/* * Copyright 2006 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.user.client.ui.ClickListener;import com.google.gwt.user.client.ui.Composite;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.SourcesTableEvents;import com.google.gwt.user.client.ui.TableListener;import com.google.gwt.user.client.ui.Widget;/** * A composite that displays a list of emails that can be selected. */public class MailList extends Composite implements TableListener, ClickListener {  private static final int VISIBLE_EMAIL_COUNT = 10;  private HTML countLabel = new HTML();  private HTML newerButton = new HTML("<a href='javascript:;'>&lt; newer</a>",    true);  private HTML olderButton = new HTML("<a href='javascript:;'>older &gt;</a>",    true);  private int startIndex, selectedRow = -1;  private FlexTable table = new FlexTable();  private HorizontalPanel navBar = new HorizontalPanel();  public MailList() {    // Setup the table.    table.setCellSpacing(0);    table.setCellPadding(2);    table.setWidth("100%");    // Hook up events.    table.addTableListener(this);    newerButton.addClickListener(this);    olderButton.addClickListener(this);    // Create the 'navigation' bar at the upper-right.    HorizontalPanel innerNavBar = new HorizontalPanel();    innerNavBar.setStyleName("mail-ListNavBar");    innerNavBar.setSpacing(8);    innerNavBar.add(newerButton);    innerNavBar.add(countLabel);    innerNavBar.add(olderButton);    navBar.setHorizontalAlignment(HorizontalPanel.ALIGN_RIGHT);    navBar.add(innerNavBar);    navBar.setWidth("100%");    initWidget(table);    setStyleName("mail-List");    initTable();    update();  }  public void onCellClicked(SourcesTableEvents sender, int row, int cell) {    // Select the row that was clicked (-1 to account for header row).    if (row > 0) {      selectRow(row - 1);    }  }  public void onClick(Widget sender) {    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();      }    }  }  /**   * 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 row.    table.setText(0, 0, "sender");    table.setText(0, 1, "email");    table.setText(0, 2, "subject");    table.setWidget(0, 3, navBar);    table.getRowFormatter().setStyleName(0, "mail-ListHeader");    // Initialize the rest of the rows.    for (int i = 0; i < VISIBLE_EMAIL_COUNT; ++i) {      table.setText(i + 1, 0, "");      table.setText(i + 1, 1, "");      table.setText(i + 1, 2, "");      table.getCellFormatter().setWordWrap(i + 1, 0, false);      table.getCellFormatter().setWordWrap(i + 1, 1, false);      table.getCellFormatter().setWordWrap(i + 1, 2, false);      table.getFlexCellFormatter().setColSpan(i + 1, 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;    Mail.get().displayItem(item);  }  private void styleRow(int row, boolean selected) {    if (row != -1) {      if (selected) {        table.getRowFormatter().addStyleName(row + 1, "mail-SelectedRow");      } else {        table.getRowFormatter().removeStyleName(row + 1, "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 + 1, 0, item.sender);      table.setText(i + 1, 1, item.email);      table.setText(i + 1, 2, item.subject);    }    // Clear any remaining slots.    for (; i < VISIBLE_EMAIL_COUNT; ++i) {      table.setHTML(i + 1, 0, "&nbsp;");      table.setHTML(i + 1, 1, "&nbsp;");      table.setHTML(i + 1, 2, "&nbsp;");    }    // Select the first row if none is selected.    if (selectedRow == -1) {      selectRow(0);    }  }}