1 files changed, 60 insertions, 0 deletions
diff --git a/server/src/org/jsoup/parser/TreeBuilder.java b/server/src/org/jsoup/parser/TreeBuilder.java
new file mode 100644
index 0000000000..e06caad501
--- /dev/null
+++ b/server/src/org/jsoup/parser/TreeBuilder.java
@@ -0,0 +1,60 @@
+package org.jsoup.parser;
+
+import org.jsoup.helper.DescendableLinkedList;
+import org.jsoup.helper.Validate;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author Jonathan Hedley
+ */
+abstract class TreeBuilder {
+    CharacterReader reader;
+    Tokeniser tokeniser;
+    protected Document doc; // current doc we are building into
+    protected DescendableLinkedList<Element> stack; // the stack of open elements
+    protected String baseUri; // current base uri, for creating new elements
+    protected Token currentToken; // currentToken is used only for error tracking.
+    protected ParseErrorList errors; // null when not tracking errors
+
+    protected void initialiseParse(String input, String baseUri, ParseErrorList errors) {
+        Validate.notNull(input, "String input must not be null");
+        Validate.notNull(baseUri, "BaseURI must not be null");
+
+        doc = new Document(baseUri);
+        reader = new CharacterReader(input);
+        this.errors = errors;
+        tokeniser = new Tokeniser(reader, errors);
+        stack = new DescendableLinkedList<Element>();
+        this.baseUri = baseUri;
+    }
+
+    Document parse(String input, String baseUri) {
+        return parse(input, baseUri, ParseErrorList.noTracking());
+    }
+
+    Document parse(String input, String baseUri, ParseErrorList errors) {
+        initialiseParse(input, baseUri, errors);
+        runParser();
+        return doc;
+    }
+
+    protected void runParser() {
+        while (true) {
+            Token token = tokeniser.read();
+            process(token);
+
+            if (token.type == Token.TokenType.EOF)
+                break;
+        }
+    }
+
+    protected abstract boolean process(Token token);
+
+    protected Element currentElement() {
+        return stack.getLast();
+    }
+}