# HG changeset patch
# User Ingo Weinzierl <ingo.weinzierl@intevation.de>
# Date 1299685686 0
# Node ID 973f244ed5682ad58f1b54ad52f536c6480b8a08
# Parent  62dd8438885fd7ce27e731eba400318c00493ae1
Improved the TransitionEngine with a method that determines if a State B is reachable from a State A.

artifacts/trunk@1445 c6561f87-3c4e-4783-a992-168aeb5c3f6f

diff -r 62dd8438885f -r 973f244ed568 ChangeLog
--- a/ChangeLog	Wed Mar 09 14:02:03 2011 +0000
+++ b/ChangeLog	Wed Mar 09 15:48:06 2011 +0000
@@ -1,3 +1,8 @@
+2011-03-09  Ingo Weinzierl <ingo@intevation.de>
+
+	* artifact-database/src/main/java/de/intevation/artifactdatabase/transition/TransitionEngine.java:
+	  New method to determine if a state B is reachable from a state A.
+
 2011-03-09  Ingo Weinzierl <ingo@intevation.de>
 
 	* artifact-database/src/main/java/de/intevation/artifactdatabase/data/DefaultStateData.java:
diff -r 62dd8438885f -r 973f244ed568 artifact-database/src/main/java/de/intevation/artifactdatabase/transition/TransitionEngine.java
--- a/artifact-database/src/main/java/de/intevation/artifactdatabase/transition/TransitionEngine.java	Wed Mar 09 14:02:03 2011 +0000
+++ b/artifact-database/src/main/java/de/intevation/artifactdatabase/transition/TransitionEngine.java	Wed Mar 09 15:48:06 2011 +0000
@@ -85,6 +85,10 @@
         List<Transition> transitions = getTransitions(state);
         List<State>      reachable   = new ArrayList<State>();
 
+        if (transitions == null) {
+            return reachable;
+        }
+
         for (Transition t: transitions) {
             if (t.isValid(state)) {
                 reachable.add(engine.getState(t.getTo()));
@@ -93,5 +97,36 @@
 
         return reachable;
     }
+
+
+    /**
+     * Determines if a state with a given identifier is reachable from a current
+     * state.
+     *
+     * @param targetId The identifier of the target state.
+     * @param state The start state.
+     * @param stateEngine The StateEngine.
+     *
+     * @return true, if the target state is reachable, otherwise false.
+     */
+    public boolean isStateReachable(
+        String      targetId,
+        State       state,
+        StateEngine stateEngine)
+    {
+        List<State> reachable = getReachableStates(state, stateEngine);
+
+        if (reachable == null || reachable.size() == 0) {
+            return false;
+        }
+
+        for (State s: reachable) {
+            if (targetId.equals(s.getID())) {
+                return true;
+            }
+        }
+
+        return false;
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :