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/*
* Copyright (C) 2022 Archie L. Cobbs. All rights reserved.
*/
package org.dellroad.stuff.vaadin7;
import com.vaadin.data.Container;
import com.vaadin.data.Item;
import com.vaadin.data.Property;
import com.vaadin.data.util.ObjectProperty;
import com.vaadin.ui.Table;
import java.io.Serializable;
import java.util.Comparator;
/**
* Defines a Vaadin property, having a name, which is also the property ID, and its type.
* This class provides a mechanism for the explicit naming and identification of Vaadin properties.
*
*
*
*
*
*
* For a given instance, def.{@link #getPropertyId getPropertyId()} is the property ID
* and you can access the value using def.{@link #read read(item)}.
*
*
* Example:
*
* PropertyDef<Integer> def = new PropertyDef<Integer>("age", Integer.class, -1);
* def.addTo(container);
* def.addTo(item, property);
* ...
* int age = def.read(item);
* ...
* Property prop = this.get(container, itemId);
*
*
*
* Instances are serializable if the default value is.
*
* @param property's value type
*/
public class PropertyDef implements Serializable {
/**
* Comparator that sorts instances by name.
*/
public static final Comparator> SORT_BY_NAME = new Comparator>() {
@Override
public int compare(PropertyDef p1, PropertyDef p2) {
return p1.getName().compareTo(p2.getName());
}
};
private static final long serialVersionUID = -8991380517167562622L;
private final String name;
private final Class type;
private final T defaultValue;
/**
* Convenience contructor.
*
*
* Equivalent to:
*
* PropertyDef(name, type, null);
*
*
* @param name property name; also serves as the property ID
* @param type property type
* @throws IllegalArgumentException if {@code name} or {@code type} is null
*/
public PropertyDef(String name, Class type) {
this(name, type, null);
}
/**
* Primary constructor.
*
* @param name property name; also serves as the property ID
* @param type property type
* @param defaultValue default value for the property; may be null
* @throws IllegalArgumentException if {@code name} or {@code type} is null
*/
public PropertyDef(String name, Class type, T defaultValue) {
if (name == null)
throw new IllegalArgumentException("null name");
if (type == null)
throw new IllegalArgumentException("null type");
this.name = name;
this.type = type;
this.defaultValue = defaultValue;
}
/**
* Get the name of this property. This is also used as the property ID.
*
* @return property name, never null
*/
public String getName() {
return this.name;
}
/**
* Get the ID of this property. Returns the same thing as {@link #getName()}.
*
* @return property name, never null
*/
public String getPropertyId() {
return this.getName();
}
/**
* Get the type of the property value that this instance represents.
*
* @return property type, never null
*/
public Class getType() {
return this.type;
}
/**
* Get the default value for this property.
*
* @return property default value
*/
public T getDefaultValue() {
return this.defaultValue;
}
/**
* Create a simple {@link ObjectProperty} using the given value.
*
* @param value property value
* @param readOnly whether property should be read-only
* @return new property
*/
public ObjectProperty createProperty(T value, boolean readOnly) {
return new ObjectProperty<>(value, this.getType(), readOnly);
}
/**
* Create a read/write {@link ObjectProperty} using the given value.
*
*
* Equivalent to:
*
* {@link #createProperty(Object, boolean) createProperty()}(value, false);
*
*
* @param value property value
* @return new property
*/
public ObjectProperty createProperty(T value) {
return this.createProperty(value, false);
}
/**
* Create a read/write {@link ObjectProperty} using the default value.
*
*
* Equivalent to:
*
* {@link #createProperty(Object) createProperty()}(def.getDefaultValue());
*
*
* @return new property
*/
public ObjectProperty createProperty() {
return this.createProperty(this.getDefaultValue());
}
/**
* Get the property that this instance represents from the given {@link Item}.
*
* @param item item with property
* @return property, or null if not found
* @throws ClassCastException if the property found has a different type than this instance
*/
public Property get(Item item) {
return this.cast(item.getItemProperty(this.getPropertyId()));
}
/**
* Get the property that this instance represents from the given {@link Container}.
*
* @param container the container containing the items
* @param itemId the ID of the item containing the property
* @return property, or null if not found
* @throws ClassCastException if the property found has a different type than this instance
*/
public Property get(Container container, Object itemId) {
return this.cast(container.getContainerProperty(itemId, this.getPropertyId()));
}
/**
* Verify that the given property has the same Java type as this property definition.
*
*
* This essentially verifies that property.getType() == this.getType().
*
* @param property the property to verify; may be null
* @return null if {@code property} is null, otherwise {@code property}
* @throws ClassCastException if {@code property} has a different type than this definition
*/
@SuppressWarnings("unchecked")
public Property cast(Property property) {
if (property == null)
return null;
if (property.getType() != this.getType()) {
throw new ClassCastException("property type " + property.getType().getName()
+ " != definition type " + this.getType().getName());
}
return (Property)property;
}
/**
* Add a property represented by this instance to the given {@link Container}.
*
* @param container the container to add the property to
* @return true if the operation succeeded, false if not
* @throws UnsupportedOperationException if the operation is not supported
*/
public boolean addTo(Container container) {
return container.addContainerProperty(this.getPropertyId(), this.getType(), this.getDefaultValue());
}
/**
* Add a property represented by this instance to the given {@link Item}.
*
* @param item the item to add the property to
* @param property the property to be added to the item and identified by this instance's name
* @return true if the operation succeeded, false if not
* @throws UnsupportedOperationException if the operation is not supported
*/
public boolean addTo(Item item, Property property) {
return item.addItemProperty(this.getPropertyId(), property);
}
/**
* Add a property represented by this instance to the given {@link Table}.
*
* @param table the table to add the property to
* @return true if the operation succeeded, false if not
* @throws UnsupportedOperationException if the operation is not supported
*/
public boolean addTo(Table table) {
return table.addContainerProperty(this.getPropertyId(), this.getType(), this.getDefaultValue());
}
/**
* Read the property that this instance represents from the given {@link Item}.
*
* @param item item with property
* @return property value, or null if not found
* @throws ClassCastException if the property in {@code item} has the wrong type
*/
public T read(Item item) {
Property property = this.get(item);
if (property == null)
return null;
return this.type.cast(property.getValue());
}
/**
* Determine whether this instance supports sorting property values.
*
*
* The implementation in {@link PropertyDef} returns true if this instance's type implements {@link Comparable}.
*
* @return true if this instance supports sorting property values
* @see #sort sort()
*/
public boolean isSortable() {
return Comparable.class.isAssignableFrom(this.type);
}
/**
* Sort two values of this property. Optional operation.
*
*
* The implementation in {@link PropertyDef} sorts null values first, then delegates to {@link Comparable}
* if the values implement it, or else throws {@link UnsupportedOperationException}.
*
* @param value1 first value, possibly null
* @param value2 second value, possibly null
* @return negative, zero, or positive based on comparing {@code value1} to {@code value2}
* @throws UnsupportedOperationException if this instance does not support sorting property values
*/
@SuppressWarnings({ "unchecked", "null" })
public int sort(T value1, T value2) {
if ((value1 == null) != (value2 == null))
return value1 == null ? -1 : 1;
if (value1 == null && value2 == null)
return 0;
try {
return ((Comparable)value1).compareTo(value2);
} catch (ClassCastException e) {
throw new UnsupportedOperationException(e);
}
}
@Override
public int hashCode() {
return this.name.hashCode()
^ this.type.hashCode()
^ (this.defaultValue != null ? this.defaultValue.hashCode() : 0);
}
@Override
public boolean equals(Object obj) {
if (obj == null || obj.getClass() != this.getClass())
return false;
final PropertyDef that = (PropertyDef)obj;
return this.name.equals(that.name)
&& this.type == that.type
&& (this.defaultValue != null ? this.defaultValue.equals(that.defaultValue) : that.defaultValue == null);
}
@Override
public String toString() {
return this.getClass().getSimpleName() + "[name=\"" + this.name + "\",type="
+ this.type.getName() + ",defaultValue=" + this.defaultValue + "]";
}
}