Fix #89 (Guarded task start() method running before guard)

CHANGES

@@ -1,5 +1,6 @@
 [1.8.3-SNAPSHOT]
 - Updated to libgdx 1.11.0
+- Start guarded task only if the guard succeeds
 
 [1.8.2]
 - Updated to libgdx 1.9.8

gdx-ai/src/com/badlogic/gdx/ai/btree/BehaviorTree.java

@@ -119,11 +119,11 @@ public void step () {
 			rootTask.run();
 		} else {
 			rootTask.setControl(this);
-			rootTask.start();
-			if (rootTask.checkGuard(this))
+			if (rootTask.checkGuard(this)) {
+				rootTask.start();
 				rootTask.run();
-			else
-				rootTask.fail();
+			} else
+				childFail(null); // actually child has not failed but child guard has failed
 		}
 	}
 

gdx-ai/src/com/badlogic/gdx/ai/btree/Decorator.java

@@ -66,11 +66,11 @@ public void run () {
 			child.run();
 		} else {
 			child.setControl(this);
-			child.start();
-			if (child.checkGuard(this))
+			if (child.checkGuard(this)) {
+				child.start();
 				child.run();
-			else
-				child.fail();
+			} else
+				childFail(null); // actually child has not failed but child guard has failed
 		}
 	}
 

gdx-ai/src/com/badlogic/gdx/ai/btree/LoopDecorator.java

@@ -51,11 +51,11 @@ public void run () {
 				child.run();
 			} else {
 				child.setControl(this);
-				child.start();
-				if (child.checkGuard(this))
+				if (child.checkGuard(this)) {
+					child.start();
 					child.run();
-				else
-					child.fail();
+				} else
+					childFail(null); // actually child has not failed but child guard has failed
 			}
 		}
 	}

gdx-ai/src/com/badlogic/gdx/ai/btree/SingleRunningChildBranch.java

@@ -84,11 +84,12 @@ public void run () {
 					runningChild = children.get(currentChildIndex);
 				}
 				runningChild.setControl(this);
-				runningChild.start();
 				if (!runningChild.checkGuard(this))
-					runningChild.fail();
-				else
+					childFail(null); // actually child has not failed but child guard has failed
+				else {
+					runningChild.start();
 					run();
+				}
 			} else {
 				// Should never happen; this case must be handled by subclasses in childXXX methods
 			}

gdx-ai/src/com/badlogic/gdx/ai/btree/branch/Parallel.java

@@ -23,7 +23,7 @@
 import com.badlogic.gdx.utils.Array;
 
 /** A {@code Parallel} is a special branch task that runs all children when stepped. 
- * Its actual behavior depends on its {@link orchestrator} and {@link policy}.<br>
+ * Its actual behavior depends on its {@link #orchestrator} and {@link #policy}.<br>
  * <br>
  * The execution of the parallel task's children depends on its {@link #orchestrator}:
  * <ul>
@@ -173,11 +173,11 @@ public void execute(Parallel<?> parallel) {
 						child.run();
 					} else {
 						child.setControl(parallel);
-						child.start();
-						if (child.checkGuard(parallel))
+						if (child.checkGuard(parallel)) {
+							child.start();
 							child.run();
-						else
-							child.fail();
+						} else
+							parallel.childFail(null); // actually child has not failed but child guard has failed
 					}
 
 					if (parallel.lastResult != null) { // Current child has finished either with success or fail
@@ -210,11 +210,11 @@ public void execute(Parallel<?> parallel) {
 						break;
 					default:
 						child.setControl(parallel);
-						child.start();
-						if (child.checkGuard(parallel))
+						if (child.checkGuard(parallel)) {
+							child.start();
 							child.run();
-						else
-							child.fail();
+						} else
+							parallel.childFail(null); // actually child has not failed but child guard has failed
 						break;
 					}