Add a section to Site Settings listing USB devices.

chrome/android/java/src/org/chromium/chrome/browser/preferences/website/SingleObjectPreferences.java

+// Copyright 2016 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.preferences.website;
+
+import android.os.Bundle;
+import android.preference.Preference;
+import android.preference.PreferenceFragment;
+import android.preference.PreferenceScreen;
+import android.support.v4.view.MenuItemCompat;
+import android.support.v7.widget.SearchView;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+import android.view.inputmethod.EditorInfo;
+import android.widget.ListView;
+
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.help.HelpAndFeedback;
+import org.chromium.chrome.browser.profiles.Profile;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * Shows the list of sites that the user has granted access to a particular
+ * item, for example a USB or Bluetooth device.
+ */
+public class SingleObjectPreferences
+        extends PreferenceFragment implements Preference.OnPreferenceClickListener {
+    public static final String EXTRA_USB_INFOS = "org.chromium.chrome.preferences.usb_infos";
+    public static final String EXTRA_SITES = "org.chromium.chrome.preferences.site_set";
+    public static final String EXTRA_CATEGORY =
+            "org.chromium.chrome.preferences.content_settings_type";
+
+    public static final String PREF_OBJECT_NAME = "object_name";
+
+    // The site settings category we are showing.
+    private SiteSettingsCategory mCategory;
+    // Canonical example of the USB device being examined.
+    private UsbInfo mUsbInfo;
+    // All of the USB device permission entries matching the canonical device.
+    private List<UsbInfo> mUsbInfos;
+    // The set of sites to display.
+    private List<Website> mSites;
+    // The view for searching the list of items.
+    private SearchView mSearchView;
+    // If not blank, represents a substring to use to search for site names.
+    private String mSearch = "";
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public void onActivityCreated(Bundle savedInstanceState) {
+        addPreferencesFromResource(R.xml.single_object_preferences);
+        int contentSettingsType = getArguments().getInt(EXTRA_CATEGORY);
+        mCategory = SiteSettingsCategory.fromContentSettingsType(contentSettingsType);
+        mUsbInfos = (List<UsbInfo>) getArguments().getSerializable(EXTRA_USB_INFOS);
+        mUsbInfo = mUsbInfos.get(0);
+        mSites = (List<Website>) getArguments().getSerializable(EXTRA_SITES);
+        String title = getArguments().getString(SingleCategoryPreferences.EXTRA_TITLE);
+        if (title != null) getActivity().setTitle(title);
+
+        setHasOptionsMenu(true);
+
+        super.onActivityCreated(savedInstanceState);
+    }
+
+    @Override
+    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {

[Theresa, 2016/08/04 16:39:55]

Would it make sense to pull this out into a super class to avoid the duplicate
code in this method and onOptionsItemSelected?

[Reilly Grant (use Gerrit), 2016/08/04 19:57:11]

Can I do that in a followup patch? I don't want to touch all of the other
PreferenceFragments in this patch since it's already big enough. It makes sense
to implement a "SearchablePreferenceFragment" with this common code in it.

[Theresa, 2016/08/04 20:22:28]

sg

+        menu.clear();
+        inflater.inflate(R.menu.website_preferences_menu, menu);
+
+        MenuItem searchItem = menu.findItem(R.id.search);
+        mSearchView = (SearchView) MenuItemCompat.getActionView(searchItem);
+        mSearchView.setImeOptions(EditorInfo.IME_FLAG_NO_FULLSCREEN);
+        SearchView.OnQueryTextListener queryTextListener = new SearchView.OnQueryTextListener() {
+            @Override
+            public boolean onQueryTextSubmit(String query) {
+                return true;
+            }
+
+            @Override
+            public boolean onQueryTextChange(String query) {
+                // Make search case-insensitive.
+                query = query.toLowerCase();
+
+                if (query.equals(mSearch)) return true;
+
+                mSearch = query;
+                getInfo();
+                return true;
+            }
+        };
+        mSearchView.setOnQueryTextListener(queryTextListener);
+
+        MenuItem help =
+                menu.add(Menu.NONE, R.id.menu_id_targeted_help, Menu.NONE, R.string.menu_help);
+        help.setIcon(R.drawable.ic_help_and_feedback);
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        if (item.getItemId() == R.id.menu_id_targeted_help) {
+            HelpAndFeedback.getInstance(getActivity())
+                    .show(getActivity(), getString(R.string.help_context_settings),
+                            Profile.getLastUsedProfile(), null);
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+
+        // First time this activity is launched the intent may have already included the set of
+        // sites with permission for this device.

[Theresa, 2016/08/04 16:39:55]

Does this comment go with resetList() (if the set of sites was included, we
don't need to call getInfo())?

[Reilly Grant (use Gerrit), 2016/08/04 19:57:11]

I've removed this comment since the one down in resetList() makes the intent
clearer.

+        if (mSites == null) {
+            getInfo();
+        } else {
+            resetList();
+        }
+    }
+
+    @Override
+    public boolean onPreferenceClick(Preference preference) {
+        if (PREF_OBJECT_NAME.equals(preference.getKey())) {
+            for (UsbInfo info : mUsbInfos) info.revoke();
+            getActivity().finish();
+            return true;
+        }
+
+        if (preference instanceof WebsitePreference) {
+            WebsitePreference websitePreference = (WebsitePreference) preference;
+            websitePreference.getExtras().putSerializable(
+                    SingleWebsitePreferences.EXTRA_SITE, websitePreference.site());
+            websitePreference.setFragment(
+                    "org.chromium.chrome.browser.preferences.website.SingleWebsitePreferences");
+        }
+        return false;
+    }
+
+    private class ResultsPopulator implements WebsitePermissionsFetcher.WebsitePermissionsCallback {
+        @Override
+        public void onWebsitePermissionsAvailable(Collection<Website> sites) {
+            // This method may be called after the activity has been destroyed.
+            // In that case, bail out.
+            if (getActivity() == null) return;
+
+            mUsbInfos.clear();
+            mSites = new LinkedList<Website>();
+            for (Website site : sites) {
+                if (mSearch.isEmpty() || site.getTitle().toLowerCase().contains(mSearch)) {
+                    for (UsbInfo info : site.getUsbInfo()) {
+                        if (info.equals(mUsbInfo)) {
+                            mUsbInfos.add(info);
+                            mSites.add(site);
+                        }
+                    }
+                }
+            }
+
+            if (mSites.isEmpty() && mSearch.isEmpty()) {
+                getActivity().finish();

[Theresa, 2016/08/04 16:39:55]

Should we display something if there are no sites with permission to access a
device (is that ever expected to happen?) rather than finishing the activity?

[Reilly Grant (use Gerrit), 2016/08/04 19:57:11]

This will happen if the user returns to this activity from
SingleWebsitePreferences after revoking some premissions. Instead of returning
to an empty list the intent is to send them all the way back to
SingleChooserPreferences which handles the case of there being no permission by
displaying a special message.

[Theresa, 2016/08/04 20:22:28]

Just to check my understanding, they're here -> single site, revoke permission
-> press back button which sends them back to this fragment, we call getInfo()
in onResume, the list is now empty so we finish the activity? Will the user see
this screen while we're fetching website perms?

[Reilly Grant (use Gerrit), 2016/08/04 21:30:25]

That's correct. In theory the user could see the old version of the activity but
in practice it happens more quickly than I've been able to notice.

+            } else {
+                resetList();
+            }
+        }
+    }
+
+    /**
+     * Refreshes the list of sites with access to the object being examined.
+     *
+     * resetList() is called to refresh the view when the data is ready.
+     */
+    private void getInfo() {
+        WebsitePermissionsFetcher fetcher = new WebsitePermissionsFetcher(new ResultsPopulator());
+        fetcher.fetchPreferencesForCategory(mCategory);
+    }
+
+    private void resetList() {
+        getPreferenceScreen().removeAll();
+        addPreferencesFromResource(R.xml.single_object_preferences);
+        ListView listView = (ListView) getView().findViewById(android.R.id.list);
+        listView.setDivider(null);

[Theresa, 2016/08/04 16:39:55]

Does this need to be called every time resetList() is executed or can it be done
once in the constructor like in SingleChooserPreference?

[Reilly Grant (use Gerrit), 2016/08/04 19:57:11]

It probably can be.

+
+        PreferenceScreen preferenceScreen = getPreferenceScreen();
+        Preference header = preferenceScreen.findPreference(PREF_OBJECT_NAME);
+        header.setTitle(mUsbInfo.getName());
+        header.setOnPreferenceClickListener(this);
+
+        for (Website site : mSites) {
+            Preference preference = new WebsitePreference(getActivity(), site, mCategory);
+            preference.setOnPreferenceClickListener(this);
+            preferenceScreen.addPreference(preference);
+        }
+
+        // Force this list to be reloaded if the activity is resumed.
+        mSites = null;
+    }
+}