlTextWriter(TextWriter writer) : this(writer, DefaultTabString) {
        } 
 

        public ChtmlTextWriter(TextWriter writer, string tabString) : base(writer, tabString) { 
            _globalSuppressedAttributes["onclick"] = true;
            _globalSuppressedAttributes["ondblclick"] = true;
            _globalSuppressedAttributes["onmousedown"] = true;
            _globalSuppressedAttributes["onmouseup"] = true; 
            _globalSuppressedAttributes["onmouseover"] = true;
            _globalSuppressedAttributes["onmousemove"] = true; 
            _globalSuppressedAttributes["onmouseout"] = true; 
            _globalSuppressedAttributes["onkeypress"] = true;
            _globalSuppressedAttributes["onkeydown"] = true; 
            _globalSuppressedAttributes["onkeyup"] = true;

            // Supress certain element attribute pairs that can happen when Html32TextWriter performs the div table
            // substitution. 
            RemoveRecognizedAttributeInternal("div", "accesskey");    // VSWhidbey 270254
            RemoveRecognizedAttributeInternal("div", "cellspacing"); 
            RemoveRecognizedAttributeInternal("div", "cellpadding"); 
            RemoveRecognizedAttributeInternal("div", "gridlines");
            RemoveRecognizedAttributeInternal("div", "rules"); 

            RemoveRecognizedAttributeInternal("span", "cellspacing");
            RemoveRecognizedAttributeInternal("span", "cellpadding");
            RemoveRecognizedAttributeInternal("span", "gridlines"); 
            RemoveRecognizedAttributeInternal("span", "rules");
        } 
 

        ///  
        /// [To be supplied.]
        /// 
        public virtual void AddRecognizedAttribute(string elementName, string attributeName) {
            Hashtable eltAttributes = (Hashtable) _recognizedAttributes[elementName]; 
            if (eltAttributes == null) {
                eltAttributes = new Hashtable(StringComparer.CurrentCultureIgnoreCase); 
                _recognizedAttributes[elementName] = eltAttributes; 
            }
            eltAttributes.Add(attributeName, true); 
        }


        ///  
        /// Override to filter out unnecessary attributes
        ///  
        protected override bool OnAttributeRender(string name, string value, HtmlTextWriterAttribute key) { 
            Hashtable elementRecognizedAttributes = (Hashtable)_recognizedAttributes[TagName];
            if (elementRecognizedAttributes != null && elementRecognizedAttributes[name] != null) { 
                return true;
            }

            if (_globalSuppressedAttributes[name] != null) { 
                return false;
            } 
 
            Hashtable elementSuppressedAttributes = (Hashtable)_suppressedAttributes[TagName];
            if (elementSuppressedAttributes != null && elementSuppressedAttributes[name] != null) { 
                return false;
            }

            return true; 
        }
 
 
        protected override bool OnStyleAttributeRender(string name,string value, HtmlTextWriterStyle key) {
            if (key == HtmlTextWriterStyle.TextDecoration) { 
                if (StringUtil.EqualsIgnoreCase("line-through", value)) {
                    return false;
                }
            } 
            return base.OnStyleAttributeRender(name, value, key);
        } 
 

        protected override bool OnTagRender(string name, HtmlTextWriterTag key) { 
            return  base.OnTagRender(name, key) && key != HtmlTextWriterTag.Span;
        }

 
        /// 
        /// [To be supplied.] 
        ///  
        public virtual void RemoveRecognizedAttribute(string elementName, string attributeName) {
            RemoveRecognizedAttributeInternal(elementName, attributeName); 
        }

        private void RemoveRecognizedAttributeInternal(string elementName, string attributeName) {
            // Since recognized attributes have precedence, we need to do two operations: add this attribute 
            // to the suppressed list, and remove it from the recognized list.
            Hashtable eltAttributes = (Hashtable) _suppressedAttributes[elementName]; 
            if (eltAttributes == null) { 
                eltAttributes = new Hashtable(StringComparer.CurrentCultureIgnoreCase);
                _suppressedAttributes[elementName] = eltAttributes; 
            }
            eltAttributes.Add(attributeName, true);

            eltAttributes = (Hashtable)_recognizedAttributes[elementName]; 
            if (eltAttributes == null) {
                eltAttributes = new Hashtable(StringComparer.CurrentCultureIgnoreCase); 
                _recognizedAttributes[elementName] = eltAttributes; 
            }
            // Note: Hashtable::Remove silently continues if the key does not exist. 
            eltAttributes.Remove(attributeName);
        }

 
        public override void WriteBreak() {
            Write("
"); 
        } 

        public override void WriteEncodedText(String text) { 
            if (null == text || text.Length == 0) {
                return;
            }
 
            int length = text.Length;
            int start = -1; 
            for(int pos = 0; pos < length; pos++) { 
                int ch = text[pos];
                if(ch > 160 && ch < 256) { 
                    if(start != -1) {
                        base.WriteEncodedText(text.Substring(start, pos - start));
                        start = -1;
                    } 
                    base.Write(text[pos]);
                } 
                else { 
                    if(start == -1) {
                        start = pos; 
                    }
                }
            }
            if(start != -1) { 
                if(start == 0) {
                    base.WriteEncodedText(text); 
                } 
                else {
                    base.WriteEncodedText(text.Substring(start, length - start)); 
                }
            }
        }
 
        protected Hashtable RecognizedAttributes {
            get { 
                return _recognizedAttributes; 
            }
        } 

        protected Hashtable SuppressedAttributes {
            get {
                return _suppressedAttributes; 
            }
        } 
 
        protected Hashtable GlobalSuppressedAttributes {
            get { 
                return _globalSuppressedAttributes;
            }
        }
    } 
}

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