Show offline filter view if offline page exists and offline

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 a21baaee261240b163ab83123410ed7339efb95e..f8e161139336c1c0a1081fd17bf22560244c5967 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
@@ -25,6 +25,7 @@ import org.chromium.chrome.browser.BookmarksBridge.BookmarkModelObserver;
 import org.chromium.chrome.browser.UrlConstants;
 import org.chromium.chrome.browser.favicon.LargeIconBridge;
 import org.chromium.chrome.browser.ntp.NewTabPageUma;
+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;
@@ -293,7 +294,25 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
         if (!state.isValid(mEnhancedBookmarksModel)) {
             state = UIState.createAllBookmarksState(mEnhancedBookmarksModel);
         }
-        if (!mStateStack.isEmpty()) {
+        boolean saveUrl = true;
+        if (mStateStack.isEmpty()) {

[Kibeom Kim (inactive), 2015/10/28 22:16:10]

I think there is one corner case you want to cover: if the current state is
STATE_LOADING, this is the first time to set an actual state, but since we only
check isEmpty() here, it won't set offline page in that case.

[jianli, 2015/10/28 23:22:50]

Not sure I understand how to hit this corner case. If current state is
STATE_LOADING, it means that setState should have already been called to set a
loading state with the actual URL and we should already check if we want to
switch to offline filter view.

[Kibeom Kim (inactive), 2015/10/29 00:30:09]

Sorry! yeah you're right, I just re-read the code and seems my memory was
incorrect :/.

+            // 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(ApplicationStatus.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();
@@ -302,7 +321,7 @@ public class EnhancedBookmarkManager implements EnhancedBookmarkDelegate {
         mStateStack.push(state);
         if (state.mState != UIState.STATE_LOADING) {
             // Loading state may be pushed to the stack but should never be stored in preferences.
-            saveUrlToPreference(state.mUrl);
+            if (saveUrl) saveUrlToPreference(state.mUrl);
             // If a loading state is replaced by another loading state, do not notify this change.
             if (mUrlChangeListener != null) mUrlChangeListener.onBookmarkUIStateChange(state.mUrl);
         }