mcs/class/System.Web/System.Web.UI.WebControls/Image.cs

   1 //
   2 // System.Web.UI.WebControls.Image.cs
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // Copyright (C) 2005-2010 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System.ComponentModel;
  30 using System.Security.Permissions;
  31
  32 namespace System.Web.UI.WebControls
  33 {
  34         // Note: this control can live inside or outside a <form> element
  35
  36         // CAS
  37         [AspNetHostingPermissionAttribute (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  38         [AspNetHostingPermissionAttribute (SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  39         // attributes
  40         [DefaultProperty ("ImageUrl")]
  41         [Designer ("System.Web.UI.Design.WebControls.PreviewControlDesigner, " + Consts.AssemblySystem_Design, "System.ComponentModel.Design.IDesigner")]
  42         public class Image : WebControl
  43         {
  44                 public Image ()
  45                         : base (HtmlTextWriterTag.Img)
  46                 {
  47                 }
  48
  49
  50                 [Bindable (true)]
  51                 [DefaultValue ("")]
  52                 [Localizable (true)]
  53                 [WebSysDescription ("")]
  54                 [WebCategory ("Appearance")]
  55                 public virtual string AlternateText {
  56                         get {
  57                                 string s = (string) ViewState ["AlternateText"];
  58                                 return (s == null) ? String.Empty : s;
  59                         }
  60                         set {
  61                                 if (value == null)
  62                                         ViewState.Remove ("AlternateText");
  63                                 else
  64                                         ViewState ["AlternateText"] = value;
  65                         }
  66                 }
  67
  68                 // not applicable to Image
  69                 [Browsable (false)]
  70                 [EditorBrowsable (EditorBrowsableState.Never)]
  71                 public override bool Enabled {
  72                         get { return base.Enabled; }
  73                         set {base.Enabled = value; }
  74                 }
  75
  76                 // not applicable to Image
  77                 [Browsable (false)]
  78                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
  79                 [EditorBrowsable (EditorBrowsableState.Never)]
  80                 public override FontInfo Font {
  81                         get { return base.Font; }
  82                 }
  83
  84                 [DefaultValue (ImageAlign.NotSet)]
  85                 [WebSysDescription ("")]
  86                 [WebCategory ("Layout")]
  87                 public virtual ImageAlign ImageAlign {
  88                         get {
  89                                 object o = ViewState ["ImageAlign"];
  90                                 return (o == null) ? ImageAlign.NotSet : (ImageAlign) o;
  91                         }
  92                         set {
  93                                 // avoid reflection
  94                                 if ((value < ImageAlign.NotSet) || (value > ImageAlign.TextTop)) {
  95                                         // invalid ImageAlign (note: 2.0 beta2 documents ArgumentException)
  96                                         throw new ArgumentOutOfRangeException (Locale.GetText ("Invalid ImageAlign value."));
  97                                 }
  98                                 ViewState ["ImageAlign"] = value;
  99                         }
 100                 }
 101
 102                 [Bindable (true)]
 103                 [DefaultValue ("")]
 104                 [Editor ("System.Web.UI.Design.ImageUrlEditor, " + Consts.AssemblySystem_Design, "System.Drawing.Design.UITypeEditor, " + Consts.AssemblySystem_Drawing)]
 105                 [UrlProperty]
 106                 [WebSysDescription ("")]
 107                 [WebCategory ("Appearance")]
 108                 public virtual string ImageUrl {
 109                         get {
 110                                 string s = (string) ViewState ["ImageUrl"];
 111                                 return (s == null) ? String.Empty : s;
 112                         }
 113                         set {
 114                                 if (value == null)
 115                                         ViewState.Remove ("ImageUrl");
 116                                 else
 117                                         ViewState ["ImageUrl"] = value;
 118                         }
 119                 }
 120
 121                 // this was added in Fx 1.1 SP1
 122                 [DefaultValue ("")]
 123                 [Editor ("System.Web.UI.Design.UrlEditor, " + Consts.AssemblySystem_Design, "System.Drawing.Design.UITypeEditor, " + Consts.AssemblySystem_Drawing)]
 124                 [UrlProperty]
 125                 [WebSysDescription ("")]
 126                 [WebCategory ("Accessibility")]
 127                 public virtual string DescriptionUrl {
 128                         get {
 129                                 string s = (string) ViewState ["DescriptionUrl"];
 130                                 return (s == null) ? String.Empty : s;
 131                         }
 132                         set {
 133                                 if (value == null)
 134                                         ViewState.Remove ("DescriptionUrl");
 135                                 else
 136                                         ViewState ["DescriptionUrl"] = value;
 137                         }
 138                 }
 139
 140                 [DefaultValue (false)]
 141                 [WebSysDescription ("")]
 142                 [WebCategory ("Accessibility")]
 143                 public virtual bool GenerateEmptyAlternateText {
 144                         get {
 145                                 object o = ViewState ["GenerateEmptyAlternateText"];
 146                                 return (o == null) ? false : (bool) o;
 147                         }
 148                         set { ViewState ["GenerateEmptyAlternateText"] = value; }
 149                 }
 150 #if NET_4_0
 151                 public override bool SupportsDisabledAttribute {
 152                         get { return RenderingCompatibilityLessThan40; }
 153                 }
 154 #endif
 155                 protected override void AddAttributesToRender (HtmlTextWriter writer)
 156                 {
 157                         base.AddAttributesToRender (writer);
 158                         // src is always present, even if empty, in 2.0
 159                         writer.AddAttribute (HtmlTextWriterAttribute.Src, ResolveClientUrl (ImageUrl));
 160                         string s = AlternateText;
 161                         if ((s.Length > 0) || GenerateEmptyAlternateText)
 162                                 writer.AddAttribute (HtmlTextWriterAttribute.Alt, s);
 163                         s = DescriptionUrl;
 164                         if (s.Length > 0)
 165                                 writer.AddAttribute (HtmlTextWriterAttribute.Longdesc, ResolveClientUrl (s));
 166
 167                         switch (ImageAlign) {
 168                                 case ImageAlign.Left:
 169                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "left", false);
 170                                         break;
 171                                 case ImageAlign.Right:
 172                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "right", false);
 173                                         break;
 174                                 case ImageAlign.Baseline:
 175                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "baseline", false);
 176                                         break;
 177                                 case ImageAlign.Top:
 178                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "top", false);
 179                                         break;
 180                                 case ImageAlign.Middle:
 181                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "middle", false);
 182                                         break;
 183                                 case ImageAlign.Bottom:
 184                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "bottom", false);
 185                                         break;
 186                                 case ImageAlign.AbsBottom:
 187                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "absbottom", false);
 188                                         break;
 189                                 case ImageAlign.AbsMiddle:
 190                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "absmiddle", false);
 191                                         break;
 192                                 case ImageAlign.TextTop:
 193                                         writer.AddAttribute (HtmlTextWriterAttribute.Align, "texttop", false);
 194                                         break;
 195                         }
 196 #if BUG_78875_FIXED
 197                         if (Context.Request.Browser.SupportsCss)
 198 #endif
 199 #if !NET_4_0
 200                         if (BorderWidth.IsEmpty)
 201                                 writer.AddStyleAttribute (HtmlTextWriterStyle.BorderWidth, "0px");
 202 #endif
 203                 }
 204
 205                 protected internal override void RenderContents (HtmlTextWriter writer)
 206                 {
 207                         base.RenderContents (writer);
 208                 }
 209         }
 210 }