Merge "Create a ChangeCache for ChangeDetails in ChangeScreen"

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeCache.java

@@ -0,0 +1,53 @@
+// Copyright (C) 2012 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.client.changes;
+
+import com.google.gerrit.reviewdb.Change;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/** A Cache to store common client side data by change */
+public class ChangeCache {
+  private static Map<Change.Id, ChangeCache> caches =
+    new HashMap<Change.Id, ChangeCache>();
+
+  public static ChangeCache get(Change.Id chg) {
+    ChangeCache cache = caches.get(chg);
+    if (cache == null) {
+      cache = new ChangeCache(chg);
+      caches.put(chg, cache);
+    }
+    return cache;
+  }
+
+  private Change.Id changeId;
+  private ChangeDetailCache detail;
+
+  protected ChangeCache(Change.Id chg) {
+    changeId = chg;
+  }
+
+  public Change.Id getChangeId() {
+    return changeId;
+  }
+
+  public ChangeDetailCache getChangeDetailCache() {
+    if (detail == null) {
+      detail = new ChangeDetailCache(changeId);
+    }
+    return detail;
+  }
+}

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeDetailCache.java

@@ -0,0 +1,57 @@
+// Copyright (C) 2012 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.client.changes;
+
+import com.google.gerrit.client.ui.ListenableValue;
+import com.google.gerrit.common.data.ChangeDetail;
+import com.google.gerrit.reviewdb.Change;
+
+import com.google.gwt.user.client.rpc.AsyncCallback;
+
+public class ChangeDetailCache extends ListenableValue<ChangeDetail> {
+  public static class GerritCallback extends
+      com.google.gerrit.client.rpc.GerritCallback<ChangeDetail> {
+    @Override
+    public void onSuccess(ChangeDetail detail) {
+      setChangeDetail(detail);
+    }
+  }
+
+  public static class IgnoreErrorCallback implements AsyncCallback<ChangeDetail> {
+    @Override
+    public void onSuccess(ChangeDetail detail) {
+      setChangeDetail(detail);
+    }
+
+    @Override
+    public void onFailure(Throwable caught) {
+    }
+  }
+
+  public static void setChangeDetail(ChangeDetail detail) {
+    Change.Id chgId = detail.getChange().getId();
+    ChangeCache.get(chgId).getChangeDetailCache().set(detail);
+  }
+
+  private final Change.Id changeId;
+
+  public ChangeDetailCache(final Change.Id chg) {
+    changeId = chg;
+  }
+
+  public void refresh() {
+    Util.DETAIL_SVC.changeDetail(changeId, new GerritCallback());
+  }
+}

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeScreen.java

@@ -17,7 +17,6 @@ package com.google.gerrit.client.changes;
 import com.google.gerrit.client.Dispatcher;
 import com.google.gerrit.client.Gerrit;
 import com.google.gerrit.client.rpc.GerritCallback;
-import com.google.gerrit.client.rpc.ScreenLoadCallback;
 import com.google.gerrit.client.ui.CommentPanel;
 import com.google.gerrit.client.ui.ComplexDisclosurePanel;
 import com.google.gerrit.client.ui.ExpandAllCommand;
@@ -39,6 +38,8 @@ import com.google.gwt.event.dom.client.ChangeHandler;
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.dom.client.KeyPressEvent;
+import com.google.gwt.event.logical.shared.ValueChangeEvent;
+import com.google.gwt.event.logical.shared.ValueChangeHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.i18n.client.LocaleInfo;
 import com.google.gwt.user.client.ui.DisclosurePanel;
@@ -59,9 +60,11 @@ import java.sql.Timestamp;
 import java.util.List;
 
 
-public class ChangeScreen extends Screen {
+public class ChangeScreen extends Screen
+    implements ValueChangeHandler<ChangeDetail> {
   private final Change.Id changeId;
   private final PatchSet.Id openPatchSetId;
+  private ChangeDetailCache detailCache;
 
   private Image starChange;
   private boolean starred;
@@ -130,7 +133,7 @@ public class ChangeScreen extends Screen {
   @Override
   protected void onLoad() {
     super.onLoad();
-    refresh();
+    detailCache.refresh();
   }
 
   @Override
@@ -156,21 +159,6 @@ public class ChangeScreen extends Screen {
     }
   }
 
-  public void refresh() {
-    Util.DETAIL_SVC.changeDetail(changeId,
-        new ScreenLoadCallback<ChangeDetail>(this) {
-          @Override
-          protected void preDisplay(final ChangeDetail r) {
-            display(r);
-          }
-
-          @Override
-          protected void postDisplay() {
-            patchSetsBlock.setRegisterKeys(true);
-          }
-        });
-  }
-
   private void setStarred(final boolean s) {
     if (s) {
       starChange.setResource(Gerrit.RESOURCES.starFilled());
@@ -183,6 +171,12 @@ public class ChangeScreen extends Screen {
   @Override
   protected void onInitUI() {
     super.onInitUI();
+
+    ChangeCache cache = ChangeCache.get(changeId);
+
+    detailCache = cache.getChangeDetailCache();
+    detailCache.addValueChangeHandler(this);
+
     addStyleName(Gerrit.RESOURCES.css().changeScreen());
 
     keysNavigation = new KeyCommandSet(Gerrit.C.sectionNavigation());
@@ -283,9 +277,15 @@ public class ChangeScreen extends Screen {
     setPageTitle(titleBuf.toString());
   }
 
+  @Override
+  public void onValueChange(ValueChangeEvent<ChangeDetail> event) {
+    if (isAttached()) {
+      display(event.getValue());
+    }
+  }
+
   void update(final ChangeDetail detail) {
-    display(detail);
-    patchSetsBlock.setRegisterKeys(true);
+    detailCache.set(detail);
   }
 
   private void display(final ChangeDetail detail) {
@@ -352,6 +352,11 @@ public class ChangeScreen extends Screen {
       dependenciesPanel.getHeader().add(new InlineLabel(
         Util.M.outdatedHeader(outdated)));
     }
+
+    if (!isCurrentView()) {
+      display();
+    }
+    patchSetsBlock.setRegisterKeys(true);
   }
 
   private void addComments(final ChangeDetail detail) {