email/activity/ShortcutPickerFragment.java

/*
 * Copyright (C) 2011 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.android.email.activity;

import com.android.email.R;
import com.android.emailcommon.provider.Account;
import com.android.emailcommon.provider.EmailContent.AccountColumns;
import com.android.emailcommon.provider.EmailContent.MailboxColumns;
import com.android.emailcommon.provider.HostAuth;
import com.android.emailcommon.provider.Mailbox;

import android.app.Activity;
import android.app.FragmentTransaction;
import android.app.ListFragment;
import android.app.LoaderManager.LoaderCallbacks;
import android.content.ContentValues;
import android.content.Context;
import android.content.CursorLoader;
import android.content.Loader;
import android.content.res.Resources;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.database.MatrixCursor.RowBuilder;
import android.database.MergeCursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;

/**
 * Fragment containing a list of accounts to show during shortcut creation.
 * <p>
 * NOTE: In order to receive callbacks, the activity containing this fragment must implement
 * the {@link PickerCallback} interface.
 */
public abstract class ShortcutPickerFragment extends ListFragment
        implements OnItemClickListener, LoaderCallbacks<Cursor> {
    /** Callback methods. Enclosing activities must implement to receive fragment notifications. */
    public static interface PickerCallback {
        /** Builds a mailbox filter for the given account. See MailboxShortcutPickerFragment. */
        public Integer buildFilter(Account account);
        /** Invoked when an account and mailbox have been selected. */
        public void onSelected(Account account, long mailboxId);
        /** Required data is missing; either the account and/or mailbox */
        public void onMissingData(boolean missingAccount, boolean missingMailbox);
    }

    /** A no-op callback */
    private final PickerCallback EMPTY_CALLBACK = new PickerCallback() {
        @Override public Integer buildFilter(Account account) { return null; }
        @Override public void onSelected(Account account, long mailboxId){ getActivity().finish(); }
        @Override public void onMissingData(boolean missingAccount, boolean missingMailbox) { }
    };
    private final static int LOADER_ID = 0;
    private final static int[] TO_VIEWS = new int[] {
        android.R.id.text1,
    };

    PickerCallback mCallback = EMPTY_CALLBACK;
    /** Cursor adapter that provides either the account or mailbox list */
    private SimpleCursorAdapter mAdapter;

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        if (activity instanceof PickerCallback) {
            mCallback = (PickerCallback) activity;
        }
        final String[] fromColumns = getFromColumns();
        mAdapter = new SimpleCursorAdapter(activity,
            android.R.layout.simple_expandable_list_item_1, null, fromColumns, TO_VIEWS, 0);
        setListAdapter(mAdapter);

        getLoaderManager().initLoader(LOADER_ID, null, this);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        ListView listView = getListView();
        listView.setOnItemClickListener(this);
        listView.setItemsCanFocus(false);
    }

    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
        mAdapter.swapCursor(data);
    }

    @Override
    public void onLoaderReset(Loader<Cursor> loader) {
        mAdapter.swapCursor(null);
    }

    /** Returns the cursor columns to map into list */
    abstract String[] getFromColumns();

    // TODO if we add meta-accounts to the database, remove this class entirely
    private static final class AccountPickerLoader extends CursorLoader {
        public AccountPickerLoader(Context context, Uri uri, String[] projection, String selection,
                String[] selectionArgs, String sortOrder) {
            super(context, uri, projection, selection, selectionArgs, sortOrder);
        }

        @Override
        public Cursor loadInBackground() {
            Cursor parentCursor = super.loadInBackground();
            int cursorCount = parentCursor.getCount();
            final Cursor returnCursor;

            if (cursorCount > 1) {
                // Only add "All accounts" if there is more than 1 account defined
                MatrixCursor allAccountCursor = new MatrixCursor(getProjection());
                addCombinedAccountRow(allAccountCursor, cursorCount);
                returnCursor = new MergeCursor(new Cursor[] { allAccountCursor, parentCursor });
            } else {
                returnCursor = parentCursor;
            }
            return returnCursor;
        }

        /** Adds a row for "All Accounts" into the given cursor */
        private void addCombinedAccountRow(MatrixCursor cursor, int accountCount) {
            Context context = getContext();
            Account account = new Account();
            account.mId = Account.ACCOUNT_ID_COMBINED_VIEW;
            Resources res = context.getResources();
            String countString = res.getQuantityString(R.plurals.picker_combined_view_account_count,
                    accountCount, accountCount);
            account.mDisplayName = res.getString(R.string.picker_combined_view_fmt, countString);
            ContentValues values = account.toContentValues();
            RowBuilder row = cursor.newRow();
            for (String rowName : cursor.getColumnNames()) {
                // special case some of the rows ...
                if (AccountColumns.ID.equals(rowName)) {
                    row.add(Account.ACCOUNT_ID_COMBINED_VIEW);
                    continue;
                } else if (AccountColumns.IS_DEFAULT.equals(rowName)) {
                    row.add(0);
                    continue;
                }
                row.add(values.get(rowName));
            }
        }
    }

    /** Account picker */
    public static class AccountShortcutPickerFragment extends ShortcutPickerFragment {
        private volatile Boolean mLoadFinished = new Boolean(false);
        private final static String[] ACCOUNT_FROM_COLUMNS = new String[] {
            AccountColumns.DISPLAY_NAME,
        };

        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);
            getActivity().setTitle(R.string.account_shortcut_picker_title);
            if (!mLoadFinished) {
                getActivity().setVisible(false);
            }
        }

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Cursor cursor = (Cursor) parent.getItemAtPosition(position);
            selectAccountCursor(cursor, true);
        }

        @Override
        public Loader<Cursor> onCreateLoader(int id, Bundle args) {
            Context context = getActivity();
            return new AccountPickerLoader(
                context, Account.CONTENT_URI, Account.CONTENT_PROJECTION, null, null, null);
        }

        @Override
        public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
            // if there is only one account, auto-select it
            // No accounts; close the dialog
            if (data.getCount() == 0) {
                mCallback.onMissingData(true, false);
                return;
            }
            if (data.getCount() == 1 && data.moveToFirst()) {
                selectAccountCursor(data, false);
                return;
            }
            super.onLoadFinished(loader, data);
            mLoadFinished = true;
            getActivity().setVisible(true);
        }

        @Override
        String[] getFromColumns() {
            return ACCOUNT_FROM_COLUMNS;
        }

        /** Selects the account specified by the given cursor */
        private void selectAccountCursor(Cursor cursor, boolean allowBack) {
            Account account = new Account();
            account.restore(cursor);
            ShortcutPickerFragment fragment = MailboxShortcutPickerFragment.newInstance(
                    getActivity(), account, mCallback.buildFilter(account));
            FragmentTransaction transaction = getFragmentManager().beginTransaction();
            transaction.replace(R.id.shortcut_list, fragment);
            if (allowBack) {
                transaction.addToBackStack(null);
            }
            transaction.commitAllowingStateLoss();
        }
    }

    // TODO if we add meta-mailboxes to the database, remove this class entirely
    private static final class MailboxPickerLoader extends CursorLoader {
        private final long mAccountId;
        private final boolean mAllowUnread;
        public MailboxPickerLoader(Context context, Uri uri, String[] projection, String selection,
                String[] selectionArgs, String sortOrder, long accountId, boolean allowUnread) {
            super(context, uri, projection, selection, selectionArgs, sortOrder);
            mAccountId = accountId;
            mAllowUnread = allowUnread;
        }

        @Override
        public Cursor loadInBackground() {
            MatrixCursor unreadCursor =
                    new MatrixCursor(MailboxShortcutPickerFragment.MATRIX_PROJECTION);
            Context context = getContext();
            if (mAllowUnread) {
                // For the special mailboxes, their ID is < 0. The UI list does not deal with
                // negative values very well, so, add MAX_VALUE to ensure they're positive, but,
                // don't clash with legitimate mailboxes.
                String mailboxName = context.getString(R.string.picker_mailbox_name_all_unread);
                unreadCursor.addRow(
                        new Object[] {
                            Integer.MAX_VALUE + Mailbox.QUERY_ALL_UNREAD,
                            Mailbox.QUERY_ALL_UNREAD,
                            mailboxName,
                        });
            }

            if (mAccountId == Account.ACCOUNT_ID_COMBINED_VIEW) {
                // Do something special for the "combined" view
                MatrixCursor combinedMailboxesCursor =
                        new MatrixCursor(MailboxShortcutPickerFragment.MATRIX_PROJECTION);
                // For the special mailboxes, their ID is < 0. The UI list does not deal with
                // negative values very well, so, add MAX_VALUE to ensure they're positive, but,
                // don't clash with legitimate mailboxes.
                String mailboxName = context.getString(R.string.picker_mailbox_name_all_inbox);
                combinedMailboxesCursor.addRow(
                        new Object[] {
                            Integer.MAX_VALUE + Mailbox.QUERY_ALL_INBOXES,
                            Mailbox.QUERY_ALL_INBOXES,
                            mailboxName
                        });
                return new MergeCursor(new Cursor[] { combinedMailboxesCursor, unreadCursor });
            }

            // Loading for a regular account; perform a normal load
            return new MergeCursor(new Cursor[] { super.loadInBackground(), unreadCursor });
        }
    }

    /** Mailbox picker */
    public static class MailboxShortcutPickerFragment extends ShortcutPickerFragment {
        /** Allow all mailboxes in the mailbox list */
        public static int FILTER_ALLOW_ALL    = 0;
        /** Only allow an account's INBOX */
        public static int FILTER_INBOX_ONLY   = 1 << 0;
        /** Allow an "unread" mailbox; this is not affected by {@link #FILTER_INBOX_ONLY} */
        public static int FILTER_ALLOW_UNREAD = 1 << 1;
        /** Fragment argument to set filter values */
        static final String ARG_FILTER  = "MailboxShortcutPickerFragment.filter";
        static final String ARG_ACCOUNT = "MailboxShortcutPickerFragment.account";

        private final static String REAL_ID = "realId";
        private final static String[] MAILBOX_FROM_COLUMNS = new String[] {
            MailboxColumns.DISPLAY_NAME,
        };
        /** Loader projection used for IMAP & POP3 accounts */
        private final static String[] IMAP_PROJECTION = new String [] {
            MailboxColumns.ID, MailboxColumns.ID + " as " + REAL_ID,
            MailboxColumns.SERVER_ID + " as " + MailboxColumns.DISPLAY_NAME
        };
        /** Loader projection used for EAS accounts */
        private final static String[] EAS_PROJECTION = new String [] {
            MailboxColumns.ID, MailboxColumns.ID + " as " + REAL_ID,
            MailboxColumns.DISPLAY_NAME
        };
        /** Loader projection used for a matrix cursor */
        private final static String[] MATRIX_PROJECTION = new String [] {
            MailboxColumns.ID, REAL_ID, MailboxColumns.DISPLAY_NAME
        };
        // TODO #ALL_MAILBOX_SELECTION is identical to MailboxesAdapter#ALL_MAILBOX_SELECTION;
        // create a common selection. Move this to the Mailbox class?
        /** Selection for all visible mailboxes for an account */
        private final static String ALL_MAILBOX_SELECTION = MailboxColumns.ACCOUNT_KEY + "=?" +
                " AND " + Mailbox.USER_VISIBLE_MAILBOX_SELECTION;
        /** Selection for just the INBOX of an account */
        private final static String INBOX_ONLY_SELECTION = ALL_MAILBOX_SELECTION +
                    " AND " + MailboxColumns.TYPE + " = " + Mailbox.TYPE_INBOX;
        private volatile Boolean mLoadFinished = new Boolean(false);
        /** The currently selected account */
        private Account mAccount;
        /** The filter values; default to allow all mailboxes */
        private Integer mFilter;

        /**
         * Builds a mailbox shortcut picker for the given account.
         */
        public static MailboxShortcutPickerFragment newInstance(
                Context context, Account account, Integer filter) {

            MailboxShortcutPickerFragment fragment = new MailboxShortcutPickerFragment();
            Bundle args = new Bundle();
            args.putParcelable(ARG_ACCOUNT, account);
            args.putInt(ARG_FILTER, filter);
            fragment.setArguments(args);
            return fragment;
        }

        /** Returns the mailbox filter */
        int getFilter() {
            if (mFilter == null) {
                mFilter = getArguments().getInt(ARG_FILTER, FILTER_ALLOW_ALL);
            }
            return mFilter;
        }

        @Override
        public void onAttach(Activity activity) {
            // Need to setup the account first thing
            mAccount = getArguments().getParcelable(ARG_ACCOUNT);
            super.onAttach(activity);
        }

        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);
            getActivity().setTitle(R.string.mailbox_shortcut_picker_title);
            if (!mLoadFinished) {
                getActivity().setVisible(false);
            }
        }

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Cursor cursor = (Cursor) parent.getItemAtPosition(position);
            long mailboxId = cursor.getLong(cursor.getColumnIndex(REAL_ID));
            mCallback.onSelected(mAccount, mailboxId);
        }

        @Override
        public Loader<Cursor> onCreateLoader(int id, Bundle args) {
            Context context = getActivity();
            // TODO Create a fully-qualified path name for Exchange accounts [code should also work
            //      for MoveMessageToDialog.java]
            HostAuth recvAuth = mAccount.getOrCreateHostAuthRecv(context);
            final String[] projection;
            final String orderBy;
            final String selection;
            if (recvAuth.isEasConnection()) {
                projection = EAS_PROJECTION;
                orderBy = MailboxColumns.DISPLAY_NAME;
            } else {
                projection = IMAP_PROJECTION;
                orderBy = MailboxColumns.SERVER_ID;
            }
            if ((getFilter() & FILTER_INBOX_ONLY) == 0) {
                selection = ALL_MAILBOX_SELECTION;
            } else {
                selection = INBOX_ONLY_SELECTION;
            }
            return new MailboxPickerLoader(
                context, Mailbox.CONTENT_URI, projection, selection,
                new String[] { Long.toString(mAccount.mId) }, orderBy, mAccount.mId,
                (getFilter() & FILTER_ALLOW_UNREAD) != 0);
        }

        @Override
        public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
            // No accounts; close the dialog
            if (data.getCount() == 0) {
                mCallback.onMissingData(false, true);
                return;
            }
            // if there is only one mailbox, auto-select it
            if (data.getCount() == 1 && data.moveToFirst()) {
                long mailboxId = data.getLong(data.getColumnIndex(REAL_ID));
                mCallback.onSelected(mAccount, mailboxId);
                return;
            }
            super.onLoadFinished(loader, data);
            mLoadFinished = true;
            getActivity().setVisible(true);
        }

        @Override
        String[] getFromColumns() {
            return MAILBOX_FROM_COLUMNS;
        }
    }
}