/*
* 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.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.CssResource;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.resources.client.ImageResource.ImageOptions;
import com.google.gwt.uibinder.client.UiConstructor;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HasVerticalAlignment;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.view.client.HasRows;
import com.google.gwt.view.client.Range;
/**
* A pager for controlling a {@link HasRows} that only supports simple page
* navigation.
*
* <p>
* <h3>Example</h3>
* {@example com.google.gwt.examples.cellview.SimplePagerExample}
* </p>
*/
public class SimplePager extends AbstractPager {
/**
* A ClientBundle that provides images for this widget.
*/
public static interface Resources extends ClientBundle {
/**
* The image used to skip ahead multiple pages.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerFastForward();
/**
* The disabled "fast forward" image.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerFastForwardDisabled();
/**
* The image used to go to the first page.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerFirstPage();
/**
* The disabled first page image.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerFirstPageDisabled();
/**
* The image used to go to the last page.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerLastPage();
/**
* The disabled last page image.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerLastPageDisabled();
/**
* The image used to go to the next page.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerNextPage();
/**
* The disabled next page image.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerNextPageDisabled();
/**
* The image used to go to the previous page.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerPreviousPage();
/**
* The disabled previous page image.
*/
@ImageOptions(flipRtl = true)
ImageResource simplePagerPreviousPageDisabled();
/**
* The styles used in this widget.
*/
@Source("SimplePager.css")
Style simplePagerStyle();
}
/**
* Styles used by this widget.
*/
public static interface Style extends CssResource {
/**
* Applied to buttons.
*/
String button();
/**
* Applied to disabled buttons.
*/
String disabledButton();
/**
* Applied to the details text.
*/
String pageDetails();
}
/**
* The location of the text relative to the paging buttons.
*/
public static enum TextLocation {
CENTER, LEFT, RIGHT;
}
/**
* An {@link Image} that acts as a button.
*/
private static class ImageButton extends Image {
private boolean disabled;
private final ImageResource resDisabled;
private final ImageResource resEnabled;
private final String styleDisabled;
public ImageButton(ImageResource resEnabled, ImageResource resDiabled,
String disabledStyle) {
super(resEnabled);
this.resEnabled = resEnabled;
this.resDisabled = resDiabled;
this.styleDisabled = disabledStyle;
}
public boolean isDisabled() {
return disabled;
}
@Override
public void onBrowserEvent(Event event) {
// Ignore events if disabled.
if (disabled) {
return;
}
super.onBrowserEvent(event);
}
public void setDisabled(boolean isDisabled) {
if (this.disabled == isDisabled) {
return;
}
this.disabled = isDisabled;
if (disabled) {
setResource(resDisabled);
getElement().getParentElement().addClassName(styleDisabled);
} else {
setResource(resEnabled);
getElement().getParentElement().removeClassName(styleDisabled);
}
}
}
private static int DEFAULT_FAST_FORWARD_ROWS = 1000;
private static Resources DEFAULT_RESOURCES;
private static Resources getDefaultResources() {
if (DEFAULT_RESOURCES == null) {
DEFAULT_RESOURCES = GWT.create(Resources.class);
}
return DEFAULT_RESOURCES;
}
private final ImageButton fastForward;
private final int fastForwardRows;
private final ImageButton firstPage;
/**
* We use an {@link HTML} so we can embed the loading image.
*/
private final HTML label = new HTML();
private final ImageButton lastPage;
private final ImageButton nextPage;
private final ImageButton prevPage;
/**
* The {@link Resources} used by this widget.
*/
private final Resources resources;
/**
* The {@link Style} used by this widget.
*/
private final Style style;
/**
* Construct a {@link SimplePager} with the default text location.
*/
public SimplePager() {
this(TextLocation.CENTER);
}
/**
* Construct a {@link SimplePager} with the specified text location.
*
* @param location the location of the text relative to the buttons
*/
@UiConstructor
// Hack for Google I/O demo
public SimplePager(TextLocation location) {
this(location, getDefaultResources(), true, DEFAULT_FAST_FORWARD_ROWS,
false);
}
/**
* Construct a {@link SimplePager} with the specified resources.
*
* @param location the location of the text relative to the buttons
* @param resources the {@link Resources} to use
* @param showFastForwardButton if true, show a fast-forward button that
* advances by a larger increment than a single page
* @param fastForwardRows the number of rows to jump when fast forwarding
* @param showLastPageButton if true, show a button to go the the last page
*/
public SimplePager(TextLocation location, Resources resources,
boolean showFastForwardButton, final int fastForwardRows,
boolean showLastPageButton) {
this.resources = resources;
this.fastForwardRows = fastForwardRows;
this.style = resources.simplePagerStyle();
this.style.ensureInjected();
// Create the buttons.
String disabledStyle = style.disabledButton();
firstPage = new ImageButton(resources.simplePagerFirstPage(),
resources.simplePagerFirstPageDisabled(), disabledStyle);
firstPage.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
firstPage();
}
});
nextPage = new ImageButton(resources.simplePagerNextPage(),
resources.simplePagerNextPageDisabled(), disabledStyle);
nextPage.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
nextPage();
}
});
prevPage = new ImageButton(resources.simplePagerPreviousPage(),
resources.simplePagerPreviousPageDisabled(), disabledStyle);
prevPage.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
previousPage();
}
});
if (showLastPageButton) {
lastPage = new ImageButton(resources.simplePagerLastPage(),
resources.simplePagerLastPageDisabled(), disabledStyle);
lastPage.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
lastPage();
}
});
} else {
lastPage = null;
}
if (showFastForwardButton) {
fastForward = new ImageButton(resources.simplePagerFastForward(),
resources.simplePagerFastForwardDisabled(), disabledStyle);
fastForward.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
setPage(getPage() + getFastForwardPages());
}
});
} else {
fastForward = null;
}
// Construct the widget.
HorizontalPanel layout = new HorizontalPanel();
layout.setVerticalAlignment(HasVerticalAlignment.ALIGN_MIDDLE);
initWidget(layout);
if (location == TextLocation.RIGHT) {
layout.add(label);
}
layout.add(firstPage);
layout.add(prevPage);
if (location == TextLocation.CENTER) {
layout.add(label);
}
layout.add(nextPage);
if (showFastForwardButton) {
layout.add(fastForward);
}
if (showLastPageButton) {
layout.add(lastPage);
}
if (location == TextLocation.LEFT) {
layout.add(label);
}
// Add style names to the cells.
firstPage.getElement().getParentElement().addClassName(style.button());
prevPage.getElement().getParentElement().addClassName(style.button());
label.getElement().getParentElement().addClassName(style.pageDetails());
nextPage.getElement().getParentElement().addClassName(style.button());
if (showFastForwardButton) {
fastForward.getElement().getParentElement().addClassName(style.button());
}
if (showLastPageButton) {
lastPage.getElement().getParentElement().addClassName(style.button());
}
// Disable the buttons by default.
setDisplay(null);
}
@Override
public void firstPage() {
super.firstPage();
}
@Override
public int getPage() {
return super.getPage();
}
@Override
public int getPageCount() {
return super.getPageCount();
}
@Override
public boolean hasNextPage() {
return super.hasNextPage();
}
@Override
public boolean hasNextPages(int pages) {
return super.hasNextPages(pages);
}
@Override
public boolean hasPage(int index) {
return super.hasPage(index);
}
@Override
public boolean hasPreviousPage() {
return super.hasPreviousPage();
}
@Override
public boolean hasPreviousPages(int pages) {
return super.hasPreviousPages(pages);
}
@Override
public void lastPage() {
super.lastPage();
}
@Override
public void lastPageStart() {
super.lastPageStart();
}
@Override
public void nextPage() {
super.nextPage();
}
@Override
public void previousPage() {
super.previousPage();
}
@Override
public void setDisplay(HasRows display) {
// Enable or disable all buttons.
boolean disableButtons = (display == null);
setFastForwardDisabled(disableButtons);
setNextPageButtonsDisabled(disableButtons);
setPrevPageButtonsDisabled(disableButtons);
super.setDisplay(display);
}
@Override
public void setPage(int index) {
super.setPage(index);
}
@Override
public void setPageSize(int pageSize) {
super.setPageSize(pageSize);
}
@Override
public void setPageStart(int index) {
super.setPageStart(index);
}
/**
* Let the page know that the table is loading. Call this method to clear all
* data from the table and hide the current range when new data is being
* loaded into the table.
*/
public void startLoading() {
getDisplay().setRowCount(0, true);
label.setHTML("");
}
/**
* Get the text to display in the pager that reflects the state of the pager.
*
* @return the text
*/
protected String createText() {
// Default text is 1 based.
NumberFormat formatter = NumberFormat.getFormat("#,###");
HasRows display = getDisplay();
Range range = display.getVisibleRange();
int pageStart = range.getStart() + 1;
int pageSize = range.getLength();
int dataSize = display.getRowCount();
int endIndex = Math.min(dataSize, pageStart + pageSize - 1);
endIndex = Math.max(pageStart, endIndex);
boolean exact = display.isRowCountExact();
return formatter.format(pageStart) + "-" + formatter.format(endIndex)
+ (exact ? " of " : " of over ") + formatter.format(dataSize);
}
@Override
protected void onRangeOrRowCountChanged() {
HasRows display = getDisplay();
label.setText(createText());
// Update the prev and first buttons.
setPrevPageButtonsDisabled(!hasPreviousPage());
// Update the next and last buttons.
if (isRangeLimited() || !display.isRowCountExact()) {
setNextPageButtonsDisabled(!hasNextPage());
setFastForwardDisabled(!hasNextPages(getFastForwardPages()));
}
}
/**
* Check if the next button is disabled. Visible for testing.
*/
boolean isNextButtonDisabled() {
return nextPage.isDisabled();
}
/**
* Check if the previous button is disabled. Visible for testing.
*/
boolean isPreviousButtonDisabled() {
return prevPage.isDisabled();
}
/**
* Get the number of pages to fast forward based on the current page size.
*
* @return the number of pages to fast forward
*/
private int getFastForwardPages() {
int pageSize = getPageSize();
return pageSize > 0 ? fastForwardRows / pageSize : 0;
}
/**
* Enable or disable the fast forward button.
*
* @param disabled true to disable, false to enable
*/
private void setFastForwardDisabled(boolean disabled) {
if (fastForward == null) {
return;
}
if (disabled) {
fastForward.setResource(resources.simplePagerFastForwardDisabled());
fastForward.getElement().getParentElement().addClassName(
style.disabledButton());
} else {
fastForward.setResource(resources.simplePagerFastForward());
fastForward.getElement().getParentElement().removeClassName(
style.disabledButton());
}
}
/**
* Enable or disable the next page buttons.
*
* @param disabled true to disable, false to enable
*/
private void setNextPageButtonsDisabled(boolean disabled) {
nextPage.setDisabled(disabled);
if (lastPage != null) {
lastPage.setDisabled(disabled);
}
}
/**
* Enable or disable the previous page buttons.
*
* @param disabled true to disable, false to enable
*/
private void setPrevPageButtonsDisabled(boolean disabled) {
firstPage.setDisabled(disabled);
prevPage.setDisabled(disabled);
}
}