javafx.scene.control.cell.TreeItemPropertyValueFactory Maven / Gradle / Ivy
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package javafx.scene.control.cell;
import javafx.beans.property.Property;
import javafx.beans.property.ReadOnlyObjectWrapper;
import javafx.beans.value.ObservableValue;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeTableColumn;
import javafx.scene.control.TreeTableColumn.CellDataFeatures;
import javafx.util.Callback;
import com.sun.javafx.property.PropertyReference;
import com.sun.javafx.scene.control.Logging;
import sun.util.logging.PlatformLogger;
/**
* A convenience implementation of the Callback interface, designed specifically
* for use within the {@link TreeTableColumn}
* {@link TreeTableColumn#cellValueFactoryProperty() cell value factory}. An example
* of how to use this class is:
*
*
* TreeTableColumn<Person,String> firstNameCol = new TreeTableColumn<Person,String>("First Name");
* firstNameCol.setCellValueFactory(new TreeItemPropertyValueFactory<Person,String>("firstName"));
*
*
* In this example, the "firstName" string is used as a reference to an assumed
* firstNameProperty()
method in the Person
class type
* (which is the class type of the TreeTableView). Additionally, this method must
* return a {@link Property} instance. If a method meeting these requirements
* is found, then the {@link TreeTableCell} is populated with this ObservableValue.
* In addition, the TreeTableView will automatically add an observer to the
* returned value, such that any changes fired will be observed by the TreeTableView,
* resulting in the cell immediately updating.
*
* If no method matching this pattern exists, there is fall-through support
* for attempting to call get<property>() or is<property>() (that is,
* getFirstName()
or isFirstName()
in the example
* above). If a method matching this pattern exists, the value returned from this method
* is wrapped in a {@link ReadOnlyObjectWrapper} and returned to the TreeTableCell.
* However, in this situation, this means that the TreeTableCell will not be able
* to observe the ObservableValue for changes (as is the case in the first
* approach above).
*
*
For reference (and as noted in the TreeTableColumn
* {@link TreeTableColumn#cellValueFactory cell value factory} documentation), the
* long form of the code above would be the following:
*
*
* TreeTableColumn<Person,String> firstNameCol = new TreeTableColumn<Person,String>("First Name");
* firstNameCol.setCellValueFactory(new Callback<CellDataFeatures<Person, String>, ObservableValue<String>>() {
* public ObservableValue<String> call(CellDataFeatures<Person, String> p) {
* // p.getValue() returns the TreeItem instance for a particular
* // TreeTableView row, and the second getValue() call returns the
* // Person instance contained within the TreeItem.
* return p.getValue().getValue().firstNameProperty();
* }
* });
* }
*
*
* @see TreeTableColumn
* @see TreeTableView
* @see TreeTableCell
* @see PropertyValueFactory
* @see MapValueFactory
* @since JavaFX 8.0
*/
public class TreeItemPropertyValueFactory implements Callback, ObservableValue> {
private final String property;
private Class columnClass;
private String previousProperty;
private PropertyReference propertyRef;
/**
* Creates a default PropertyValueFactory to extract the value from a given
* TableView row item reflectively, using the given property name.
*
* @param property The name of the property with which to attempt to
* reflectively extract a corresponding value for in a given object.
*/
public TreeItemPropertyValueFactory(String property) {
this.property = property;
}
/** {@inheritDoc} */
@Override public ObservableValue call(CellDataFeatures param) {
TreeItem treeItem = param.getValue();
return getCellDataReflectively((T)treeItem.getValue());
}
/**
* Returns the property name provided in the constructor.
*/
public final String getProperty() { return property; }
private ObservableValue getCellDataReflectively(T rowData) {
if (getProperty() == null || getProperty().isEmpty() || rowData == null) return null;
try {
// we attempt to cache the property reference here, as otherwise
// performance suffers when working in large data models. For
// a bit of reference, refer to RT-13937.
if (columnClass == null || previousProperty == null ||
! columnClass.equals(rowData.getClass()) ||
! previousProperty.equals(getProperty())) {
// create a new PropertyReference
this.columnClass = rowData.getClass();
this.previousProperty = getProperty();
this.propertyRef = new PropertyReference(rowData.getClass(), getProperty());
}
return propertyRef.getProperty(rowData);
} catch (IllegalStateException e) {
try {
// attempt to just get the value
T value = propertyRef.get(rowData);
return new ReadOnlyObjectWrapper(value);
} catch (IllegalStateException e2) {
// fall through to logged exception below
}
// log the warning and move on
final PlatformLogger logger = Logging.getControlsLogger();
if (logger.isLoggable(PlatformLogger.WARNING)) {
logger.finest("Can not retrieve property '" + getProperty() +
"' in TreeItemPropertyValueFactory: " + this +
" with provided class type: " + rowData.getClass(), e);
}
}
return null;
}
}