svn commit: r521575 - /incubator/wicket/branches/wicket-1.x/jdk-1.4/wicket/src/main/java/wicket/Component.java

[ivaynberg]

Author: ivaynberg
Date: Thu Mar 22 21:15:37 2007
New Revision: 521575

URL: http://svn.apache.org/viewvc?view=rev&rev=521575
Log:
WICKET-365 support for markup placeholder tag

Modified:
    
incubator/wicket/branches/wicket-1.x/jdk-1.4/wicket/src/main/java/wicket/Component.java

Modified: 
incubator/wicket/branches/wicket-1.x/jdk-1.4/wicket/src/main/java/wicket/Component.java
URL: 
http://svn.apache.org/viewvc/incubator/wicket/branches/wicket-1.x/jdk-1.4/wicket/src/main/java/wicket/Component.java?view=diff&rev=521575&r1=521574&r2=521575
==============================================================================
--- 
incubator/wicket/branches/wicket-1.x/jdk-1.4/wicket/src/main/java/wicket/Component.java
 (original)
+++ 
incubator/wicket/branches/wicket-1.x/jdk-1.4/wicket/src/main/java/wicket/Component.java
 Thu Mar 22 21:15:37 2007
@@ -39,6 +39,7 @@
 import wicket.markup.WicketTag;
 import wicket.markup.html.IHeaderContributor;
 import wicket.markup.html.internal.HtmlHeaderContainer;
+import wicket.markup.parser.XmlTag;
 import wicket.model.IAssignmentAwareModel;
 import wicket.model.IInheritableModel;
 import wicket.model.IModel;
@@ -379,6 +380,7 @@
                }
        }
 
+
        /**
         * Action used with IAuthorizationStrategy to determine whether a 
component
         * is allowed to be enabled.
@@ -519,6 +521,13 @@
        /** Visibility boolean */
        private static final int FLAG_VISIBLE = 0x0010;
 
+       /**
+        * Ouput a placeholder tag if the component is not visible. This is 
useful
+        * in ajax mode to go to visible(false) to visible(true) without the
+        * overhead of repaiting a visible parent container
+        */
+       private static final int FLAG_PLACEHOLDER = 0x8000;
+
        /** Log. */
        private static final Log log = LogFactory.getLog(Component.class);
 
@@ -1537,6 +1546,19 @@
                }
                else
                {
+                       if (getFlag(FLAG_PLACEHOLDER))
+                       {
+                               // write out a placeholder tag into the markup
+                               final ComponentTag tag = markupStream.getTag();
+
+                               getResponse().write("<");
+                               getResponse().write(tag.getName());
+                               getResponse().write(" id=\"");
+                               getResponse().write(getMarkupId());
+                               getResponse().write("\" 
style=\"display:none\"></");
+                               getResponse().write(tag.getName());
+                               getResponse().write(">");
+                       }
                        markupStream.skipComponent();
                }
        }
@@ -2131,6 +2153,42 @@
 
                        // Change visibility
                        setFlag(FLAG_VISIBLE, visible);
+               }
+               return this;
+       }
+
+
+       /**
+        * Render a placeholder tag when the component is not visible. The tag 
is of
+        * form: &lt;componenttag style="display:none;" id="componentid"/&gt;. 
This
+        * method will also call <code>setOutputMarkupId(true)</code>.
+        * 
+        * This is useful, for example, in ajax situations where the component
+        * starts out invisible and then becomes visible through an ajax update.
+        * With a placeholder tag already in the markup you do not need to 
repaint
+        * this component's parent, instead you can repaint the component 
directly.
+        * 
+        * When this method is called with parameter <code>false</code> the
+        * outputmarkupid flag is not reverted to false.
+        * 
+        * @param outputTag
+        * @return this for chaining
+        */
+       public final Component setOutputMarkupPlaceholderTag(final boolean 
outputTag)
+       {
+               if (outputTag != getFlag(FLAG_PLACEHOLDER))
+               {
+                       if (outputTag)
+                       {
+                               setOutputMarkupId(true);
+                               setFlag(FLAG_PLACEHOLDER, true);
+                       }
+                       else
+                       {
+                               setFlag(FLAG_PLACEHOLDER, false);
+                               // I think it's better to not setOutputMarkupId 
to false...
+                               // user can do it if we want
+                       }
                }
                return this;
        }