com.google.gwt.user.cellview.client.Header Maven / Gradle / Ivy
/*
* Copyright 2010 Google Inc.
*
* 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.google.gwt.user.cellview.client;
import com.google.gwt.cell.client.Cell;
import com.google.gwt.cell.client.Cell.Context;
import com.google.gwt.cell.client.ValueUpdater;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
/**
* A table column header or footer.
*
* @param the {@link Cell} type
*/
public abstract class Header {
private final Cell cell;
private ValueUpdater updater;
/**
* Construct a Header with a given {@link Cell}.
*
* @param cell the {@link Cell} responsible for rendering items in the header
*/
public Header(Cell cell) {
this.cell = cell;
}
/**
* Return the {@link Cell} responsible for rendering items in the header.
*
* @return the header Cell
*/
public Cell getCell() {
return cell;
}
/**
* Get the key for the header value. By default, the key is the same as the
* value. Override this method to return a custom key.
*
* @return the key associated with the value
*/
public Object getKey() {
return getValue();
}
/**
* Return the header value.
*
* @return the header value
*/
public abstract H getValue();
/**
* Handle a browser event that took place within the header.
*
* @param context the context of the header
* @param elem the parent Element
* @param event the native browser event
*/
public void onBrowserEvent(Context context, Element elem, NativeEvent event) {
cell.onBrowserEvent(context, elem, getValue(), event, updater);
}
/**
* Render the header.
*
* @param context the context of the header
* @param sb a {@link SafeHtmlBuilder} to render into
*/
public void render(Context context, SafeHtmlBuilder sb) {
cell.render(context, getValue(), sb);
}
/**
* Set the {@link ValueUpdater}.
*
* @param updater the value updater to use
*/
public void setUpdater(ValueUpdater updater) {
this.updater = updater;
}
}