Reader Mode support for low-end devices

chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeManager.java b/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeManager.java
index 1cf61ad2cda32070f1e9b05faf3ec49c0272dd38..7d4f59cfdb9d2bc2ce450192f8535ab4bd6a85c7 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeManager.java
@@ -4,7 +4,11 @@
 
 package org.chromium.chrome.browser.dom_distiller;
 
+import android.app.Activity;
 import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+import android.support.customtabs.CustomTabsIntent;
 import android.text.TextUtils;
 
 import org.chromium.base.ApiCompatibilityUtils;
@@ -17,7 +21,9 @@ import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.compositor.bottombar.OverlayPanel.PanelState;
 import org.chromium.chrome.browser.compositor.bottombar.OverlayPanel.StateChangeReason;
 import org.chromium.chrome.browser.compositor.bottombar.readermode.ReaderModePanel;
+import org.chromium.chrome.browser.customtabs.CustomTabActivity;
 import org.chromium.chrome.browser.device.DeviceClassManager;
+import org.chromium.chrome.browser.document.ChromeLauncherActivity;
 import org.chromium.chrome.browser.infobar.InfoBar;
 import org.chromium.chrome.browser.infobar.InfoBarContainer;
 import org.chromium.chrome.browser.infobar.InfoBarContainer.InfoBarContainerObserver;
@@ -26,9 +32,13 @@ import org.chromium.chrome.browser.tabmodel.TabCreatorManager;
 import org.chromium.chrome.browser.tabmodel.TabModel;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
 import org.chromium.chrome.browser.tabmodel.TabModelSelectorTabObserver;
+import org.chromium.chrome.browser.util.IntentUtils;
 import org.chromium.chrome.browser.widget.findinpage.FindToolbarObserver;
 import org.chromium.components.dom_distiller.content.DistillablePageUtils;
 import org.chromium.components.dom_distiller.core.DomDistillerUrlUtils;
+import org.chromium.components.navigation_interception.InterceptNavigationDelegate;
+import org.chromium.components.navigation_interception.NavigationParams;
+import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.content_public.browser.WebContentsObserver;
@@ -48,21 +58,22 @@ import java.util.concurrent.TimeUnit;
 public class ReaderModeManager extends TabModelSelectorTabObserver
         implements InfoBarContainerObserver, ReaderModeManagerDelegate {
 
-    /**
-     * POSSIBLE means reader mode can be entered.
-     */
+    /** POSSIBLE means reader mode can be entered. */
     public static final int POSSIBLE = 0;
 
-    /**
-     * NOT_POSSIBLE means reader mode cannot be entered.
-     */
+    /** NOT_POSSIBLE means reader mode cannot be entered. */
     public static final int NOT_POSSIBLE = 1;
 
-    /**
-     * STARTED means reader mode is currently in reader mode.
-     */
+    /** STARTED means reader mode is currently in reader mode. */
     public static final int STARTED = 2;
 
+    /** The scheme used to access DOM-Distiller. */
+    public static final String DOM_DISTILLER_SCHEME = "chrome-distiller";
+
+    /** The intent extra that indicates origin from Reader Mode */
+    public static final String EXTRA_READER_MODE_PARENT =
+            "org.chromium.chrome.browser.dom_distiller.EXTRA_READER_MODE_PARENT";
+
     // The url of the last page visited if the last page was reader mode page.  Otherwise null.
     private String mReaderModePageUrl;
 
@@ -84,6 +95,12 @@ public class ReaderModeManager extends TabModelSelectorTabObserver
     // The primary means of getting the currently active tab.
     private TabModelSelector mTabModelSelector;
 
+    // If the activity this manager is associated with is a custom tab.
+    private boolean mIsCustomTab;
+
+    // Hold on to the InterceptNavigationDelegate that the custom tab uses.
+    InterceptNavigationDelegate mCustomTabNavigationDelegate;
+
     private final int mHeaderBackgroundColor;
     private boolean mIsFullscreenModeEntered;
     private boolean mIsFindToolbarShowing;
@@ -145,9 +162,53 @@ public class ReaderModeManager extends TabModelSelectorTabObserver
         };
     }
 
+    /**
+     * Notify the manager that the current activity is a custom tab.
+     */
+    public void setIsCustomTab() {
+        mIsCustomTab = true;
+    }
+
     // TabModelSelectorTabObserver:
 
     @Override
+    public void onLoadUrl(Tab tab, LoadUrlParams params, int loadType) {
+        // If a distiller URL was loaded and this is a custom tab, add a navigation
+        // handler to bring any navigations back to the main chrome activity.
+        if (tab == null || !mIsCustomTab
+                || !DomDistillerUrlUtils.isDistilledPage(params.getUrl())) {
+            return;
+        }
+
+        ContentViewCore cvc = tab.getContentViewCore();
+        if (cvc == null) return;
+
+        mCustomTabNavigationDelegate = new InterceptNavigationDelegate() {
+            @Override
+            public boolean shouldIgnoreNavigation(NavigationParams params) {
+                if (DomDistillerUrlUtils.isDistilledPage(params.url) || params.isExternalProtocol) {
+                    return false;
+                }
+
+                Intent returnIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(params.url));
+                returnIntent.setClassName(mChromeActivity, ChromeLauncherActivity.class.getName());
+
+                // Set the parent ID of the tab to be created.
+                returnIntent.putExtra(EXTRA_READER_MODE_PARENT,
+                        IntentUtils.safeGetInt(mChromeActivity.getIntent().getExtras(),
+                                EXTRA_READER_MODE_PARENT, Tab.INVALID_TAB_ID));
+
+                mChromeActivity.startActivity(returnIntent);
+                mChromeActivity.finish();
+                return true;
+            }
+        };
+
+        DomDistillerTabUtils.setInterceptNavigationDelegate(mCustomTabNavigationDelegate,
+                cvc.getWebContents());
+    }
+
+    @Override
     public void onShown(Tab shownTab) {
         int shownTabId = shownTab.getId();
 
@@ -383,6 +444,11 @@ public class ReaderModeManager extends TabModelSelectorTabObserver
         }
     }
 
+    @Override
+    public boolean supportsOverlayPanelUI() {
+        return !SysUtils.isLowEndDevice();
+    }
+
     /**
      * @return True if the keyboard might be showing. This is not 100% accurate; see
      *         UiUtils.isKeyboardShowing(...).
@@ -497,6 +563,7 @@ public class ReaderModeManager extends TabModelSelectorTabObserver
      * Open a link from the panel in a new tab.
      * @param url The URL to load.
      */
+    @Override
     public void createNewTab(String url) {
         if (mChromeActivity == null) return;
 
@@ -511,6 +578,29 @@ public class ReaderModeManager extends TabModelSelectorTabObserver
                 TabModel.TabLaunchType.FROM_LINK, mChromeActivity.getActivityTab());
     }
 
+    @Override
+    public void distillInCustomTab() {
+        WebContents baseWebContents = getBasePageWebContents();
+        if (baseWebContents == null || mChromeActivity == null || mTabModelSelector == null) return;
+
+        String url = baseWebContents.getUrl();
+        if (url == null) return;
+
+        String distillerUrl =
+                DomDistillerUrlUtils.getDistillerViewUrlFromUrl(DOM_DISTILLER_SCHEME, url);
+
+        Intent customTabIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(distillerUrl));
+        customTabIntent.setClassName(mChromeActivity, CustomTabActivity.class.getName());
+
+        customTabIntent.putExtra(CustomTabsIntent.EXTRA_TITLE_VISIBILITY_STATE,
+                CustomTabsIntent.SHOW_PAGE_TITLE);
+
+        // Add the parent ID as an intent extra for back button functionality.
+        customTabIntent.putExtra(EXTRA_READER_MODE_PARENT, mTabModelSelector.getCurrentTabId());
+
+        mChromeActivity.startActivity(customTabIntent);
+    }
+
     /**
      * @return Whether the Reader Mode panel is opened (state is EXPANDED or MAXIMIZED).
      */
@@ -586,8 +676,18 @@ public class ReaderModeManager extends TabModelSelectorTabObserver
                 && !CommandLine.getInstance().hasSwitch(
                         ChromeSwitches.DISABLE_READER_MODE_BOTTOM_BAR)
                 && !DeviceFormFactor.isTablet(context)
-                && DomDistillerTabUtils.isDistillerHeuristicsEnabled()
-                && !SysUtils.isLowEndDevice();
+                && DomDistillerTabUtils.isDistillerHeuristicsEnabled();
         return enabled;
     }
+
+    /**
+     * Determine if Reader Mode created the intent for a tab being created.
+     * @param activity The current Activity handling the intent.
+     * @param intent The Intent creating a new tab.
+     * @return True if the intent was created by Reader Mode.
+     */
+    public static boolean isReaderModeCreatedIntent(Activity activity, Intent intent) {
+        return activity != null && intent != null && isEnabled(activity)
+                && intent.getExtras().containsKey(EXTRA_READER_MODE_PARENT);
+    }
 }