Java tutorial
/* * This file is part of nori. * Copyright (c) 2014 vomitcuddle <shinku@dollbooru.org> * License: ISC */ package com.cuddlesoft.nori.fragment; import android.app.Activity; import android.app.DownloadManager; import android.app.WallpaperManager; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.net.Uri; import android.os.AsyncTask; import android.os.Build; import android.os.Bundle; import android.os.Environment; import android.preference.PreferenceManager; import android.support.v4.app.DialogFragment; import android.support.v4.app.Fragment; import android.support.v4.view.MenuItemCompat; import android.support.v7.widget.ShareActionProvider; import android.text.TextUtils; 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.Toast; import com.cuddlesoft.nori.R; import com.cuddlesoft.nori.util.NetworkUtils; import com.cuddlesoft.norilib.Image; import com.cuddlesoft.norilib.clients.SearchClient; import java.io.IOException; import java.io.InputStream; import java.net.URL; /** Fragment used to display images in {@link com.cuddlesoft.nori.ImageViewerActivity}. */ public abstract class ImageFragment extends Fragment { /** String to prepend to Pixiv IDs to open them in the system web browser. */ private static final String PIXIV_URL_PREFIX = "http://www.pixiv.net/member_illust.php?mode=medium&illust_id="; /** Bundle identifier used to save the displayed image object in {@link #onSaveInstanceState(android.os.Bundle)}. */ protected static final String BUNDLE_ID_IMAGE = "com.cuddlesoft.nori.Image"; /** Image object displayed in this fragment. */ protected Image image; /** Class used for communication with the class that contains this fragment. */ protected ImageFragmentListener listener; /** * Check if the {@link android.support.v4.view.ViewPager} containing this fragment can scroll horizontally. * * @param direction Direction being scrolled in. * @return true if the {@link android.support.v4.view.ViewPager} containing this fragment can scroll horizontally. */ public abstract boolean canScroll(int direction); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Get the image object from the fragment's arguments bundle. image = getArguments().getParcelable(BUNDLE_ID_IMAGE); // Enable options menu items for fragment. setHasOptionsMenu(true); } @Override public void onAttach(Activity activity) { super.onAttach(activity); try { listener = (ImageFragmentListener) getActivity(); } catch (ClassCastException e) { throw new ClassCastException(activity.toString() + " must implement OnFragmentInteractionListener"); } } @Override public void onDetach() { super.onDetach(); listener = null; } @Override public abstract View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState); @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { inflater.inflate(R.menu.image, menu); // Set up ShareActionProvider MenuItem shareItem = menu.findItem(R.id.action_share); ShareActionProvider shareActionProvider = (ShareActionProvider) MenuItemCompat.getActionProvider(shareItem); shareActionProvider.setShareIntent(getShareIntent()); // Hide the view on Pixiv menu item, if the Image does not have a Pixiv source URL. MenuItem shareOnPixivItem = menu.findItem(R.id.action_viewOnPixiv); if (image.pixivId == null || TextUtils.isEmpty(image.pixivId)) { shareOnPixivItem.setVisible(false); } } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.action_tags: showTagListDialog(); return true; case R.id.action_download: downloadImage(); return true; case R.id.action_viewOnWeb: viewOnWeb(); return true; case R.id.action_viewOnPixiv: viewOnPixiv(); return true; case R.id.action_setAsWallpaper: setAsWallpaper(); return true; default: return super.onOptionsItemSelected(item); } } /** * Evaluate the current network conditions using the {@link com.cuddlesoft.nori.util.NetworkUtils} class to decide * if lower resolution images should be loaded to conserve bandwidth. * * @return True if lower resolution images should be used. */ protected boolean shouldLoadImageSamples() { SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getActivity()); return preferences.getBoolean(getString(R.string.preference_image_viewer_conserveBandwidth_key), false) || NetworkUtils.shouldFetchImageSamples(getActivity()); } /** * Get {@link android.content.Intent} to be sent by the {@link android.support.v7.widget.ShareActionProvider}. * * @return Share intent. */ protected Intent getShareIntent() { // Send web URL to image. Intent intent = new Intent(Intent.ACTION_SEND); intent.putExtra(Intent.EXTRA_TEXT, image.webUrl); intent.setType("text/plain"); return intent; } /** * Show the {@link com.cuddlesoft.nori.fragment.TagListDialogFragment} for the current image. */ protected void showTagListDialog() { DialogFragment tagListFragment = TagListDialogFragment.newInstance(image, listener.getSearchClientSettings()); tagListFragment.show(getFragmentManager(), "TagListDialogFragment"); } /** * Use the system {@link android.app.DownloadManager} service to download the image. */ protected void downloadImage() { // Get download manager system service. DownloadManager downloadManager = (DownloadManager) getActivity() .getSystemService(Context.DOWNLOAD_SERVICE); // Extract file name from URL. String fileName = image.fileUrl.substring(image.fileUrl.lastIndexOf("/") + 1); // Create download directory, if it does not already exist. //noinspection ResultOfMethodCallIgnored Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).mkdirs(); // Create and queue download request. DownloadManager.Request request = new DownloadManager.Request(Uri.parse(image.fileUrl)).setTitle(fileName) .setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName) .setVisibleInDownloadsUi(true); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { // Trigger media scanner to add image to system gallery app on Honeycomb and above. request.allowScanningByMediaScanner(); // Show download UI notification on Honeycomb and above. request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED); } downloadManager.enqueue(request); } /** * Opens the image Danbooru page in the system web browser. */ protected void viewOnWeb() { // Create and send intent to display the image in the web browser. Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(image.webUrl)); startActivity(intent); } /** * Opens the image Pixiv page in the system web browser. */ protected void viewOnPixiv() { // Create and send to intent to display the image's pixiv page in the web browser. Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(PIXIV_URL_PREFIX + image.pixivId)); startActivity(intent); } /** * Downloads the full-resolution image in the background and sets it as the wallpaper. */ protected void setAsWallpaper() { // Fetch and set full-screen image as wallpaper on background thread. final Context context = getActivity(); final String imageUrl = image.fileUrl; final WallpaperManager wallpaperManager = WallpaperManager.getInstance(getActivity()); new AsyncTask<Void, Void, Exception>() { @Override protected Exception doInBackground(Void... ignored) { try { InputStream inputStream = new URL(imageUrl).openStream(); wallpaperManager.setStream(inputStream); } catch (IOException e) { return e; } return null; } @Override protected void onPostExecute(Exception error) { if (error != null) { // Show error message to the user. Toast.makeText(context, String.format(context.getString(R.string.toast_couldNotSetWallpaper), error.getLocalizedMessage()), Toast.LENGTH_LONG).show(); } } }.execute(); } public static interface ImageFragmentListener { /** * Should return the {@link SearchClient.Settings} object with the same settings used to fetch the image displayed by this fragment. */ public SearchClient.Settings getSearchClientSettings(); } }