[StartSurface] Sort Tabs in descending order of the last shown time

The tabs are ordered from the most recent to the least recent ones
in the tab grid and carousel in start surfaces.

Bug: 982018
Change-Id: I974c492555751c5f2d7eebe8c6d871d05a41fb22
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1746907Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Commit-Queue: Ganggui Tang <gogerald@chromium.org>
Auto-Submit: Ganggui Tang <gogerald@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688515}

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

@@ -190,7 +190,8 @@ public class TabGridDialogMediator {
     private void updateGridTabSwitcher() {
         if (!isVisible() || mTabSwitcherResetHandler == null) return;
         mTabSwitcherResetHandler.resetWithTabList(
-                mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter(), false);
+                mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter(), false,
+                false);
     }
 
     private void updateDialog() {

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

@@ -229,18 +229,18 @@ public class TabListCoordinator implements Destroyable {
     }
 
     /**
-     * @see TabListMediator#resetWithListOfTabs(List, boolean)
+     * @see TabListMediator#resetWithListOfTabs(List, boolean, boolean)
      */
-    boolean resetWithListOfTabs(@Nullable List<Tab> tabs, boolean quickMode) {
+    boolean resetWithListOfTabs(@Nullable List<Tab> tabs, boolean quickMode, boolean mruMode) {
         if (mMode == TabListMode.STRIP && tabs != null && tabs.size() > 1) {
             TabGroupUtils.maybeShowIPH(
                     FeatureConstants.TAB_GROUPS_TAP_TO_SEE_ANOTHER_TAB_FEATURE, mRecyclerView);
         }
-        return mMediator.resetWithListOfTabs(tabs, quickMode);
+        return mMediator.resetWithListOfTabs(tabs, quickMode, mruMode);
     }
 
     boolean resetWithListOfTabs(@Nullable List<Tab> tabs) {
-        return resetWithListOfTabs(tabs, false);
+        return resetWithListOfTabs(tabs, false, false);
     }
 
     void softCleanup() {

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

@@ -51,6 +51,8 @@ import org.chromium.ui.modelutil.PropertyModel;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -62,6 +64,10 @@ import java.util.Map;
  * TODO(yusufo): Move some of the logic here to a parent component to make the above true.
  */
 class TabListMediator {
+    // Comparator to sort Tabs in descending order of the last shown time.
+    private static final Comparator<Tab> LAST_SHOWN_COMPARATOR =
+            (a, b) -> (Long.compare(b.getTimestampMillis(), a.getTimestampMillis()));
+
     private boolean mVisible;
     private boolean mShownIPH;
 
@@ -742,30 +748,38 @@ class TabListMediator {
      * Initialize the component with a list of tabs to show in a grid.
      * @param tabs The list of tabs to be shown.
      * @param quickMode Whether to skip capturing the selected live tab for the thumbnail.
+     * @param mruMode Whether to sort the Tabs in MRU order.
      * @return Whether the {@link TabListRecyclerView} can be shown quickly.
      */
-    boolean resetWithListOfTabs(@Nullable List<Tab> tabs, boolean quickMode) {
-        mVisible = tabs != null;
-        if (areTabsUnchanged(tabs)) {
-            if (tabs == null) return true;
+    boolean resetWithListOfTabs(@Nullable List<Tab> tabs, boolean quickMode, boolean mruMode) {
+        List<Tab> tabsList = tabs;
+        if (tabs != null && mruMode) {
+            // Make a copy to sort since the input may be unmodifiable.
+            tabsList = new ArrayList<>(tabs);
+            Collections.sort(tabsList, LAST_SHOWN_COMPARATOR);
+        }
 
-            for (int i = 0; i < tabs.size(); i++) {
-                Tab tab = tabs.get(i);
+        mVisible = tabsList != null;
+        if (areTabsUnchanged(tabsList)) {
+            if (tabsList == null) return true;
+
+            for (int i = 0; i < tabsList.size(); i++) {
+                Tab tab = tabsList.get(i);
                 boolean isSelected = mTabModelSelector.getCurrentTab() == tab;
                 updateTab(i, tab, isSelected, false, quickMode);
             }
             return true;
         }
         mModel.set(new ArrayList<>());
-        if (tabs == null) {
+        if (tabsList == null) {
             return true;
         }
         Tab currentTab = mTabModelSelector.getCurrentTab();
         if (currentTab == null) return false;
 
-        for (int i = 0; i < tabs.size(); i++) {
+        for (int i = 0; i < tabsList.size(); i++) {
             addTabInfoToModel(
-                    tabs.get(i), i, isSelectedTab(tabs.get(i).getId(), currentTab.getId()));
+                    tabsList.get(i), i, isSelectedTab(tabsList.get(i).getId(), currentTab.getId()));
         }
         return false;
     }
@@ -976,13 +990,11 @@ class TabListMediator {
         return mTabModelSelector.getCurrentTabId();
     }
 
+    // Find the index of the currently selected tab in the TabListRecyclerView.
+    // Note that Tabs may have different index in TabListModel/TabListRecyclerView and
+    // mTabModelSelector, like when resetWithListOfTabs is called with 'mruMode = true'.
     int indexOfSelected() {
-        Tab nextTab = TabModelUtils.getTabById(mTabModelSelector.getCurrentModel(), mNextTabId);
-        if (nextTab != null) {
-            return getIndexOfTab(nextTab, !mActionsOnAllRelatedTabs);
-        }
-
-        return mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter().index();
+        return mModel.indexFromId(selectedTabId());
     }
 
     @VisibleForTesting

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

@@ -215,7 +215,7 @@ public class TabSwitcherCoordinator implements Destroyable, TabSwitcher,
 
     // ResetHandler implementation.
     @Override
-    public boolean resetWithTabList(@Nullable TabList tabList, boolean quickMode) {
+    public boolean resetWithTabList(@Nullable TabList tabList, boolean quickMode, boolean mruMode) {
         List<Tab> tabs = null;
         if (tabList != null) {
             tabs = new ArrayList<>();
@@ -223,7 +223,8 @@ public class TabSwitcherCoordinator implements Destroyable, TabSwitcher,
                 tabs.add(tabList.getTabAt(i));
             }
         }
-        return mTabListCoordinator.resetWithListOfTabs(tabs, quickMode);
+
+        return mTabListCoordinator.resetWithListOfTabs(tabs, quickMode, mruMode);
     }
 
     private Rect getTabGridCardPosition(int index) {

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

@@ -122,6 +122,8 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
     private int mTabIdwhenShown;
     private int mIndexInNewModelWhenSwitched;
 
+    private boolean mShowTabsInMruOrder;
+
     /**
      * Interface to delegate resetting the tab grid.
      */
@@ -130,9 +132,10 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
          * Reset the tab grid with the given {@link TabList}, which can be null.
          * @param tabList The {@link TabList} to show the tabs for in the grid.
          * @param quickMode Whether to skip capturing the selected live tab for the thumbnail.
+         * @param mruMode Whether order the Tabs by MRU.
          * @return Whether the {@link TabListRecyclerView} can be shown quickly.
          */
-        boolean resetWithTabList(@Nullable TabList tabList, boolean quickMode);
+        boolean resetWithTabList(@Nullable TabList tabList, boolean quickMode, boolean mruMode);
 
         /**
          * Release the thumbnail {@link Bitmap} but keep the {@link TabGridViewHolder}.
@@ -175,7 +178,7 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
 
                 TabList currentTabModelFilter =
                         mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter();
-                mResetHandler.resetWithTabList(currentTabModelFilter, false);
+                mResetHandler.resetWithTabList(currentTabModelFilter, false, mShowTabsInMruOrder);
                 mContainerViewModel.set(IS_INCOGNITO, currentTabModelFilter.isIncognito());
                 if (mTabGridDialogResetHandler != null) {
                     mTabGridDialogResetHandler.hideDialog(false);
@@ -243,9 +246,16 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
         mContainerView = containerView;
 
         mSoftClearTabListRunnable = mResetHandler::softCleanup;
-        mClearTabListRunnable = () -> mResetHandler.resetWithTabList(null, false);
+        mClearTabListRunnable =
+                () -> mResetHandler.resetWithTabList(null, false, mShowTabsInMruOrder);
         mHandler = new Handler();
         mTabSelectionEditorController = tabSelectionEditorController;
+
+        // TODO(crbug.com/982018): Let the start surface pass in the parameter and add unit test for
+        // it. This is a temporary solution to keep this change minimum.
+        String feature = ChromeFeatureList.getFieldTrialParamByFeature(
+                ChromeFeatureList.START_SURFACE_ANDROID, "start_surface_variation");
+        mShowTabsInMruOrder = feature.equals("twopanes") || feature.equals("single");
     }
 
     void setBottomControlsHeight(int bottomControlsHeight) {
@@ -388,13 +398,16 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
         boolean quick = false;
         if (FeatureUtilities.isTabToGtsAnimationEnabled()) {
             quick = mResetHandler.resetWithTabList(
-                    mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter(),
-                    false);
+                    mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter(), false,
+                    mShowTabsInMruOrder);
         }
+
         int initialPosition = Math.max(
                 mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter().index()
                         - INITIAL_SCROLL_INDEX_OFFSET,
                 0);
+        // In MRU order, selected Tab is always at the first position.
+        if (mShowTabsInMruOrder) initialPosition = 0;
         mContainerViewModel.set(INITIAL_SCROLL_INDEX, initialPosition);
         return quick;
     }
@@ -403,7 +416,7 @@ class TabSwitcherMediator implements TabSwitcher.Controller, TabListRecyclerView
     public void showOverview(boolean animate) {
         mResetHandler.resetWithTabList(
                 mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter(),
-                FeatureUtilities.isTabToGtsAnimationEnabled());
+                FeatureUtilities.isTabToGtsAnimationEnabled(), mShowTabsInMruOrder);
         if (!animate) mContainerViewModel.set(ANIMATE_VISIBILITY_CHANGES, false);
         setVisibility(true);
         mModelIndexWhenShown = mTabModelSelector.getCurrentModelIndex();

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

@@ -346,7 +346,7 @@ public class GridTabSwitcherMediatorUnitTest {
         mMediator.setCleanupDelayForTesting(0);
         mMediator.postHiding();
         verify(mResetHandler).softCleanup();
-        verify(mResetHandler).resetWithTabList(eq(null), eq(false));
+        verify(mResetHandler).resetWithTabList(eq(null), eq(false), eq(false));
     }
 
     @Test
@@ -357,7 +357,7 @@ public class GridTabSwitcherMediatorUnitTest {
 
         doReturn(true).when(mTabModelFilter).isIncognito();
         mTabModelSelectorObserverCaptor.getValue().onTabModelSelected(mTabModel, null);
-        verify(mResetHandler).resetWithTabList(eq(mTabModelFilter), eq(false));
+        verify(mResetHandler).resetWithTabList(eq(mTabModelFilter), eq(false), eq(false));
         verify(mTabGridDialogResetHandler).hideDialog(eq(false));
         assertThat(mModel.get(TabListContainerProperties.IS_INCOGNITO), equalTo(true));
 
@@ -371,7 +371,7 @@ public class GridTabSwitcherMediatorUnitTest {
 
         doReturn(true).when(mTabModelFilter).isIncognito();
         mTabModelSelectorObserverCaptor.getValue().onTabModelSelected(mTabModel, null);
-        verify(mResetHandler).resetWithTabList(eq(mTabModelFilter), eq(false));
+        verify(mResetHandler).resetWithTabList(eq(mTabModelFilter), eq(false), eq(false));
         verify(mTabGridDialogResetHandler, never()).hideDialog(eq(false));
         assertThat(mModel.get(TabListContainerProperties.IS_INCOGNITO), equalTo(true));
 

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

@@ -250,7 +250,7 @@ public class TabGridDialogMediatorUnitTest {
         // Current tab ID should not update.
         assertThat(mMediator.getCurrentTabIdForTest(), equalTo(TAB1_ID));
         assertThat(mModel.get(TabGridSheetProperties.HEADER_TITLE), equalTo(DIALOG_TITLE1));
-        verify(mTabSwitcherResetHandler).resetWithTabList(mTabGroupModelFilter, false);
+        verify(mTabSwitcherResetHandler).resetWithTabList(mTabGroupModelFilter, false, false);
     }
 
     @Test
@@ -270,7 +270,7 @@ public class TabGridDialogMediatorUnitTest {
         // Current tab ID should be updated to TAB1_ID now.
         assertThat(mMediator.getCurrentTabIdForTest(), equalTo(TAB1_ID));
         assertThat(mModel.get(TabGridSheetProperties.HEADER_TITLE), equalTo(DIALOG_TITLE1));
-        verify(mTabSwitcherResetHandler).resetWithTabList(mTabGroupModelFilter, false);
+        verify(mTabSwitcherResetHandler).resetWithTabList(mTabGroupModelFilter, false, false);
     }
 
     @Test
@@ -288,7 +288,8 @@ public class TabGridDialogMediatorUnitTest {
         assertThat(mMediator.getCurrentTabIdForTest(), equalTo(Tab.INVALID_TAB_ID));
         assertThat(mModel.get(TabGridSheetProperties.ANIMATION_SOURCE_RECT), equalTo(null));
         verify(mDialogResetHandler).resetWithListOfTabs(null);
-        verify(mTabSwitcherResetHandler, never()).resetWithTabList(mTabGroupModelFilter, false);
+        verify(mTabSwitcherResetHandler, never())
+                .resetWithTabList(mTabGroupModelFilter, false, false);
     }
 
     @Test
@@ -310,7 +311,8 @@ public class TabGridDialogMediatorUnitTest {
         assertThat(mModel.get(TabGridSheetProperties.HEADER_TITLE), equalTo(DIALOG_TITLE1));
         // Dialog should still be hidden.
         assertThat(mModel.get(TabGridSheetProperties.IS_DIALOG_VISIBLE), equalTo(false));
-        verify(mTabSwitcherResetHandler, never()).resetWithTabList(mTabGroupModelFilter, false);
+        verify(mTabSwitcherResetHandler, never())
+                .resetWithTabList(mTabGroupModelFilter, false, false);
     }
 
     @Test
@@ -323,7 +325,7 @@ public class TabGridDialogMediatorUnitTest {
         mTabModelObserverCaptor.getValue().tabClosureUndone(mTab1);
 
         assertThat(mModel.get(TabGridSheetProperties.HEADER_TITLE), equalTo(DIALOG_TITLE1));
-        verify(mTabSwitcherResetHandler).resetWithTabList(mTabGroupModelFilter, false);
+        verify(mTabSwitcherResetHandler).resetWithTabList(mTabGroupModelFilter, false, false);
     }
 
     @Test
@@ -338,7 +340,8 @@ public class TabGridDialogMediatorUnitTest {
         assertThat(mModel.get(TabGridSheetProperties.HEADER_TITLE), equalTo(DIALOG_TITLE1));
         // Dialog should still be hidden.
         assertThat(mModel.get(TabGridSheetProperties.IS_DIALOG_VISIBLE), equalTo(false));
-        verify(mTabSwitcherResetHandler, never()).resetWithTabList(mTabGroupModelFilter, false);
+        verify(mTabSwitcherResetHandler, never())
+                .resetWithTabList(mTabGroupModelFilter, false, false);
     }
 
     @Test

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

@@ -741,7 +741,7 @@ public class TabListMediatorUnitTest {
 
         // Assume that two tabs are in the same group before ungroup.
         List<Tab> tabs = new ArrayList<>(Arrays.asList(mTab2));
-        mMediator.resetWithListOfTabs(tabs, false);
+        mMediator.resetWithListOfTabs(tabs, false, false);
 
         assertThat(mModel.size(), equalTo(1));
         assertThat(mModel.get(0).get(TabProperties.TAB_ID), equalTo(TAB2_ID));
@@ -773,7 +773,7 @@ public class TabListMediatorUnitTest {
 
         // Assume that two tabs are in the same group before ungroup.
         List<Tab> tabs = new ArrayList<>(Arrays.asList(mTab1));
-        mMediator.resetWithListOfTabs(tabs, false);
+        mMediator.resetWithListOfTabs(tabs, false, false);
 
         assertThat(mModel.size(), equalTo(1));
         assertThat(mModel.get(0).get(TabProperties.TAB_ID), equalTo(TAB1_ID));
@@ -971,7 +971,7 @@ public class TabListMediatorUnitTest {
         // Assume there are 3 tabs in TabModel, mTab2 just grouped with mTab1;
         Tab tab3 = prepareTab(TAB3_ID, TAB3_TITLE);
         List<Tab> tabs = new ArrayList<>(Arrays.asList(mTab1, tab3));
-        mMediator.resetWithListOfTabs(tabs, false);
+        mMediator.resetWithListOfTabs(tabs, false, false);
         assertThat(mModel.size(), equalTo(2));
 
         // Assume undo grouping mTab2 with mTab1.
@@ -995,7 +995,7 @@ public class TabListMediatorUnitTest {
         // Assume there are 3 tabs in TabModel, tab3 just grouped with mTab1;
         Tab tab3 = prepareTab(TAB3_ID, TAB3_TITLE);
         List<Tab> tabs = new ArrayList<>(Arrays.asList(mTab1, mTab2));
-        mMediator.resetWithListOfTabs(tabs, false);
+        mMediator.resetWithListOfTabs(tabs, false, false);
         assertThat(mModel.size(), equalTo(2));
 
         // Assume undo grouping tab3 with mTab1.
@@ -1019,7 +1019,7 @@ public class TabListMediatorUnitTest {
         // Assume there are 3 tabs in TabModel, mTab1 just grouped with mTab2;
         Tab tab3 = prepareTab(TAB3_ID, TAB3_TITLE);
         List<Tab> tabs = new ArrayList<>(Arrays.asList(mTab2, tab3));
-        mMediator.resetWithListOfTabs(tabs, false);
+        mMediator.resetWithListOfTabs(tabs, false, false);
         assertThat(mModel.size(), equalTo(2));
 
         // Assume undo grouping tab3 with mTab1.
@@ -1089,7 +1089,7 @@ public class TabListMediatorUnitTest {
         for (int i = 0; i < mTabModel.getCount(); i++) {
             tabs.add(mTabModel.getTabAt(i));
         }
-        mMediator.resetWithListOfTabs(tabs, false);
+        mMediator.resetWithListOfTabs(tabs, false, false);
         for (Callback<Drawable> callback : mCallbackCaptor.getAllValues()) {
             callback.onResult(new ColorDrawable(Color.RED));
         }