--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common/test/src/main/java/com/redhat/thermostat/testutils/StubExecutor.java	Thu Jun 30 10:20:27 2016 -0400
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2012-2016 Red Hat, Inc.
+ *
+ * This file is part of Thermostat.
+ *
+ * Thermostat is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2, or (at your
+ * option) any later version.
+ *
+ * Thermostat is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Thermostat; see the file COPYING.  If not see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Linking this code with other modules is making a combined work
+ * based on this code.  Thus, the terms and conditions of the GNU
+ * General Public License cover the whole combination.
+ *
+ * As a special exception, the copyright holders of this code give
+ * you permission to link this code with independent modules to
+ * produce an executable, regardless of the license terms of these
+ * independent modules, and to copy and distribute the resulting
+ * executable under terms of your choice, provided that you also
+ * meet, for each linked independent module, the terms and conditions
+ * of the license of that module.  An independent module is a module
+ * which is not derived from or based on this code.  If you modify
+ * this code, you may extend this exception to your version of the
+ * library, but you are not obligated to do so.  If you do not wish
+ * to do so, delete this exception statement from your version.
+ */
+
+package com.redhat.thermostat.testutils;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.AbstractExecutorService;
+import java.util.concurrent.TimeUnit;
+
+public class StubExecutor extends AbstractExecutorService {
+    @Override
+    public void shutdown() {
+    }
+
+    @Override
+    public List<Runnable> shutdownNow() {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public boolean isShutdown() {
+        return false;
+    }
+
+    @Override
+    public boolean isTerminated() {
+        return false;
+    }
+
+    @Override
+    public boolean awaitTermination(long l, TimeUnit timeUnit) throws InterruptedException {
+        return false;
+    }
+
+    @Override
+    public void execute(Runnable runnable) {
+        runnable.run();
+    }
+}
\ No newline at end of file

--- a/vm-heap-analysis/client-core/src/main/java/com/redhat/thermostat/vm/heap/analysis/client/core/internal/HeapDumpDetailsController.java	Thu Jun 30 08:43:12 2016 -0400
+++ b/vm-heap-analysis/client-core/src/main/java/com/redhat/thermostat/vm/heap/analysis/client/core/internal/HeapDumpDetailsController.java	Thu Jun 30 10:20:27 2016 -0400
@@ -87,14 +87,8 @@
 
     public void setDump(HeapDump dump) {
         this.heapDump = dump;
-        ObjectHistogram histogram = null;
 
-        try {
-            histogram = dump.getHistogram();
-        } catch (IOException e) {
-            log.log(Level.SEVERE, "unexpected error while reading heap dump", e);
-        }
-
+        ObjectHistogram histogram = readHistogram();
         Objects.requireNonNull(histogram);
 
         heapHistogramView = histogramViewProvider.createView();
@@ -125,17 +119,33 @@
         dump.searchObjects("A_RANDOM_PATTERN", 1);
     }
 
+    private ObjectHistogram readHistogram() {
+        try {
+            return heapDump.getHistogram();
+        } catch (IOException e) {
+            log.log(Level.SEVERE, "unexpected error while reading heap dump", e);
+            return null;
+        }
+    }
+
     private void searchForObject(final String searchText) {
-        
+
         appService.getApplicationExecutor().execute(new Runnable() {
             @Override
             public void run() {
-                Collection<String> objectIds = heapDump.wildcardSearch(searchText);
-
-                ObjectHistogram toDisplay = new ObjectHistogram();
-                for (String id : objectIds) {
-                    JavaHeapObject heapObject = heapDump.findObject(id);
-                    toDisplay.addThing(heapObject);
+                ObjectHistogram toDisplay;
+                if (searchText == null || searchText.trim().isEmpty()) {
+                    toDisplay = readHistogram();
+                    if (toDisplay == null) {
+                        return;
+                    }
+                } else {
+                    toDisplay = new ObjectHistogram();
+                    Collection<String> objectIds = heapDump.wildcardSearch(searchText);
+                    for (String id : objectIds) {
+                        JavaHeapObject heapObject = heapDump.findObject(id);
+                        toDisplay.addThing(heapObject);
+                    }
                 }
                 heapHistogramView.setHistogram(toDisplay);
             }

--- a/vm-heap-analysis/client-core/src/test/java/com/redhat/thermostat/vm/heap/analysis/client/core/internal/HeapDumpDetailsControllerTest.java	Thu Jun 30 08:43:12 2016 -0400
+++ b/vm-heap-analysis/client-core/src/test/java/com/redhat/thermostat/vm/heap/analysis/client/core/internal/HeapDumpDetailsControllerTest.java	Thu Jun 30 10:20:27 2016 -0400
@@ -36,22 +36,10 @@
 
 package com.redhat.thermostat.vm.heap.analysis.client.core.internal;
 
-import junit.framework.Assert;
-
-import static junit.framework.Assert.assertTrue;
-import static org.mockito.Matchers.anyInt;
-import static org.mockito.Matchers.isA;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import java.io.IOException;
-
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-
+import com.redhat.thermostat.common.ActionEvent;
+import com.redhat.thermostat.common.ActionListener;
 import com.redhat.thermostat.common.ApplicationService;
+import com.redhat.thermostat.testutils.StubExecutor;
 import com.redhat.thermostat.vm.heap.analysis.client.core.HeapDumpDetailsView;
 import com.redhat.thermostat.vm.heap.analysis.client.core.HeapDumpDetailsViewProvider;
 import com.redhat.thermostat.vm.heap.analysis.client.core.HeapHistogramView;
@@ -64,15 +52,39 @@
 import com.redhat.thermostat.vm.heap.analysis.client.core.ObjectRootsViewProvider;
 import com.redhat.thermostat.vm.heap.analysis.common.HeapDump;
 import com.redhat.thermostat.vm.heap.analysis.common.ObjectHistogram;
+import com.sun.tools.hat.internal.model.JavaClass;
+import com.sun.tools.hat.internal.model.JavaHeapObject;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+
+import java.io.IOException;
+import java.util.Collections;
+
+import static junit.framework.Assert.fail;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Matchers.isA;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 public class HeapDumpDetailsControllerTest {
 
     private HeapDumpDetailsView view;
     private HeapDumpDetailsViewProvider viewProvider;
     private HeapHistogramViewProvider histogramProvider;
+    private HeapHistogramView histogramView;
     private HeapTreeMapViewProvider treeMapProvider;
     private ObjectDetailsViewProvider objectDetailsProvider;
     private ObjectRootsViewProvider objectRootsProvider;
+    private ApplicationService appService;
+
+    private HeapDumpDetailsController controller;
 
     @Before
     public void setUp() {
@@ -80,7 +92,7 @@
         view = mock(HeapDumpDetailsView.class);
         when(viewProvider.createView()).thenReturn(view);
 
-        HeapHistogramView histogramView = mock(HeapHistogramView.class);
+        histogramView = mock(HeapHistogramView.class);
         histogramProvider = mock(HeapHistogramViewProvider.class);
         when(histogramProvider.createView()).thenReturn(histogramView);
 
@@ -95,36 +107,24 @@
         ObjectRootsView objectRootsView = mock(ObjectRootsView.class);
         objectRootsProvider = mock(ObjectRootsViewProvider.class);
         when(objectRootsProvider.createView()).thenReturn(objectRootsView);
+
+        appService = mock(ApplicationService.class);
+        when(appService.getApplicationExecutor()).thenReturn(new StubExecutor());
+
+        controller = new HeapDumpDetailsController(appService, viewProvider, histogramProvider, treeMapProvider,
+                objectDetailsProvider, objectRootsProvider);
     }
 
-    @After
-    public void tearDown() {
-        viewProvider = null;
-        histogramProvider = null;
-        objectDetailsProvider = null;
-        objectRootsProvider = null;
-    }
-
-    @Test
+    @Test(expected = NullPointerException.class)
     public void testSetDumpFailsWithEmptyDump() throws IOException {
-        HeapDumpDetailsController controller = setupController();
-
         HeapDump emptyDump = mock(HeapDump.class);
         when(emptyDump.getHistogram()).thenReturn(null);
 
-        boolean caught = false;
-        try {
-            controller.setDump(emptyDump);
-        } catch (NullPointerException e) {
-            caught = true;
-        }
-        assertTrue("Null pointer exception expected", caught);
+        controller.setDump(emptyDump);
     }
 
     @Test
     public void testSetDumpWorksWithValidDump() throws IOException {
-        HeapDumpDetailsController controller = setupController();
-
         HeapDump dump = mock(HeapDump.class);
         ObjectHistogram histogram = mock(ObjectHistogram.class);
         when(dump.getHistogram()).thenReturn(histogram);
@@ -132,7 +132,7 @@
         try {
             controller.setDump(dump);
         } catch (NullPointerException e) {
-            Assert.fail("Did not expect null pointer exception");
+            fail("Did not expect null pointer exception");
         }
 
         verify(dump).searchObjects(isA(String.class), anyInt());
@@ -140,11 +140,62 @@
                 isA(HeapTreeMapView.class));
     }
 
-    private HeapDumpDetailsController setupController() {
-        ApplicationService appService = mock(ApplicationService.class);
-        return new HeapDumpDetailsController(
-                appService, viewProvider, histogramProvider, treeMapProvider,
-                objectDetailsProvider, objectRootsProvider);
+    @Test
+    public void testEmptySearchStringDisplaysFullHistogram() throws IOException {
+        HeapDump dump = mock(HeapDump.class);
+        ObjectHistogram histogram = mock(ObjectHistogram.class);
+        when(dump.getHistogram()).thenReturn(histogram);
+
+        controller.setDump(dump);
+        verify(histogramView).setHistogram(histogram);
+
+        ArgumentCaptor<ActionListener> captor =
+                ArgumentCaptor.forClass(ActionListener.class);
+        verify(histogramView).addHistogramActionListener(captor.capture());
+        ActionListener<HeapHistogramView.HistogramAction> listener = captor.getValue();
+
+        ActionEvent<HeapHistogramView.HistogramAction> actionEvent = new ActionEvent<>(this, HeapHistogramView.HistogramAction.SEARCH);
+        actionEvent.setPayload("");
+        listener.actionPerformed(actionEvent);
+
+        verify(histogramView, times(2)).setHistogram(histogram);
+
+        verify(dump, never()).wildcardSearch(anyString());
+        verify(dump, never()).findObject(anyString());
+    }
+
+    @Test
+    public void testNonEmptySearchStringDisplaysFilteredHistogram() throws IOException {
+        HeapDump dump = mock(HeapDump.class);
+        ObjectHistogram histogram = mock(ObjectHistogram.class);
+        String objectId = "objectId";
+        when(dump.getHistogram()).thenReturn(histogram);
+        when(dump.wildcardSearch(anyString())).thenReturn(Collections.singleton(objectId));
+        JavaHeapObject javaHeapObject = mock(JavaHeapObject.class);
+        when(javaHeapObject.getClazz()).thenReturn(mock(JavaClass.class));
+        when(dump.findObject(anyString())).thenReturn(javaHeapObject);
+
+        controller.setDump(dump);
+        verify(histogramView).setHistogram(histogram);
+
+        ArgumentCaptor<ActionListener> captor =
+                ArgumentCaptor.forClass(ActionListener.class);
+        verify(histogramView).addHistogramActionListener(captor.capture());
+        ActionListener<HeapHistogramView.HistogramAction> listener = captor.getValue();
+
+        ActionEvent<HeapHistogramView.HistogramAction> actionEvent = new ActionEvent<>(this, HeapHistogramView.HistogramAction.SEARCH);
+        String searchTerm = "SEARCH_TERM";
+        actionEvent.setPayload(searchTerm);
+        listener.actionPerformed(actionEvent);
+
+        verify(histogramView, times(1)).setHistogram(histogram); // verify full histogram still displayed only once
+        verify(dump).wildcardSearch(searchTerm);
+        verify(dump).findObject(objectId);
+
+        ArgumentCaptor<ObjectHistogram> histogramCaptor = ArgumentCaptor.forClass(ObjectHistogram.class);
+        verify(histogramView, times(2)).setHistogram(histogramCaptor.capture());
+        ObjectHistogram objectHistogram = histogramCaptor.getValue();
+        assertThat(objectHistogram.getHistogram().size(), is(1));
     }
 
 }