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.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.ArrayList; import java.util.Collection; /** * Shows the list of sites that the user has granted access to a particular USB device. */ public class UsbDevicePreferences 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 ArrayList<UsbInfo> mUsbInfos; // The set of sites to display. private ArrayList<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.usb_device_preferences); ListView listView = (ListView) getView().findViewById(android.R.id.list); listView.setDivider(null); int contentSettingsType = getArguments().getInt(EXTRA_CATEGORY); mCategory = SiteSettingsCategory.fromContentSettingsType(contentSettingsType); mUsbInfos = (ArrayList<UsbInfo>) getArguments().getSerializable(EXTRA_USB_INFOS); mUsbInfo = mUsbInfos.get(0); mSites = (ArrayList<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) { 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(); if (mSites == null) { getInfo(); } else { resetList(); } } @Override public boolean onPreferenceClick(Preference preference) { if (PREF_OBJECT_NAME.equals(preference.getKey())) { for (int i = 0; i < mUsbInfos.size(); ++i) mUsbInfos.get(i).revoke(); getActivity().finish(); return true; } 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 ArrayList<Website>(); for (Website site : sites) { for (UsbInfo info : site.getUsbInfo()) { if (info.getObject().equals(mUsbInfo.getObject())) { mUsbInfos.add(info); if (mSearch.isEmpty() || site.getTitle().toLowerCase().contains(mSearch)) { mSites.add(site); } } } } // After revoking a site's permission to access a device the user may end up back at // this activity. It is awkward to display this empty list because there's no action // that can be taken from it. In this case we dismiss this activity as well, taking // them back to UsbChooserPreferences which will now no longer offer the option to // examine the permissions for this device. if (mUsbInfos.isEmpty()) { getActivity().finish(); } 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.usb_device_preferences); PreferenceScreen preferenceScreen = getPreferenceScreen(); Preference header = preferenceScreen.findPreference(PREF_OBJECT_NAME); header.setTitle(mUsbInfo.getName()); header.setOnPreferenceClickListener(this); for (int i = 0; i < mSites.size(); ++i) { Website site = mSites.get(i); Preference preference = new WebsitePreference(getActivity(), site, mCategory); preference.getExtras().putSerializable(SingleWebsitePreferences.EXTRA_SITE, site); preference.setFragment(SingleWebsitePreferences.class.getCanonicalName()); preferenceScreen.addPreference(preference); } // Force this list to be reloaded if the activity is resumed. mSites = null; } }