:: com :: sun :: star :: form :: component ::

Description

specifies the model of a control used for displaying images stored in a database.

As every ::com::sun::star::form::DataAwareControlModel, an image control can be bound to a database field. This means that for instance with every record change, the content of the database field is taken, interpreted as image, and displayed in the control.
Unlike other more text-based controls, it does not interpret the content of the field as text or double, but as binary stream (see ::com::sun::star::sdb::XColumn::getBinaryStream).

Usually, an image control model can be bound to binary columns only, namely ::com::sun::star::sdbc::DataType::BINARY, ::com::sun::star::sdbc::DataType::VARBINARY, ::com::sun::star::sdbc::DataType::LONGVARBINARY, ::com::sun::star::sdbc::DataType::OTHER, ::com::sun::star::sdbc::DataType::LONGVARCHAR

Note that besides taking the image to be displayed from the bound field, there is another option. The ::com::sun::star::awt::UnoControlImageControlModel::ImageURL property specifies the URL of an image to be displayed. If this property is changed from outside, the respective file is loaded and set as image source.

In a usual data form, the scenario will be as follows:

• There is a DatabaseImageControl as part of the document model, which acts as control model for an ::com::sun::star::form::control::ImageControl.
• The control is an ::com::sun::star::awt::XImageConsumer for the ::com::sun::star::awt::XImageProducer supplied by the model.
• Whenever the form's cursor is positioned on a new record, the column the control model is bound to is examined for a binary data stream. This stream is set as source at the image producer, which notifies it's consumers, which leads to the control displaying the image.
• When the user by some interaction tells the control to contain a new image, this is exchanged by URL. For example, implementations of the control service may allow the user to browse for image. After this, the URL of the image is set as ::com::sun::star::awt::UnoControlImageControlModel::ImageURL property at the model.
  Now the control loads the image determined by the property value, and starts producing a new data stream, which is displayed by the control (which is a consumer for this stream).
  From now on, the control and thus the database record counts as modified. If the cursor of the form is moved further, the modified record is saved, means the content of the image pointed to by ::com::sun::star::awt::UnoControlImageControlModel::ImageURL is saved into the column.