[Enhanced Bookmark]Rewrite initialization logic

chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java b/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java
index e0678dc87b683c2d529220d1ceeb5f740e918e9a..cd92109eb9ebca75538702478ea7a51293d8de59 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkManager.java
@@ -7,9 +7,8 @@ package org.chromium.chrome.browser.enhancedbookmarks;
 import android.app.Activity;
 import android.app.ActivityManager;
 import android.content.Context;
-import android.preference.PreferenceManager;
 import android.support.v4.widget.DrawerLayout;
-import android.util.Log;
+import android.text.TextUtils;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
@@ -18,21 +17,15 @@ import android.widget.ViewSwitcher;
 import org.chromium.base.ApplicationStatus;
 import org.chromium.base.ObserverList;
 import org.chromium.chrome.R;
-import org.chromium.chrome.browser.UrlConstants;
 import org.chromium.chrome.browser.bookmark.BookmarksBridge.BookmarkItem;
 import org.chromium.chrome.browser.bookmark.BookmarksBridge.BookmarkModelObserver;
 import org.chromium.chrome.browser.favicon.LargeIconBridge;
-import org.chromium.chrome.browser.offlinepages.OfflinePageUtils;
 import org.chromium.chrome.browser.partnerbookmarks.PartnerBookmarksShim;
 import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.chrome.browser.snackbar.SnackbarManager;
 import org.chromium.chrome.browser.snackbar.SnackbarManager.SnackbarManageable;
 import org.chromium.components.bookmarks.BookmarkId;
-import org.chromium.ui.base.DeviceFormFactor;
 
-import java.io.UnsupportedEncodingException;
-import java.net.URLDecoder;
-import java.net.URLEncoder;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
@@ -45,7 +38,6 @@ import java.util.Stack;
  * {@link EnhancedBookmarkActivity} (phone) and {@link EnhancedBookmarkPage} (tablet).
  */
 public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
-    private static final String PREF_LAST_USED_URL = "enhanced_bookmark_last_used_url";
     private static final int FAVICON_MAX_CACHE_SIZE_BYTES = 10 * 1024 * 1024; // 10MB
 
     private Activity mActivity;
@@ -61,8 +53,9 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
     private ViewSwitcher mViewSwitcher;
     private DrawerLayout mDrawer;
     private EnhancedBookmarkDrawerListView mDrawerListView;
-    private final Stack<UIState> mStateStack = new Stack<>();
+    private final Stack<EnhancedBookmarkUIState> mStateStack = new Stack<>();
     private LargeIconBridge mLargeIconBridge;
+    private String mInitialUrl;
 
     private final BookmarkModelObserver mBookmarkModelObserver = new BookmarkModelObserver() {
 
@@ -71,7 +64,7 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
                 boolean isDoingExtensiveChanges) {
             // If the folder is removed in folder mode, show the parent folder or falls back to all
             // bookmarks mode.
-            if (getCurrentState() == UIState.STATE_FOLDER
+            if (getCurrentState() == EnhancedBookmarkUIState.STATE_FOLDER
                     && node.getId().equals(mStateStack.peek().mFolder)) {
                 if (mEnhancedBookmarksModel.getTopLevelFolderIDs(true, true).contains(
                         node.getId())) {
@@ -90,21 +83,29 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
         }
 
         @Override
-        public void bookmarkModelLoaded() {
-            initializeIfBookmarkModelLoaded();
-        }
-
-        @Override
         public void bookmarkModelChanged() {
             // If the folder no longer exists in folder mode, we need to fall back. Relying on the
             // default behavior by setting the folder mode again.
-            if (getCurrentState() == UIState.STATE_FOLDER) {
+            if (getCurrentState() == EnhancedBookmarkUIState.STATE_FOLDER) {
                 setState(mStateStack.peek());
             }
             clearSelection();
         }
     };
 
+    private final Runnable mModelLoadedRunnable = new Runnable() {
+        @Override
+        public void run() {
+            mSearchView.onEnhancedBookmarkDelegateInitialized(EnhancedBookmarkManager.this);
+            mDrawerListView.onEnhancedBookmarkDelegateInitialized(EnhancedBookmarkManager.this);
+            mContentView.onEnhancedBookmarkDelegateInitialized(EnhancedBookmarkManager.this);
+            if (!TextUtils.isEmpty(mInitialUrl)) {
+                setState(EnhancedBookmarkUIState.createStateFromUrl(mInitialUrl,
+                        mEnhancedBookmarksModel));
+            }
+        }
+    };
+
     /**
      * Creates an instance of {@link EnhancedBookmarkManager}. It also initializes resources,
      * bookmark models and jni bridges.
@@ -123,7 +124,8 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
                 ((SnackbarManageable) activity).getSnackbarManager());
         mSearchView = (EnhancedBookmarkSearchView) getView().findViewById(R.id.eb_search_view);
         mEnhancedBookmarksModel.addObserver(mBookmarkModelObserver);
-        initializeIfBookmarkModelLoaded();
+        initializeToLoadingState();
+        mEnhancedBookmarksModel.runAfterBookmarkModelLoaded(mModelLoadedRunnable);
 
         // Load partner bookmarks explicitly. We load partner bookmarks in the deferred startup
         // code, but that might be executed much later. Especially on L, showing loading
@@ -204,75 +206,33 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
     }
 
     /**
-     * Updates UI based on the new URL on tablet. If the bookmark model is not loaded yet, creates a
-     * temporary loading state carrying this url. This method is supposed to align with
+     * Updates UI based on the new URL. If the bookmark model is not loaded yet, cache the url and
+     * it will be picked up later when the model is loaded. This method is supposed to align with
      * {@link EnhancedBookmarkPage#updateForUrl(String)}
      * <p>
      * @param url The url to navigate to.
      */
     public void updateForUrl(String url) {
-        if (mEnhancedBookmarksModel != null && mEnhancedBookmarksModel.isBookmarkModelLoaded()) {
-            setState(UIState.createStateFromUrl(url, mEnhancedBookmarksModel));
-        } else {
-            // Note this does not guarantee to update the UI, as at this time the onCreateView()
-            // might not has even been called yet.
-            setState(UIState.createLoadingState(url));
-        }
-    }
+        // Bookmark model is null if the manager has been destroyed.
+        if (mEnhancedBookmarksModel == null) return;
 
-    /**
-     * Initialization method that has 3 different behaviors based on whether bookmark model is
-     * loaded. If the bookmark model is not loaded yet, it pushes a loading state to backstack which
-     * contains the url from preference. If the model is loaded and the backstack is empty, it
-     * creates a state by fetching the last visited bookmark url stored in preference. If the
-     * bookmark model is loaded but backstack contains a pending loading state, it creates a new
-     * state by getting the url of the loading state and replace the previous loading state with the
-     * new normal state.
-     */
-    private void initializeIfBookmarkModelLoaded() {
         if (mEnhancedBookmarksModel.isBookmarkModelLoaded()) {
-            mSearchView.onEnhancedBookmarkDelegateInitialized(this);
-            mDrawerListView.onEnhancedBookmarkDelegateInitialized(this);
-            mContentView.onEnhancedBookmarkDelegateInitialized(this);
-            if (mStateStack.isEmpty()) {
-                setState(UIState.createStateFromUrl(getUrlFromPreference(),
-                        mEnhancedBookmarksModel));
-            } else if (mStateStack.peek().mState == UIState.STATE_LOADING) {
-                String url = mStateStack.pop().mUrl;
-                setState(UIState.createStateFromUrl(url, mEnhancedBookmarksModel));
-            }
+            setState(EnhancedBookmarkUIState.createStateFromUrl(url, mEnhancedBookmarksModel));
         } else {
-            mContentView.showLoadingUi();
-            mDrawerListView.showLoadingUi();
-            mContentView.showLoadingUi();
-            if (mStateStack.isEmpty() || mStateStack.peek().mState != UIState.STATE_LOADING) {
-                setState(UIState.createLoadingState(getUrlFromPreference()));
-            } else if (!mStateStack.isEmpty()) {
-                // Refresh the UI. This is needed because on tablet, updateForUrl might set up
-                // loading state too early and at that time all UI components are not created yet.
-                // Therefore we need to set the previous loading state once again to trigger all UI
-                // updates.
-                setState(mStateStack.pop());
-            }
+            mInitialUrl = url;
         }
     }
 
     /**
-     * Saves url to preference. Note this method should be used after the main view is attached to
-     * an activity.
+     * Puts all UI elements to loading state. This state might be overridden synchronously by
+     * {@link #updateForUrl(String)}, if the bookmark model is already loaded.
      */
-    private void saveUrlToPreference(String url) {
-        PreferenceManager.getDefaultSharedPreferences(mActivity).edit()
-                .putString(PREF_LAST_USED_URL, url).apply();
-    }
-
-    /**
-     * Fetches url to preference. Note this method should be used after the main view is attached to
-     * an activity.
-     */
-    private String getUrlFromPreference() {
-        return PreferenceManager.getDefaultSharedPreferences(mActivity).getString(
-                PREF_LAST_USED_URL, UrlConstants.BOOKMARKS_URL);
+    private void initializeToLoadingState() {
+        mContentView.showLoadingUi();
+        mDrawerListView.showLoadingUi();
+        mContentView.showLoadingUi();
+        assert mStateStack.isEmpty();
+        setState(EnhancedBookmarkUIState.createLoadingState());
     }
 
     /**
@@ -288,41 +248,30 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
      * and back button are not controlled by the manager: the tab handles back key and backstack
      * navigation.
      */
-    private void setState(UIState state) {
+    private void setState(EnhancedBookmarkUIState state) {
         if (!state.isValid(mEnhancedBookmarksModel)) {
-            state = UIState.createAllBookmarksState(mEnhancedBookmarksModel);
+            state = EnhancedBookmarkUIState.createAllBookmarksState(mEnhancedBookmarksModel);
         }
-        boolean saveUrl = true;
-        if (mStateStack.isEmpty()) {
-            // When offline page feature is enabled, show offline filter view if there is offline
-            // page and there is no network connection.
-            if (mEnhancedBookmarksModel.getOfflinePageBridge() != null
-                    && !mEnhancedBookmarksModel.getOfflinePageBridge().getAllPages().isEmpty()
-                    && !OfflinePageUtils.isConnected(mActivity.getApplicationContext())
-                    && !DeviceFormFactor.isTablet(mActivity.getApplicationContext())) {
-                UIState filterState = UIState.createFilterState(
-                        EnhancedBookmarkFilter.OFFLINE_PAGES, mEnhancedBookmarksModel);
-                if (state.mState != UIState.STATE_LOADING) {
-                    state = filterState;
-                } else {
-                    state.mUrl = filterState.mUrl;
-                }
-                // Showing offline filter view is just a temporary thing and it will not be saved
-                // to the preference.
-                saveUrl = false;
-            }
-        } else {
-            if (mStateStack.peek().equals(state)) return;
-            if (mStateStack.peek().mState == UIState.STATE_LOADING) {
-                mStateStack.pop();
-            }
+
+        if (!mStateStack.isEmpty() && mStateStack.peek().equals(state)) return;
+
+        // The loading state is not persisted in history stack and once we have a valid state it
+        // shall be removed.
+        if (!mStateStack.isEmpty()
+                && mStateStack.peek().mState == EnhancedBookmarkUIState.STATE_LOADING) {
+            mStateStack.pop();
         }
         mStateStack.push(state);
-        if (state.mState != UIState.STATE_LOADING) {
+
+        if (state.mState != EnhancedBookmarkUIState.STATE_LOADING) {
             // Loading state may be pushed to the stack but should never be stored in preferences.
-            if (saveUrl) saveUrlToPreference(state.mUrl);
+            if (state.mShouldPersist) {
+                EnhancedBookmarkUtils.setLastUsedUrl(mActivity, state.mUrl);
+            }
             // If a loading state is replaced by another loading state, do not notify this change.
-            if (mUrlChangeListener != null) mUrlChangeListener.onBookmarkUIStateChange(state.mUrl);
+            if (mUrlChangeListener != null) {
+                mUrlChangeListener.onBookmarkUIStateChange(state.mUrl);
+            }
         }
 
         clearSelection();
@@ -337,18 +286,18 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
     @Override
     public void openFolder(BookmarkId folder) {
         closeSearchUI();
-        setState(UIState.createFolderState(folder, mEnhancedBookmarksModel));
+        setState(EnhancedBookmarkUIState.createFolderState(folder, mEnhancedBookmarksModel));
     }
 
     @Override
     public void openAllBookmarks() {
         closeSearchUI();
-        setState(UIState.createAllBookmarksState(mEnhancedBookmarksModel));
+        setState(EnhancedBookmarkUIState.createAllBookmarksState(mEnhancedBookmarksModel));
     }
 
     @Override
     public void openFilter(EnhancedBookmarkFilter filter) {
-        setState(UIState.createFilterState(filter, mEnhancedBookmarksModel));
+        setState(EnhancedBookmarkUIState.createFilterState(filter, mEnhancedBookmarksModel));
     }
 
     @Override
@@ -391,18 +340,18 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
     public void notifyStateChange(EnhancedBookmarkUIObserver observer) {
         int state = getCurrentState();
         switch (state) {
-            case UIState.STATE_ALL_BOOKMARKS:
+            case EnhancedBookmarkUIState.STATE_ALL_BOOKMARKS:
                 observer.onAllBookmarksStateSet();
                 break;
-            case UIState.STATE_FOLDER:
+            case EnhancedBookmarkUIState.STATE_FOLDER:
                 observer.onFolderStateSet(mStateStack.peek().mFolder);
                 break;
-            case UIState.STATE_LOADING:
+            case EnhancedBookmarkUIState.STATE_LOADING:
                 // In loading state, onEnhancedBookmarkDelegateInitialized() is not called for all
                 // UIObservers, which means that there will be no observers at the time. Do nothing.
                 assert mUIObservers.isEmpty();
                 break;
-            case UIState.STATE_FILTER:
+            case EnhancedBookmarkUIState.STATE_FILTER:
                 observer.onFilterStateSet(mStateStack.peek().mFilter);
                 break;
             default:
@@ -466,7 +415,7 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
 
     @Override
     public int getCurrentState() {
-        if (mStateStack.isEmpty()) return UIState.STATE_LOADING;
+        if (mStateStack.isEmpty()) return EnhancedBookmarkUIState.STATE_LOADING;
         return mStateStack.peek().mState;
     }
 
@@ -479,132 +428,4 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
     public SnackbarManager getSnackbarManager() {
         return ((SnackbarManageable) mActivity).getSnackbarManager();
     }
-
-    /**
-     * Internal state that represents a url. Note every state needs to have a _valid_ url. For
-     * loading state, {@link #mUrl} indicates the target to open after the bookmark model is loaded.
-     */
-    static class UIState {
-        private static final int STATE_INVALID = 0;
-        static final int STATE_LOADING = 1;
-        static final int STATE_ALL_BOOKMARKS = 2;
-        static final int STATE_FOLDER = 3;
-        static final int STATE_FILTER = 4;
-
-        private static final String TAG = "UIState";
-        private static final String URL_CHARSET = "UTF-8";
-        /**
-         * One of the STATE_* constants.
-         */
-        private int mState;
-        private String mUrl;
-        private BookmarkId mFolder;
-        private EnhancedBookmarkFilter mFilter;
-
-        private static UIState createLoadingState(String url) {
-            UIState state = new UIState();
-            state.mUrl = url;
-            state.mState = STATE_LOADING;
-            return state;
-        }
-
-        private static UIState createAllBookmarksState(EnhancedBookmarksModel bookmarkModel) {
-            return createStateFromUrl(UrlConstants.BOOKMARKS_URL, bookmarkModel);
-        }
-
-        private static UIState createFolderState(BookmarkId folder,
-                EnhancedBookmarksModel bookmarkModel) {
-            return createStateFromUrl(UrlConstants.BOOKMARKS_FOLDER_URL + folder.toString(),
-                    bookmarkModel);
-        }
-
-        private static UIState createFilterState(
-                EnhancedBookmarkFilter filter, EnhancedBookmarksModel bookmarkModel) {
-            return createStateFromUrl(
-                    UrlConstants.BOOKMARKS_FILTER_URL + filter.toString(), bookmarkModel);
-        }
-
-        /**
-         * @return A state corresponding to the url. If the url is not valid, return all_bookmarks.
-         */
-        private static UIState createStateFromUrl(String url,
-                EnhancedBookmarksModel bookmarkModel) {
-            UIState state = new UIState();
-            state.mState = STATE_INVALID;
-            state.mUrl = url;
-
-            if (url.equals(UrlConstants.BOOKMARKS_URL)) {
-                state.mState = STATE_ALL_BOOKMARKS;
-            } else if (url.startsWith(UrlConstants.BOOKMARKS_FOLDER_URL)) {
-                String suffix = decodeSuffix(url, UrlConstants.BOOKMARKS_FOLDER_URL);
-                if (!suffix.isEmpty()) {
-                    state.mFolder = BookmarkId.getBookmarkIdFromString(suffix);
-                    state.mState = STATE_FOLDER;
-                }
-            } else if (url.startsWith(UrlConstants.BOOKMARKS_FILTER_URL)) {
-                String suffix = decodeSuffix(url, UrlConstants.BOOKMARKS_FILTER_URL);
-                if (!suffix.isEmpty()) {
-                    state.mState = STATE_FILTER;
-                    state.mFilter = EnhancedBookmarkFilter.valueOf(suffix);
-                }
-            }
-
-            if (!state.isValid(bookmarkModel)) {
-                state.mState = STATE_ALL_BOOKMARKS;
-                state.mUrl = UrlConstants.BOOKMARKS_URL;
-            }
-
-            return state;
-        }
-
-        private UIState() {
-        }
-
-        /**
-         * @return Whether this state is valid.
-         */
-        private boolean isValid(EnhancedBookmarksModel bookmarkModel) {
-            if (mUrl == null || mState == STATE_INVALID) return false;
-
-            if (mState == STATE_FOLDER) {
-                if (mFolder == null) return false;
-
-                return bookmarkModel.doesBookmarkExist(mFolder)
-                        && !mFolder.equals(bookmarkModel.getRootFolderId());
-            }
-
-            return true;
-        }
-
-        private static String decodeSuffix(String url, String prefix) {
-            String suffix = url.substring(prefix.length());
-            try {
-                suffix = URLDecoder.decode(suffix, URL_CHARSET);
-            } catch (UnsupportedEncodingException e) {
-                Log.w(TAG, "Bookmark URL parsing failed. " + URL_CHARSET + " not supported.");
-            }
-            return suffix;
-        }
-
-        private static String encodeUrl(String prefix, String suffix) {
-            try {
-                suffix = URLEncoder.encode(suffix, URL_CHARSET);
-            } catch (UnsupportedEncodingException e) {
-                Log.w(TAG, "Bookmark URL parsing failed. " + URL_CHARSET + " not supported.");
-            }
-            return prefix + suffix;
-        }
-
-        @Override
-        public int hashCode() {
-            return 31 * mUrl.hashCode() + mState;
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (!(obj instanceof UIState)) return false;
-            UIState other = (UIState) obj;
-            return mState == other.mState && mUrl.equals(other.mUrl);
-        }
-    }
 }