Java tutorial
// 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.util.Pair; 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.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.Map; /** * Shows a list of USB devices that the user has granted websites permission to access. * * When the user selects an item UsbDevicePreferences is launched to show which sites have access * to the device. */ public class UsbChooserPreferences extends PreferenceFragment { // The site settings category we are showing. private SiteSettingsCategory mCategory; // Multiple sites may have access to the same device. A canonical UsbInfo for each device is // therefore arbitrarily chosen to represent it. private Map<String, Pair<ArrayList<UsbInfo>, ArrayList<Website>>> mPermissionsByObject = 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.usb_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(); for (Website site : sites) { for (UsbInfo info : site.getUsbInfo()) { if (mSearch.isEmpty() || info.getName().toLowerCase().contains(mSearch)) { Pair<ArrayList<UsbInfo>, ArrayList<Website>> entry = mPermissionsByObject .get(info.getObject()); if (entry == null) { entry = Pair.create(new ArrayList<UsbInfo>(), new ArrayList<Website>()); mPermissionsByObject.put(info.getObject(), entry); } entry.first.add(info); entry.second.add(site); } } } resetList(); } } /** * Refreshes |mPermissionsByObject| with new data from native. * * 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.usb_chooser_preferences); if (mPermissionsByObject.isEmpty() && mSearch.isEmpty() && mEmptyView != null) { mEmptyView.setText(R.string.website_settings_usb_no_devices); } for (Pair<ArrayList<UsbInfo>, ArrayList<Website>> entry : mPermissionsByObject.values()) { Preference preference = new Preference(getActivity()); Bundle extras = preference.getExtras(); extras.putInt(UsbDevicePreferences.EXTRA_CATEGORY, mCategory.toContentSettingsType()); extras.putString(SingleCategoryPreferences.EXTRA_TITLE, getActivity().getTitle().toString()); extras.putSerializable(UsbDevicePreferences.EXTRA_USB_INFOS, entry.first); extras.putSerializable(UsbDevicePreferences.EXTRA_SITES, entry.second); preference.setIcon(R.drawable.settings_usb); preference.setTitle(entry.first.get(0).getName()); preference.setFragment(UsbDevicePreferences.class.getCanonicalName()); getPreferenceScreen().addPreference(preference); } } }