Download Home : Hide chips that don't match search query

Details :
1 - Search filter is cascaded before the type filter in the filter chain,
    hence chips that don't have item types in the search text will be hidden.
2 - Empty view will show a different string when we are in search mode
    and we have no matching results.

Bug: 892332
Change-Id: Ib99534b9c1a0b3f5333d4646356863a8639cd926
Reviewed-on: https://chromium-review.googlesource.com/c/1275140
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598876}

chrome/android/java/src/org/chromium/chrome/browser/download/home/empty/EmptyCoordinator.java

@@ -31,6 +31,7 @@ public class EmptyCoordinator implements OfflineItemFilterObserver, FilterCoordi
     private final EmptyView mView;
 
     private boolean mShowingPrefetch;
+    private boolean mInSearchMode;
 
     /** Creates a {@link EmptyCoordinator} instance that monitors {@code source}. */
     public EmptyCoordinator(Context context, PrefetchStatusProvider prefetchStatusProvider,
@@ -51,6 +52,14 @@ public class EmptyCoordinator implements OfflineItemFilterObserver, FilterCoordi
         return mView.getView();
     }
 
+    /**
+     * Method to inform the coordinator about a change in search mode.
+     * @param inSearchMode Whether we are currently in active search mode.
+     */
+    public void setInSearchMode(boolean inSearchMode) {
+        mInSearchMode = inSearchMode;
+    }
+
     // OfflineItemFilterObserver implementation.
     @Override
     public void onItemsAdded(Collection<OfflineItem> items) {
@@ -93,13 +102,15 @@ public class EmptyCoordinator implements OfflineItemFilterObserver, FilterCoordi
                 iconId = R.drawable.ic_library_news_feed;
 
                 if (mPrefetchStatusProvider.enabled()) {
-                    textId = R.string.download_manager_prefetch_tab_empty;
+                    textId = mInSearchMode ? R.string.download_manager_prefetch_tab_no_results
+                                           : R.string.download_manager_prefetch_tab_empty;
                 } else {
                     textId = R.string.download_manager_enable_prefetch_message;
                 }
             } else {
                 iconId = R.drawable.downloads_big;
-                textId = R.string.download_manager_ui_empty;
+                textId = mInSearchMode ? R.string.download_manager_no_results
+                                       : R.string.download_manager_ui_empty;
             }
 
             mModel.set(EmptyProperties.EMPTY_TEXT_RES_ID, textId);

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/DateOrderedListCoordinator.java

@@ -5,6 +5,7 @@
 package org.chromium.chrome.browser.download.home.list;
 
 import android.content.Context;
+import android.text.TextUtils;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
@@ -164,8 +165,7 @@ public class DateOrderedListCoordinator implements ToolbarCoordinator.ToolbarLis
 
     @Override
     public void setSearchQuery(String query) {
-        // TODO(crbug.com/881047): Check with UX, if the text on empty view should change during
-        // search.
+        mEmptyCoordinator.setInSearchMode(!TextUtils.isEmpty(query));
         mMediator.onFilterStringChanged(query);
     }
 

chrome/android/java/src/org/chromium/chrome/browser/download/home/list/DateOrderedListMediator.java

@@ -126,8 +126,8 @@ class DateOrderedListMediator {
         //         [OffTheRecordOfflineItemFilter] ->
         //             [InvalidStateOfflineItemFilter] ->
         //                 [DeleteUndoOfflineItemFilter] ->
-        //                     [TypeOfflineItemFilter] ->
-        //                         [SearchOfflineItemFitler] ->
+        //                     [SearchOfflineItemFitler] ->
+        //                         [TypeOfflineItemFilter] ->
         //                             [DateOrderedListMutator] ->
         //                                 [ListItemModel]
 
@@ -141,9 +141,9 @@ class DateOrderedListMediator {
         mOffTheRecordFilter = new OffTheRecordOfflineItemFilter(offTheRecord, mSource);
         mInvalidStateFilter = new InvalidStateOfflineItemFilter(mOffTheRecordFilter);
         mDeleteUndoFilter = new DeleteUndoOfflineItemFilter(mInvalidStateFilter);
-        mTypeFilter = new TypeOfflineItemFilter(mDeleteUndoFilter);
-        mSearchFilter = new SearchOfflineItemFilter(mTypeFilter);
-        mListMutator = new DateOrderedListMutator(mSearchFilter, mModel, new JustNowProvider());
+        mSearchFilter = new SearchOfflineItemFilter(mDeleteUndoFilter);
+        mTypeFilter = new TypeOfflineItemFilter(mSearchFilter);
+        mListMutator = new DateOrderedListMutator(mTypeFilter, mModel, new JustNowProvider());
 
         mSearchFilter.addObserver(new EmptyStateObserver(mSearchFilter, dateOrderedListObserver));
         mThumbnailProvider = new ThumbnailProviderImpl(
@@ -224,7 +224,7 @@ class DateOrderedListMediator {
      *         options are available.
      */
     public OfflineItemFilterSource getFilterSource() {
-        return mDeleteUndoFilter;
+        return mSearchFilter;
     }
 
     /**

chrome/android/java/strings/android_chrome_strings.grd

@@ -2512,6 +2512,9 @@ To change this setting, <ph name="BEGIN_LINK">&lt;resetlink&gt;</ph>reset sync<p
       <message name="IDS_DOWNLOAD_MANAGER_PREFETCH_TAB_EMPTY" desc="Tab text indicating that there is no prefetched content.">
         No content here
       </message>
+      <message name="IDS_DOWNLOAD_MANAGER_PREFETCH_TAB_NO_RESULTS" desc="Tab text indicating that no prefetched content matched a search query.">
+        No content found
+      </message>
       <message name="IDS_DOWNLOAD_MANAGER_ENABLE_PREFETCH_MESSAGE" desc="Tab text indicating that users can enable prefetch to allow chrome to download articles on Wi-Fi.">
         Allow Chrome to download articles for you when on Wi-Fi under settings.
       </message>