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- /*
- * Copyright 2000-2014 Vaadin Ltd.
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not
- * use this file except in compliance with the License. You may obtain a copy of
- * the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations under
- * the License.
- */
- package com.vaadin.data.util.filter;
-
- import com.vaadin.data.Container.Filter;
- import com.vaadin.data.Item;
- import com.vaadin.data.Property;
-
- /**
- * Simple container filter checking whether an item property value is null.
- *
- * This filter also directly supports in-memory filtering.
- *
- * @since 6.6
- */
- public final class IsNull implements Filter {
-
- private final Object propertyId;
-
- /**
- * Constructor for a filter that compares the value of an item property with
- * null.
- *
- * For in-memory filtering, a simple == check is performed. For other
- * containers, the comparison implementation is container dependent but
- * should correspond to the in-memory null check.
- *
- * @param propertyId
- * the identifier (not null) of the property whose value to check
- */
- public IsNull(Object propertyId) {
- this.propertyId = propertyId;
- }
-
- @Override
- public boolean passesFilter(Object itemId, Item item)
- throws UnsupportedOperationException {
- final Property<?> p = item.getItemProperty(getPropertyId());
- if (null == p) {
- return false;
- }
- return null == p.getValue();
- }
-
- @Override
- public boolean appliesToProperty(Object propertyId) {
- return getPropertyId().equals(propertyId);
- }
-
- @Override
- public boolean equals(Object obj) {
- if (obj == null) {
- return false;
- }
-
- // Only objects of the same class can be equal
- if (!getClass().equals(obj.getClass())) {
- return false;
- }
- final IsNull o = (IsNull) obj;
-
- // Checks the properties one by one
- return (null != getPropertyId()) ? getPropertyId().equals(
- o.getPropertyId()) : null == o.getPropertyId();
- }
-
- @Override
- public int hashCode() {
- return (null != getPropertyId() ? getPropertyId().hashCode() : 0);
- }
-
- /**
- * Returns the property id of the property tested by the filter, not null
- * for valid filters.
- *
- * @return property id (not null)
- */
- public Object getPropertyId() {
- return propertyId;
- }
-
- }
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