[TabSelectionEditor] Change menu option enable condition

This CL enables "Group tab" menu option only when there are more than
one un-grouped tabs in the current TabModel.

Change-Id: Ia7a7bde1a32fe5d8411b3a6dfd95cb232df3fa76
Bug: 970266, 987146
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1717603Reviewed-by: Theresa <twellington@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Commit-Queue: Mei Liang <meiliang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#681336}

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_groups/TabGroupModelFilter.java

@@ -448,6 +448,13 @@ public class TabGroupModelFilter extends TabModelFilter {
         return getRelatedTabList(group.getTabIdList());
     }
 
+    @Override
+    public boolean hasOtherRelatedTabs(Tab tab) {
+        int groupId = tab.getRootId();
+        TabGroup group = mGroupIdToGroupMap.get(groupId);
+        return group != null && group.size() > 1;
+    }
+
     private List<Tab> getRelatedTabList(List<Integer> ids) {
         List<Tab> tabs = new ArrayList<>();
         for (Integer id : ids) {

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabSelectionEditorMediator.java

@@ -11,7 +11,6 @@ import android.view.View;
 import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tabmodel.TabModel;
-import org.chromium.chrome.browser.tabmodel.TabModelFilter;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
 import org.chromium.chrome.browser.tabmodel.TabModelUtils;
 import org.chromium.chrome.browser.tasks.tab_groups.TabGroupModelFilter;
@@ -117,26 +116,14 @@ class TabSelectionEditorMediator
 
     @Override
     public void show() {
-        mResetHandler.resetWithListOfTabs(getTabsToShow());
+        List<Tab> nonGroupedTabs = mTabModelSelector.getTabModelFilterProvider()
+                                           .getCurrentTabModelFilter()
+                                           .getTabsWithNoOtherRelatedTabs();
+        mResetHandler.resetWithListOfTabs(nonGroupedTabs);
         mSelectionDelegate.setSelectionModeEnabledForZeroItems(true);
         mModel.set(TabSelectionEditorProperties.IS_VISIBLE, true);
     }
 
-    private List<Tab> getTabsToShow() {
-        List<Tab> tabs = new ArrayList<>();
-        TabModelFilter tabModelFilter =
-                mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter();
-        for (int i = 0; i < tabModelFilter.getCount(); i++) {
-            Tab tab = tabModelFilter.getTabAt(i);
-            // TODO(977302): This filtered out the tabs that has related tabs. This should be done
-            // at the TabModelFilter.
-            if (tabModelFilter.getRelatedTabList(tab.getId()).size() == 1) {
-                tabs.add(tab);
-            }
-        }
-        return tabs;
-    }
-
     @Override
     public boolean handleBackPressed() {
         if (!isEditorVisible()) return false;

chrome/android/features/tab_ui/junit/src/org/chromium/chrome/browser/tasks/tab_groups/TabGroupModelFilterUnitTest.java

@@ -654,4 +654,28 @@ public class TabGroupModelFilterUnitTest {
         // Verify that the signal is not ignored.
         verify(mTabGroupModelFilterObserver).didMoveTabOutOfGroup(mTab3, POSITION2);
     }
+
+    @Test
+    public void getNonGroupedTab() {
+        Tab[] expectedNonGroupedTabs = new Tab[]{mTab1, mTab4};
+        List<Tab> nonGroupedTabs = mTabGroupModelFilter.getTabsWithNoOtherRelatedTabs();
+        assertArrayEquals(expectedNonGroupedTabs, nonGroupedTabs.toArray());
+
+        // Group mTab4 with mTab2 and mTab3
+        mTabGroupModelFilter.mergeTabsToGroup(mTab4.getId(), mTab2.getId());
+
+        Tab[] expectedNonGroupedTabs_AfterGrouping = new Tab[]{mTab1};
+        List<Tab> nonGroupedTabs_AfterGrouping =
+                mTabGroupModelFilter.getTabsWithNoOtherRelatedTabs();
+        assertArrayEquals(expectedNonGroupedTabs_AfterGrouping,
+                nonGroupedTabs_AfterGrouping.toArray());
+
+        // UnGroup mTab3 for its group.
+        mTabGroupModelFilter.moveTabOutOfGroup(TAB3_ID);
+        Tab[] expectedNonGroupedTabs_AfterUnGrouping = new Tab[]{mTab1, mTab3};
+        List<Tab> nonGroupedTabs_AfterUnGrouping =
+                mTabGroupModelFilter.getTabsWithNoOtherRelatedTabs();
+        assertArrayEquals(expectedNonGroupedTabs_AfterUnGrouping,
+                nonGroupedTabs_AfterUnGrouping.toArray());
+    }
 }

chrome/android/java/src/org/chromium/chrome/browser/appmenu/AppMenuPropertiesDelegateImpl.java

@@ -268,6 +268,13 @@ public class AppMenuPropertiesDelegateImpl implements AppMenuPropertiesDelegate
             if (!FeatureUtilities.isTabGroupsAndroidUiImprovementsEnabled()
                     || DeviceClassManager.enableAccessibilityLayout()) {
                 menu.findItem(R.id.menu_group_tabs).setVisible(false);
+            } else {
+                boolean shouldEnabled = mTabModelSelector.getTabModelFilterProvider()
+                                                .getCurrentTabModelFilter()
+                                                .getTabsWithNoOtherRelatedTabs()
+                                                .size()
+                        > 1;
+                menu.findItem(R.id.menu_group_tabs).setEnabled(shouldEnabled);
             }
         }
 

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelFilter.java

@@ -84,6 +84,31 @@ public abstract class TabModelFilter extends EmptyTabModelObserver implements Ta
         return Collections.unmodifiableList(relatedTab);
     }
 
+    /**
+     * @return An unmodifiable list of {@link Tab}s that are not related to any tabs
+     */
+    @NonNull
+    final public List<Tab> getTabsWithNoOtherRelatedTabs() {
+        List<Tab> tabs = new ArrayList<>();
+        for (int i = 0; i < mTabModel.getCount(); i++) {
+            Tab tab = mTabModel.getTabAt(i);
+            if (!hasOtherRelatedTabs(tab)) {
+                tabs.add(tab);
+            }
+        }
+        return Collections.unmodifiableList(tabs);
+    }
+
+    /**
+     * Any of the concrete class that defined a relationship between tabs should override this
+     * method. By default, the given {@link Tab} has no related tabs, other than itself.
+     * @param tab A {@link Tab}.
+     * @return Whether the given {@link Tab} has other related tabs that is not itself.
+     */
+    public boolean hasOtherRelatedTabs(Tab tab) {
+        return false;
+    }
+
     /**
      * Concrete class requires to define what's the behavior when {@link TabModel} added a
      * {@link Tab}.