/*
* Copyright 2011 SWM Services GmbH.
*
* 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 de.swm.commons.mobile.client.widgets;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.user.client.ui.Label;
import de.swm.commons.mobile.client.SWMMobile;
import de.swm.commons.mobile.client.event.DragController;
import de.swm.commons.mobile.client.event.DragEvent;
import de.swm.commons.mobile.client.event.DragEventsHandler;
import de.swm.commons.mobile.client.utils.IsSWMMobileWidgetHelper;
import de.swm.commons.mobile.client.widgets.scroll.ScrollPanel;
import java.util.List;
/**
* Indes scroll panel is a address book like widget that orders his entries alphabetically including a selection index
* displayed on the right.
*/
public class IndexedScrollPanelWithPager extends HorizontalPanel {
private static final double INNER_HEIGHT = 90.0;
private static final double OUTER_HEIGHT = 100.0;
private static final String[] letters = { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P",
"Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };
/**
* Inner class that represents the alphabetical selection index.
*/
public class IndexPanel extends VerticalPanel implements DragEventsHandler {
private static final int PADDING = 4;
private static final int NO_OF_LETTERS = 26;
private final IsSWMMobileWidgetHelper myWidgetHelper = new IsSWMMobileWidgetHelper();
private final int[] sectionHeight = new int[NO_OF_LETTERS];
private int absY, letterHeight;
private final ScrollPanel scroller;
/**
* Default constructor.
*
* @param scroller the indexed scroller.
*/
public IndexPanel(final ScrollPanel scroller) {
this.scroller = scroller;
addStyleName(SWMMobile.getTheme().getMGWTCssBundle().getIndexPanelCss().indexPanel());
for (int i = 0; i < NO_OF_LETTERS; i++) {
add(new Label(letters[i]));
sectionHeight[i] = -1;
}
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
@Override
public void execute() {
absY = getAbsoluteTop() + PADDING; // include padding
letterHeight = getWidget(0).getElement().getClientHeight();
}
});
}
/**
* Updates the positions.
*/
void updateSectionPositions() {
for (int i = 0; i < NO_OF_LETTERS; i++) {
sectionHeight[i] = -1;
}
ListPanel list = (ListPanel) scroller.getWidget();
int s = 0;
for (int i = 0; i < list.getWidgetCount(); i++) {
ListItem item = list.getItem(i);
if (item.getElement().getClassName()
.contains(SWMMobile.getTheme().getMGWTCssBundle().getIndexPanelCss().indexHeaderListItem())) {
sectionHeight[s++] = item.getElement().getOffsetTop();
}
}
}
@Override
public void onLoad() {
super.onLoad();
DragController.get().addDragEventsHandler(this);
myWidgetHelper.checkInitialLoad(this);
}
@Override
public void onUnload() {
DragController.get().removeDragEventsHandler(this);
}
@Override
public void onDragStart(DragEvent e) {
// do nothing
}
@Override
public void onDragMove(DragEvent e) {
int index = (((int) e.getY()) - absY) / letterHeight;
index = Math.max(0, index);
index = Math.min(NO_OF_LETTERS - 1, index);
if (sectionHeight[index] >= 0) {
scroller.setScrollPosition(-sectionHeight[index]);
}
}
@Override
public void onDragEnd(DragEvent e) {
int index = (((int) e.getY()) - absY) / letterHeight;
index = Math.max(0, index);
index = Math.min(NO_OF_LETTERS - 1, index);
if (sectionHeight[index] >= 0) {
scroller.setScrollPosition(-sectionHeight[index]);
}
}
}
private final IndexPanel indexPanel;
private final ScrollPanel scroller;
private final ListPanel list;
/**
* Default constructor.
*/
public IndexedScrollPanelWithPager() {
addStyleName(SWMMobile.getTheme().getMGWTCssBundle().getIndexPanelCss().indexedScrollPanel());
getElement().getStyle().setHeight(INNER_HEIGHT, Unit.PCT); // compensation for height of header panel
scroller = new ScrollPanel();
scroller.getElement().getStyle().setHeight(OUTER_HEIGHT, Unit.PCT);
list = new ListPanel();
createAlphabeticalIndex();
scroller.add(list);
add(scroller);
indexPanel = new IndexPanel(scroller);
add(indexPanel);
}
/**
* Create the basic index structure,.
*/
private void createAlphabeticalIndex() {
for (int i = 0; i < letters.length; i++) {
ListItem item = new ListItem();
item.addStyleName(SWMMobile.getTheme().getMGWTCssBundle().getIndexPanelCss().indexHeaderListItem());
item.add(new Label(letters[i]));
item.setDisabled(true);
list.add(item);
}
}
/**
* Adds the items to the pannel.
*
* @param sectionIndex the selection index
* @param items the items
*/
public void setIndexedItems(int sectionIndex, List<ListItem> items) {
int pos = findIndexedSectionPosition(sectionIndex);
if (pos >= 0) {
for (int j = items.size(); j > 0; j--) {
list.insert(items.get(j - 1), (pos + 1));
}
}
}
/**
* Clears all entries.
*
* @see de.swm.commons.mobile.client.base.PanelBase#clear()
*/
@Override
public void clear() {
list.clear();
createAlphabeticalIndex();
}
/**
* Updated the index.
*/
public void updateIndex() {
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
@Override
public void execute() {
indexPanel.updateSectionPositions();
}
});
}
/**
* Finds the screen position of an concrete index
*
* @param sectionIndex the index
* @return the screen position.
*/
private int findIndexedSectionPosition(int sectionIndex) {
ListPanel list = (ListPanel) scroller.getWidget();
int s = 0;
for (int i = 0; i < list.getWidgetCount(); i++) {
ListItem item = list.getItem(i);
if (item.getElement().getClassName()
.contains(SWMMobile.getTheme().getMGWTCssBundle().getIndexPanelCss().indexHeaderListItem())) {
if (s == sectionIndex) {
return i;
}
s++;
}
}
return -1;
}
}