1 files changed, 160 insertions, 0 deletions
diff --git a/gerrit-gwtexpui/src/main/java/com/google/gwtexpui/linker/server/Permutation.java b/gerrit-gwtexpui/src/main/java/com/google/gwtexpui/linker/server/Permutation.java
new file mode 100644
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--- /dev/null
+++ b/gerrit-gwtexpui/src/main/java/com/google/gwtexpui/linker/server/Permutation.java
@@ -0,0 +1,160 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gwtexpui.linker.server;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Arrays;
+
+/** A single permutation of the compiled GWT application. */
+public class Permutation {
+  private final PermutationSelector selector;
+  private final String cacheHTML;
+  private final String[] values;
+
+  Permutation(PermutationSelector sel, String cacheHTML, String[] values) {
+    this.selector = sel;
+    this.cacheHTML = cacheHTML;
+    this.values = values;
+  }
+
+  boolean matches(String[] r) {
+    return Arrays.equals(values, r);
+  }
+
+  /**
+   * Append GWT bootstrap for this permutation onto the end of the body.
+   * <p>
+   * The GWT bootstrap for this particular permutation is appended onto the end
+   * of the {@code body} element of the passed host page.
+   * <p>
+   * To keep the bootstrap code small and simple, not all GWT features are
+   * actually supported. The {@code gwt:property}, {@code gwt:onPropertyErrorFn}
+   * and {@code gwt:onLoadErrorFn} meta tags are ignored and not handled.
+   * <p>
+   * Load order may differ from the standard GWT {@code nocache.js}. The browser
+   * is asked to load the iframe immediately, rather than after the body has
+   * finished loading.
+   *
+   * @param dom host page HTML document.
+   */
+  public void inject(Document dom) {
+    String moduleName = selector.getModuleName();
+    String moduleFunc = moduleName;
+
+    StringBuilder s = new StringBuilder();
+    s.append("\n");
+    s.append("function " + moduleFunc + "(){");
+    s.append("var s,l,t");
+    s.append(",w=window");
+    s.append(",d=document");
+    s.append(",n='" + moduleName + "'");
+    s.append(",f=d.createElement('iframe')");
+    s.append(";");
+
+    // Callback to execute the module once both s and l are true.
+    //
+    s.append("function m(){");
+    s.append("if(s&&l){");
+    // Base path needs to be absolute. There isn't an easy way to do this
+    // other than forcing an image to load and then pulling the URL back.
+    //
+    s.append("var b,i=d.createElement('img');");
+    s.append("i.src=n+'/clear.cache.gif';");
+    s.append("b=i.src;");
+    s.append("b=b.substring(0,b.lastIndexOf('/')+1);");
+    s.append(moduleFunc + "=null;"); // allow us to GC
+    s.append("f.contentWindow.gwtOnLoad(undefined,n,b);");
+    s.append("}");
+    s.append("}");
+
+    // Set s true when the module script has finished loading. The
+    // exact name here is known to the IFrameLinker and is called by
+    // the code in the iframe.
+    //
+    s.append(moduleFunc + ".onScriptLoad=function(){");
+    s.append("s=1;m();");
+    s.append("};");
+
+    // Set l true when the browser has finished processing the iframe
+    // tag, and everything else on the page.
+    //
+    s.append(moduleFunc + ".r=function(){");
+    s.append("l=1;m();");
+    s.append("};");
+
+    // Prevents mixed mode security in IE6/7.
+    s.append("f.src=\"javascript:''\";");
+    s.append("f.id=n;");
+    s.append("f.style.cssText"
+        + "='position:absolute;width:0;height:0;border:none';");
+    s.append("f.tabIndex=-1;");
+    s.append("d.body.appendChild(f);");
+
+    // The src has to be set after the iframe is attached to the DOM to avoid
+    // refresh quirks in Safari. We have to use the location.replace trick to
+    // avoid FF2 refresh quirks.
+    //
+    s.append("f.contentWindow.location.replace(n+'/" + cacheHTML + "');");
+
+    // defer attribute here is to workaround IE running immediately.
+    //
+    s.append("d.write('<script defer=\"defer\">" //
+        + moduleFunc + ".r()</'+'script>');");
+    s.append("}");
+    s.append(moduleFunc + "();");
+    s.append("\n//");
+
+    final Element html = dom.getDocumentElement();
+    final Element head = (Element) html.getElementsByTagName("head").item(0);
+    final Element body = (Element) html.getElementsByTagName("body").item(0);
+
+    for (String css : selector.getCSS()) {
+      if (isRelativeURL(css)) {
+        css = moduleName + '/' + css;
+      }
+
+      final Element link = dom.createElement("link");
+      link.setAttribute("rel", "stylesheet");
+      link.setAttribute("href", css);
+      head.appendChild(link);
+    }
+
+    final Element script = dom.createElement("script");
+    script.setAttribute("type", "text/javascript");
+    script.setAttribute("language", "javascript");
+    script.appendChild(dom.createComment(s.toString()));
+    body.appendChild(script);
+  }
+
+  private static boolean isRelativeURL(String src) {
+    if (src.startsWith("/")) {
+      return false;
+    }
+
+    try {
+      // If it parses as a URL, assume it is not relative.
+      //
+      new URL(src);
+      return false;
+    } catch (MalformedURLException e) {
+    }
+
+    return true;
+  }
+}