akonadi
#include <entitytreemodel.h>
Public Types | |
enum | CollectionFetchStrategy { FetchNoCollections, FetchFirstLevelChildCollections, FetchCollectionsRecursive, InvisibleCollectionFetch } |
enum | FetchState { IdleState, FetchingState } |
enum | HeaderGroup { EntityTreeHeaders, CollectionTreeHeaders, ItemListHeaders, UserHeaders = 10, EndHeaderGroup = 32 } |
enum | ItemPopulationStrategy { NoItemPopulation, ImmediatePopulation, LazyPopulation } |
enum | Roles { ItemIdRole = Qt::UserRole + 1, ItemRole = Qt::UserRole + 2, MimeTypeRole = Qt::UserRole + 3, CollectionIdRole = Qt::UserRole + 10, CollectionRole = Qt::UserRole + 11, RemoteIdRole, CollectionChildOrderRole, AmazingCompletionRole, ParentCollectionRole, ColumnCountRole, LoadedPartsRole, AvailablePartsRole, SessionRole, CollectionRefRole, CollectionDerefRole, PendingCutRole, EntityUrlRole, UnreadCountRole, FetchStateRole, CollectionSyncProgressRole, IsPopulatedRole, UserRole = Qt::UserRole + 500, TerminalUserRole = 2000, EndRole = 65535 } |
Signals | |
void | collectionFetched (int collectionId) |
void | collectionPopulated (Akonadi::Collection::Id collectionId) |
void | collectionTreeFetched (const Akonadi::Collection::List &collections) |
Public Member Functions | |
EntityTreeModel (ChangeRecorder *monitor, QObject *parent=0) | |
virtual | ~EntityTreeModel () |
virtual bool | canFetchMore (const QModelIndex &parent) const |
CollectionFetchStrategy | collectionFetchStrategy () const |
virtual int | columnCount (const QModelIndex &parent=QModelIndex()) const |
virtual QVariant | data (const QModelIndex &index, int role=Qt::DisplayRole) const |
virtual bool | dropMimeData (const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) |
virtual void | fetchMore (const QModelIndex &parent) |
virtual Qt::ItemFlags | flags (const QModelIndex &index) const |
virtual bool | hasChildren (const QModelIndex &parent=QModelIndex()) const |
virtual QVariant | headerData (int section, Qt::Orientation orientation, int role=Qt::DisplayRole) const |
bool | includeRootCollection () const |
bool | includeUnsubscribed () const |
virtual QModelIndex | index (int row, int column, const QModelIndex &parent=QModelIndex()) const |
bool | isCollectionPopulated (Akonadi::Collection::Id) const |
bool | isCollectionTreeFetched () const |
ItemPopulationStrategy | itemPopulationStrategy () const |
virtual QModelIndexList | match (const QModelIndex &start, int role, const QVariant &value, int hits=1, Qt::MatchFlags flags=Qt::MatchFlags(Qt::MatchStartsWith|Qt::MatchWrap)) const |
virtual QMimeData * | mimeData (const QModelIndexList &indexes) const |
virtual QStringList | mimeTypes () const |
virtual QModelIndex | parent (const QModelIndex &index) const |
QString | rootCollectionDisplayName () const |
virtual int | rowCount (const QModelIndex &parent=QModelIndex()) const |
void | setCollectionFetchStrategy (CollectionFetchStrategy strategy) |
virtual bool | setData (const QModelIndex &index, const QVariant &value, int role=Qt::EditRole) |
void | setIncludeRootCollection (bool include) |
void | setIncludeUnsubscribed (bool show) |
void | setItemPopulationStrategy (ItemPopulationStrategy strategy) |
void | setRootCollectionDisplayName (const QString &name) |
void | setShowSystemEntities (bool show) |
virtual Qt::DropActions | supportedDropActions () const |
bool | systemEntitiesShown () const |
Static Public Member Functions | |
static QModelIndexList | modelIndexesForItem (const QAbstractItemModel *model, const Item &item) |
static QModelIndex | modelIndexForCollection (const QAbstractItemModel *model, const Collection &collection) |
Protected Member Functions | |
void | clearAndReset () |
virtual int | entityColumnCount (HeaderGroup headerGroup) const |
virtual QVariant | entityData (const Item &item, int column, int role=Qt::DisplayRole) const |
virtual QVariant | entityData (const Collection &collection, int column, int role=Qt::DisplayRole) const |
virtual QVariant | entityHeaderData (int section, Qt::Orientation orientation, int role, HeaderGroup headerGroup) const |
virtual bool | entityMatch (const Item &item, const QVariant &value, Qt::MatchFlags flags) const |
virtual bool | entityMatch (const Collection &collection, const QVariant &value, Qt::MatchFlags flags) const |
Detailed Description
A model for collections and items together.
Akonadi models and views provide a high level way to interact with the akonadi server. Most applications will use these classes.
Models provide an interface for viewing, updating, deleting and moving Items and Collections. Additionally, the models are updated automatically if another application changes the data or inserts of deletes items etc.
- Note
- The EntityTreeModel should be used with the EntityTreeView or the EntityListView class either directly or indirectly via proxy models.
Retrieving Collections and Items from the model
If you want to retrieve and Item or Collection from the model, and already have a valid QModelIndex for the correct row, the Collection can be retrieved like this:
And similarly for Items. This works even if there is a proxy model between the calling code and the EntityTreeModel.
If you want to retrieve a Collection for a particular Collection::Id and you do not yet have a valid QModelIndex, use modelIndexForCollection.
Using EntityTreeModel in your application
The responsibilities which fall to the application developer are
- Configuring the ChangeRecorder and EntityTreeModel
- Making use of this class via proxy models
- Subclassing for type specific display information
Creating and configuring the EntityTreeModel
This class is a wrapper around a Akonadi::ChangeRecorder object. The model represents a part of the collection and item tree configured in the ChangeRecorder. The structure of the model mirrors the structure of Collections and Items on the Akonadi server.
The following code creates a model which fetches items and collections relevant to addressees (contacts), and automatically manages keeping the items up to date.
The EntityTreeModel will show items of a different type by changing the line
to a different mimetype. KABC::addresseeMimeType() is an alias for "text/directory". If changed to KMime::Message::mimeType() (an alias for "message/rfc822") the model would instead contain emails. The model can be configured to contain items of any mimetype known to Akonadi.
- Note
- The EntityTreeModel does some extra configuration on the Monitor, such as setting itemFetchScope() and collectionFetchScope() to retrieve all ancestors. This is necessary for proper function of the model.
- See also
- Akonadi::ItemFetchScope::AncestorRetrieval.
- akonadi-mimetypes.
The EntityTreeModel can be further configured for certain behaviours such as fetching of collections and items.
The model can be configured to not fetch items into the model (ie, fetch collections only) by setting
The items may be fetched lazily, i.e. not inserted into the model until request by the user for performance reasons.
The Collection tree is always built immediately if Collections are to be fetched.
This will typically be used with a EntityMimeTypeFilterModel in a configuration such as KMail4.5 or AkonadiConsole.
The CollectionFetchStrategy determines how the model will be populated with Collections. That is, if FetchNoCollections is set, no collections beyond the root of the model will be fetched. This can be used in combination with setting a particular Collection to monitor.
This has the effect of creating a model of only a list of Items, and not collections. This is similar in behaviour and aims to the ItemModel. By using FetchFirstLevelCollections instead, a mixed list of entities can be created.
- Note
- It is important that you set only one Collection to be monitored in the monitor object. This one collection will be the root of the tree. If you need a model with a more complex structure, consider monitoring a common ancestor and using a SelectionProxyModel.
- See also
- lazy-model-population
It is also possible to show the root Collection as part of the selectable model:
By default the displayed name of the root collection is '[*]', because it doesn't require i18n, and is generic. It can be changed too.
This feature is used in KAddressBook.
If items are to be fetched by the model, it is necessary to specify which parts of the items are to be fetched, using the ItemFetchScope class. By default, only the basic metadata is fetched. To fetch all item data, including all attributes:
Using EntityTreeModel with Proxy models
An Akonadi::SelectionProxyModel can be used to simplify managing selection in one view through multiple proxy models to a representation in another view. The selectionModel of the initial view is used to create a proxied model which filters out anything not related to the current selection.
The SelectionProxyModel can handle complex selections.
See the KSelectionProxyModel documentation for the valid configurations of a Akonadi::SelectionProxyModel.
Obviously, the SelectionProxyModel may be used in a view, or further processed with other proxy models. Typically, the result from this model will be further filtered to remove collections from the item list as in the above example.
There are several advantages of using EntityTreeModel with the SelectionProxyModel, namely the items can be fetched and cached instead of being fetched many times, and the chain of proxies from the core model to the view is automatically handled. There is no need to manage all the mapToSource and mapFromSource calls manually.
A KDescendantsProxyModel can be used to represent all descendants of a model as a flat list. For example, to show all descendant items in a selected Collection in a list:
Note that it is important in this case to use the DescendantEntitesProxyModel before the EntityMimeTypeFilterModel. Otherwise, by filtering out the collections first, you would also be filtering out their child items.
This pattern is used in KAddressBook.
It would not make sense to use a KDescendantsProxyModel with LazyPopulation.
Subclassing EntityTreeModel
Usually an application will create a subclass of an EntityTreeModel and use that in several views via proxy models.
The subclassing is necessary in order for the data in the model to have type-specific representation in applications
For example, the headerData for an EntityTreeModel will be different depending on whether it is in a view showing only Collections in which case the header data should be "AddressBooks" for example, or only Items, in which case the headerData would be for example "Family Name", "Given Name" and "Email addres" for contacts or "Subject", "Sender", "Date" in the case of emails.
Additionally, the actual data shown in the rows of the model should be type specific.
In summary, it must be possible to have different numbers of columns, different data in hte rows of those columns, and different titles for each column depending on the contents of the view.
The way this is accomplished is by using the EntityMimeTypeFilterModel for splitting the model into a "CollectionTree" and an "Item List" as in the above example, and using a type-specific EntityTreeModel subclass to return the type-specific data, typically for only one type (for example, contacts or emails).
The following protected virtual methods should be implemented in the subclass:
- int entityColumnCount( HeaderGroup headerGroup ) const; – Implement to return the number of columns for a HeaderGroup. If the HeaderGroup is CollectionTreeHeaders, return the number of columns to display for the Collection tree, and if it is ItemListHeaders, return the number of columns to display for the item. In the case of addressee, this could be for example, two (for given name and family name) or for emails it could be three (for subject, sender, date). This is a decision of the subclass implementor.
- QVariant entityHeaderData( int section, Qt::Orientation orientation, int role, HeaderGroup headerGroup ) const; – Implement to return the data for each section for a HeaderGroup. For example, if the header group is CollectionTreeHeaders in a contacts model, the string "Address books" might be returned for column 0, whereas if the headerGroup is ItemListHeaders, the strings "Given Name", "Family Name", "Email Address" might be returned for the columns 0, 1, and 2.
- QVariant entityData( const Collection &collection, int column, int role = Qt::DisplayRole ) const; – Implement to return data for a particular Collection. Typically this will be the name of the collection or the EntityDisplayAttribute.
- QVariant entityData( const Item &item, int column, int role = Qt::DisplayRole ) const; – Implement to return the data for a particular item and column. In the case of email for example, this would be the actual subject, sender and date of the email.
- Note
- The entityData methods are just for convenience. the QAbstractItemMOdel::data method can be overridden if required.
The application writer must then properly configure proxy models for the views, so that the correct data is shown in the correct view. That is the purpose of these lines in the above example
Progress reporting
The EntityTreeModel uses asynchronous Akonadi::Job instances to fill and update itself. For example, a job is run to fetch the contents of collections (that is, list the items in it). Additionally, individual Akonadi::Items can be fetched in different parts at different times.
To indicate that such a job is underway, the EntityTreeModel makes the FetchState available. The FetchState returned from a QModelIndex representing a Akonadi::Collection will be FetchingState if a listing of the items in that collection is underway, otherwise the state is IdleState.
- Since
- 4.4
Definition at line 317 of file entitytreemodel.h.
Member Enumeration Documentation
Describes what collections shall be fetched by and represent in the model.
Definition at line 484 of file entitytreemodel.h.
Describes the state of fetch jobs related to particular collections.
- Since
- 4.5
Enumerator | |
---|---|
IdleState |
There is no fetch of items in this collection in progress. |
FetchingState |
There is a fetch of items in this collection in progress. |
Definition at line 372 of file entitytreemodel.h.
Describes what header information the model shall return.
Definition at line 381 of file entitytreemodel.h.
Describes how the model should populated its items.
Definition at line 406 of file entitytreemodel.h.
Describes the roles for items.
Roles for collections are defined by the superclass.
Enumerator | |
---|---|
ItemIdRole |
The item id. |
ItemRole |
The Item. |
MimeTypeRole |
The mimetype of the entity. |
CollectionIdRole |
The collection id. |
CollectionRole |
The collection. |
RemoteIdRole |
The remoteId of the entity. |
CollectionChildOrderRole |
Ordered list of child items if available. |
AmazingCompletionRole |
Role used to implement amazing completion. |
ParentCollectionRole |
The parent collection of the entity. |
ColumnCountRole |
Used by proxies to determine the number of columns for a header group. |
LoadedPartsRole |
Parts available in the model for the item. |
AvailablePartsRole |
Parts available in the Akonadi server for the item. |
SessionRole |
The Session used by this model |
CollectionRefRole |
Used to increase the reference count on a Collection |
CollectionDerefRole |
Used to decrease the reference count on a Collection |
PendingCutRole |
Used to indicate items which are to be cut |
EntityUrlRole |
The akonadi:/ Url of the entity as a string. Item urls will contain the mimetype. |
UnreadCountRole |
Returns the number of unread items in a collection.
|
FetchStateRole |
Returns the FetchState of a particular item.
|
CollectionSyncProgressRole |
Returns the progress of synchronization in percent for a particular collection.
|
IsPopulatedRole |
Returns whether a Collection has been populated, i.e. whether its items have been fetched.
|
UserRole |
First role for user extensions. |
TerminalUserRole |
Last role for user extensions. Don't use a role beyond this or headerData will break. |
Definition at line 325 of file entitytreemodel.h.
Constructor & Destructor Documentation
|
explicit |
Creates a new entity tree model.
- Parameters
-
monitor The ChangeRecorder whose entities should be represented in the model. parent The parent object.
Definition at line 55 of file entitytreemodel.cpp.
|
virtual |
Destroys the entity tree model.
Definition at line 74 of file entitytreemodel.cpp.
Member Function Documentation
|
protected |
Clears and resets the model.
Always call this instead of the reset method in the superclass. Using the reset method will not reliably clear or refill the model.
Definition at line 118 of file entitytreemodel.cpp.
|
signal |
Emitted once a collection has been fetched for the very first time.
This is like a dataChanged(), but specific to the initial loading, in order to update the GUI (window caption, state of actions). Usually, the GUI uses Akonadi::Monitor to be notified of further changes to the collections.
- Parameters
-
collectionId the identifier of the fetched collection
- Since
- 4.9.3
EntityTreeModel::CollectionFetchStrategy EntityTreeModel::collectionFetchStrategy | ( | ) | const |
Returns the collection fetch strategy of the model.
Definition at line 1161 of file entitytreemodel.cpp.
|
signal |
Signal emitted when a collection has been populated, i.e.
its items have been fetched.
- Parameters
-
collectionId id of the collection which has been populated
- See also
- collectionTreeFetched
- Since
- 4.10
|
signal |
Signal emitted when the collection tree has been fetched for the first time.
- Parameters
-
collections list of collections which have been fetched
- Since
- 4.10
|
protectedvirtual |
Provided for convenience of subclasses.
Definition at line 136 of file entitytreemodel.cpp.
|
protectedvirtual |
Provided for convenience of subclasses.
Definition at line 166 of file entitytreemodel.cpp.
|
protectedvirtual |
Reimplement this to provide different header data.
This is needed when using one model with multiple proxies and views, and each should show different header data.
Definition at line 695 of file entitytreemodel.cpp.
|
protectedvirtual |
Reimplement this in a subclass to return true if item
matches value
with flags
in the AmazingCompletionRole.
Definition at line 932 of file entitytreemodel.cpp.
|
protectedvirtual |
Reimplement this in a subclass to return true if collection
matches value
with flags
in the AmazingCompletionRole.
Definition at line 940 of file entitytreemodel.cpp.
bool EntityTreeModel::includeRootCollection | ( | ) | const |
Returns whether the root collection is provided by the model.
Definition at line 1117 of file entitytreemodel.cpp.
bool EntityTreeModel::includeUnsubscribed | ( | ) | const |
Returns whether unsubscribed entities will be included in the listing.
- Since
- 4.5
Definition at line 91 of file entitytreemodel.cpp.
bool EntityTreeModel::isCollectionPopulated | ( | Akonadi::Collection::Id | id | ) | const |
Returns whether the collection has been populated.
- See also
- collectionPopulated
- Since
- 4.12
Definition at line 926 of file entitytreemodel.cpp.
bool EntityTreeModel::isCollectionTreeFetched | ( | ) | const |
Returns whether the collection tree has been fetched at initialisation.
- See also
- collectionTreeFetched
- Since
- 4.10
Definition at line 919 of file entitytreemodel.cpp.
EntityTreeModel::ItemPopulationStrategy EntityTreeModel::itemPopulationStrategy | ( | ) | const |
Returns the item population strategy of the model.
Definition at line 1103 of file entitytreemodel.cpp.
|
virtual |
Reimplemented to handle the AmazingCompletionRole.
Definition at line 948 of file entitytreemodel.cpp.
|
static |
Returns a QModelIndex in model
which points to item
.
This method can be used through proxy models if model
is a proxy model.
- Parameters
-
model the model to query for the item item the item to look for
- See also
- modelIndexForCollection
- Since
- 4.5
Definition at line 1201 of file entitytreemodel.cpp.
|
static |
Returns a QModelIndex in model
which points to collection
.
This method can be used through proxy models if model
is a proxy model.
This can be useful for example if an id is stored in a config file and needs to be used in the application.
Note however, that to restore view state such as scrolling, selection and expansion of items in trees, the ETMViewStateSaver can be used for convenience.
- See also
- modelIndexesForItem
- Since
- 4.5
Definition at line 1192 of file entitytreemodel.cpp.
QString EntityTreeModel::rootCollectionDisplayName | ( | ) | const |
Returns the display name of the root collection.
Definition at line 1131 of file entitytreemodel.cpp.
void EntityTreeModel::setCollectionFetchStrategy | ( | CollectionFetchStrategy | strategy | ) |
Sets the collection fetch strategy
of the model.
Definition at line 1137 of file entitytreemodel.cpp.
void EntityTreeModel::setIncludeRootCollection | ( | bool | include | ) |
Sets whether the root collection shall be provided by the model.
- Parameters
-
include enables root collection if set as true
- See also
- setRootCollectionDisplayName()
Definition at line 1109 of file entitytreemodel.cpp.
void EntityTreeModel::setIncludeUnsubscribed | ( | bool | show | ) |
Sets whether unsubscribed entities will be included in the listing.
By default it's true
- Parameters
-
show enables displaying of unsubscribed entities if set as true
Note that it is possible to change the monitor's fetchscope directly, bypassing this method, which will lead to inconsistencies. Use this method for turning on/off listing of subscribed folders.
- Since
- 4.5
Definition at line 97 of file entitytreemodel.cpp.
void EntityTreeModel::setItemPopulationStrategy | ( | ItemPopulationStrategy | strategy | ) |
Sets the item population strategy
of the model.
Definition at line 1076 of file entitytreemodel.cpp.
void EntityTreeModel::setRootCollectionDisplayName | ( | const QString & | name | ) |
Sets the display name
of the root collection of the model.
The default display name is "[*]".
- Parameters
-
name the name to display for the root collection
- Note
- The display name for the root collection is only used if the root collection has been included with setIncludeRootCollection().
Definition at line 1123 of file entitytreemodel.cpp.
void EntityTreeModel::setShowSystemEntities | ( | bool | show | ) |
Some Entities are hidden in the model, but exist for internal purposes, for example, custom object directories in groupware resources.
They are hidden by default, but can be shown by setting show
to true.
- Parameters
-
show enabled displaying of hidden entities if set as true
Most applications will not need to use this feature.
Definition at line 112 of file entitytreemodel.cpp.
bool EntityTreeModel::systemEntitiesShown | ( | ) | const |
Returns true
if internal system entities are shown, and false
otherwise.
Definition at line 106 of file entitytreemodel.cpp.
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