XmppActivity.java

  1package eu.siacs.conversations.ui;
  2
  3import android.annotation.SuppressLint;
  4import android.app.Activity;
  5import android.app.AlertDialog;
  6import android.app.AlertDialog.Builder;
  7import android.app.PendingIntent;
  8import android.content.ClipData;
  9import android.content.ClipboardManager;
 10import android.content.ComponentName;
 11import android.content.Context;
 12import android.content.DialogInterface;
 13import android.content.DialogInterface.OnClickListener;
 14import android.content.Intent;
 15import android.content.IntentSender.SendIntentException;
 16import android.content.ServiceConnection;
 17import android.content.SharedPreferences;
 18import android.content.pm.PackageManager;
 19import android.content.pm.ResolveInfo;
 20import android.content.res.Resources;
 21import android.graphics.Bitmap;
 22import android.graphics.Color;
 23import android.graphics.Point;
 24import android.graphics.drawable.BitmapDrawable;
 25import android.graphics.drawable.Drawable;
 26import android.net.Uri;
 27import android.nfc.NdefMessage;
 28import android.nfc.NdefRecord;
 29import android.nfc.NfcAdapter;
 30import android.nfc.NfcEvent;
 31import android.os.AsyncTask;
 32import android.os.Bundle;
 33import android.os.IBinder;
 34import android.preference.PreferenceManager;
 35import android.text.InputType;
 36import android.util.DisplayMetrics;
 37import android.util.Log;
 38import android.view.MenuItem;
 39import android.view.View;
 40import android.view.inputmethod.InputMethodManager;
 41import android.widget.EditText;
 42import android.widget.ImageView;
 43
 44import com.google.zxing.BarcodeFormat;
 45import com.google.zxing.EncodeHintType;
 46import com.google.zxing.WriterException;
 47import com.google.zxing.common.BitMatrix;
 48import com.google.zxing.qrcode.QRCodeWriter;
 49import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
 50
 51import net.java.otr4j.session.SessionID;
 52
 53import java.io.FileNotFoundException;
 54import java.lang.ref.WeakReference;
 55import java.util.Hashtable;
 56import java.util.List;
 57import java.util.concurrent.RejectedExecutionException;
 58
 59import eu.siacs.conversations.Config;
 60import eu.siacs.conversations.R;
 61import eu.siacs.conversations.entities.Account;
 62import eu.siacs.conversations.entities.Contact;
 63import eu.siacs.conversations.entities.Conversation;
 64import eu.siacs.conversations.entities.Message;
 65import eu.siacs.conversations.entities.Presences;
 66import eu.siacs.conversations.services.AvatarService;
 67import eu.siacs.conversations.services.XmppConnectionService;
 68import eu.siacs.conversations.services.XmppConnectionService.XmppConnectionBinder;
 69import eu.siacs.conversations.utils.ExceptionHelper;
 70import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 71import eu.siacs.conversations.xmpp.jid.Jid;
 72
 73public abstract class XmppActivity extends Activity {
 74
 75	protected static final int REQUEST_ANNOUNCE_PGP = 0x0101;
 76	protected static final int REQUEST_INVITE_TO_CONVERSATION = 0x0102;
 77
 78	public XmppConnectionService xmppConnectionService;
 79	public boolean xmppConnectionServiceBound = false;
 80
 81	protected int mPrimaryTextColor;
 82	protected int mSecondaryTextColor;
 83	protected int mSecondaryBackgroundColor;
 84	protected int mColorRed;
 85	protected int mColorOrange;
 86	protected int mColorGreen;
 87	protected int mPrimaryColor;
 88
 89	protected boolean mUseSubject = true;
 90
 91	private DisplayMetrics metrics;
 92
 93	protected interface OnValueEdited {
 94		public void onValueEdited(String value);
 95	}
 96
 97	public interface OnPresenceSelected {
 98		public void onPresenceSelected();
 99	}
100
101	protected ServiceConnection mConnection = new ServiceConnection() {
102
103		@Override
104		public void onServiceConnected(ComponentName className, IBinder service) {
105			XmppConnectionBinder binder = (XmppConnectionBinder) service;
106			xmppConnectionService = binder.getService();
107			xmppConnectionServiceBound = true;
108			onBackendConnected();
109		}
110
111		@Override
112		public void onServiceDisconnected(ComponentName arg0) {
113			xmppConnectionServiceBound = false;
114		}
115	};
116
117	@Override
118	protected void onStart() {
119		super.onStart();
120		if (!xmppConnectionServiceBound) {
121			connectToBackend();
122		}
123	}
124
125	public void connectToBackend() {
126		Intent intent = new Intent(this, XmppConnectionService.class);
127		intent.setAction("ui");
128		startService(intent);
129		bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
130	}
131
132	@Override
133	protected void onStop() {
134		super.onStop();
135		if (xmppConnectionServiceBound) {
136			unbindService(mConnection);
137			xmppConnectionServiceBound = false;
138		}
139	}
140
141	protected void hideKeyboard() {
142		InputMethodManager inputManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
143
144		View focus = getCurrentFocus();
145
146		if (focus != null) {
147
148			inputManager.hideSoftInputFromWindow(focus.getWindowToken(),
149					InputMethodManager.HIDE_NOT_ALWAYS);
150		}
151	}
152
153	public boolean hasPgp() {
154		return xmppConnectionService.getPgpEngine() != null;
155	}
156
157	public void showInstallPgpDialog() {
158		Builder builder = new AlertDialog.Builder(this);
159		builder.setTitle(getString(R.string.openkeychain_required));
160		builder.setIconAttribute(android.R.attr.alertDialogIcon);
161		builder.setMessage(getText(R.string.openkeychain_required_long));
162		builder.setNegativeButton(getString(R.string.cancel), null);
163		builder.setNeutralButton(getString(R.string.restart),
164				new OnClickListener() {
165
166					@Override
167					public void onClick(DialogInterface dialog, int which) {
168						if (xmppConnectionServiceBound) {
169							unbindService(mConnection);
170							xmppConnectionServiceBound = false;
171						}
172						stopService(new Intent(XmppActivity.this,
173								XmppConnectionService.class));
174						finish();
175					}
176				});
177		builder.setPositiveButton(getString(R.string.install),
178				new OnClickListener() {
179
180					@Override
181					public void onClick(DialogInterface dialog, int which) {
182						Uri uri = Uri
183								.parse("market://details?id=org.sufficientlysecure.keychain");
184						Intent marketIntent = new Intent(Intent.ACTION_VIEW,
185								uri);
186						PackageManager manager = getApplicationContext()
187								.getPackageManager();
188						List<ResolveInfo> infos = manager
189								.queryIntentActivities(marketIntent, 0);
190						if (infos.size() > 0) {
191							startActivity(marketIntent);
192						} else {
193							uri = Uri.parse("http://www.openkeychain.org/");
194							Intent browserIntent = new Intent(
195									Intent.ACTION_VIEW, uri);
196							startActivity(browserIntent);
197						}
198						finish();
199					}
200				});
201		builder.create().show();
202	}
203
204	abstract void onBackendConnected();
205
206	public boolean onOptionsItemSelected(MenuItem item) {
207		switch (item.getItemId()) {
208			case R.id.action_settings:
209				startActivity(new Intent(this, SettingsActivity.class));
210				break;
211			case R.id.action_accounts:
212				startActivity(new Intent(this, ManageAccountActivity.class));
213				break;
214			case android.R.id.home:
215				finish();
216				break;
217			case R.id.action_show_qr_code:
218				showQrCode();
219				break;
220		}
221		return super.onOptionsItemSelected(item);
222	}
223
224	@Override
225	protected void onCreate(Bundle savedInstanceState) {
226		super.onCreate(savedInstanceState);
227		metrics = getResources().getDisplayMetrics();
228		ExceptionHelper.init(getApplicationContext());
229		mPrimaryTextColor = getResources().getColor(R.color.primarytext);
230		mSecondaryTextColor = getResources().getColor(R.color.secondarytext);
231		mColorRed = getResources().getColor(R.color.red);
232		mColorOrange = getResources().getColor(R.color.orange);
233		mColorGreen = getResources().getColor(R.color.green);
234		mPrimaryColor = getResources().getColor(R.color.primary);
235		mSecondaryBackgroundColor = getResources().getColor(
236				R.color.secondarybackground);
237		if (getPreferences().getBoolean("use_larger_font", false)) {
238			setTheme(R.style.ConversationsTheme_LargerText);
239		}
240		mUseSubject = getPreferences().getBoolean("use_subject", true);
241	}
242
243	protected SharedPreferences getPreferences() {
244		return PreferenceManager
245				.getDefaultSharedPreferences(getApplicationContext());
246	}
247
248	public boolean useSubjectToIdentifyConference() {
249		return mUseSubject;
250	}
251
252	public void switchToConversation(Conversation conversation) {
253		switchToConversation(conversation, null, false);
254	}
255
256	public void switchToConversation(Conversation conversation, String text,
257									 boolean newTask) {
258		Intent viewConversationIntent = new Intent(this,
259				ConversationActivity.class);
260		viewConversationIntent.setAction(Intent.ACTION_VIEW);
261		viewConversationIntent.putExtra(ConversationActivity.CONVERSATION,
262				conversation.getUuid());
263		if (text != null) {
264			viewConversationIntent.putExtra(ConversationActivity.TEXT, text);
265		}
266		viewConversationIntent.setType(ConversationActivity.VIEW_CONVERSATION);
267		if (newTask) {
268			viewConversationIntent.setFlags(viewConversationIntent.getFlags()
269					| Intent.FLAG_ACTIVITY_NEW_TASK
270					| Intent.FLAG_ACTIVITY_SINGLE_TOP);
271		} else {
272			viewConversationIntent.setFlags(viewConversationIntent.getFlags()
273					| Intent.FLAG_ACTIVITY_CLEAR_TOP);
274		}
275		startActivity(viewConversationIntent);
276		finish();
277	}
278
279	public void switchToContactDetails(Contact contact) {
280		Intent intent = new Intent(this, ContactDetailsActivity.class);
281		intent.setAction(ContactDetailsActivity.ACTION_VIEW_CONTACT);
282		intent.putExtra("account", contact.getAccount().getJid().toBareJid().toString());
283		intent.putExtra("contact", contact.getJid().toString());
284		startActivity(intent);
285	}
286
287	public void switchToAccount(Account account) {
288		Intent intent = new Intent(this, EditAccountActivity.class);
289		intent.putExtra("jid", account.getJid().toBareJid().toString());
290		startActivity(intent);
291	}
292
293	protected void inviteToConversation(Conversation conversation) {
294		Intent intent = new Intent(getApplicationContext(),
295				ChooseContactActivity.class);
296		intent.putExtra("conversation", conversation.getUuid());
297		startActivityForResult(intent, REQUEST_INVITE_TO_CONVERSATION);
298	}
299
300	protected void announcePgp(Account account, final Conversation conversation) {
301		xmppConnectionService.getPgpEngine().generateSignature(account,
302				"online", new UiCallback<Account>() {
303
304					@Override
305					public void userInputRequried(PendingIntent pi,
306												  Account account) {
307						try {
308							startIntentSenderForResult(pi.getIntentSender(),
309									REQUEST_ANNOUNCE_PGP, null, 0, 0, 0);
310						} catch (final SendIntentException ignored) {
311						}
312					}
313
314					@Override
315					public void success(Account account) {
316						xmppConnectionService.databaseBackend
317								.updateAccount(account);
318						xmppConnectionService.sendPresencePacket(account,
319								xmppConnectionService.getPresenceGenerator()
320										.sendPresence(account));
321						if (conversation != null) {
322							conversation
323									.setNextEncryption(Message.ENCRYPTION_PGP);
324							xmppConnectionService.databaseBackend
325									.updateConversation(conversation);
326						}
327					}
328
329					@Override
330					public void error(int error, Account account) {
331						displayErrorDialog(error);
332					}
333				});
334	}
335
336	protected void displayErrorDialog(final int errorCode) {
337		runOnUiThread(new Runnable() {
338
339			@Override
340			public void run() {
341				AlertDialog.Builder builder = new AlertDialog.Builder(
342						XmppActivity.this);
343				builder.setIconAttribute(android.R.attr.alertDialogIcon);
344				builder.setTitle(getString(R.string.error));
345				builder.setMessage(errorCode);
346				builder.setNeutralButton(R.string.accept, null);
347				builder.create().show();
348			}
349		});
350
351	}
352
353	protected void showAddToRosterDialog(final Conversation conversation) {
354		final Jid jid = conversation.getContactJid();
355		AlertDialog.Builder builder = new AlertDialog.Builder(this);
356		builder.setTitle(jid.toString());
357		builder.setMessage(getString(R.string.not_in_roster));
358		builder.setNegativeButton(getString(R.string.cancel), null);
359		builder.setPositiveButton(getString(R.string.add_contact),
360				new DialogInterface.OnClickListener() {
361
362					@Override
363					public void onClick(DialogInterface dialog, int which) {
364						final Jid jid = conversation.getContactJid();
365						Account account = conversation.getAccount();
366						Contact contact = account.getRoster().getContact(jid);
367						xmppConnectionService.createContact(contact);
368						switchToContactDetails(contact);
369					}
370				});
371		builder.create().show();
372	}
373
374	private void showAskForPresenceDialog(final Contact contact) {
375		AlertDialog.Builder builder = new AlertDialog.Builder(this);
376		builder.setTitle(contact.getJid().toString());
377		builder.setMessage(R.string.request_presence_updates);
378		builder.setNegativeButton(R.string.cancel, null);
379		builder.setPositiveButton(R.string.request_now,
380				new DialogInterface.OnClickListener() {
381
382					@Override
383					public void onClick(DialogInterface dialog, int which) {
384						if (xmppConnectionServiceBound) {
385							xmppConnectionService.sendPresencePacket(contact
386									.getAccount(), xmppConnectionService
387									.getPresenceGenerator()
388									.requestPresenceUpdatesFrom(contact));
389						}
390					}
391				});
392		builder.create().show();
393	}
394
395	private void warnMutalPresenceSubscription(final Conversation conversation,
396											   final OnPresenceSelected listener) {
397		AlertDialog.Builder builder = new AlertDialog.Builder(this);
398		builder.setTitle(conversation.getContact().getJid().toString());
399		builder.setMessage(R.string.without_mutual_presence_updates);
400		builder.setNegativeButton(R.string.cancel, null);
401		builder.setPositiveButton(R.string.ignore, new OnClickListener() {
402
403			@Override
404			public void onClick(DialogInterface dialog, int which) {
405				conversation.setNextCounterpart(null);
406				if (listener != null) {
407					listener.onPresenceSelected();
408				}
409			}
410		});
411		builder.create().show();
412	}
413
414	protected void quickEdit(String previousValue, OnValueEdited callback) {
415		quickEdit(previousValue, callback, false);
416	}
417
418	protected void quickPasswordEdit(String previousValue,
419									 OnValueEdited callback) {
420		quickEdit(previousValue, callback, true);
421	}
422
423	@SuppressLint("InflateParams")
424	private void quickEdit(final String previousValue,
425						   final OnValueEdited callback, boolean password) {
426		AlertDialog.Builder builder = new AlertDialog.Builder(this);
427		View view = getLayoutInflater().inflate(R.layout.quickedit, null);
428		final EditText editor = (EditText) view.findViewById(R.id.editor);
429		OnClickListener mClickListener = new OnClickListener() {
430
431			@Override
432			public void onClick(DialogInterface dialog, int which) {
433				String value = editor.getText().toString();
434				if (!previousValue.equals(value) && value.trim().length() > 0) {
435					callback.onValueEdited(value);
436				}
437			}
438		};
439		if (password) {
440			editor.setInputType(InputType.TYPE_CLASS_TEXT
441					| InputType.TYPE_TEXT_VARIATION_PASSWORD);
442			editor.setHint(R.string.password);
443			builder.setPositiveButton(R.string.accept, mClickListener);
444		} else {
445			builder.setPositiveButton(R.string.edit, mClickListener);
446		}
447		editor.requestFocus();
448		editor.setText(previousValue);
449		builder.setView(view);
450		builder.setNegativeButton(R.string.cancel, null);
451		builder.create().show();
452	}
453
454	public void selectPresence(final Conversation conversation,
455							   final OnPresenceSelected listener) {
456		final Contact contact = conversation.getContact();
457		if (conversation.hasValidOtrSession()) {
458			SessionID id = conversation.getOtrSession().getSessionID();
459			Jid jid;
460			try {
461				jid = Jid.fromString(id.getAccountID() + "/" + id.getUserID());
462			} catch (InvalidJidException e) {
463				jid = null;
464			}
465			conversation.setNextCounterpart(jid);
466			listener.onPresenceSelected();
467		} else 	if (!contact.showInRoster()) {
468			showAddToRosterDialog(conversation);
469		} else {
470			Presences presences = contact.getPresences();
471			if (presences.size() == 0) {
472				if (!contact.getOption(Contact.Options.TO)
473						&& !contact.getOption(Contact.Options.ASKING)
474						&& contact.getAccount().getStatus() == Account.STATUS_ONLINE) {
475					showAskForPresenceDialog(contact);
476				} else if (!contact.getOption(Contact.Options.TO)
477						|| !contact.getOption(Contact.Options.FROM)) {
478					warnMutalPresenceSubscription(conversation, listener);
479				} else {
480					conversation.setNextCounterpart(null);
481					listener.onPresenceSelected();
482				}
483			} else if (presences.size() == 1) {
484				String presence = presences.asStringArray()[0];
485				try {
486					conversation.setNextCounterpart(Jid.fromParts(contact.getJid().getLocalpart(),contact.getJid().getDomainpart(),presence));
487				} catch (InvalidJidException e) {
488					conversation.setNextCounterpart(null);
489				}
490				listener.onPresenceSelected();
491			} else {
492				final StringBuilder presence = new StringBuilder();
493				AlertDialog.Builder builder = new AlertDialog.Builder(this);
494				builder.setTitle(getString(R.string.choose_presence));
495				final String[] presencesArray = presences.asStringArray();
496				int preselectedPresence = 0;
497				for (int i = 0; i < presencesArray.length; ++i) {
498					if (presencesArray[i].equals(contact.lastseen.presence)) {
499						preselectedPresence = i;
500						break;
501					}
502				}
503				presence.append(presencesArray[preselectedPresence]);
504				builder.setSingleChoiceItems(presencesArray,
505						preselectedPresence,
506						new DialogInterface.OnClickListener() {
507
508							@Override
509							public void onClick(DialogInterface dialog,
510												int which) {
511								presence.delete(0, presence.length());
512								presence.append(presencesArray[which]);
513							}
514						});
515				builder.setNegativeButton(R.string.cancel, null);
516				builder.setPositiveButton(R.string.ok, new OnClickListener() {
517
518					@Override
519					public void onClick(DialogInterface dialog, int which) {
520						try {
521							conversation.setNextCounterpart(Jid.fromParts(contact.getJid().getLocalpart(),contact.getJid().getDomainpart(),presence.toString()));
522						} catch (InvalidJidException e) {
523							conversation.setNextCounterpart(null);
524						}
525						listener.onPresenceSelected();
526					}
527				});
528				builder.create().show();
529			}
530		}
531	}
532
533	protected void onActivityResult(int requestCode, int resultCode,
534									final Intent data) {
535		super.onActivityResult(requestCode, resultCode, data);
536		if (requestCode == REQUEST_INVITE_TO_CONVERSATION
537				&& resultCode == RESULT_OK) {
538			String contactJid = data.getStringExtra("contact");
539			String conversationUuid = data.getStringExtra("conversation");
540			Conversation conversation = xmppConnectionService
541					.findConversationByUuid(conversationUuid);
542			if (conversation.getMode() == Conversation.MODE_MULTI) {
543				xmppConnectionService.invite(conversation, contactJid);
544			}
545			Log.d(Config.LOGTAG, "inviting " + contactJid + " to "
546					+ conversation.getName());
547		}
548	}
549
550	public int getSecondaryTextColor() {
551		return this.mSecondaryTextColor;
552	}
553
554	public int getPrimaryTextColor() {
555		return this.mPrimaryTextColor;
556	}
557
558	public int getWarningTextColor() {
559		return this.mColorRed;
560	}
561
562	public int getPrimaryColor() {
563		return this.mPrimaryColor;
564	}
565
566	public int getSecondaryBackgroundColor() {
567		return this.mSecondaryBackgroundColor;
568	}
569
570	public int getPixel(int dp) {
571		DisplayMetrics metrics = getResources().getDisplayMetrics();
572		return ((int) (dp * metrics.density));
573	}
574
575	public boolean copyTextToClipboard(String text, int labelResId) {
576		ClipboardManager mClipBoardManager = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
577		String label = getResources().getString(labelResId);
578		if (mClipBoardManager != null) {
579			ClipData mClipData = ClipData.newPlainText(label, text);
580			mClipBoardManager.setPrimaryClip(mClipData);
581			return true;
582		}
583		return false;
584	}
585
586	protected void registerNdefPushMessageCallback() {
587			NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
588			if (nfcAdapter != null && nfcAdapter.isEnabled()) {
589				nfcAdapter.setNdefPushMessageCallback(new NfcAdapter.CreateNdefMessageCallback() {
590					@Override
591					public NdefMessage createNdefMessage(NfcEvent nfcEvent) {
592                        return new NdefMessage(new NdefRecord[]{
593                                NdefRecord.createUri(getShareableUri()),
594                                NdefRecord.createApplicationRecord("eu.siacs.conversations")
595                        });
596					}
597				}, this);
598			}
599	}
600
601	protected void unregisterNdefPushMessageCallback() {
602		NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
603		if (nfcAdapter != null && nfcAdapter.isEnabled()) {
604			nfcAdapter.setNdefPushMessageCallback(null,this);
605		}
606	}
607
608	protected String getShareableUri() {
609		return null;
610	}
611
612	@Override
613	public void onResume() {
614		super.onResume();
615		if (this.getShareableUri()!=null) {
616			this.registerNdefPushMessageCallback();
617		}
618	}
619
620	@Override
621	public void onPause() {
622		super.onPause();
623		this.unregisterNdefPushMessageCallback();
624	}
625
626	protected void showQrCode() {
627		String uri = getShareableUri();
628		if (uri!=null) {
629			Point size = new Point();
630			getWindowManager().getDefaultDisplay().getSize(size);
631			final int width = (size.x < size.y ? size.x : size.y);
632			Bitmap bitmap = createQrCodeBitmap(uri, width);
633			ImageView view = new ImageView(this);
634			view.setImageBitmap(bitmap);
635			AlertDialog.Builder builder = new AlertDialog.Builder(this);
636			builder.setView(view);
637			builder.create().show();
638		}
639	}
640
641	protected Bitmap createQrCodeBitmap(String input, int size) {
642		try {
643			final QRCodeWriter QR_CODE_WRITER = new QRCodeWriter();
644			final Hashtable<EncodeHintType, Object> hints = new Hashtable<>();
645			hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
646			final BitMatrix result = QR_CODE_WRITER.encode(input, BarcodeFormat.QR_CODE, size, size, hints);
647			final int width = result.getWidth();
648			final int height = result.getHeight();
649			final int[] pixels = new int[width * height];
650			for (int y = 0; y < height; y++) {
651				final int offset = y * width;
652				for (int x = 0; x < width; x++) {
653					pixels[offset + x] = result.get(x, y) ? Color.BLACK : Color.TRANSPARENT;
654				}
655			}
656			final Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
657			bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
658			return bitmap;
659		} catch (final WriterException e) {
660			return null;
661		}
662	}
663
664	public AvatarService avatarService() {
665		return xmppConnectionService.getAvatarService();
666	}
667
668	class BitmapWorkerTask extends AsyncTask<Message, Void, Bitmap> {
669		private final WeakReference<ImageView> imageViewReference;
670		private Message message = null;
671
672		public BitmapWorkerTask(ImageView imageView) {
673			imageViewReference = new WeakReference<>(imageView);
674		}
675
676		@Override
677		protected Bitmap doInBackground(Message... params) {
678			message = params[0];
679			try {
680				return xmppConnectionService.getFileBackend().getThumbnail(
681						message, (int) (metrics.density * 288), false);
682			} catch (FileNotFoundException e) {
683				return null;
684			}
685		}
686
687		@Override
688		protected void onPostExecute(Bitmap bitmap) {
689			if (bitmap != null) {
690				final ImageView imageView = imageViewReference.get();
691				if (imageView != null) {
692					imageView.setImageBitmap(bitmap);
693					imageView.setBackgroundColor(0x00000000);
694				}
695			}
696		}
697	}
698
699	public void loadBitmap(Message message, ImageView imageView) {
700		Bitmap bm;
701		try {
702			bm = xmppConnectionService.getFileBackend().getThumbnail(message,
703					(int) (metrics.density * 288), true);
704		} catch (FileNotFoundException e) {
705			bm = null;
706		}
707		if (bm != null) {
708			imageView.setImageBitmap(bm);
709			imageView.setBackgroundColor(0x00000000);
710		} else {
711			if (cancelPotentialWork(message, imageView)) {
712				imageView.setBackgroundColor(0xff333333);
713				final BitmapWorkerTask task = new BitmapWorkerTask(imageView);
714				final AsyncDrawable asyncDrawable = new AsyncDrawable(
715						getResources(), null, task);
716				imageView.setImageDrawable(asyncDrawable);
717				try {
718					task.execute(message);
719				} catch (final RejectedExecutionException ignored) {
720                }
721			}
722		}
723	}
724
725	public static boolean cancelPotentialWork(Message message,
726											  ImageView imageView) {
727		final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);
728
729		if (bitmapWorkerTask != null) {
730			final Message oldMessage = bitmapWorkerTask.message;
731			if (oldMessage == null || message != oldMessage) {
732				bitmapWorkerTask.cancel(true);
733			} else {
734				return false;
735			}
736		}
737		return true;
738	}
739
740	private static BitmapWorkerTask getBitmapWorkerTask(ImageView imageView) {
741		if (imageView != null) {
742			final Drawable drawable = imageView.getDrawable();
743			if (drawable instanceof AsyncDrawable) {
744				final AsyncDrawable asyncDrawable = (AsyncDrawable) drawable;
745				return asyncDrawable.getBitmapWorkerTask();
746			}
747		}
748		return null;
749	}
750
751	static class AsyncDrawable extends BitmapDrawable {
752		private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference;
753
754		public AsyncDrawable(Resources res, Bitmap bitmap,
755							 BitmapWorkerTask bitmapWorkerTask) {
756			super(res, bitmap);
757			bitmapWorkerTaskReference = new WeakReference<>(
758					bitmapWorkerTask);
759		}
760
761		public BitmapWorkerTask getBitmapWorkerTask() {
762			return bitmapWorkerTaskReference.get();
763		}
764	}
765}