Java tutorial
/* * Copyright (C) 2013 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.ute.bihapi.wydarzeniatekstowe.thirdScreenActivities; import android.annotation.SuppressLint; import android.annotation.TargetApi; import android.app.Activity; import android.app.SearchManager; import android.content.Context; import android.database.Cursor; import android.net.Uri; import android.os.Build; import android.os.Bundle; import android.os.SystemClock; import android.provider.ContactsContract.CommonDataKinds; import android.provider.ContactsContract.Contacts; import android.support.v4.app.ListFragment; import android.support.v4.app.LoaderManager; import android.support.v4.content.CursorLoader; import android.support.v4.content.Loader; import android.support.v4.widget.CursorAdapter; import android.text.SpannableString; import android.text.TextUtils; import android.text.style.TextAppearanceSpan; import android.util.Log; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.AbsListView; import android.widget.AdapterView; import android.widget.AlphabetIndexer; import android.widget.ListView; import android.widget.SearchView; import android.widget.SectionIndexer; import android.widget.TextView; import com.ute.bihapi.wydarzeniatekstowe.R; import com.ute.bihapi.wydarzeniatekstowe.thirdScreenActivities.util.Utils; import java.util.Locale; /** * This fragment displays a list of contacts stored in the Contacts Provider. Each item in the list * shows the contact's thumbnail photo and display name. On devices with large screens, this * fragment's UI appears as part of a two-pane layout, along with the UI of * {@link ContactDetailFragment}. On smaller screens, this fragment's UI appears as a single pane. * * This Fragment retrieves contacts based on a search string. If the user doesn't enter a search * string, then the list contains all the contacts in the Contacts Provider. If the user enters a * search string, then the list contains only those contacts whose data matches the string. The * Contacts Provider itself controls the matching algorithm, which is a "substring" search: if the * search string is a substring of any of the contacts data, then there is a match. * * On newer API platforms, the search is implemented in a SearchView in the ActionBar; as the user * types the search string, the list automatically refreshes to display results ("type to filter"). * On older platforms, the user must enter the full string and trigger the search. In response, the * trigger starts a new Activity which loads a fresh instance of this fragment. The resulting UI * displays the filtered list and disables the search feature to prevent furthering searching. */ public class ContactsListFragment extends ListFragment implements AdapterView.OnItemClickListener, LoaderManager.LoaderCallbacks<Cursor> { // Defines a tag for identifying log entries private static final String TAG = "ContactsListFragment"; // Bundle key for saving previously selected search result item private static final String STATE_PREVIOUSLY_SELECTED_KEY = "com.example.android.contactslist.ui.SELECTED_ITEM"; private ContactsAdapter mAdapter; // The main query adapter private String mSearchTerm; // Stores the current search query term // Contact selected listener that allows the activity holding this fragment to be notified of // a contact being selected private OnContactsInteractionListener mOnContactSelectedListener; // Stores the previously selected search item so that on a configuration change the same item // can be reselected again private int mPreviouslySelectedSearchItem = 0; // Whether or not the search query has changed since the last time the loader was refreshed private boolean mSearchQueryChanged; // Whether or not this is a search result view of this fragment, only used on pre-honeycomb // OS versions as search results are shown in-line via Action Bar search from honeycomb onward private boolean mIsSearchResultView = false; /** * Fragments require an empty constructor. */ public ContactsListFragment() { } /** * In platform versions prior to Android 3.0, the ActionBar and SearchView are not supported, * and the UI gets the search string from an EditText. However, the fragment doesn't allow * another search when search results are already showing. This would confuse the user, because * the resulting search would re-query the Contacts Provider instead of searching the listed * results. This method sets the search query and also a boolean that tracks if this Fragment * should be displayed as a search result view or not. * * @param query The contacts search query. */ public void setSearchQuery(String query) { if (TextUtils.isEmpty(query)) { mIsSearchResultView = false; } else { mSearchTerm = query; mIsSearchResultView = true; } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Let this fragment contribute menu items setHasOptionsMenu(true); // Create the main contacts adapter mAdapter = new ContactsAdapter(getActivity()); if (savedInstanceState != null) { // If we're restoring state after this fragment was recreated then // retrieve previous search term and previously selected search // result. mSearchTerm = savedInstanceState.getString(SearchManager.QUERY); mPreviouslySelectedSearchItem = savedInstanceState.getInt(STATE_PREVIOUSLY_SELECTED_KEY, 0); } } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate the list fragment layout return inflater.inflate(R.layout.contact_list_fragment, container, false); } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); // Set up ListView, assign adapter and set some listeners. The adapter was previously // created in onCreate(). setListAdapter(mAdapter); getListView().setOnItemClickListener(this); getListView().setOnScrollListener(new AbsListView.OnScrollListener() { @Override public void onScrollStateChanged(AbsListView absListView, int scrollState) { // Pause image loader to ensure smoother scrolling when flinging if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_FLING) { //mImageLoader.setPauseWork(true); } else { //mImageLoader.setPauseWork(false); } } @Override public void onScroll(AbsListView absListView, int i, int i1, int i2) { } }); getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE); // If there's a previously selected search item from a saved state then don't bother // initializing the loader as it will be restarted later when the query is populated into // the action bar search view (see onQueryTextChange() in onCreateOptionsMenu()). if (mPreviouslySelectedSearchItem == 0) { // Initialize the loader, and create a loader identified by ContactsQuery.QUERY_ID getLoaderManager().initLoader(ContactsQuery.QUERY_ID, null, this); } } @Override public void onAttach(Activity activity) { super.onAttach(activity); try { // Assign callback listener which the holding activity must implement. This is used // so that when a contact item is interacted with (selected by the user) the holding // activity will be notified and can take further action such as populating the contact // detail pane (if in multi-pane layout) or starting a new activity with the contact // details (single pane layout). mOnContactSelectedListener = (OnContactsInteractionListener) activity; } catch (ClassCastException e) { throw new ClassCastException(activity.toString() + " must implement OnContactsInteractionListener"); } } @Override public void onPause() { super.onPause(); } @Override public void onItemClick(AdapterView<?> parent, View v, int position, long id) { // Gets the Cursor object currently bound to the ListView final Cursor cursor = mAdapter.getCursor(); // Moves to the Cursor row corresponding to the ListView item that was clicked cursor.moveToPosition(position); // Creates a contact lookup Uri from contact ID and lookup_key final Uri uri = Contacts.getLookupUri(cursor.getLong(ContactsQuery.ID), cursor.getString(ContactsQuery.LOOKUP_KEY)); // Notifies the parent activity that the user selected a contact. In a two-pane layout, the // parent activity loads a ContactDetailFragment that displays the details for the selected // contact. In a single-pane layout, the parent activity starts a new activity that // displays contact details in its own Fragment. mOnContactSelectedListener.onContactSelected(uri); getListView().setItemChecked(position, true); } /** * Called when ListView selection is cleared, for example * when search mode is finished and the currently selected * contact should no longer be selected. */ private void onSelectionCleared() { // Uses callback to notify activity this contains this fragment mOnContactSelectedListener.onSelectionCleared(); // Clears currently checked item getListView().clearChoices(); } // This method uses APIs from newer OS versions than the minimum that this app supports. This // annotation tells Android lint that they are properly guarded so they won't run on older OS // versions and can be ignored by lint. @TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH) @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { // Inflate the menu items inflater.inflate(R.menu.contact_list_menu, menu); // Locate the search item MenuItem searchItem = menu.findItem(R.id.menu_search); // In versions prior to Android 3.0, hides the search item to prevent additional // searches. In Android 3.0 and later, searching is done via a SearchView in the ActionBar. // Since the search doesn't create a new Activity to do the searching, the menu item // doesn't need to be turned off. if (mIsSearchResultView) { searchItem.setVisible(false); } // In version 3.0 and later, sets up and configures the ActionBar SearchView if (Utils.hasHoneycomb()) { // Retrieves the system search manager service final SearchManager searchManager = (SearchManager) getActivity() .getSystemService(Context.SEARCH_SERVICE); // Retrieves the SearchView from the search menu item final SearchView searchView = (SearchView) searchItem.getActionView(); // Assign searchable info to SearchView searchView.setSearchableInfo(searchManager.getSearchableInfo(getActivity().getComponentName())); // Set listeners for SearchView searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() { @Override public boolean onQueryTextSubmit(String queryText) { // Nothing needs to happen when the user submits the search string return true; } @Override public boolean onQueryTextChange(String newText) { // Called when the action bar search text has changed. Updates // the search filter, and restarts the loader to do a new query // using the new search string. String newFilter = !TextUtils.isEmpty(newText) ? newText : null; // Don't do anything if the filter is empty if (mSearchTerm == null && newFilter == null) { return true; } // Don't do anything if the new filter is the same as the current filter if (mSearchTerm != null && mSearchTerm.equals(newFilter)) { return true; } // Updates current filter to new filter mSearchTerm = newFilter; // Restarts the loader. This triggers onCreateLoader(), which builds the // necessary content Uri from mSearchTerm. mSearchQueryChanged = true; getLoaderManager().restartLoader(ContactsQuery.QUERY_ID, null, ContactsListFragment.this); return true; } }); if (Utils.hasICS()) { // This listener added in ICS searchItem.setOnActionExpandListener(new MenuItem.OnActionExpandListener() { @Override public boolean onMenuItemActionExpand(MenuItem menuItem) { // Nothing to do when the action item is expanded return true; } @Override public boolean onMenuItemActionCollapse(MenuItem menuItem) { // When the user collapses the SearchView the current search string is // cleared and the loader restarted. if (!TextUtils.isEmpty(mSearchTerm)) { onSelectionCleared(); } mSearchTerm = null; getLoaderManager().restartLoader(ContactsQuery.QUERY_ID, null, ContactsListFragment.this); return true; } }); } if (mSearchTerm != null) { // If search term is already set here then this fragment is // being restored from a saved state and the search menu item // needs to be expanded and populated again. // Stores the search term (as it will be wiped out by // onQueryTextChange() when the menu item is expanded). final String savedSearchTerm = mSearchTerm; // Expands the search menu item if (Utils.hasICS()) { searchItem.expandActionView(); } // Sets the SearchView to the previous search string searchView.setQuery(savedSearchTerm, false); } } } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); if (!TextUtils.isEmpty(mSearchTerm)) { // Saves the current search string outState.putString(SearchManager.QUERY, mSearchTerm); // Saves the currently selected contact outState.putInt(STATE_PREVIOUSLY_SELECTED_KEY, getListView().getCheckedItemPosition()); } } @Override public boolean onOptionsItemSelected(MenuItem item) { if (!Utils.hasHoneycomb()) { getActivity().onSearchRequested(); } return super.onOptionsItemSelected(item); } @Override public Loader<Cursor> onCreateLoader(int id, Bundle args) { // If this is the loader for finding contacts in the Contacts Provider // (the only one supported) if (id == ContactsQuery.QUERY_ID) { Uri contentUri; // There are two types of searches, one which displays all contacts and // one which filters contacts by a search query. If mSearchTerm is set // then a search query has been entered and the latter should be used. if (mSearchTerm == null) { // Since there's no search string, use the content URI that searches the entire // Contacts table contentUri = ContactsQuery.CONTENT_URI; } else { // Since there's a search string, use the special content Uri that searches the // Contacts table. The URI consists of a base Uri and the search string. contentUri = Uri.withAppendedPath(ContactsQuery.FILTER_URI, Uri.encode(mSearchTerm)); } // Returns a new CursorLoader for querying the Contacts table. No arguments are used // for the selection clause. The search string is either encoded onto the content URI, // or no contacts search string is used. The other search criteria are constants. See // the ContactsQuery interface. return new CursorLoader(getActivity(), contentUri, ContactsQuery.PROJECTION, ContactsQuery.SELECTION, null, ContactsQuery.SORT_ORDER); } Log.e(TAG, "onCreateLoader - incorrect ID provided (" + id + ")"); return null; } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor data) { // This swaps the new cursor into the adapter. if (loader.getId() == ContactsQuery.QUERY_ID) { mAdapter.swapCursor(data); // If this is a two-pane layout and there is a search query then // there is some additional work to do around default selected // search item. if (!TextUtils.isEmpty(mSearchTerm) && mSearchQueryChanged) { // Selects the first item in results, unless this fragment has // been restored from a saved state (like orientation change) // in which case it selects the previously selected search item. if (data != null && data.moveToPosition(mPreviouslySelectedSearchItem)) { // Creates the content Uri for the previously selected contact by appending the // contact's ID to the Contacts table content Uri final Uri uri = Uri.withAppendedPath(Contacts.CONTENT_URI, String.valueOf(data.getLong(ContactsQuery.ID))); mOnContactSelectedListener.onContactSelected(uri); getListView().setItemChecked(mPreviouslySelectedSearchItem, true); } else { // No results, clear selection. onSelectionCleared(); } // Only restore from saved state one time. Next time fall back // to selecting first item. If the fragment state is saved again // then the currently selected item will once again be saved. mPreviouslySelectedSearchItem = 0; mSearchQueryChanged = false; } } } @Override public void onLoaderReset(Loader<Cursor> loader) { if (loader.getId() == ContactsQuery.QUERY_ID) { // When the loader is being reset, clear the cursor from the adapter. This allows the // cursor resources to be freed. mAdapter.swapCursor(null); } } /** * This is a subclass of CursorAdapter that supports binding Cursor columns to a view layout. * If those items are part of search results, the search string is marked by highlighting the * query text. An {@link AlphabetIndexer} is used to allow quicker navigation up and down the * ListView. */ private class ContactsAdapter extends CursorAdapter implements SectionIndexer { private LayoutInflater mInflater; // Stores the layout inflater private AlphabetIndexer mAlphabetIndexer; // Stores the AlphabetIndexer instance private TextAppearanceSpan highlightTextSpan; // Stores the highlight text appearance style /** * Instantiates a new Contacts Adapter. * @param context A context that has access to the app's layout. */ public ContactsAdapter(Context context) { super(context, null, 0); // Stores inflater for use later mInflater = LayoutInflater.from(context); // Loads a string containing the English alphabet. To fully localize the app, provide a // strings.xml file in res/values-<x> directories, where <x> is a locale. In the file, // define a string with android:name="alphabet" and contents set to all of the // alphabetic characters in the language in their proper sort order, in upper case if // applicable. final String alphabet = context.getString(R.string.alphabet); // Instantiates a new AlphabetIndexer bound to the column used to sort contact names. // The cursor is left null, because it has not yet been retrieved. mAlphabetIndexer = new AlphabetIndexer(null, ContactsQuery.DISPLAY_NAME, alphabet); // Defines a span for highlighting the part of a display name that matches the search // string highlightTextSpan = new TextAppearanceSpan(getActivity(), R.style.searchTextHiglight); } /** * Identifies the start of the search string in the display name column of a Cursor row. * E.g. If displayName was "Adam" and search query (mSearchTerm) was "da" this would * return 1. * * @param displayName The contact display name. * @return The starting position of the search string in the display name, 0-based. The * method returns -1 if the string is not found in the display name, or if the search * string is empty or null. */ private int indexOfSearchQuery(String displayName) { if (!TextUtils.isEmpty(mSearchTerm)) { return displayName.toLowerCase(Locale.getDefault()) .indexOf(mSearchTerm.toLowerCase(Locale.getDefault())); } return -1; } /** * Overrides newView() to inflate the list item views. */ @Override public View newView(Context context, Cursor cursor, ViewGroup viewGroup) { // Inflates the list item layout. final View itemLayout = mInflater.inflate(R.layout.contact_list_item, viewGroup, false); // Creates a new ViewHolder in which to store handles to each view resource. This // allows bindView() to retrieve stored references instead of calling findViewById for // each instance of the layout. final ViewHolder holder = new ViewHolder(); holder.text1 = (TextView) itemLayout.findViewById(android.R.id.text1); holder.text2 = (TextView) itemLayout.findViewById(android.R.id.text2); // Stores the resourceHolder instance in itemLayout. This makes resourceHolder // available to bindView and other methods that receive a handle to the item view. itemLayout.setTag(holder); // Returns the item layout view return itemLayout; } /** * Binds data from the Cursor to the provided view. */ @Override public void bindView(View view, Context context, Cursor cursor) { // Gets handles to individual view resources final ViewHolder holder = (ViewHolder) view.getTag(); final String displayName = cursor.getString(ContactsQuery.DISPLAY_NAME); final int startIndex = indexOfSearchQuery(displayName); if (startIndex == -1) { // If the user didn't do a search, or the search string didn't match a display // name, show the display name without highlighting holder.text1.setText(displayName); if (TextUtils.isEmpty(mSearchTerm)) { // If the search search is empty, hide the second line of text holder.text2.setVisibility(View.GONE); } else { // Shows a second line of text that indicates the search string matched // something other than the display name holder.text2.setVisibility(View.VISIBLE); } } else { // If the search string matched the display name, applies a SpannableString to // highlight the search string with the displayed display name // Wraps the display name in the SpannableString final SpannableString highlightedName = new SpannableString(displayName); // Sets the span to start at the starting point of the match and end at "length" // characters beyond the starting point highlightedName.setSpan(highlightTextSpan, startIndex, startIndex + mSearchTerm.length(), 0); // Binds the SpannableString to the display name View object holder.text1.setText(highlightedName); // Since the search string matched the name, this hides the secondary message holder.text2.setVisibility(View.GONE); } // Processes the QuickContactBadge. A QuickContactBadge first appears as a contact's // thumbnail image with styling that indicates it can be touched for additional // information. When the user clicks the image, the badge expands into a dialog box // containing the contact's details and icons for the built-in apps that can handle // each detail type. // Generates the contact lookup Uri final Uri contactUri = Contacts.getLookupUri(cursor.getLong(ContactsQuery.ID), cursor.getString(ContactsQuery.LOOKUP_KEY)); } /** * Overrides swapCursor to move the new Cursor into the AlphabetIndex as well as the * CursorAdapter. */ @Override public Cursor swapCursor(Cursor newCursor) { // Update the AlphabetIndexer with new cursor as well mAlphabetIndexer.setCursor(newCursor); return super.swapCursor(newCursor); } /** * An override of getCount that simplifies accessing the Cursor. If the Cursor is null, * getCount returns zero. As a result, no test for Cursor == null is needed. */ @Override public int getCount() { if (getCursor() == null) { return 0; } return super.getCount(); } /** * Defines the SectionIndexer.getSections() interface. */ @Override public Object[] getSections() { return mAlphabetIndexer.getSections(); } /** * Defines the SectionIndexer.getPositionForSection() interface. */ @Override public int getPositionForSection(int i) { if (getCursor() == null) { return 0; } return mAlphabetIndexer.getPositionForSection(i); } /** * Defines the SectionIndexer.getSectionForPosition() interface. */ @Override public int getSectionForPosition(int i) { if (getCursor() == null) { return 0; } return mAlphabetIndexer.getSectionForPosition(i); } /** * A class that defines fields for each resource ID in the list item layout. This allows * ContactsAdapter.newView() to store the IDs once, when it inflates the layout, instead of * calling findViewById in each iteration of bindView. */ private class ViewHolder { TextView text1; TextView text2; } } /** * This interface must be implemented by any activity that loads this fragment. When an * interaction occurs, such as touching an item from the ListView, these callbacks will * be invoked to communicate the event back to the activity. */ public interface OnContactsInteractionListener { /** * Called when a contact is selected from the ListView. * @param contactUri The contact Uri. */ public void onContactSelected(Uri contactUri); /** * Called when the ListView selection is cleared like when * a contact search is taking place or is finishing. */ public void onSelectionCleared(); } /** * This interface defines constants for the Cursor and CursorLoader, based on constants defined * in the {@link android.provider.ContactsContract.Contacts} class. */ public interface ContactsQuery { // An identifier for the loader final static int QUERY_ID = 1; // A content URI for the Contacts table final static Uri CONTENT_URI = Contacts.CONTENT_URI; // The search/filter query Uri final static Uri FILTER_URI = Contacts.CONTENT_FILTER_URI; // The selection clause for the CursorLoader query. The search criteria defined here // restrict results to contacts that have a display name and are linked to visible groups. // Notice that the search on the string provided by the user is implemented by appending // the search string to CONTENT_FILTER_URI. @SuppressLint("InlinedApi") final static String SELECTION = (Utils.hasHoneycomb() ? Contacts.DISPLAY_NAME_PRIMARY : Contacts.DISPLAY_NAME) + "<>''" + " AND " + Contacts.IN_VISIBLE_GROUP + "=1"; // The desired sort order for the returned Cursor. In Android 3.0 and later, the primary // sort key allows for localization. In earlier versions. use the display name as the sort // key. @SuppressLint("InlinedApi") final static String SORT_ORDER = Utils.hasHoneycomb() ? Contacts.SORT_KEY_PRIMARY : Contacts.DISPLAY_NAME; // The projection for the CursorLoader query. This is a list of columns that the Contacts // Provider should return in the Cursor. @SuppressLint("InlinedApi") final static String[] PROJECTION = { // The contact's row id Contacts._ID, // A pointer to the contact that is guaranteed to be more permanent than _ID. Given // a contact's current _ID value and LOOKUP_KEY, the Contacts Provider can generate // a "permanent" contact URI. Contacts.LOOKUP_KEY, // In platform version 3.0 and later, the Contacts table contains // DISPLAY_NAME_PRIMARY, which either contains the contact's displayable name or // some other useful identifier such as an email address. This column isn't // available in earlier versions of Android, so you must use Contacts.DISPLAY_NAME // instead. Utils.hasHoneycomb() ? Contacts.DISPLAY_NAME_PRIMARY : Contacts.DISPLAY_NAME, // The sort order column for the returned Cursor, used by the AlphabetIndexer SORT_ORDER, }; // The query column numbers which map to each value in the projection final static int ID = 0; final static int LOOKUP_KEY = 1; final static int DISPLAY_NAME = 2; //final static int SORT_KEY = 4; } }