/*
* 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.sample.showcase.client.content.cell;
import com.google.gwt.cell.client.AbstractCell;
import com.google.gwt.cell.client.Cell;
import com.google.gwt.cell.client.CheckboxCell;
import com.google.gwt.cell.client.CompositeCell;
import com.google.gwt.cell.client.FieldUpdater;
import com.google.gwt.cell.client.HasCell;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Element;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.sample.showcase.client.content.cell.ContactDatabase.Category;
import com.google.gwt.sample.showcase.client.content.cell.ContactDatabase.ContactInfo;
import com.google.gwt.sample.showcase.client.content.cell.CwCellList.ContactCell;
import com.google.gwt.user.client.ui.AbstractImagePrototype;
import com.google.gwt.view.client.DefaultSelectionEventManager;
import com.google.gwt.view.client.ListDataProvider;
import com.google.gwt.view.client.SelectionModel;
import com.google.gwt.view.client.TreeViewModel;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
/**
* The {@link TreeViewModel} used to organize contacts into a hierarchy.
*/
public class ContactTreeViewModel implements TreeViewModel {
/**
* The images used for this example.
*/
static interface Images extends ClientBundle {
ImageResource contact();
ImageResource contactsGroup();
}
/**
* The cell used to render categories.
*/
private static class CategoryCell extends AbstractCell<Category> {
/**
* The html of the image used for contacts.
*/
private final String imageHtml;
public CategoryCell(ImageResource image) {
this.imageHtml = AbstractImagePrototype.create(image).getHTML();
}
@Override
public void render(Context context, Category value, SafeHtmlBuilder sb) {
if (value != null) {
sb.appendHtmlConstant(imageHtml).appendEscaped(" ");
sb.appendEscaped(value.getDisplayName());
}
}
}
/**
* Tracks the number of contacts in a category that begin with the same
* letter.
*/
private static class LetterCount implements Comparable<LetterCount> {
private final Category category;
private final char firstLetter;
private int count;
/**
* Construct a new {@link LetterCount} for one contact.
*
* @param category the category
* @param firstLetter the first letter of the contacts name
*/
public LetterCount(Category category, char firstLetter) {
this.category = category;
this.firstLetter = firstLetter;
this.count = 1;
}
public int compareTo(LetterCount o) {
return (o == null) ? -1 : (firstLetter - o.firstLetter);
}
@Override
public boolean equals(Object o) {
return compareTo((LetterCount) o) == 0;
}
@Override
public int hashCode() {
return firstLetter;
}
/**
* Increment the count.
*/
public void increment() {
count++;
}
}
/**
* A Cell used to render the LetterCount.
*/
private static class LetterCountCell extends AbstractCell<LetterCount> {
@Override
public void render(Context context, LetterCount value, SafeHtmlBuilder sb) {
if (value != null) {
sb.appendEscaped(value.firstLetter + " (" + value.count + ")");
}
}
}
/**
* The static images used in this model.
*/
private static Images images;
private final ListDataProvider<Category> categoryDataProvider;
private final Cell<ContactInfo> contactCell;
private final DefaultSelectionEventManager<ContactInfo> selectionManager =
DefaultSelectionEventManager.createCheckboxManager();
private final SelectionModel<ContactInfo> selectionModel;
public ContactTreeViewModel(final SelectionModel<ContactInfo> selectionModel) {
this.selectionModel = selectionModel;
if (images == null) {
images = GWT.create(Images.class);
}
// Create a data provider that provides categories.
categoryDataProvider = new ListDataProvider<Category>();
List<Category> categoryList = categoryDataProvider.getList();
for (Category category : ContactDatabase.get().queryCategories()) {
categoryList.add(category);
}
// Construct a composite cell for contacts that includes a checkbox.
List<HasCell<ContactInfo, ?>> hasCells = new ArrayList<HasCell<ContactInfo, ?>>();
hasCells.add(new HasCell<ContactInfo, Boolean>() {
private CheckboxCell cell = new CheckboxCell(true, false);
public Cell<Boolean> getCell() {
return cell;
}
public FieldUpdater<ContactInfo, Boolean> getFieldUpdater() {
return null;
}
public Boolean getValue(ContactInfo object) {
return selectionModel.isSelected(object);
}
});
hasCells.add(new HasCell<ContactInfo, ContactInfo>() {
private ContactCell cell = new ContactCell(images.contact());
public Cell<ContactInfo> getCell() {
return cell;
}
public FieldUpdater<ContactInfo, ContactInfo> getFieldUpdater() {
return null;
}
public ContactInfo getValue(ContactInfo object) {
return object;
}
});
contactCell = new CompositeCell<ContactInfo>(hasCells) {
@Override
public void render(Context context, ContactInfo value, SafeHtmlBuilder sb) {
sb.appendHtmlConstant("<table><tbody><tr>");
super.render(context, value, sb);
sb.appendHtmlConstant("</tr></tbody></table>");
}
@Override
protected Element getContainerElement(Element parent) {
// Return the first TR element in the table.
return parent.getFirstChildElement().getFirstChildElement().getFirstChildElement();
}
@Override
protected <X> void render(Context context, ContactInfo value,
SafeHtmlBuilder sb, HasCell<ContactInfo, X> hasCell) {
Cell<X> cell = hasCell.getCell();
sb.appendHtmlConstant("<td>");
cell.render(context, hasCell.getValue(value), sb);
sb.appendHtmlConstant("</td>");
}
};
}
public <T> NodeInfo<?> getNodeInfo(T value) {
if (value == null) {
// Return top level categories.
return new DefaultNodeInfo<Category>(categoryDataProvider,
new CategoryCell(images.contactsGroup()));
} else if (value instanceof Category) {
// Return the first letters of each first name.
Category category = (Category) value;
List<ContactInfo> contacts = ContactDatabase.get().queryContactsByCategory(
category);
Map<Character, LetterCount> counts = new TreeMap<Character, LetterCount>();
for (ContactInfo contact : contacts) {
Character first = contact.getFirstName().charAt(0);
LetterCount count = counts.get(first);
if (count == null) {
count = new LetterCount(category, first);
counts.put(first, count);
} else {
count.increment();
}
}
List<LetterCount> orderedCounts = new ArrayList<LetterCount>(
counts.values());
return new DefaultNodeInfo<LetterCount>(
new ListDataProvider<LetterCount>(orderedCounts),
new LetterCountCell());
} else if (value instanceof LetterCount) {
// Return the contacts with the specified character and first name.
LetterCount count = (LetterCount) value;
List<ContactInfo> contacts = ContactDatabase.get().queryContactsByCategoryAndFirstName(
count.category, count.firstLetter + "");
ListDataProvider<ContactInfo> dataProvider = new ListDataProvider<ContactInfo>(
contacts, ContactInfo.KEY_PROVIDER);
return new DefaultNodeInfo<ContactInfo>(
dataProvider, contactCell, selectionModel, selectionManager, null);
}
// Unhandled type.
String type = value.getClass().getName();
throw new IllegalArgumentException("Unsupported object type: " + type);
}
public boolean isLeaf(Object value) {
return value instanceof ContactInfo;
}
}