org.primefaces.component.datatable.feature.ScrollFeature Maven / Gradle / Ivy
/*
* Copyright 2009-2014 PrimeTek.
*
* 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 org.primefaces.component.datatable.feature;
import java.io.IOException;
import java.util.Map;
import javax.faces.context.FacesContext;
import org.primefaces.component.datatable.DataTable;
import org.primefaces.component.datatable.DataTableRenderer;
public class ScrollFeature implements DataTableFeature {
public void decode(FacesContext context, DataTable table) {
throw new RuntimeException("RowScrollFeature should not decode.");
}
public void encode(FacesContext context, DataTableRenderer renderer, DataTable table) throws IOException {
Map params = context.getExternalContext().getRequestParameterMap();
int scrollRows = table.getScrollRows();
String clientId = table.getClientId(context);
boolean isVirtualScroll = table.isVirtualScroll();
boolean isLazy = table.isLazy();
int scrollOffset = 0;
if(isVirtualScroll) {
scrollOffset = Integer.parseInt(params.get(table.getClientId(context) + "_first"));
int rowCount = table.getRowCount();
int virtualScrollRows = (scrollRows * 2);
scrollRows = (scrollOffset + virtualScrollRows) > rowCount ? (rowCount - scrollOffset) : virtualScrollRows;
}
else {
scrollOffset = Integer.parseInt(params.get(table.getClientId(context) + "_scrollOffset"));
table.setScrollOffset(scrollOffset);
}
if (isLazy) {
table.loadLazyScrollData(scrollOffset, scrollRows);
}
if (table.isSelectionEnabled()) {
table.findSelectedRowKeys();
}
int firstIndex = (isLazy && isVirtualScroll) ? 0 : scrollOffset;
int lastIndex = (firstIndex + scrollRows);
for (int i = firstIndex; i < lastIndex; i++) {
table.setRowIndex(i);
if (table.isRowAvailable()) {
int rowIndex = (isLazy && isVirtualScroll) ? scrollOffset + i : i;
renderer.encodeRow(context, table, clientId, rowIndex);
}
}
}
public boolean shouldDecode(FacesContext context, DataTable table) {
return false;
}
public boolean shouldEncode(FacesContext context, DataTable table) {
return context.getExternalContext().getRequestParameterMap().containsKey(table.getClientId(context) + "_scrolling");
}
}