Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,279 @@
+//------------------------------------------------------------------------------
+// <copyright file="Image.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI.WebControls {
+
+    using System;
+    using System.ComponentModel;
+    using System.Drawing.Design;
+    using System.Web;
+    using System.Web.UI;
+    using System.Web.Util;
+
+    /// <devdoc>
+    ///    <para>Displays an image on a page.</para>
+    /// </devdoc>
+    [
+    DefaultProperty("ImageUrl"),
+    Designer("System.Web.UI.Design.WebControls.PreviewControlDesigner, " + AssemblyRef.SystemDesign),
+    ]
+    public class Image : WebControl {
+
+        private bool _urlResolved;
+
+
+        /// <devdoc>
+        /// <para>Initializes a new instance of the <see cref='System.Web.UI.WebControls.Image'/> class.</para>
+        /// </devdoc>
+        public Image() : base(HtmlTextWriterTag.Img) {
+        }
+
+
+        /// <devdoc>
+        ///    <para>Specifies alternate text displayed when the image fails to load.</para>
+        /// </devdoc>
+        [
+        Localizable(true),
+        Bindable(true),
+        WebCategory("Appearance"),
+        DefaultValue(""),
+        WebSysDescription(SR.Image_AlternateText)
+        ]
+        public virtual string AlternateText {
+            get {
+                string s = (string)ViewState["AlternateText"];
+                return((s == null) ? String.Empty : s);
+            }
+            set {
+                ViewState["AlternateText"] = value;
+            }
+        }
+
+
+        /// <devdoc>
+        /// </devdoc>
+        [
+        DefaultValue(""),
+        Editor("System.Web.UI.Design.UrlEditor, " + AssemblyRef.SystemDesign, typeof(UITypeEditor)),
+        UrlProperty(),
+        WebCategory("Accessibility"),
+        WebSysDescription(SR.Image_DescriptionUrl)
+        ]
+        public virtual string DescriptionUrl {
+            get {
+                string s = (string)ViewState["DescriptionUrl"];
+                return((s == null) ? String.Empty : s);
+            }
+            set {
+                ViewState["DescriptionUrl"] = value;
+            }
+        }
+
+
+        /// <devdoc>
+        ///    <para>Gets the font properties for the alternate text. This property is read-only.</para>
+        /// </devdoc>
+        [
+        Browsable(false),
+        EditorBrowsableAttribute(EditorBrowsableState.Never),
+        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
+        ]
+        public override FontInfo Font {
+            // Font is meaningless for image, so hide it from the developer by
+            // making it non-browsable.
+            get {
+                return base.Font;
+            }
+        }
+
+
+        [
+        Browsable(false),
+        EditorBrowsableAttribute(EditorBrowsableState.Never)
+        ]
+        public override bool Enabled {
+            get {
+                return base.Enabled;
+            }
+            set {
+                base.Enabled = value;
+            }
+        }
+
+        [
+        DefaultValue(false),
+        WebCategory("Accessibility"),
+        WebSysDescription(SR.Image_GenerateEmptyAlternateText)
+        ]
+        public virtual bool GenerateEmptyAlternateText {
+            get {
+                object o = ViewState["GenerateEmptyAlternateText"];
+                return((o == null) ? false : (bool)o);
+            }
+            set {
+                ViewState["GenerateEmptyAlternateText"] = value;
+            }
+        }
+
+
+        /// <devdoc>
+        ///    <para>Gets or
+        ///       sets the alignment of the image within the text flow.</para>
+        /// </devdoc>
+        [
+        WebCategory("Layout"),
+        DefaultValue(ImageAlign.NotSet),
+        WebSysDescription(SR.Image_ImageAlign)
+        ]
+        public virtual ImageAlign ImageAlign {
+            get {
+                object o = ViewState["ImageAlign"];
+                return((o == null) ? ImageAlign.NotSet : (ImageAlign)o);
+            }
+            set {
+                if (value < ImageAlign.NotSet || value > ImageAlign.TextTop) {
+                    throw new ArgumentOutOfRangeException("value");
+                }
+                ViewState["ImageAlign"] = value;
+            }
+        }
+
+
+        /// <devdoc>
+        ///    <para>Gets or sets
+        ///       the URL reference to the image to display.</para>
+        /// </devdoc>
+        [
+        Bindable(true),
+        WebCategory("Appearance"),
+        DefaultValue(""),
+        Editor("System.Web.UI.Design.ImageUrlEditor, " + AssemblyRef.SystemDesign, typeof(UITypeEditor)),
+        UrlProperty(),
+        WebSysDescription(SR.Image_ImageUrl)
+        ]
+        public virtual string ImageUrl {
+            get {
+                string s = (string)ViewState["ImageUrl"];
+                return((s == null) ? String.Empty : s);
+            }
+            set {
+                ViewState["ImageUrl"] = value;
+            }
+        }
+
+        public override bool SupportsDisabledAttribute {
+            get {
+                return RenderingCompatibility < VersionUtil.Framework40;
+            }
+        }
+
+        // Perf work: Specially for AdRotator which uses the control while it
+        // resolves the url on its own.
+        internal bool UrlResolved {
+            get {
+                return _urlResolved;
+            }
+            set {
+                _urlResolved = value;
+            }
+        }
+
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// <para>Adds the attributes of an <see cref='System.Web.UI.WebControls.Image'/> to the output stream for rendering on
+        ///    the client.</para>
+        /// </devdoc>
+        protected override void AddAttributesToRender(HtmlTextWriter writer) {
+            base.AddAttributesToRender(writer);
+
+            string s = ImageUrl;
+            if (!UrlResolved) {
+                s = ResolveClientUrl(s);
+            }
+
+            if (RenderingCompatibility >= VersionUtil.Framework45) {
+                // If targeting 4.5 or above, only render the 'src' attribute if it really does contain something.
+                // Additionally, in DesignMode include the 'src' attribute so that icon looks same as in Dev10.
+                // More info: Dev10 #865118; DevDiv #423125
+                if (!String.IsNullOrEmpty(s) || DesignMode) {
+                    writer.AddAttribute(HtmlTextWriterAttribute.Src, s);
+                }
+            }
+            else {
+                // Otherwise, for compat, run the logic that was in the product from versions 2.0 through 4.0.
+                if (s.Length > 0 || !EnableLegacyRendering) {
+                    writer.AddAttribute(HtmlTextWriterAttribute.Src, s);
+                }
+            }
+
+            s = DescriptionUrl;
+            if (s.Length != 0) {
+                writer.AddAttribute(HtmlTextWriterAttribute.Longdesc, ResolveClientUrl(s));
+            }
+
+            // always write out alt for accessibility purposes
+            s = AlternateText;
+            if (s.Length > 0 || GenerateEmptyAlternateText) {
+                writer.AddAttribute(HtmlTextWriterAttribute.Alt,s);
+            }
+
+            ImageAlign align = ImageAlign;
+            if (align != ImageAlign.NotSet) {
+                string imageAlignValue;
+                switch (align) {
+                    case ImageAlign.Left:
+                        imageAlignValue = "left";
+                        break;
+                    case ImageAlign.Right:
+                        imageAlignValue = "right";
+                        break;
+                    case ImageAlign.Baseline:
+                        imageAlignValue = "baseline";
+                        break;
+                    case ImageAlign.Top:
+                        imageAlignValue = "top";
+                        break;
+                    case ImageAlign.Middle:
+                        imageAlignValue = "middle";
+                        break;
+                    case ImageAlign.Bottom:
+                        imageAlignValue = "bottom";
+                        break;
+                    case ImageAlign.AbsBottom:
+                        imageAlignValue = "absbottom";
+                        break;
+                    case ImageAlign.AbsMiddle:
+                        imageAlignValue = "absmiddle";
+                        break;
+                    default:
+                        imageAlignValue = "texttop";
+                        break;
+                }
+                writer.AddAttribute(HtmlTextWriterAttribute.Align, imageAlignValue);
+            }
+
+            if (BorderWidth.IsEmpty && (RenderingCompatibility < VersionUtil.Framework40)) {
+                if (EnableLegacyRendering) {
+                    writer.AddAttribute(HtmlTextWriterAttribute.Border, "0", false);
+                }
+                else {
+                    writer.AddStyleAttribute(HtmlTextWriterStyle.BorderWidth, "0px");
+                }
+            }
+        }
+
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// </devdoc>
+        protected internal override void RenderContents(HtmlTextWriter writer) {
+            // Do not render the children of a button since it does not
+            // make sense to have children of an <input> tag.
+        }
+    }
+}
+