com.vaadin.client.connectors.AbstractMultiSelectConnector Maven / Gradle / Ivy
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/*
* Copyright 2000-2016 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.client.connectors;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.function.BiConsumer;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.IsWidget;
import com.google.gwt.user.client.ui.Widget;
import com.vaadin.client.data.DataSource;
import com.vaadin.client.ui.HasRequiredIndicator;
import com.vaadin.shared.Range;
import com.vaadin.shared.Registration;
import com.vaadin.shared.data.selection.MultiSelectServerRpc;
import com.vaadin.shared.ui.ListingJsonConstants;
import com.vaadin.shared.ui.abstractmultiselect.AbstractMultiSelectState;
import elemental.json.JsonObject;
/**
* A base connector class for multiselects.
*
* Does not care about the framework provided selection model for now, instead
* just passes selection information per item.
*
* @author Vaadin Ltd.
*
* @since 8.0
*/
public abstract class AbstractMultiSelectConnector
extends AbstractListingConnector implements HasRequiredIndicator {
/**
* Abstraction layer to help populate different multiselect widgets based on
* same JSON data.
*/
public interface MultiSelectWidget {
/**
* Sets the given items to the select.
*
* @param items
* the items for the select
*/
void setItems(List items);
/**
* Adds a selection change listener the select.
*
* @param selectionChangeListener
* the listener to add, not {@code null}
* @return a registration handle to remove the listener
*/
Registration addSelectionChangeListener(
BiConsumer, Set> selectionChangeListener);
/**
* Returns the caption for the given item.
*
* @param item
* the item, not {@code null}
* @return caption of the item
*/
static String getCaption(JsonObject item) {
return item.getString(ListingJsonConstants.JSONKEY_ITEM_VALUE);
}
/**
* Returns the key for the given item.
*
* @param item
* the item, not {@code null}
* @return key of the item
*/
static String getKey(JsonObject item) {
return getRowKey(item);
}
/**
* Returns whether the given item is enabled or not.
*
* Disabling items is not supported by all multiselects.
*
* @param item
* the item, not {@code null}
* @return {@code true} enabled, {@code false} if not
*/
static boolean isEnabled(JsonObject item) {
return !(item.hasKey(ListingJsonConstants.JSONKEY_ITEM_DISABLED)
&& item.getBoolean(
ListingJsonConstants.JSONKEY_ITEM_DISABLED));
}
/**
* Returns whether this item is selected or not.
*
* @param item
* the item, not {@code null}
* @return {@code true} is selected, {@code false} if not
*/
static boolean isSelected(JsonObject item) {
return item.getBoolean(ListingJsonConstants.JSONKEY_ITEM_SELECTED);
}
/**
* Returns the optional icon URL for the given item.
*
* Item icons are not supported by all multiselects.
*
* @param item
* the item
* @return the optional icon URL, or an empty optional if none specified
*/
static Optional getIconUrl(JsonObject item) {
return Optional.ofNullable(
item.getString(ListingJsonConstants.JSONKEY_ITEM_ICON));
}
}
/**
* Returns the multiselect widget for this connector.
*
* This is used because {@link #getWidget()} returns a class
* ({@link Widget}) instead of an interface ({@link IsWidget}), and most
* multiselects extends {@link Composite}.
*
* @return the multiselect widget
*/
public abstract MultiSelectWidget getMultiSelectWidget();
@Override
protected void init() {
super.init();
MultiSelectServerRpc rpcProxy = getRpcProxy(MultiSelectServerRpc.class);
getMultiSelectWidget().addSelectionChangeListener(
(addedItems, removedItems) -> rpcProxy
.updateSelection(addedItems, removedItems));
}
@Override
public AbstractMultiSelectState getState() {
return (AbstractMultiSelectState) super.getState();
}
@Override
public void setDataSource(DataSource dataSource) {
dataSource.addDataChangeHandler(this::onDataChange);
super.setDataSource(dataSource);
}
/**
* This method handles the parsing of the new JSON data containing the items
* and the selection information.
*
* @param range
* the updated range, never {@code null}
*/
protected void onDataChange(Range range) {
assert range.getStart() == 0
&& range.getEnd() == getDataSource().size() : getClass()
.getSimpleName()
+ " only supports full updates, but got range " + range;
List items = new ArrayList<>(range.length());
for (int i = 0; i < range.getEnd(); i++) {
items.add(getDataSource().getRow(i));
}
getMultiSelectWidget().setItems(items);
}
@Override
public boolean isRequiredIndicatorVisible() {
return getState().required && !isReadOnly();
}
}