com.google.gwt.user.cellview.client.PageSizePager 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.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.uibinder.client.UiConstructor;
import com.google.gwt.user.client.ui.Anchor;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.view.client.HasRows;
import com.google.gwt.view.client.Range;
/**
* A simple pager that controls the page size.
*/
public class PageSizePager extends AbstractPager {
/**
* The increment by which to grow or shrink the page size.
*/
private final int increment;
/**
* The main layout widget.
*/
private final FlexTable layout = new FlexTable();
// TODO(jlabanca): I18N button text.
private final Anchor showMoreButton = new Anchor("Show More");
private final Anchor showLessButton = new Anchor("Show Less");
/**
* Construct a PageSizePager with a given increment.
*
* @param increment the amount by which to increase the page size
*/
@UiConstructor
public PageSizePager(final int increment) {
this.increment = increment;
initWidget(layout);
layout.setCellPadding(0);
layout.setCellSpacing(0);
// Show more button.
showMoreButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
// Display should be non-null, but we check defensively.
HasRows display = getDisplay();
if (display != null) {
Range range = display.getVisibleRange();
int pageSize = Math.min(range.getLength() + increment,
display.getRowCount()
+ (display.isRowCountExact() ? 0 : increment));
display.setVisibleRange(range.getStart(), pageSize);
}
}
});
showLessButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
// Display should be non-null, but we check defensively.
HasRows display = getDisplay();
if (display != null) {
Range range = display.getVisibleRange();
int pageSize = Math.max(range.getLength() - increment, increment);
display.setVisibleRange(range.getStart(), pageSize);
}
}
});
// Add the buttons to the pager.
layout.setWidget(0, 0, showLessButton);
layout.setText(0, 1, " | ");
layout.setWidget(0, 2, showMoreButton);
// Hide the buttons by default.
setDisplay(null);
}
@Override
public void setDisplay(HasRows display) {
// Hide the buttons if the display is null. If the display is non-null, the
// buttons will be displayed in onRangeOrRowCountChanged().
if (display == null) {
showLessButton.setVisible(false);
showMoreButton.setVisible(false);
}
super.setDisplay(display);
}
@Override
public void setPageSize(int pageSize) {
super.setPageSize(pageSize);
}
@Override
protected void onRangeOrRowCountChanged() {
// Assumes a page start index of 0.
HasRows display = getDisplay();
int pageSize = display.getVisibleRange().getLength();
boolean hasLess = pageSize > increment;
boolean hasMore = !display.isRowCountExact()
|| pageSize < display.getRowCount();
showLessButton.setVisible(hasLess);
showMoreButton.setVisible(hasMore);
layout.setText(0, 1, (hasLess && hasMore) ? " | " : "");
}
/**
* Visible for testing.
*/
boolean isShowLessButtonVisible() {
return showLessButton.isVisible();
}
/**
* Visible for testing.
*/
boolean isShowMoreButtonVisible() {
return showMoreButton.isVisible();
}
}