Java tutorial
/* * Copyright (C) 2012 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.starup.traven.travelkorea; import android.annotation.TargetApi; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.location.Location; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.os.AsyncTask; import android.os.Build.VERSION_CODES; import android.os.Bundle; import android.preference.PreferenceManager; import android.support.v4.app.Fragment; import android.util.TypedValue; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewGroup.LayoutParams; import android.view.ViewTreeObserver; import android.widget.AbsListView; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.BaseAdapter; import android.widget.GridView; import android.widget.ImageButton; import android.widget.ImageView; import com.google.android.gms.common.api.GoogleApiClient; import com.google.android.gms.location.LocationServices; import com.starup.traven.travelkorea.common.logger.Log; import com.starup.traven.travelkorea.provider.Images; import com.starup.traven.travelkorea.ui.RecyclingImageView; import com.starup.traven.travelkorea.util.ImageCache; import com.starup.traven.travelkorea.util.ImageFetcher; import com.starup.traven.travelkorea.util.Utils; import org.xmlpull.v1.XmlPullParserException; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.ListIterator; import com.starup.traven.travelkorea.XMLParser.VisitKoreaXmlParser; import com.starup.traven.travelkorea.XMLParser.VisitKoreaXmlParser.Entry; /** * The main fragment that powers the ImageGridActivity screen. Fairly straight forward GridView * implementation with the key addition being the ImageWorker class w/ImageCache to load children * asynchronously, keeping the UI nice and smooth and caching thumbnails for quick retrieval. The * cache is retained over configuration changes like orientation change so the images are populated * quickly if, for example, the user rotates the device. */ public class ImageGridFragment extends Fragment implements AdapterView.OnItemClickListener { private GridView mGridView = null; private int mAge; private int mGender; private int mLanguage; private String langService = "EngService"; private String contentID = "82"; private String radius = "2000"; private String mapX = "126.981106"; private String mapY = "37.568477"; private static final String service_key = "tcMsl%2FuAaldSmyvnY78FqTHtqWLrQUg%2FYLDcNX389OGxcA%2BpXV2ejk86zNsw1XJZXNwUiIw6F8e6BbToTVpblg%3D%3D"; private static final String URL1 = "http://api.visitkorea.or.kr/openapi/service/rest/"; // +langService private static final String URL2 = "/locationBasedList?ServiceKey=" + service_key + "&contentTypeId="; // +contentID private static final String URL3 = "&mapX="; // +mapX private static final String URL4 = "&mapY="; // +mapY private static final String URL5 = "&radius=";//radius private static final String URl6 = "&listYN=Y&MobileOS=AND&MobileApp=TourAPI3.0_Guide&arrange=A&numOfRows=100&pageNo=1"; public String getURL() { Location loc = ((MainActivity) getActivity()).mLastLocation; if (loc != null) { mapX = Double.toString(loc.getLongitude()); mapY = Double.toString(loc.getLatitude()); } String visitURL = URL1 + langService + URL2 + contentID + URL3 + mapX + URL4 + mapY + URL5 + radius + URl6; return visitURL; } private static final String TAG = "ImageGridFragment"; private static final String IMAGE_CACHE_DIR = "thumbs"; private int mImageThumbSize; private int mImageThumbSpacing; private ImageAdapter mAdapter; private ImageFetcher mImageFetcher; /** * VisitKorea Open API connection. */ public static final String WIFI = "Wi-Fi"; public static final String ANY = "Any"; // Whether there is a Wi-Fi connection. private static boolean wifiConnected = false; // Whether there is a mobile connection. private static boolean mobileConnected = false; // Whether the display should be refreshed. public static boolean refreshDisplay = true; // The user's current network preference setting. public static String sPref = null; private List<Entry> mGridData = null; ImageButton[] imageButton = new ImageButton[5]; /** * Empty constructor as per the Fragment documentation */ public ImageGridFragment() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setHasOptionsMenu(true); radius = getResources().getString(R.string.distance); mGridData = new ArrayList<Entry>(0); mImageThumbSize = getResources().getDimensionPixelSize(R.dimen.image_thumbnail_size); mImageThumbSpacing = getResources().getDimensionPixelSize(R.dimen.image_thumbnail_spacing); mAdapter = new ImageAdapter(getActivity()); ImageCache.ImageCacheParams cacheParams = new ImageCache.ImageCacheParams(getActivity(), IMAGE_CACHE_DIR); cacheParams.setMemCacheSizePercent(0.25f); // Set memory cache to 25% of app memory // The ImageFetcher takes care of loading images into our ImageView children asynchronously mImageFetcher = new ImageFetcher(getActivity(), mImageThumbSize); mImageFetcher.setLoadingImage(R.drawable.empty_photo); mImageFetcher.addImageCache(getActivity().getSupportFragmentManager(), cacheParams); // Gets the user's network preference settings SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(getActivity()); // Retrieves a string value for the preferences. The second parameter // is the default value to use if a preference value is not found. sPref = sharedPrefs.getString("listPref", "Wi-Fi"); updateConnectedFlags(); updateOption(); } public void updateOption() { mAge = ((MainActivity) getActivity()).myinfo.age; mGender = ((MainActivity) getActivity()).myinfo.gender; mLanguage = ((MainActivity) getActivity()).myinfo.language; if (mLanguage == 1) { langService = "KorService"; } else if (mLanguage == 2) { langService = "ChsService"; } else if (mLanguage == 3) { langService = "JpnService"; } else { langService = "EngService"; } if (langService.equals("KorService")) { if (contentID == "82") { contentID = "39"; } else if (contentID == "80") { contentID = "32"; } else if (contentID == "79") { contentID = "38"; } else if (contentID == "88") { contentID = "14"; } else if (contentID == "85") { contentID = "15"; } } Location loc = ((MainActivity) getActivity()).mLastLocation; if (loc != null) { mapX = Double.toString(loc.getLongitude()); mapY = Double.toString(loc.getLatitude()); } } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { final View v = inflater.inflate(R.layout.image_grid_fragment, container, false); mGridView = (GridView) v.findViewById(R.id.gridView); mGridView.setAdapter(mAdapter); mGridView.setOnItemClickListener(this); mGridView.setOnScrollListener(new AbsListView.OnScrollListener() { @Override public void onScrollStateChanged(AbsListView absListView, int scrollState) { // Pause fetcher to ensure smoother scrolling when flinging if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_FLING) { // Before Honeycomb pause image loading on scroll to help with performance if (!Utils.hasHoneycomb()) { mImageFetcher.setPauseWork(true); } } else { mImageFetcher.setPauseWork(false); } } @Override public void onScroll(AbsListView absListView, int firstVisibleItem, int visibleItemCount, int totalItemCount) { } }); // This listener is used to get the final width of the GridView and then calculate the // number of columns and the width of each column. The width of each column is variable // as the GridView has stretchMode=columnWidth. The column width is used to set the height // of each view so we get nice square thumbnails. mGridView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() { @TargetApi(VERSION_CODES.JELLY_BEAN) @Override public void onGlobalLayout() { if (mAdapter.getNumColumns() == 0) { final int numColumns = (int) Math .floor(mGridView.getWidth() / (mImageThumbSize + mImageThumbSpacing)); if (numColumns > 0) { final int columnWidth = (mGridView.getWidth() / numColumns) - mImageThumbSpacing; mAdapter.setNumColumns(numColumns); mAdapter.setItemHeight(columnWidth); if (BuildConfig.DEBUG) { Log.d(TAG, "onCreateView - numColumns set to " + numColumns); } if (Utils.hasJellyBean()) { mGridView.getViewTreeObserver().removeOnGlobalLayoutListener(this); } else { mGridView.getViewTreeObserver().removeGlobalOnLayoutListener(this); } } } } }); addListenerOnButton(v); return v; } public void addListenerOnButton(View v) { imageButton[0] = (ImageButton) v.findViewById(R.id.foodButton); imageButton[1] = (ImageButton) v.findViewById(R.id.hotelButton); imageButton[2] = (ImageButton) v.findViewById(R.id.shoppingButton); imageButton[3] = (ImageButton) v.findViewById(R.id.cultureButton); imageButton[4] = (ImageButton) v.findViewById(R.id.concertButton); for (int i = 0; i < 5; i++) { imageButton[i].setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { mAge = ((MainActivity) getActivity()).myinfo.age; mGender = ((MainActivity) getActivity()).myinfo.gender; mLanguage = ((MainActivity) getActivity()).myinfo.language; if (mLanguage == 1) { langService = "KorService"; } else if (mLanguage == 2) { langService = "ChsService"; } else if (mLanguage == 3) { langService = "JpnService"; } else { langService = "EngService"; } boolean temp = langService.equals("KorService"); String currentID = contentID; if (arg0.getId() == R.id.foodButton) { contentID = langService.equals("KorService") ? "39" : "82"; } else if (arg0.getId() == R.id.hotelButton) { contentID = langService.equals("KorService") ? "32" : "80"; } else if (arg0.getId() == R.id.shoppingButton) { contentID = langService.equals("KorService") ? "38" : "79"; } else if (arg0.getId() == R.id.cultureButton) { contentID = langService.equals("KorService") ? "14" : "78"; } else if (arg0.getId() == R.id.concertButton) { contentID = langService.equals("KorService") ? "15" : "85"; } // if (contentID != currentID) { mGridData.clear(); loadPage(); } } }); } } @Override public void onResume() { super.onResume(); loadPage(); //updateOption(); mImageFetcher.setExitTasksEarly(false); mAdapter.notifyDataSetChanged(); } @Override public void onPause() { super.onPause(); mImageFetcher.setPauseWork(false); mImageFetcher.setExitTasksEarly(true); mImageFetcher.flushCache(); } @Override public void onDestroy() { super.onDestroy(); mImageFetcher.closeCache(); } @TargetApi(VERSION_CODES.JELLY_BEAN) @Override public void onItemClick(AdapterView<?> parent, View v, int position, long id) { final Intent i = new Intent(getActivity(), ImageDetailActivity.class); i.putExtra("langService", langService); i.putExtra("contenttypeId", mGridData.get(position).contenttypeId); i.putExtra("contentid", mGridData.get(position).contentid); startActivity(i); } // Checks the network connection and sets the wifiConnected and mobileConnected // variables accordingly. private void updateConnectedFlags() { ConnectivityManager connMgr = (ConnectivityManager) getActivity() .getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo activeInfo = connMgr.getActiveNetworkInfo(); if (activeInfo != null && activeInfo.isConnected()) { wifiConnected = activeInfo.getType() == ConnectivityManager.TYPE_WIFI; mobileConnected = activeInfo.getType() == ConnectivityManager.TYPE_MOBILE; } else { wifiConnected = false; mobileConnected = false; } } // Uses AsyncTask subclass to download the XML feed from stackoverflow.com. // This avoids UI lock up. To prevent network operations from // causing a delay that results in a poor user experience, always perform // network operations on a separate thread from the UI. private void loadPage() { updateOption(); new DownloadXmlTask().execute(getURL()); // if (((sPref.equals(ANY)) && (wifiConnected || mobileConnected)) // || ((sPref.equals(WIFI)) && (wifiConnected))) { // // AsyncTask subclass // } else { // showErrorPage(); // } } private void showErrorPage() { ; } // Implementation of AsyncTask used to download XML feed from stackoverflow.com. private class DownloadXmlTask extends AsyncTask<String, Void, String> { static final String Tag = "DownloadTask"; @Override protected String doInBackground(String... urls) { try { return loadXmlFromNetwork(urls[0]); } catch (IOException e) { return getResources().getString(R.string.connection_error); } catch (XmlPullParserException e) { return getResources().getString(R.string.xml_error); } } @Override protected void onPostExecute(String result) { //setContentView(R.layout.main); // Displays the HTML string in the UI via a WebView //WebView myWebView = (WebView) findViewById(R.id.webview); //myWebView.loadData(result, "text/html", null); android.util.Log.i(Tag, "onPoseExecute"); if (result.equals("OK")) { //mGridAdapter.setGridData(mGridData); mAdapter.notifyDataSetChanged(); } } } // Uploads XML from stackoverflow.com, parses it, and combines it with // HTML markup. Returns HTML string. private String loadXmlFromNetwork(String urlString) throws XmlPullParserException, IOException { InputStream stream = null; VisitKoreaXmlParser stackOverflowXmlParser = new VisitKoreaXmlParser(); try { stream = downloadUrl(urlString); mGridData = null; mGridData = stackOverflowXmlParser.parse(stream); ListIterator<Entry> iter = mGridData.listIterator(); while (iter.hasNext()) { Entry entry = iter.next(); if (entry.firstimage == null) { iter.remove(); } } // Makes sure that the InputStream is closed after the app is // finished using it. } finally { if (stream != null) { stream.close(); } } return "OK"; } // Given a string representation of a URL, sets up a connection and gets // an input stream. private InputStream downloadUrl(String urlString) throws IOException { URL url = new URL(urlString); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setReadTimeout(10000 /* milliseconds */); conn.setConnectTimeout(15000 /* milliseconds */); conn.setRequestMethod("GET"); conn.setDoInput(true); // Starts the query conn.connect(); InputStream stream = conn.getInputStream(); return stream; } // @Override // public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { // inflater.inflate(R.menu.main_menu, menu); // } // @Override // public boolean onOptionsItemSelected(MenuItem item) { // switch (item.getItemId()) { // case R.id.clear_cache: // mImageFetcher.clearCache(); // Toast.makeText(getActivity(), R.string.clear_cache_complete_toast, // Toast.LENGTH_SHORT).show(); // return true; // } // return super.onOptionsItemSelected(item); // } /** * The main adapter that backs the GridView. This is fairly standard except the number of * columns in the GridView is used to create a fake top row of empty views as we use a * transparent ActionBar and don't want the real top row of images to start off covered by it. */ private class ImageAdapter extends BaseAdapter { private final Context mContext; private int mItemHeight = 0; private int mNumColumns = 0; private int mActionBarHeight = 0; private GridView.LayoutParams mImageViewLayoutParams; public ImageAdapter(Context context) { super(); mContext = context; mImageViewLayoutParams = new GridView.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); // Calculate ActionBar height TypedValue tv = new TypedValue(); if (context.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true)) { mActionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data, context.getResources().getDisplayMetrics()); } } @Override public int getCount() { int val = 0; if (mGridData != null) val = mGridData.size(); return val; } @Override public Object getItem(int position) { return mGridData.get(position); } public long getItemId(int position) { return position; } // @Override // public int getViewTypeCount() { // // Two types of views, the normal ImageView and the top row of empty views // return 2; // } // @Override // public int getItemViewType(int position) { // return (position < mNumColumns) ? 1 : 0; // } // @Override // public boolean hasStableIds() { // return true; // } @Override public View getView(int position, View convertView, ViewGroup container) { // Now handle the main ImageView thumbnails ImageView imageView; if (convertView == null) { // if it's not recycled, instantiate and initialize imageView = new RecyclingImageView(mContext); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); imageView.setLayoutParams(mImageViewLayoutParams); } else { // Otherwise re-use the converted view imageView = (ImageView) convertView; } // Check the height matches our calculated column width if (imageView.getLayoutParams().height != mItemHeight) { imageView.setLayoutParams(mImageViewLayoutParams); } // Finally load the image asynchronously into the ImageView, this also takes care of // setting a placeholder image while the background thread runs //mImageFetcher.loadImage(Images.imageThumbUrls[position - mNumColumns], imageView); if (mGridData != null) { String image_url = mGridData.get(position).firstimage; if (image_url != null) mImageFetcher.loadImage(image_url, imageView); } return imageView; //END_INCLUDE(load_gridview_item) } /** * Sets the item height. Useful for when we know the column width so the height can be set * to match. * * @param height */ public void setItemHeight(int height) { if (height == mItemHeight) { return; } mItemHeight = height; mImageViewLayoutParams = new GridView.LayoutParams(LayoutParams.MATCH_PARENT, mItemHeight); mImageFetcher.setImageSize(height); notifyDataSetChanged(); } public void setNumColumns(int numColumns) { mNumColumns = numColumns; } public int getNumColumns() { return mNumColumns; } } }