Create entry to PWSharing through ShareHelper

chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java

Index: chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java b/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
index 97583b682427c1491325995f4a6fa8c3e7c6c11d..4337a76c7e78c51fa3d1556fe705aef92ed4f433 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
@@ -26,6 +26,7 @@ import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Build;
+import android.os.StrictMode;
 import android.support.annotation.Nullable;
 import android.support.v7.app.AlertDialog;
 import android.text.TextUtils;
@@ -35,25 +36,34 @@ import android.view.View;
 import android.widget.AdapterView;
 import android.widget.AdapterView.OnItemClickListener;
 
+import org.chromium.base.ActivityState;
 import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.base.ApplicationState;
 import org.chromium.base.ApplicationStatus;
+import org.chromium.base.ApplicationStatus.ActivityStateListener;
 import org.chromium.base.Callback;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.StreamUtil;
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.R;
+import org.chromium.chrome.browser.physicalweb.PhysicalWebShareActivity;
+import org.chromium.chrome.browser.printing.PrintShareActivity;
+import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.components.dom_distiller.core.DomDistillerUrlUtils;
 import org.chromium.ui.UiUtils;
 
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -104,6 +114,12 @@ public class ShareHelper {
     /** If non-null, will be used instead of the real activity. */
     private static FakeIntentReceiver sFakeIntentReceiverForTesting;
 
+    /** Variables for adding options dynamically to app chooser. */
+    private static Set<Activity> sPendingShareActivities =
+            Collections.synchronizedSet(new HashSet<Activity>());
+    private static ActivityStateListener sStateListener;
+    private static AsyncTask<Void, Void, Void> sStateChangeTask;
+
     private ShareHelper() {}
 
     private static void fireIntent(Activity activity, Intent intent) {
@@ -681,4 +697,154 @@ public class ShareHelper {
         if (packageName == null || className == null) return null;
         return new ComponentName(packageName, className);
     }
+
+    /**
+     * Dynamically add Chrome activities to Share chooser.
+     *
+     * @param activity The activity that will be triggering the share action.
+     * @param options  List of ShareActivity to add to the chooser.
+     * @param callback The callback to be triggered after the options have been enabled.  This
+     *                 may or may not be synchronous depending on whether this will require
+     *                 interacting with the Android framework.
+     */
+    public static void enableShareActivitiesAndStartShareIntent(final Activity activity,
+            final Tab currentTab, final Runnable callback) {
+        ThreadUtils.assertOnUiThread();
+
+        if (sStateListener == null) {
+            sStateListener = new ActivityStateListener() {
+                @Override
+                public void onActivityStateChange(Activity activity, int newState) {
+                    if (newState == ActivityState.PAUSED) return;
+                    unregisterActivity(activity);
+                }
+            };
+        }
+        ApplicationStatus.registerStateListenerForAllActivities(sStateListener);
+        boolean wasEmpty = sPendingShareActivities.isEmpty();
+        sPendingShareActivities.add(activity);
+
+        final List<ShareActivity> options = getEnabledShareActivities(currentTab);
+        if (options.isEmpty()) {
+            callback.run();
+        } else {
+            waitForPendingStateChangeTask();
+            if (wasEmpty) {
+                sStateChangeTask = new AsyncTask<Void, Void, Void>() {
+                    @Override
+                    protected Void doInBackground(Void... params) {
+                        if (sPendingShareActivities.isEmpty()) return null;
+
+                        for (int i = 0; i < options.size(); i++) {
+                            activity.getPackageManager().setComponentEnabledSetting(
+                                    new ComponentName(activity, options.get(i).getClass()),
+                                    PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
+                                    PackageManager.DONT_KILL_APP);
+                        }
+                        return null;
+                    }
+
+                    @Override
+                    protected void onPostExecute(Void result) {
+                        if (sStateChangeTask == this) {
+                            sStateChangeTask = null;
+                        } else {
+                            waitForPendingStateChangeTask();
+                        }
+                        callback.run();
+                    }
+                }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+            } else {
+                callback.run();
+            }
+        }
+    }
+
+    /**
+     * @param currentTab The current tab of the chrome activity.
+     * @return list of all share activities to be enabled.
+     */
+    public static List<ShareActivity> getEnabledShareActivities(final Tab currentTab) {
+        return filterEnabledShareActivities(getPotentialShareActivitiesList(),
+                currentTab);
+    }
+
+    /**
+     * @return List of all potential options to add to the share chooser.
+     */
+    private static List<ShareActivity> getPotentialShareActivitiesList() {
+        List<ShareActivity> potentialActivities = new ArrayList<ShareActivity>(2);
+        potentialActivities.add(new PrintShareActivity());
+        potentialActivities.add(new PhysicalWebShareActivity());
+        return potentialActivities;
+    }
+
+    /**
+     * @param potentialOptions  List of the potential ShareActivities to enable.
+     * @param currentTab        The current tab of the chrome activity.
+     * @return Filtered list of options to enable for share chooser.
+     */
+    private static List<ShareActivity> filterEnabledShareActivities(
+            List<ShareActivity> potentialOptions, final Tab currentTab) {
+        List<ShareActivity> enabledShareActivities = new ArrayList<ShareActivity>(2);
+        for (ShareActivity p: potentialOptions) {
+            if (p.featureIsEnabled(currentTab)) {
+                enabledShareActivities.add(p);
+            }
+        }
+        return enabledShareActivities;
+    }
+
+    /**
+     * Disables Components after Share Chooser is done.
+     */
+    public static void unregisterActivity(final Activity activity) {
+        ThreadUtils.assertOnUiThread();
+
+        sPendingShareActivities.remove(activity);
+        if (!sPendingShareActivities.isEmpty()) return;
+        ApplicationStatus.unregisterActivityStateListener(sStateListener);
+        final List<ShareActivity> options = getPotentialShareActivitiesList();
+
+        waitForPendingStateChangeTask();
+        sStateChangeTask = new AsyncTask<Void, Void, Void>() {
+            @Override
+            protected Void doInBackground(Void... params) {
+                if (!sPendingShareActivities.isEmpty()) return null;
+
+                for (int i = 0; i < options.size(); i++) {
+                        activity.getPackageManager().setComponentEnabledSetting(
+                                new ComponentName(activity, options.get(i).getClass()),
+                                PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
+                                PackageManager.DONT_KILL_APP);
+                    }
+                return null;
+            }
+
+            @Override
+            protected void onPostExecute(Void result) {
+                if (sStateChangeTask == this) sStateChangeTask = null;
+            }
+        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+    }
+
+    /**
+     * Waits for any pending state change operations to be completed.
+     *
+     * This will avoid timing issues described here: crbug.com/649453.
+     */
+    public static void waitForPendingStateChangeTask() {
+        ThreadUtils.assertOnUiThread();
+
+        if (sStateChangeTask == null) return;
+        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
+        try {
+            sStateChangeTask.get();
+            sStateChangeTask = null;
+        } catch (InterruptedException | ExecutionException e) {
+            Log.e(TAG, "Share Helper state change task did not complete as expected");
+        } finally {
+            StrictMode.setThreadPolicy(oldPolicy);
+        }
+    }
 }