/*
* Copyright 2007 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.mail.client;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.DockLayoutPanel;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.ResizeComposite;
import com.google.gwt.user.client.ui.ScrollPanel;
import com.google.gwt.user.client.ui.HTMLTable.Cell;
/**
* A composite that displays a list of emails that can be selected.
*/
public class MailList extends ResizeComposite implements ClickHandler {
private static final int VISIBLE_EMAIL_COUNT = 20;
/**
* Callback when mail items are selected.
*/
public interface Listener {
void onItemSelected(MailItem item);
}
private Listener listener;
private HTML countLabel = new HTML();
private HTML newerButton = new HTML("<a href='javascript:;'>< newer</a>",
true);
private HTML olderButton = new HTML("<a href='javascript:;'>older ></a>",
true);
private int startIndex, selectedRow = -1;
private FlexTable header = new FlexTable();
private FlexTable table = new FlexTable();
private HorizontalPanel navBar = new HorizontalPanel();
public MailList() {
// Setup the table.
table.setCellSpacing(0);
table.setCellPadding(0);
// Hook up events.
table.addClickHandler(this);
newerButton.addClickHandler(this);
olderButton.addClickHandler(this);
// Create the 'navigation' bar at the upper-right.
HorizontalPanel innerNavBar = new HorizontalPanel();
navBar.setStyleName("mail-ListNavBar");
innerNavBar.add(newerButton);
innerNavBar.add(countLabel);
innerNavBar.add(olderButton);
navBar.setHorizontalAlignment(HorizontalPanel.ALIGN_RIGHT);
navBar.add(innerNavBar);
navBar.setWidth("100%");
DockLayoutPanel dock = new DockLayoutPanel(Unit.EM);
dock.addNorth(header, 2);
dock.add(new ScrollPanel(table));
header.setWidth("100%");
table.setWidth("100%");
initWidget(dock);
setStyleName("mail-List");
initTable();
update();
}
public void onClick(ClickEvent event) {
Object sender = event.getSource();
if (sender == olderButton) {
// Move forward a page.
startIndex += VISIBLE_EMAIL_COUNT;
if (startIndex >= MailItems.getMailItemCount()) {
startIndex -= VISIBLE_EMAIL_COUNT;
} else {
styleRow(selectedRow, false);
selectedRow = -1;
update();
}
} else if (sender == newerButton) {
// Move back a page.
startIndex -= VISIBLE_EMAIL_COUNT;
if (startIndex < 0) {
startIndex = 0;
} else {
styleRow(selectedRow, false);
selectedRow = -1;
update();
}
} else if (sender == table) {
// Select the row that was clicked (-1 to account for header row).
Cell cell = table.getCellForEvent(event);
if (cell != null) {
int row = cell.getRowIndex();
selectRow(row);
}
}
}
/**
* Sets the listener that will be notified when an item is selected.
*/
public void setListener(Listener listener) {
this.listener = listener;
}
@Override
protected void onLoad() {
// Select the first row if none is selected.
if (selectedRow == -1) {
selectRow(0);
}
}
/**
* Initializes the table so that it contains enough rows for a full page of
* emails. Also creates the images that will be used as 'read' flags.
*/
private void initTable() {
// Create the header.
header.getRowFormatter().setStyleName(0, "mail-ListHeader");
header.getElement().getStyle().setProperty("tableLayout", "fixed");
header.setCellSpacing(0);
header.getColumnFormatter().setWidth(0, "96px");
header.getColumnFormatter().setWidth(1, "160px");
header.getColumnFormatter().setWidth(3, "256px");
header.setText(0, 0, "Sender");
header.setText(0, 1, "Email");
header.setText(0, 2, "Subject");
header.setWidget(0, 3, navBar);
// Initialize the table.
table.getElement().getStyle().setProperty("tableLayout", "fixed");
header.setCellSpacing(0);
table.getColumnFormatter().setWidth(0, "96px");
table.getColumnFormatter().setWidth(1, "160px");
for (int i = 0; i < VISIBLE_EMAIL_COUNT; ++i) {
table.setText(i, 0, "");
table.setText(i, 1, "");
table.setText(i, 2, "");
table.getCellFormatter().setWordWrap(i, 0, false);
table.getCellFormatter().setWordWrap(i, 1, false);
table.getCellFormatter().setWordWrap(i, 2, false);
table.getFlexCellFormatter().setColSpan(i, 2, 2);
}
}
/**
* Selects the given row (relative to the current page).
*
* @param row the row to be selected
*/
private void selectRow(int row) {
// When a row (other than the first one, which is used as a header) is
// selected, display its associated MailItem.
MailItem item = MailItems.getMailItem(startIndex + row);
if (item == null) {
return;
}
styleRow(selectedRow, false);
styleRow(row, true);
item.read = true;
selectedRow = row;
if (listener != null) {
listener.onItemSelected(item);
}
}
private void styleRow(int row, boolean selected) {
if (row != -1) {
if (selected) {
table.getRowFormatter().addStyleName(row, "mail-SelectedRow");
} else {
table.getRowFormatter().removeStyleName(row, "mail-SelectedRow");
}
}
}
private void update() {
// Update the older/newer buttons & label.
int count = MailItems.getMailItemCount();
int max = startIndex + VISIBLE_EMAIL_COUNT;
if (max > count) {
max = count;
}
newerButton.setVisible(startIndex != 0);
olderButton.setVisible(startIndex + VISIBLE_EMAIL_COUNT < count);
countLabel.setText("" + (startIndex + 1) + " - " + max + " of " + count);
// Show the selected emails.
int i = 0;
for (; i < VISIBLE_EMAIL_COUNT; ++i) {
// Don't read past the end.
if (startIndex + i >= MailItems.getMailItemCount()) {
break;
}
MailItem item = MailItems.getMailItem(startIndex + i);
// Add a new row to the table, then set each of its columns to the
// email's sender and subject values.
table.setText(i, 0, item.sender);
table.setText(i, 1, item.email);
table.setText(i, 2, item.subject);
}
// Clear any remaining slots.
for (; i < VISIBLE_EMAIL_COUNT; ++i) {
table.setHTML(i, 0, " ");
table.setHTML(i, 1, " ");
table.setHTML(i, 2, " ");
}
}
}