--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts/src/main/java/org/dive4elements/artifacts/CallContext.java	Thu Apr 25 10:50:31 2013 +0200
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2010 by Intevation GmbH
+ *
+ * This program is free software under the LGPL (>=v2.1)
+ * Read the file LGPL.txt coming with the software for details
+ * or visit http://www.gnu.org/licenses/ if it does not exist.
+ */
+
+package de.intevation.artifacts;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+
+/**
+ * Instances of this interface are given to feed(), advance(), describe()
+ * and out() to enable the artifact to communicate with the runtime system.
+ * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
+ */
+public interface CallContext
+{
+    interface Listener {
+        void setup(Document config, Node listenerNode);
+        void init(CallContext callContext);
+        void close(CallContext callContext);
+    }
+
+    /**
+     * Constant to signal that nothing should be done
+     * with the artifact after method return.
+     */
+    int NOTHING    = 0;
+    /**
+     * Constant to signal that the database timestamp
+     * should be updated after method return.
+     */
+    int TOUCH      = 1;
+    /**
+     * Constant to signal that the artifact should be stored
+     * after method return.
+     */
+    int STORE      = 2;
+    /**
+     * Constant to signal that the artifact fork a backgroud thread
+     * and should be hold in memory till it signals that it has
+     * finished its operation.
+     */
+    int BACKGROUND = 3;
+    // int DELETE     = 4;
+    // int FOREVER    = 5;
+
+    /**
+     * This method may be called from feed(), describe(), advance()
+     * and out to signal what should happend with artefact after
+     * the current method call returns.
+     * @param action Valid values are NOTHING, TOUCH, STORE, BACKGROUND.
+     */
+    void afterCall(int action);
+
+    /**
+     * When send to background with a afterCall(BACKGROUND) this
+     * method is to be called from the background thread to signal
+     * that the background operation has ended.
+     * @param action Same semantics as in afterCall.
+     */
+    void afterBackground(int action);
+
+    /**
+     * Returns true, if the object forked a background thread and has not
+     * finished it yet.
+     */
+    boolean isInBackground();
+
+    /**
+     * Adds a background message for the current Artifact or Collection.
+     *
+     * @param msg The message.
+     */
+    void addBackgroundMessage(Message msg);
+
+    /**
+     * Returns the background messages of the current Artifact or Collection.
+     *
+     * @return the list of background messages.
+     */
+    LinkedList<Message> getBackgroundMessages();
+
+    /**
+     * Access to the global context of the runtime system.
+     * @return The global context.
+     */
+    Object globalContext();
+
+    /**
+     * Access to the artifact database itself.
+     * @return The database.
+     */
+    ArtifactDatabase getDatabase();
+
+    /**
+     * The meta data of the current call. Used to transport
+     * language preferences of the callee e.g.
+     * @return The meta information of this call.
+     */
+    CallMeta getMeta();
+
+    /**
+     * Each call context has a clipboard.
+     * getContextValue is used to fetch data from this board.
+     * @param key Key of the requested item.
+     * @return The value stored for the specified value, null if
+     *         no item with this key exists.
+     */
+    Object getContextValue(Object key);
+
+    /**
+     * Each call context has a clipboard.
+     * putContextValue is used to store a key/value pair onto this board.
+     * @param key   The key of the pair
+     * @param value The value of the pair.
+     * @return The formerly stored value under the given key.
+     */
+    Object putContextValue(Object key, Object value);
+
+    /**
+     * Returns the time to live of the current artifact.
+     * @return The time to live of the current artifact.
+     */
+    Long getTimeToLive();
+
+    /**
+     * Get a list of DataProvider that get provide 'key' type of data to
+     * other facets.
+     */
+    public List<DataProvider> getDataProvider(Object key);
+
+    /**
+     * Register a DataProvider that can provide 'key' type of data to
+     * other facets.
+     */
+    public Object registerDataProvider(Object key, DataProvider provider);
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :