Java tutorial
/* * Copyright (C) 2015 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.onyx.deskclock.deskclock.worldclock; import android.content.Context; import android.media.AudioManager; import android.os.Build; import android.os.Bundle; import android.support.v4.text.TextUtilsCompat; import android.support.v7.app.ActionBar; import android.support.v7.widget.AppCompatCheckBox; import android.support.v7.widget.SearchView; import android.support.v7.widget.Toolbar; import android.text.TextUtils; import android.text.format.DateFormat; import android.util.TypedValue; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.CheckBox; import android.widget.CompoundButton; import android.widget.ListView; import android.widget.RelativeLayout; import android.widget.SectionIndexer; import android.widget.TextView; import com.onyx.deskclock.deskclock.BaseActivity; import com.onyx.deskclock.R; import com.onyx.deskclock.deskclock.Utils; import com.onyx.deskclock.deskclock.actionbarmenu.AbstractMenuItemController; import com.onyx.deskclock.deskclock.actionbarmenu.ActionBarMenuManager; import com.onyx.deskclock.deskclock.actionbarmenu.MenuItemControllerFactory; import com.onyx.deskclock.deskclock.actionbarmenu.NavUpMenuItemController; import com.onyx.deskclock.deskclock.actionbarmenu.SearchMenuItemController; import com.onyx.deskclock.deskclock.actionbarmenu.SettingMenuItemController; import com.onyx.deskclock.deskclock.data.City; import com.onyx.deskclock.deskclock.data.DataModel; import java.util.ArrayList; import java.util.Calendar; import java.util.Collection; import java.util.Collections; import java.util.Comparator; import java.util.HashSet; import java.util.List; import java.util.Locale; import java.util.Set; import java.util.TimeZone; /** * This activity allows the user to alter the cities selected for display. * * Note, it is possible for two instances of this Activity to exist simultaneously: * * <ul> * <li>Clock Tab-> Tap Floating Action Button</li> * <li>Digital Widget -> Tap any city clock</li> * </ul> * * As a result, {@link #onResume()} conservatively refreshes itself from the backing * {@link DataModel} which may have changed since this activity was last displayed. */ public final class CitySelectionActivity extends BaseActivity { /** The list of all selected and unselected cities, indexed and possibly filtered. */ private ListView mCitiesList; /** The adapter that presents all of the selected and unselected cities. */ private CityAdapter mCitiesAdapter; /** Manages all action bar menu display and click handling. */ private final ActionBarMenuManager mActionBarMenuManager = new ActionBarMenuManager(this); /** Menu item controller for search view. */ private SearchMenuItemController mSearchMenuItemController; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setVolumeControlStream(AudioManager.STREAM_ALARM); setContentView(R.layout.cities_activity); RelativeLayout relativeLayout_back = (RelativeLayout) findViewById(R.id.back_function_layout); relativeLayout_back.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { finish(); } }); Toolbar toolbar = (Toolbar) findViewById(R.id.alarm_toolbar); setSupportActionBar(toolbar); ActionBar actionBar = getSupportActionBar(); if (actionBar != null) { actionBar.setDisplayShowTitleEnabled(false); } mSearchMenuItemController = new SearchMenuItemController(new SearchView.OnQueryTextListener() { @Override public boolean onQueryTextSubmit(String query) { return false; } @Override public boolean onQueryTextChange(String query) { mCitiesAdapter.filter(query); updateFastScrolling(); return true; } }, savedInstanceState); mCitiesAdapter = new CityAdapter(this, mSearchMenuItemController); mActionBarMenuManager.addMenuItemController(new NavUpMenuItemController(this)) .addMenuItemController(mSearchMenuItemController) .addMenuItemController(new SortOrderMenuItemController()) .addMenuItemController(new SettingMenuItemController(this)) .addMenuItemController(MenuItemControllerFactory.getInstance().buildMenuItemControllers(this)); mCitiesList = (ListView) findViewById(R.id.cities_list); mCitiesList.setScrollBarStyle(View.SCROLLBARS_INSIDE_INSET); mCitiesList.setAdapter(mCitiesAdapter); updateFastScrolling(); } @Override public void onSaveInstanceState(Bundle bundle) { super.onSaveInstanceState(bundle); mSearchMenuItemController.saveInstance(bundle); } @Override public void onResume() { super.onResume(); // Recompute the contents of the adapter before displaying on screen. mCitiesAdapter.refresh(); } @Override public void onPause() { super.onPause(); // Save the selected cities. DataModel.getDataModel().setSelectedCities(mCitiesAdapter.getSelectedCities()); } @Override public boolean onCreateOptionsMenu(Menu menu) { // mActionBarMenuManager.createOptionsMenu(menu, getMenuInflater()); return true; } @Override public boolean onPrepareOptionsMenu(Menu menu) { // mActionBarMenuManager.prepareShowMenu(menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // if (mActionBarMenuManager.handleMenuItemClick(item)) { // return true; // } return super.onOptionsItemSelected(item); } /** * Fast scrolling is only enabled while no filtering is happening. */ private void updateFastScrolling() { final boolean enabled = !mCitiesAdapter.isFiltering(); mCitiesList.setFastScrollAlwaysVisible(enabled); mCitiesList.setFastScrollEnabled(enabled); } /** * This adapter presents data in 2 possible modes. If selected cities exist the format is: * * <pre> * Selected Cities * City 1 (alphabetically first) * City 2 (alphabetically second) * ... * A City A1 (alphabetically first starting with A) * City A2 (alphabetically second starting with A) * ... * B City B1 (alphabetically first starting with B) * City B2 (alphabetically second starting with B) * ... * </pre> * * If selected cities do not exist, that section is removed and all that remains is: * * <pre> * A City A1 (alphabetically first starting with A) * City A2 (alphabetically second starting with A) * ... * B City B1 (alphabetically first starting with B) * City B2 (alphabetically second starting with B) * ... * </pre> */ private static final class CityAdapter extends BaseAdapter implements View.OnClickListener, CompoundButton.OnCheckedChangeListener, SectionIndexer { /** The type of the single optional "Selected Cities" header entry. */ private static final int VIEW_TYPE_SELECTED_CITIES_HEADER = 0; /** The type of each city entry. */ private static final int VIEW_TYPE_CITY = 1; private final Context mContext; private final LayoutInflater mInflater; /** The 12-hour time pattern for the current locale. */ private final String mPattern12; /** The 24-hour time pattern for the current locale. */ private final String mPattern24; /** {@code true} time should honor {@link #mPattern24}; {@link #mPattern12} otherwise. */ private boolean mIs24HoursMode; /** A calendar used to format time in a particular timezone. */ private final Calendar mCalendar; /** The list of cities which may be filtered by a search term. */ private List<City> mFilteredCities = Collections.emptyList(); /** A mutable set of cities currently selected by the user. */ // API >= 23 // private final Set<City> mUserSelectedCities = new ArraySet<>(); private final Set<City> mUserSelectedCities = new HashSet<>(); /** The number of user selections at the top of the adapter to avoid indexing. */ private int mOriginalUserSelectionCount; /** The precomputed section headers. */ private String[] mSectionHeaders; /** The corresponding location of each precomputed section header. */ private Integer[] mSectionHeaderPositions; /** Menu item controller for search. Search query is maintained here. */ private final SearchMenuItemController mSearchMenuItemController; public CityAdapter(Context context, SearchMenuItemController searchMenuItemController) { mContext = context; mSearchMenuItemController = searchMenuItemController; mInflater = LayoutInflater.from(context); mCalendar = Calendar.getInstance(); mCalendar.setTimeInMillis(System.currentTimeMillis()); final Locale locale = Locale.getDefault(); // API >= 18 // mPattern24 = DateFormat.getBestDateTimePattern(locale, "Hm"); // String pattern12 = DateFormat.getBestDateTimePattern(locale, "hma"); mPattern24 = Utils.getDatePattern(locale, "Hm"); String pattern12 = Utils.getDatePattern(locale, "hma"); if (Build.VERSION.SDK_INT >= 17) { if (TextUtils.getLayoutDirectionFromLocale(locale) == View.LAYOUT_DIRECTION_RTL) { // There's an RTL layout bug that causes jank when fast-scrolling through // the list in 12-hour mode in an RTL locale. We can work around this by // ensuring the strings are the same length by using "hh" instead of "h". pattern12 = pattern12.replaceAll("h", "hh"); } } else { if (TextUtilsCompat.getLayoutDirectionFromLocale(locale) == View.LAYOUT_DIRECTION_RTL) { pattern12 = pattern12.replaceAll("h", "hh"); } } mPattern12 = pattern12; } @Override public int getCount() { final int headerCount = hasHeader() ? 1 : 0; return headerCount + mFilteredCities.size(); } @Override public City getItem(int position) { if (hasHeader()) { final int itemViewType = getItemViewType(position); switch (itemViewType) { case VIEW_TYPE_SELECTED_CITIES_HEADER: return null; case VIEW_TYPE_CITY: return mFilteredCities.get(position - 1); } throw new IllegalStateException("unexpected item view type: " + itemViewType); } return mFilteredCities.get(position); } @Override public long getItemId(int position) { return position; } @Override public synchronized View getView(int position, View view, ViewGroup parent) { final int itemViewType = getItemViewType(position); switch (itemViewType) { case VIEW_TYPE_SELECTED_CITIES_HEADER: if (view == null) { view = mInflater.inflate(R.layout.city_list_header, parent, false); } return view; case VIEW_TYPE_CITY: final City city = getItem(position); final TimeZone timeZone = city.getTimeZone(); // Inflate a new view if necessary. if (view == null) { view = mInflater.inflate(R.layout.city_list_item, parent, false); final TextView index = (TextView) view.findViewById(R.id.index); final TextView name = (TextView) view.findViewById(R.id.city_name); final TextView time = (TextView) view.findViewById(R.id.city_time); final AppCompatCheckBox selected = (AppCompatCheckBox) view.findViewById(R.id.city_onoff); view.setTag(new CityItemHolder(index, name, time, selected)); } // Bind data into the child views. final CityItemHolder holder = (CityItemHolder) view.getTag(); holder.selected.setTag(city); holder.selected.setChecked(mUserSelectedCities.contains(city)); holder.selected.setContentDescription(city.getName()); holder.selected.setOnCheckedChangeListener(this); holder.name.setText(city.getName(), TextView.BufferType.SPANNABLE); holder.time.setText(getTimeCharSequence(timeZone)); final boolean showIndex = getShowIndex(position); holder.index.setVisibility(showIndex ? View.VISIBLE : View.INVISIBLE); if (showIndex) { switch (getCitySort()) { case NAME: holder.index.setText(city.getIndexString()); holder.index.setTextSize(TypedValue.COMPLEX_UNIT_SP, 24); break; case UTC_OFFSET: holder.index.setText(Utils.getGMTHourOffset(timeZone, false)); holder.index.setTextSize(TypedValue.COMPLEX_UNIT_SP, 14); break; } } // skip checkbox and other animations view.jumpDrawablesToCurrentState(); view.setOnClickListener(this); return view; } throw new IllegalStateException("unexpected item view type: " + itemViewType); } @Override public int getViewTypeCount() { return 2; } @Override public int getItemViewType(int position) { return hasHeader() && position == 0 ? VIEW_TYPE_SELECTED_CITIES_HEADER : VIEW_TYPE_CITY; } @Override public void onCheckedChanged(CompoundButton b, boolean checked) { final City city = (City) b.getTag(); if (checked) { mUserSelectedCities.add(city); if (Build.VERSION.SDK_INT >= 16) { b.announceForAccessibility(mContext.getString(R.string.city_checked, city.getName())); } } else { mUserSelectedCities.remove(city); if (Build.VERSION.SDK_INT >= 16) { b.announceForAccessibility(mContext.getString(R.string.city_unchecked, city.getName())); } } } @Override public void onClick(View v) { final CheckBox b = (CheckBox) v.findViewById(R.id.city_onoff); b.setChecked(!b.isChecked()); } @Override public Object[] getSections() { if (mSectionHeaders == null) { // Make an educated guess at the expected number of sections. final int approximateSectionCount = getCount() / 5; final List<String> sections = new ArrayList<>(approximateSectionCount); final List<Integer> positions = new ArrayList<>(approximateSectionCount); // Add a section for the "Selected Cities" header if it exists. if (hasHeader()) { sections.add("+"); positions.add(0); } for (int position = 0; position < getCount(); position++) { // Add a section if this position should show the section index. if (getShowIndex(position)) { final City city = getItem(position); switch (getCitySort()) { case NAME: sections.add(city.getIndexString()); break; case UTC_OFFSET: final TimeZone timezone = city.getTimeZone(); sections.add(Utils.getGMTHourOffset(timezone, Utils.isPreL())); break; } positions.add(position); } } mSectionHeaders = sections.toArray(new String[sections.size()]); mSectionHeaderPositions = positions.toArray(new Integer[positions.size()]); } return mSectionHeaders; } @Override public int getPositionForSection(int sectionIndex) { return getSections().length == 0 ? 0 : mSectionHeaderPositions[sectionIndex]; } @Override public int getSectionForPosition(int position) { if (getSections().length == 0) { return 0; } for (int i = 0; i < mSectionHeaderPositions.length - 2; i++) { if (position < mSectionHeaderPositions[i]) continue; if (position >= mSectionHeaderPositions[i + 1]) continue; return i; } return mSectionHeaderPositions.length - 1; } /** * Clear the section headers to force them to be recomputed if they are now stale. */ private void clearSectionHeaders() { mSectionHeaders = null; mSectionHeaderPositions = null; } /** * Rebuilds all internal data structures from scratch. */ private void refresh() { // Update the 12/24 hour mode. mIs24HoursMode = DateFormat.is24HourFormat(mContext); // Refresh the user selections. final List<City> selected = DataModel.getDataModel().getSelectedCities(); mUserSelectedCities.clear(); mUserSelectedCities.addAll(selected); mOriginalUserSelectionCount = selected.size(); // Recompute section headers. clearSectionHeaders(); // Recompute filtered cities. filter(mSearchMenuItemController.getQueryText()); } /** * Filter the cities using the given {@code queryText}. */ private void filter(String queryText) { mSearchMenuItemController.setQueryText(queryText); final String query = queryText.trim().toUpperCase(); // Compute the filtered list of cities. final List<City> filteredCities; if (TextUtils.isEmpty(query)) { filteredCities = DataModel.getDataModel().getAllCities(); } else { final List<City> unselected = DataModel.getDataModel().getUnselectedCities(); filteredCities = new ArrayList<>(unselected.size()); for (City city : unselected) { if (city.getNameUpperCase().startsWith(query)) { filteredCities.add(city); } } } // Swap in the filtered list of cities and notify of the data change. mFilteredCities = filteredCities; notifyDataSetChanged(); } private boolean isFiltering() { return !TextUtils.isEmpty(mSearchMenuItemController.getQueryText().trim()); } private Collection<City> getSelectedCities() { return mUserSelectedCities; } private boolean hasHeader() { return !isFiltering() && mOriginalUserSelectionCount > 0; } private DataModel.CitySort getCitySort() { return DataModel.getDataModel().getCitySort(); } private Comparator<City> getCitySortComparator() { return DataModel.getDataModel().getCityIndexComparator(); } private CharSequence getTimeCharSequence(TimeZone timeZone) { mCalendar.setTimeZone(timeZone); return DateFormat.format(mIs24HoursMode ? mPattern24 : mPattern12, mCalendar); } private boolean getShowIndex(int position) { // Indexes are never displayed on filtered cities. if (isFiltering()) { return false; } if (hasHeader()) { // None of the original user selections should show their index. if (position <= mOriginalUserSelectionCount) { return false; } // The first item after the original user selections must always show its index. if (position == mOriginalUserSelectionCount + 1) { return true; } } else { // None of the original user selections should show their index. if (position < mOriginalUserSelectionCount) { return false; } // The first item after the original user selections must always show its index. if (position == mOriginalUserSelectionCount) { return true; } } // Otherwise compare the city with its predecessor to test if it is a header. final City priorCity = getItem(position - 1); final City city = getItem(position); return getCitySortComparator().compare(priorCity, city) != 0; } /** * Cache the child views of each city item view. */ private static final class CityItemHolder { private final TextView index; private final TextView name; private final TextView time; private final CheckBox selected; public CityItemHolder(TextView index, TextView name, TextView time, CheckBox selected) { this.index = index; this.name = name; this.time = time; this.selected = selected; } } } private final class SortOrderMenuItemController extends AbstractMenuItemController { private static final int SORT_MENU_RES_ID = R.id.menu_item_sort; @Override public int getId() { return SORT_MENU_RES_ID; } @Override public void showMenuItem(Menu menu) { final MenuItem sortMenuItem = menu.findItem(SORT_MENU_RES_ID); final String title; if (DataModel.getDataModel().getCitySort() == DataModel.CitySort.NAME) { title = getString(R.string.menu_item_sort_by_gmt_offset); } else { title = getString(R.string.menu_item_sort_by_name); } sortMenuItem.setTitle(title); sortMenuItem.setVisible(true); } @Override public boolean handleMenuItemClick(MenuItem item) { // Save the new sort order. DataModel.getDataModel().toggleCitySort(); // Section headers are influenced by sort order and must be cleared. mCitiesAdapter.clearSectionHeaders(); // Honor the new sort order in the adapter. mCitiesAdapter.filter(mSearchMenuItemController.getQueryText()); return true; } } }