1 files changed, 42 insertions, 8 deletions

diff --git a/systemtap/org.eclipse.linuxtools.systemtap.ui.ide/src/org/eclipse/linuxtools/internal/systemtap/ui/ide/structures/TreeTapsetParser.java b/systemtap/org.eclipse.linuxtools.systemtap.ui.ide/src/org/eclipse/linuxtools/internal/systemtap/ui/ide/structures/TreeTapsetParser.java
index 2009bd6762..e3b5f2ebe1 100644
--- a/systemtap/org.eclipse.linuxtools.systemtap.ui.ide/src/org/eclipse/linuxtools/internal/systemtap/ui/ide/structures/TreeTapsetParser.java
+++ b/systemtap/org.eclipse.linuxtools.systemtap.ui.ide/src/org/eclipse/linuxtools/internal/systemtap/ui/ide/structures/TreeTapsetParser.java
@@ -13,6 +13,8 @@ package org.eclipse.linuxtools.internal.systemtap.ui.ide.structures;
 
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.linuxtools.internal.systemtap.ui.ide.IDEPlugin;
 import org.eclipse.linuxtools.systemtap.structures.TreeNode;
 
 /**
@@ -21,6 +23,9 @@ import org.eclipse.linuxtools.systemtap.structures.TreeNode;
  */
 public abstract class TreeTapsetParser extends TapsetParser {
 
+    protected TreeNode tree = null;
+    private TreeNode forcedTree = null;
+
     protected TreeTapsetParser(String jobTitle) {
         super(jobTitle);
     }
@@ -30,24 +35,53 @@ public abstract class TreeTapsetParser extends TapsetParser {
      * actions during the run; a call to super.run() is necessary.
      */
     @Override
-    protected IStatus run(IProgressMonitor monitor) {
-        resetTree();
-        return null;
+    protected final synchronized IStatus run(IProgressMonitor monitor) {
+        if (forcedTree != null) {
+            tree = forcedTree;
+            forcedTree = null;
+            return new Status(IStatus.OK, IDEPlugin.PLUGIN_ID, ""); //$NON-NLS-1$
+        } else {
+            tree = new TreeNode(null, false);
+            return runAction(monitor);
+        }
+    }
+
+    protected IStatus runAction(IProgressMonitor monitor) {
+        return new Status(!monitor.isCanceled() ? IStatus.OK : IStatus.CANCEL,
+                IDEPlugin.PLUGIN_ID, ""); //$NON-NLS-1$
     }
 
     /**
      * @return The tree that this parser constructs.
      */
-    abstract TreeNode getTree();
+    public final synchronized TreeNode getTree() {
+        return tree;
+    }
 
     /**
-     * Clears & resets the tree that this parser constructs.
+     * Forcefully set this parser's tree, and subsequently fire update events
+     * that normally get called when a parse operation completes.
+     * @param tree The tree to put into this parser.
      */
-    abstract protected void resetTree();
+    final synchronized void setTree(TreeNode tree) {
+        String errorMessage = isValidTree(tree);
+        if (errorMessage != null) {
+            throw new IllegalArgumentException(errorMessage);
+        }
+        cancel();
+        forcedTree = tree;
+        schedule();
+    }
 
     /**
-     * Clean up everything from the last parse run.
+     * Check if the provided tree a valid tree for this parser.
+     * Called internally by {@link #setTree(TreeNode)}.
+     * @param tree The tree to check for validity. 
+     * @return <code>null</code> if the tree is valid; otherwise,
+     * an error message signifying why the tree is invalid.
      */
-    abstract void dispose();
+    protected String isValidTree(TreeNode tree) {
+        return null;
+    }
 
 }