~ubuntu-branches/ubuntu/oneiric/kdepim/oneiric-updates

/******************************************************************************

 *

 *  Copyright 2008 Szymon Tomasz Stefanek <pragma@kvirc.net>

 *

 *  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; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  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, write to the Free Software

 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 *

 *******************************************************************************/

#ifndef __MESSAGELIST_CORE_MODEL_H__

#define __MESSAGELIST_CORE_MODEL_H__

#include <QAbstractItemModel>

#include <QList>

#include <QHash>

#include <QMultiHash>

#include <QDate>

#include <QTimer>

#include <messagelist/core/aggregation.h>

#include <messagelist/core/enums.h>

#include <messagelist/core/sortorder.h>

#include <time.h> // time_t

#include <messagelist/messagelist_export.h>

class QTime;

namespace MessageList

{

namespace Core

{

typedef long int MessageItemSetReference;

class ViewItemJob;

class Filter;

class GroupHeaderItem;

class Item;

class Manager;

class MessageItem;

class Theme;

class StorageModel;

class ModelInvariantRowMapper;

class MessageItemSetManager;

class View;

class ModelPrivate;

/**

 * This class manages the huge tree of displayable objects: GroupHeaderItems and MessageItems.

 * The tree is exposed via a 'hacked' QAbstractItemModel interface to a QTreeView

 * subclass (which is MessageList::View).

 *

 * The keypoint in this class is that it has to be non-blocking in manipulating the tree:

 * fill, cleanup and update operations are performed in timed chunks. Perfect non-blocking

 * behaviour is not possible since there are some small operations that basically can't be

 * split in chunks. However, these exceptions apply to a minority of tasks and in the

 * average case the user will not notice.

 *

 * The data for building the tree is obtained from a subclass of StorageModel. The

 * StorageModel must offer a consistent rappresentation of a "flat" folder containing

 * messages.

 */

class MESSAGELIST_EXPORT Model : public QAbstractItemModel

{

  friend class Item;

  friend class ItemPrivate;

  Q_OBJECT

public:

  /**

   * Creates the mighty Model attached to the specified View.

   */

  Model( View *pParent );

  /**

   * Destroys the mighty model along with the tree of items it manages.

   */

  ~Model();

  /**

   * Returns the StorageModel currently set.

   */

  StorageModel *storageModel() const;

  /**

   * Sets the storage model from that the messages to be displayed should be fetched.

   * The model is then reset and a new fill operation is started. The fill operation may

   * or may not complete before setStorageModel() returns. This depends on the fill

   * strategy and the size of the folder. You can check if the fill operation has

   * completed by looking at the return value of isLoading().

   *

   * Pre-selection is the action of automatically selecting a message just after the folder

   * has finished loading. We may want to select the message that was selected the last

   * time this folder has been open, or we may want to select the first unread message.

   * We also may want to do no pre-selection at all (for example, when the user

   * starts navigating the view before the pre-selection could actually be made

   * and pre-selecting would confuse him). The pre-selection is applied once

   * loading is complete.

   */

  void setStorageModel( StorageModel *storageModel, PreSelectionMode preSelectionMode = PreSelectLastSelected );

  /**

   * Aborts any pending message pre-selection. This may be done if the user

   * starts navigating the view and selecting items before we actually could

   * apply the pre-selection.

   */

  void abortMessagePreSelection();

  /**

   * Attempt to select the message with the specified unique id AND storage row as soon

   * as possible (either now or when the view finishes loading). Please note that BOTH the uniqueId

   * and the storage row are needed in order to perform the operation in all cases.

   *

   * This is a very special function. It can be called ONLY when the model is actually

   * loading: it will assert if you do otherwise. This call is actually the only

   * way to select an item that hasn't been read from the storage yet.

   */

  void activateMessageAfterLoading( unsigned long uniqueIdOfMessage, int row );

  /**

   * Returns the hidden root item that all the messages are (or will be) attached to.

   * The returned value is never 0.

   */

  Item *rootItem() const;

  /**

   * Returns true if the view is currently loading, that is

   * it's in the first (possibly lenghty) job batch after attacching to a StorageModel.

   */

  bool isLoading() const;

  /**

   * Returns the message item that is at the _current_ storage row index

   * or zero if no such storage item is found. Please note that this may return 0

   * also if the specified storage row hasn't been actually read yet. This may happen

   * if isLoading() returns true. In this case the only thing you can do is to retry in a while.

   */

  MessageItem * messageItemByStorageRow( int row ) const;

  /**

   * Sets the Aggregation mode.

   * Does not reload the model in any way: you need to call setStorageModel( storageModel() ) for this to happen.

   * The pointer ownership remains of the caller which must ensure its validity until the next

   * call to setAggretation() or until this Model dies. The caller, in fact, is Widget which

   * takes care of meeting the above conditions. The aggregation pointer must not be null.

   */

  void setAggregation( const Aggregation * aggregation );

  /**

   * Sets the Theme.

   * Does not reload the model in any way: you need to call setStorageModel( storageModel() ) for this to happen.

   * The pointer ownership remains of the caller which must ensure its validity until the next

   * call to setTheme() or until this Model dies. The caller, in fact, is Widget which

   * takes care of meeting the above conditions. The theme pointer must not be null.

   */

  void setTheme( const Theme * theme );

  /**

   * Sets the sort order. As with setTheme() and setAggregation(), this does not reload the

   * model in any way.

   */

  void setSortOrder( const SortOrder * sortOrder );

  /**

   * Sets the Filter to be applied on messages. filter may be null (no filter is applied).

   * The pointer ownership remains of the caller which must ensure its validity until the next

   * call to setFilter() or until this Model dies. The caller, in fact, is Widget which

   * takes care of meeting the above conditions. The Filter pointer may be null.

   */

  void setFilter( const Filter *filter );

  /**

   * Creates a persistent set for the specified MessageItems and

   * returns its reference. Later you can use this reference

   * to retrieve the list of MessageItems that are still valid.

   * See persistentSetActualMessageList() for that.

   *

   * Persistent sets consume resources (both memory and CPU time

   * while manipulating the view) so be sure to call deletePersistentSet()

   * when you no longer need it.

   */

  MessageItemSetReference createPersistentSet( const QList< MessageItem * > &items );

  /**

   * Returns the list of MessageItems that are still existing in the

   * set pointed by the specified reference. This list will contain

   * at most the messages that you have passed to createPersistentSet()

   * but may contain less (even 0) if these MessageItem object were removed

   * from the view for some reason.

   */

  QList< MessageItem * > persistentSetCurrentMessageItemList( MessageItemSetReference ref );

  /**

   * Deletes the persistent set pointed by the specified reference.

   * If the set does not exist anymore, nothing happens.

   */

  void deletePersistentSet( MessageItemSetReference ref );

  // Mandatory QAbstractItemModel interface.

  virtual int columnCount( const QModelIndex &parent = QModelIndex() ) const;

  virtual QVariant data( const QModelIndex &index, int role = Qt::DisplayRole ) const;

  virtual QVariant headerData(int section, Qt::Orientation orientation, int role) const;

  virtual QModelIndex index( int row, int column, const QModelIndex &parent = QModelIndex() ) const;

  QModelIndex index( Item *item, int column ) const;

  virtual QModelIndex parent( const QModelIndex &index ) const;

  virtual int rowCount( const QModelIndex &parent = QModelIndex() ) const;

  virtual Qt::ItemFlags flags( const QModelIndex &index ) const;

  /// Called when user initiates a drag from the messagelist

  virtual QMimeData* mimeData( const QModelIndexList& indexes ) const;

Q_SIGNALS:

  /**

   * Notify the outside when updating the status bar with a message

   * could be useful

   */

  void statusMessage( const QString &message );

private:

  Q_PRIVATE_SLOT(d, void checkIfDateChanged())

  Q_PRIVATE_SLOT(d, void viewItemJobStep())

  Q_PRIVATE_SLOT(d, void slotStorageModelRowsInserted( const QModelIndex &, int, int ))

  Q_PRIVATE_SLOT(d, void slotStorageModelRowsRemoved( const QModelIndex &, int, int ))

  Q_PRIVATE_SLOT(d, void slotStorageModelDataChanged( const QModelIndex &, const QModelIndex & ))

  Q_PRIVATE_SLOT(d, void slotStorageModelHeaderDataChanged( Qt::Orientation, int, int ))

  Q_PRIVATE_SLOT(d, void slotStorageModelLayoutChanged())

  friend class ModelPrivate;

  ModelPrivate * const d;

};

} // namespace Core

} // namespace MessageList

#endif //!__MESSAGELIST_CORE_MODEL_H__