Java tutorial
package edu.mit.mobile.android.livingpostcards; /* * Copyright (C) 2012-2013 MIT Mobile Experience Lab * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation version 2 * of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ import android.annotation.TargetApi; import android.app.AlertDialog; import android.app.Dialog; import android.content.ContentValues; import android.content.DialogInterface; import android.content.Intent; import android.content.SharedPreferences; import android.content.SharedPreferences.Editor; import android.database.Cursor; import android.net.Uri; import android.os.AsyncTask; import android.os.Build; import android.os.Bundle; import android.preference.PreferenceManager; import android.support.v4.app.DialogFragment; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentTransaction; import android.support.v4.app.LoaderManager.LoaderCallbacks; import android.support.v4.app.NavUtils; import android.support.v4.content.CursorLoader; import android.support.v4.content.Loader; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.EditText; import android.widget.Toast; import com.actionbarsherlock.ActionBarSherlock; import com.actionbarsherlock.ActionBarSherlock.OnCreateOptionsMenuListener; import com.actionbarsherlock.ActionBarSherlock.OnOptionsItemSelectedListener; import com.actionbarsherlock.ActionBarSherlock.OnPrepareOptionsMenuListener; import com.actionbarsherlock.app.ActionBar; import com.actionbarsherlock.view.Menu; import com.actionbarsherlock.view.MenuItem; import edu.mit.mobile.android.flipr.R; import edu.mit.mobile.android.livingpostcards.DeleteDialogFragment.OnDeleteListener; import edu.mit.mobile.android.livingpostcards.auth.Authenticator; import edu.mit.mobile.android.livingpostcards.data.Card; import edu.mit.mobile.android.livingpostcards.data.CardMedia; import edu.mit.mobile.android.locast.Constants; import edu.mit.mobile.android.locast.data.JsonSyncableItem; import edu.mit.mobile.android.locast.data.PrivatelyAuthorable; import edu.mit.mobile.android.locast.sync.LocastSyncService; public class CardEditActivity extends FragmentActivity implements OnCreateOptionsMenuListener, OnOptionsItemSelectedListener, LoaderCallbacks<Cursor>, OnPrepareOptionsMenuListener, OnDeleteListener, OnClickListener { private static final String[] CARD_PROJECTION = new String[] { Card._ID, Card.COL_TITLE, Card.COL_DESCRIPTION, Card.COL_DRAFT, Card.COL_TIMING, Card.COL_AUTHOR_URI, Card.COL_PRIVACY }; private static final String TAG = CardEditActivity.class.getSimpleName(); public static final String PREF_DIALOG_COLLABORATIVE_SEEN = "CardEditActivity.DIALOG_COLLABORATIVE_SEEN"; private static final String TAG_DELETE_DIALOG = "delete-dialog"; private static final String TAG_DIALOG_COLLABORATIVE = "dialog-collaborative"; private Uri mCard; private CardMediaEditFragment mCardViewFragment; private final ActionBarSherlock mSherlock = ActionBarSherlock.wrap(this); private String mUserUri; private boolean mIsEditable; private boolean mIsDraft; private EditText mTitle; private EditText mDescription; private final SetCollabDescDialogFragment.OnMarkCollaborativeListener mOnMarkCollabListener = new SetCollabDescDialogFragment.OnMarkCollaborativeListener() { @TargetApi(Build.VERSION_CODES.GINGERBREAD) @Override public void onMarkCollaborative() { final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(CardEditActivity.this); final boolean neverShowAgain = false; if (neverShowAgain) { final Editor e = prefs.edit().putBoolean(PREF_DIALOG_COLLABORATIVE_SEEN, true); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) { e.apply(); // this was introduced in Gingerbread } else { e.commit(); } } setCollaborative(true); } }; private boolean mIsOwner; private boolean mIsCollaborative; private boolean mSaveOnPause = false; @Override protected void onCreate(Bundle arg0) { super.onCreate(arg0); mSherlock.setContentView(R.layout.activity_card_edit); final ActionBar ab = mSherlock.getActionBar(); ab.setDisplayHomeAsUpEnabled(true); mTitle = (EditText) findViewById(R.id.title); mDescription = (EditText) findViewById(R.id.description); final View addFrame = findViewById(R.id.add_frame); addFrame.setOnClickListener(this); mCard = getIntent().getData(); final String action = getIntent().getAction(); final FragmentManager fm = getSupportFragmentManager(); if (Intent.ACTION_EDIT.equals(action) || Intent.ACTION_DELETE.equals(action)) { final FragmentTransaction ft = fm.beginTransaction(); final Fragment f = fm.findFragmentById(R.id.card_edit_fragment); if (f != null) { mCardViewFragment = (CardMediaEditFragment) f; } else { mCardViewFragment = CardMediaEditFragment.newInstance(Card.MEDIA.getUri(mCard)); ft.replace(R.id.card_edit_fragment, mCardViewFragment); } // if the dialog has been automatically restored by the system, hook it in. final SetCollabDescDialogFragment collab = (SetCollabDescDialogFragment) fm .findFragmentByTag(TAG_DIALOG_COLLABORATIVE); if (collab != null) { collab.setOnMarkCollaborativeListener(mOnMarkCollabListener); } mUserUri = Authenticator.getUserUri(this, Authenticator.ACCOUNT_TYPE); getSupportLoaderManager().initLoader(0, null, this); // if this isn't null, it was saved automatically for us. So hook it back in. final DeleteDialogFragment deleteDialog = (DeleteDialogFragment) fm .findFragmentByTag(TAG_DELETE_DIALOG); if (deleteDialog != null) { deleteDialog.registerOnDeleteListener(this); } else if (Intent.ACTION_DELETE.equals(action)) { onDeletePostcard(); } ft.commit(); } } private void onDeletePostcard() { final DeleteDialogFragment del = DeleteDialogFragment.newInstance(mCard, getText(R.string.delete_postcard), getText(R.string.postcard_edit_delete_confirm_message)); del.registerOnDeleteListener(this); del.show(getSupportFragmentManager(), TAG_DELETE_DIALOG); } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.publish: onPublish(); return true; case R.id.save: onSave(); return true; case R.id.delete: onDeletePostcard(); return true; case android.R.id.home: { final Intent i = new Intent(Intent.ACTION_VIEW, mCard); NavUtils.navigateUpTo(this, i); } return true; case R.id.add_frame: // this is conceptually starting it for a result, but the result isn't actually // used. startActivityForResult(new Intent(CameraActivity.ACTION_ADD_PHOTO, mCard), 0); return true; case R.id.make_collaborative: onMakeCollaborative(); return true; case R.id.make_personal: onMakePersonal(); return true; default: return false; } } /** * Queries the card media to determine if the card media have any contributors other than the * owner of the card. * * @param card * @return */ private boolean hasNonOwnerContributors(Uri card) { boolean hasNonOwnerContributors = false; final String myAuthorUri = Authenticator.getUserUri(this); final String[] proj = new String[] { CardMedia.COL_AUTHOR_URI }; final Cursor media = Card.MEDIA.query(getContentResolver(), card, proj); final int cardMediaAuthorCol = media.getColumnIndexOrThrow(CardMedia.COL_AUTHOR_URI); try { for (media.moveToFirst(); !hasNonOwnerContributors && !media.isAfterLast(); media.moveToNext()) { final String cardAuthor = media.getString(cardMediaAuthorCol); hasNonOwnerContributors |= !myAuthorUri.equals(cardAuthor); } } finally { media.close(); } return hasNonOwnerContributors; } public static class SetCollabDescDialogFragment extends DialogFragment implements DialogInterface.OnClickListener { public interface OnMarkCollaborativeListener { public void onMarkCollaborative(); } private OnMarkCollaborativeListener mListener; public void setOnMarkCollaborativeListener(OnMarkCollaborativeListener l) { mListener = l; } @Override public Dialog onCreateDialog(Bundle savedInstanceState) { return new AlertDialog.Builder(getActivity()).setIcon(R.drawable.ic_launcher) .setTitle(R.string.make_collaborative).setPositiveButton(R.string.make_collaborative, this) .setMessage(R.string.make_collaborative_feature_description) .setNegativeButton(android.R.string.cancel, this).setCancelable(true).create(); } @Override public void onDestroy() { super.onDestroy(); mListener = null; } @Override public void onClick(DialogInterface dialog, int which) { switch (which) { case DialogInterface.BUTTON_POSITIVE: mListener.onMarkCollaborative(); break; case DialogInterface.BUTTON_NEGATIVE: dismiss(); break; } } } private void setCollaborative(boolean collaborative) { final boolean success = Card.setCollaborative(getContentResolver(), mCard, collaborative); if (success) { if (Constants.DEBUG) { Log.d(TAG, mCard + " saved successfully."); } LocastSyncService.startSync(this, mCard, true); } } private void onMakeCollaborative() { if (mIsCollaborative) { return; } final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this); final boolean dialogSeen = prefs.getBoolean(PREF_DIALOG_COLLABORATIVE_SEEN, false); if (!dialogSeen) { final SetCollabDescDialogFragment df = new SetCollabDescDialogFragment(); df.setOnMarkCollaborativeListener(mOnMarkCollabListener); df.show(getSupportFragmentManager(), TAG_DIALOG_COLLABORATIVE); } else { setCollaborative(true); Toast.makeText(this, R.string.notice_make_collaborative_success, Toast.LENGTH_SHORT).show(); } } private void onMakePersonal() { if (!mIsCollaborative) { return; } new AsyncTask<Uri, Void, Boolean>() { @Override protected Boolean doInBackground(Uri... params) { boolean madePersonal = false; if (!hasNonOwnerContributors(mCard)) { madePersonal = Card.setCollaborative(getContentResolver(), mCard, false); } return madePersonal; } @Override protected void onPostExecute(Boolean result) { if (result) { Toast.makeText(CardEditActivity.this, R.string.notice_make_card_personal_success, Toast.LENGTH_SHORT).show(); } else { Toast.makeText(CardEditActivity.this, R.string.notice_cannot_make_card_personal, Toast.LENGTH_LONG).show(); } } }.execute(mCard); } private boolean validate() { if (mTitle.length() == 0) { mTitle.setError(getString(R.string.postcard_edit_title_empty)); mTitle.requestFocus(); return false; } return true; } @Override protected void onPause() { super.onPause(); if (mSaveOnPause) { save(); } } /** * Saves the card without any validation. * * @return true if save was successful. */ private boolean save() { final ContentValues cv = new ContentValues(); cv.put(Card.COL_DRAFT, mIsDraft); cv.put(Card.COL_TITLE, mTitle.getText().toString()); cv.put(Card.COL_DESCRIPTION, mDescription.getText().toString()); cv.put(Card.COL_TIMING, mCardViewFragment.getAnimationTiming()); final int updated = getContentResolver().update(mCard, cv, null, null); final boolean success = updated == 1; if (success) { if (Constants.DEBUG) { Log.d(TAG, mCard + " saved successfully."); } LocastSyncService.startSync(this, mCard, true); } return success; } private void onSave() { if (!validate()) { return; } if (save()) { finish(); } else { Toast.makeText(this, R.string.err_publish_fail, Toast.LENGTH_LONG).show(); } } protected void onPublish() { if (!validate()) { return; } mIsDraft = false; if (save()) { LocastSyncService.startSync(this, mCard, true); finish(); Toast.makeText(this, R.string.notice_publish_success, Toast.LENGTH_LONG).show(); } else { Toast.makeText(this, R.string.err_publish_fail, Toast.LENGTH_LONG).show(); } } @Override public boolean onCreateOptionsMenu(Menu menu) { mSherlock.getMenuInflater().inflate(R.menu.activity_card_edit, menu); return true; } @Override public boolean onPrepareOptionsMenu(android.view.Menu menu) { return mSherlock.dispatchPrepareOptionsMenu(menu); } @Override public boolean onPrepareOptionsMenu(Menu menu) { // only the owner can do the following. menu.findItem(R.id.delete).setVisible(mIsOwner); menu.findItem(R.id.delete_photos).setVisible(mIsOwner); menu.findItem(R.id.publish).setVisible(mIsOwner && mIsDraft); menu.findItem(R.id.save).setVisible(mIsOwner && !mIsDraft); final MenuItem makeCollab = menu.findItem(R.id.make_collaborative); makeCollab.setVisible(mIsOwner && !mIsCollaborative); final MenuItem makePersonal = menu.findItem(R.id.make_personal); makePersonal.setVisible(mIsOwner && mIsCollaborative); return true; } @Override public boolean onCreateOptionsMenu(android.view.Menu menu) { return mSherlock.dispatchCreateOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(android.view.MenuItem item) { return mSherlock.dispatchOptionsItemSelected(item); } @Override public Loader<Cursor> onCreateLoader(int arg0, Bundle arg1) { return new CursorLoader(this, mCard, CARD_PROJECTION, null, null, null); } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor c) { if (c.moveToFirst()) { mTitle.setText(c.getString(c.getColumnIndex(Card.COL_TITLE))); mDescription.setText(c.getString(c.getColumnIndex(Card.COL_DESCRIPTION))); mIsEditable = PrivatelyAuthorable.canEdit(mUserUri, c); findViewById(R.id.add_frame).setVisibility(mIsEditable ? View.VISIBLE : View.GONE); mIsOwner = mUserUri.equals(c.getString(c.getColumnIndexOrThrow(Card.COL_AUTHOR_URI))); final String privacy = c.getString(c.getColumnIndexOrThrow(Card.COL_PRIVACY)); mIsCollaborative = Card.PRIVACY_PUBLIC.equals(privacy); mTitle.setEnabled(mIsEditable && mIsOwner); mDescription.setEnabled(mIsEditable && mIsOwner); mIsDraft = JsonSyncableItem.isDraft(c); mSherlock.dispatchInvalidateOptionsMenu(); final int timing = c.getInt(c.getColumnIndexOrThrow(Card.COL_TIMING)); mCardViewFragment.setAnimationTiming(timing); mSaveOnPause = true; } else { mSaveOnPause = false; finish(); } } @Override public void onLoaderReset(Loader<Cursor> arg0) { mSaveOnPause = false; } @Override public void onDelete(Uri item, boolean deleted) { if (mCard.equals(item) && deleted) { mSaveOnPause = false; setResult(RESULT_OK); // no need to call finish, as the loader will automatically reload, which will result in // no data being loaded, which will then call finish() } else if (Intent.ACTION_DELETE.equals(getIntent().getAction()) && !deleted) { setResult(RESULT_CANCELED); finish(); } } @Override public void onClick(View v) { switch (v.getId()) { case R.id.add_frame: // this is conceptually starting it for a result, but the result isn't actually // used. startActivityForResult(new Intent(CameraActivity.ACTION_ADD_PHOTO, mCard), 0); break; default: break; } } }