Add a way to cache and show zero suggest results before native

chrome/android/java/src/org/chromium/chrome/browser/omnibox/LocationBarLayout.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.omnibox;
 
 import static org.chromium.chrome.browser.toolbar.ToolbarPhone.URL_FOCUS_CHANGE_ANIMATION_DURATION_MS;
 
 import android.Manifest;
 import android.animation.Animator;
@@ skipping 210 matching lines @@
 
     // True if the user has just selected a suggestion from the suggestion list. This suppresses
     // the recording of the dismissal of the suggestion list. (The list is only considered to have
     // been dismissed if the user didn't choose one of the suggestions shown.) This signal is used
     // instead of a parameter to hideSuggestions because that method is often called from multiple
     // code paths in a not necessarily obvious or even deterministic order.
     private boolean mSuggestionSelectionInProgress;
 
     private Runnable mShowSuggestions;
 
+    private boolean mShowCachedZeroSuggestResults;
+
+    private DeferredOnSelectionRunnable mDeferredOnSelection;
+
+    private abstract class DeferredOnSelectionRunnable implements Runnable {
+        protected final OmniboxSuggestion mSuggestion;
+        protected final int mPosition;
+        protected boolean mShouldLog;
+
+        public DeferredOnSelectionRunnable(OmniboxSuggestion suggestion, int position) {
+            this.mSuggestion = suggestion;
+            this.mPosition = position;
+        }
+
+        /**
+         * Set whether the selection matches with native results for logging to make sense.
+         * @param log Whether the selection should be logged in native code.
+         */
+        public void setShouldLog(boolean log) {
+            mShouldLog = log;
+        }
+
+        /**
+         * @return Whether the selection should be logged in native code.
+         */
+        public boolean shouldLog() {
+            return mShouldLog;
+        }
+    }
+
     /**
      * Listener for receiving the messages related with interacting with the omnibox during startup.
      */
     public interface OmniboxLivenessListener {
         /**
          * Called after the first draw when the omnibox can receive touch events.
          */
         void onOmniboxInteractive();
 
         /**
@@ skipping 515 matching lines @@
 
     @Override
     public void initializeControls(WindowDelegate windowDelegate,
             WindowAndroid windowAndroid) {
         mWindowDelegate = windowDelegate;
         mWindowAndroid = windowAndroid;
 
         // If the user focused the omnibox prior to the native libraries being initialized,
         // autocomplete will not always be enabled, so we force it enabled in that case.
         mUrlBar.setIgnoreTextChangesForAutocomplete(false);
+        mAutocomplete = new AutocompleteController(this);
     }
 
     /**
+     * Sets to show cached zero suggest results. This will start both caching zero suggest results
+     * in shared preferences and also attempt to show them when appropriate without needing native
+     * initialization. See {@link LocationBarLayout#showCachedZeroSuggestResultsIfAvailable()} for
+     * showing the loaded results before native initialization.
+     * @param showCachedZeroSuggestResults Whether cached zero suggest should be shown.
+     */
+    public void setShowCachedZeroSuggestResults(boolean showCachedZeroSuggestResults) {
+        mShowCachedZeroSuggestResults = showCachedZeroSuggestResults;
+        if (mShowCachedZeroSuggestResults) mAutocomplete.setUseCachedZeroSuggestResults();
+    }
+
+    /**
+     * Signals the omnibox to shows the cached zero suggest results if they have been loaded from
+     * cache successfully.
+     */
+    public void showCachedZeroSuggestResultsIfAvailable() {
+        if (!mShowCachedZeroSuggestResults || mSuggestionList == null) return;
+        setSuggestionsListVisibility(true);
+        mSuggestionList.updateLayoutParams();
+    }
+
+    /**
      * @param focusable Whether the url bar should be focusable.
      */
     public void setUrlBarFocusable(boolean focusable) {
         if (mUrlBar == null) return;
         mUrlBar.setFocusable(focusable);
         mUrlBar.setFocusableInTouchMode(focusable);
     }
 
     /**
      * @return The WindowDelegate for the LocationBar. This should be used for all Window related
@@ skipping 10 matching lines @@
     public void onNativeLibraryReady() {
         mNativeInitialized = true;
 
         mSecurityButton.setOnClickListener(this);
         mNavigationButton.setOnClickListener(this);
         mVerboseStatusTextView.setOnClickListener(this);
         updateMicButtonState();
         mDeleteButton.setOnClickListener(this);
         mMicButton.setOnClickListener(this);
 
-        mAutocomplete = new AutocompleteController(this);
-
         mOmniboxPrerender = new OmniboxPrerender();
 
         for (Runnable deferredRunnable : mDeferredNativeRunnables) {
             post(deferredRunnable);
         }
         mDeferredNativeRunnables.clear();
 
         mUrlBar.onOmniboxFullyFunctional();
         updateVisualsForState();
     }
@@ skipping 732 matching lines @@
         mOmniboxResultsContainer.addView(mSuggestionList);
 
         // Start with visibility GONE to ensure that show() is called. http://crbug.com/517438
         mSuggestionList.setVisibility(GONE);
         mSuggestionList.setAdapter(mSuggestionListAdapter);
         mSuggestionList.setClipToPadding(false);
         mSuggestionListAdapter.setSuggestionDelegate(new OmniboxSuggestionDelegate() {
             @Override
             public void onSelection(OmniboxSuggestion suggestion, int position) {
                 mSuggestionSelectionInProgress = true;
+                if (mShowCachedZeroSuggestResults && !mNativeInitialized) {
+                    mDeferredOnSelection = new DeferredOnSelectionRunnable(suggestion, position) {
+                        @Override
+                        public void run() {
+                            onSelection(this.mSuggestion, this.mPosition);
+                        }
+                    };
+                    return;
+                }
                 String suggestionMatchUrl = updateSuggestionUrlIfNeeded(
                         suggestion, position, false);
                 loadUrlFromOmniboxMatch(suggestionMatchUrl, suggestion.getTransition(), position,
                         suggestion.getType());
                 hideSuggestions();
                 UiUtils.hideKeyboard(mUrlBar);
             }
 
             @Override
             public void onRefineSuggestion(OmniboxSuggestion suggestion) {
@@ skipping 152 matching lines @@
     /**
      * Hides the omnibox suggestion popup.
      *
      * <p>
      * Signals the autocomplete controller to stop generating omnibox suggestions.
      *
      * @see AutocompleteController#stop(boolean)
      */
     @Override
     public void hideSuggestions() {
-        if (mAutocomplete == null) return;
+        if (mAutocomplete == null || !mNativeInitialized) return;
 
         if (mShowSuggestions != null) removeCallbacks(mShowSuggestions);
 
         recordSuggestionsDismissed();
 
         stopAutocomplete(true);
 
         setSuggestionsListVisibility(false);
         clearSuggestions(true);
         updateNavigationButton();
@@ skipping 152 matching lines @@
         }
     }
 
     @Override
     public void onSuggestionsReceived(List<OmniboxSuggestion> newSuggestions,
             String inlineAutocompleteText) {
         // This is a callback from a listener that is set up by onNativeLibraryReady,
         // so can only be called once the native side is set up.
         assert mNativeInitialized : "Suggestions received before native side intialialized";
 
-        if (getCurrentTab() == null) {
-            // If the current tab is not available, drop the suggestions and hide the autocomplete.
-            hideSuggestions();
-            return;
+        if (mDeferredOnSelection != null) {
+            mDeferredOnSelection.setShouldLog(newSuggestions.size() > mDeferredOnSelection.mPosition
+                    && mDeferredOnSelection.mSuggestion.equals(
+                            newSuggestions.get(mDeferredOnSelection.mPosition)));
+            mDeferredOnSelection.run();
+            mDeferredOnSelection = null;
         }
-
         String userText = mUrlBar.getTextWithoutAutocomplete();
         mUrlTextAfterSuggestionsReceived = userText + inlineAutocompleteText;
 
         boolean itemsChanged = false;
         boolean itemCountChanged = false;
         // If the length of the incoming suggestions matches that of those currently being shown,
         // replace them inline to allow transient entries to retain their proper highlighting.
         if (mSuggestionItems.size() == newSuggestions.size()) {
             for (int index = 0; index < newSuggestions.size(); index++) {
                 OmniboxResultItem suggestionItem = mSuggestionItems.get(index);
@@ skipping 58 matching lines @@
             if (!isUrlFocusChangeInProgress()) {
                 mShowSuggestions.run();
             } else {
                 postDelayed(mShowSuggestions, ToolbarPhone.URL_FOCUS_CHANGE_ANIMATION_DURATION_MS);
             }
         }
 
         // Update the navigation button to show the default suggestion's icon.
         updateNavigationButton();
 
-        if (!CommandLine.getInstance().hasSwitch(ChromeSwitches.DISABLE_INSTANT)
+        if (mNativeInitialized
+                && !CommandLine.getInstance().hasSwitch(ChromeSwitches.DISABLE_INSTANT)
                 && PrivacyPreferencesManager.getInstance().shouldPrerender()) {
             mOmniboxPrerender.prerenderMaybe(
                     userText,
                     getOriginalUrl(),
                     mAutocomplete.getCurrentNativeAutocompleteResult(),
                     getCurrentTab().getProfile(),
                     getCurrentTab());
         }
     }
 
@@ skipping 126 matching lines @@
 
     private void loadUrlFromOmniboxMatch(String url, int transition, int matchPosition, int type) {
         // loadUrl modifies AutocompleteController's state clearing the native
         // AutocompleteResults needed by onSuggestionsSelected. Therefore,
         // loadUrl should should be invoked last.
         Tab currentTab = getCurrentTab();
         String currentPageUrl = getCurrentTabUrl();
         WebContents webContents = currentTab != null ? currentTab.getWebContents() : null;
         long elapsedTimeSinceModified = mNewOmniboxEditSessionTimestamp > 0
                 ? (SystemClock.elapsedRealtime() - mNewOmniboxEditSessionTimestamp) : -1;
-        mAutocomplete.onSuggestionSelected(matchPosition, type, currentPageUrl,
-                mUrlFocusedFromFakebox, elapsedTimeSinceModified, mUrlBar.getAutocompleteLength(),
-                webContents);
+        boolean shouldSkipNativeLog = mShowCachedZeroSuggestResults
+                && (mDeferredOnSelection != null)
+                && !mDeferredOnSelection.shouldLog();
+        if (!shouldSkipNativeLog) {
+            mAutocomplete.onSuggestionSelected(matchPosition, type, currentPageUrl,
+                    mUrlFocusedFromFakebox, elapsedTimeSinceModified,
+                    mUrlBar.getAutocompleteLength(),
+                    webContents);
+        }
         loadUrl(url, transition);
     }
 
     /**
      * Load the url given with the given transition. Exposed for child classes to overwrite as
      * necessary.
      */
     protected void loadUrl(String url, int transition) {
         Tab currentTab = getCurrentTab();
 
@@ skipping 321 matching lines @@
     public void setTitleToPageTitle() { }
 
     @Override
     public void setShowTitle(boolean showTitle) { }
 
     @Override
     public boolean mustQueryUrlBarLocationForSuggestions() {
         return DeviceFormFactor.isTablet(getContext());
     }
 }