Add a section to Site Settings listing USB devices.

chrome/android/java/src/org/chromium/chrome/browser/preferences/website/SingleChooserPreferences.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.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 android.widget.TextView;
+
+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.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Shows a list of items that the user has granted to websites through a chooser. For example,

[Theresa, 2016/08/04 16:39:54]

nit: "Shows a list of items that the user has granted websites permission to
access.."?

[Reilly Grant (use Gerrit), 2016/08/04 19:57:10]

Done.

+ * this could show all USB devices the user has granted sites permission to connect to or all
+ * Bluetooth devices that have been paired. When the user selects an item,
+ * SingleObjectPreferences is launched to show which sites have access to the item.
+ */
+public class SingleChooserPreferences
+        extends PreferenceFragment implements Preference.OnPreferenceClickListener {
+    // The site settings category we are showing.
+    private SiteSettingsCategory mCategory;
+    // Multiple sites may have access to the same object. A canonical UsbInfo for each object is

[Theresa, 2016/08/04 01:11:47]

Does using a UsbInfo object work if this is displaying Bluetooth devices?

[Reilly Grant (use Gerrit), 2016/08/04 01:15:52]

When Bluetooth starts storing permissions we will have to add a class like
ObjectInfo from which UsbInfo and BluetoothInfo both derive and so this code
will probably change to operate on this new parent class. Since that isn't
necessary at the moment I'm working work UsbInfos directly.

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

That sounds like a good plan. Will you please add a TODO or note somewhere? The
JavaDoc for the class makes it sound like things besides USB are already
supported.

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

Done.

+    // therefore arbitrarily chosen to represent the object. |mPermissionsByObject| lists all of
+    // the individual permission grants for that object. |mSitesByObject| lists all of the sites
+    // with access to that object.
+    //
+    // UsbInfo's hashCode() and equals() methods compare only the object they represent, not the
+    // origin to which permission was granted.
+    private Map<UsbInfo, LinkedList<UsbInfo>> mPermissionsByObject = new HashMap<>();
+    private Map<UsbInfo, LinkedList<Website>> mSitesByObject = new HashMap<>();
+    // The view to show when the list is empty.
+    private TextView mEmptyView;
+    // 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
+    public void onActivityCreated(Bundle savedInstanceState) {
+        addPreferencesFromResource(R.xml.single_chooser_preferences);
+        ListView listView = (ListView) getView().findViewById(android.R.id.list);
+        mEmptyView = (TextView) getView().findViewById(android.R.id.empty);
+        listView.setEmptyView(mEmptyView);
+        listView.setDivider(null);
+
+        String category = getArguments().getString(SingleCategoryPreferences.EXTRA_CATEGORY);
+        mCategory = SiteSettingsCategory.fromString(category);
+        String title = getArguments().getString(SingleCategoryPreferences.EXTRA_TITLE);
+        getActivity().setTitle(title);
+
+        setHasOptionsMenu(true);
+
+        super.onActivityCreated(savedInstanceState);
+    }
+
+    @Override
+    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
+        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();
+
+        getInfo();
+    }
+
+    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;
+
+            mPermissionsByObject.clear();
+            mSitesByObject.clear();
+            for (Website site : sites) {
+                for (UsbInfo info : site.getUsbInfo()) {
+                    if (mSearch.isEmpty() || info.getName().toLowerCase().contains(mSearch)) {
+                        LinkedList<UsbInfo> permissionSet = mPermissionsByObject.get(info);
+                        if (permissionSet == null) {
+                            permissionSet = new LinkedList<>();
+                            mPermissionsByObject.put(info, permissionSet);
+                        }
+                        permissionSet.add(info);
+                        LinkedList<Website> sitesSet = mSitesByObject.get(info);
+                        if (sitesSet == null) {
+                            sitesSet = new LinkedList<>();
+                            mSitesByObject.put(info, sitesSet);
+                        }
+                        sitesSet.add(site);
+                    }
+                }
+            }
+
+            resetList();
+        }
+    }
+
+    /**
+     * Refreshes |mPermissionsByObject| and |mSitesByObject| with new data from C++.

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

nit: s/C++/native

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

Done.

+     *
+     * 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_chooser_preferences);
+
+        if (mSitesByObject.isEmpty()) {

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

Does it matter if this is mSitesByObject vs mPermissionsByObject?

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

No, the key sets should be equal.

+            if (mEmptyView != null) {
+                mEmptyView.setText(R.string.no_saved_website_settings);
+            }
+            return;
+        }
+
+        for (Map.Entry<UsbInfo, LinkedList<UsbInfo>> entry : mPermissionsByObject.entrySet()) {
+            Preference preference = new Preference(getActivity());
+            preference.getExtras().putSerializable(
+                    SingleObjectPreferences.EXTRA_USB_INFOS, entry.getValue());
+            preference.setIcon(R.drawable.settings_usb);
+            preference.setOnPreferenceClickListener(this);
+            preference.setTitle(entry.getKey().getName());
+            getPreferenceScreen().addPreference(preference);
+        }
+    }
+
+    @Override
+    public boolean onPreferenceClick(Preference preference) {
+        Bundle extras = preference.getExtras();
+        @SuppressWarnings("unchecked")
+        List<UsbInfo> info =
+                (List<UsbInfo>) extras.getSerializable(SingleObjectPreferences.EXTRA_USB_INFOS);
+        extras.putString(
+                SingleCategoryPreferences.EXTRA_TITLE, getActivity().getTitle().toString());
+        extras.putInt(SingleObjectPreferences.EXTRA_CATEGORY, mCategory.toContentSettingsType());
+        extras.putSerializable(
+                SingleObjectPreferences.EXTRA_SITES, mSitesByObject.get(info.get(0)));
+        preference.setFragment(
+                "org.chromium.chrome.browser.preferences.website.SingleObjectPreferences");
+        return false;
+    }
+}