javafx.scene.control.cell.PropertyValueFactory Maven / Gradle / Ivy
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package javafx.scene.control.cell;
import javafx.beans.NamedArg;
import javafx.beans.property.Property;
import javafx.beans.property.ReadOnlyObjectWrapper;
import javafx.beans.value.ObservableValue;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableColumn.CellDataFeatures;
import javafx.scene.control.TableView;
import javafx.util.Callback;
import com.sun.javafx.logging.PlatformLogger;
import com.sun.javafx.logging.PlatformLogger.Level;
import com.sun.javafx.property.PropertyReference;
import com.sun.javafx.scene.control.Logging;
/**
* A convenience implementation of the Callback interface, designed specifically
* for use within the {@link TableColumn}
* {@link TableColumn#cellValueFactoryProperty() cell value factory}. An example
* of how to use this class is:
*
*
* TableColumn<Person,String> firstNameCol = new TableColumn<Person,String>("First Name");
* firstNameCol.setCellValueFactory(new PropertyValueFactory<Person,String>("firstName"));
*
*
*
* In this example, {@code Person} is the class type of the {@code TableView}
* {@link TableView#itemsProperty() items} list.
* The class {@code Person} must be declared public.
* {@code PropertyValueFactory} uses the constructor argument,
* {@code "firstName"}, to assume that {@code Person} has a public method
* {@code firstNameProperty} with no formal parameters and a return type of
* {@code ObservableValue}.
*
*
* If such a method exists, then it is invoked, and additionally assumed
* to return an instance of {@code Property}. The return value is used
* to populate the {@link TableCell}. In addition, the {@code TableView} adds
* an observer to the return value, such that any changes fired will be observed
* by the {@code TableView}, resulting in the cell immediately updating.
*
*
* If no such method exists, then {@code PropertyValueFactory}
* assumes that {@code Person} has a public method {@code getFirstName} or
* {@code isFirstName} with no formal parameters and a return type of
* {@code String}. If such a method exists, then it is invoked, and its return
* value is wrapped in a {@link ReadOnlyObjectWrapper}
* and returned to the {@code TableCell}. In this situation,
* the {@code TableCell} will not be able to observe changes to the property,
* unlike in the first approach above.
*
*
* For reference (and as noted in the TableColumn
* {@link TableColumn#cellValueFactoryProperty()} cell value factory} documentation), the
* long form of the code above would be the following:
*
*
*
* TableColumn<Person,String> firstNameCol = new TableColumn<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 Person instance for a particular TableView row
* return p.getValue().firstNameProperty();
* }
* });
* }
*
*
* Deploying an Application as a Module
*
* If the referenced class is in a named module, then it must be reflectively
* accessible to the {@code javafx.base} module.
* A class is reflectively accessible if the module
* {@link Module#isOpen(String,Module) opens} the containing package to at
* least the {@code javafx.base} module.
* Otherwise the {@link #call call(TableColumn.CellDataFeatures)} method
* will log a warning and return {@code null}.
*
*
* For example, if the {@code Person} class is in the {@code com.foo} package
* in the {@code foo.app} module, the {@code module-info.java} might
* look like this:
*
*
{@code module foo.app {
opens com.foo to javafx.base;
}}
*
*
* Alternatively, a class is reflectively accessible if the module
* {@link Module#isExported(String) exports} the containing package
* unconditionally.
*
*
* @see TableColumn
* @see TableView
* @see TableCell
* @see TreeItemPropertyValueFactory
* @see MapValueFactory
* @param The type of the class contained within the TableView.items list.
* @param The type of the class contained within the TableColumn cells.
* @since JavaFX 2.0
*/
public class PropertyValueFactory 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 PropertyValueFactory(@NamedArg("property") String property) {
this.property = property;
}
/** {@inheritDoc} */
@Override public ObservableValue call(CellDataFeatures param) {
return getCellDataReflectively(param.getValue());
}
/**
* Returns the property name provided in the constructor.
* @return the property name provided in the constructor
*/
public final String getProperty() { return property; }
private ObservableValue getCellDataReflectively(S 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());
}
if (propertyRef != null) {
if (propertyRef.hasProperty()) {
return propertyRef.getProperty(rowData);
} else {
T value = propertyRef.get(rowData);
return new ReadOnlyObjectWrapper(value);
}
}
} catch (RuntimeException e) {
// log the warning and move on
final PlatformLogger logger = Logging.getControlsLogger();
if (logger.isLoggable(Level.WARNING)) {
logger.warning("Can not retrieve property '" + getProperty() +
"' in PropertyValueFactory: " + this +
" with provided class type: " + rowData.getClass(), e);
}
propertyRef = null;
}
return null;
}
}