samples/mobilewebapp/src/main/com/google/gwt/sample/mobilewebapp/client/mobile/MobileWebAppShellMobile.java

/*
 * Copyright 2011 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.mobilewebapp.client.mobile;

import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.Display;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.uibinder.client.UiBinder;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.DeckLayoutPanel;
import com.google.gwt.user.client.ui.IsWidget;
import com.google.gwt.user.client.ui.LayoutPanel;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.sample.mobilewebapp.client.ClientFactory;
import com.google.gwt.sample.mobilewebapp.client.MobileWebAppShellBase;

/**
 * Mobile version of the UI shell.
 */
public class MobileWebAppShellMobile extends MobileWebAppShellBase {

  interface MobileWebAppShellMobileUiBinder extends UiBinder<Widget, MobileWebAppShellMobile> {
  }

  private static MobileWebAppShellMobileUiBinder uiBinder = GWT
      .create(MobileWebAppShellMobileUiBinder.class);

  /**
   * The width of the menu bar in landscape mode in EX.
   */
  private static final double LANDSCAPE_MENU_WIDTH_EX = 8.0;

  /**
   * The height of the menu bar in portrait mode in PT.
   */
  private static final double PORTRAIT_MENU_HEIGHT_PT = 28.0;

  /**
   * The button used to add items.
   */
  @UiField
  Button addButton;

  /**
   * The widget that wraps the add button.
   */
  @UiField
  Widget addButtonContainer;

  /**
   * The widget that wraps the back button.
   */
  @UiField
  Widget backButtonContainer;

  /**
   * The panel that holds the current content.
   */
  @UiField
  DeckLayoutPanel contentContainer;

  /**
   * The panel used for layout.
   */
  @UiField
  LayoutPanel layoutPanel;

  @UiField
  Widget titleBar;

  @UiField
  Element titleElem;

  /**
   * A reference to the handler for the add button.
   */
  private HandlerRegistration addButtonHandler;

  /**
   * A boolean indicating that we have not yet seen the first content widget.
   */
  private boolean firstContentWidget = true;

  /**
   * Construct a new {@link MobileWebAppShellMobile}.
   * 
   * @param clientFactory the {@link ClientFactory} of shared resources
   */
  public MobileWebAppShellMobile(ClientFactory clientFactory) {
    initWidget(uiBinder.createAndBindUi(this));

    // Initialize the add button.
    setAddButtonHandler(null);

    /*
     * Add both views to the DeckLayoutPanel so we can animate between them.
     * Using a DeckLayoutPanel here works because we only have two views, and we
     * always know that the edit view should animate in from the right side of
     * the screen. A more complex app will require more complex logic to figure
     * out which direction to animate.
     */
    contentContainer.add(clientFactory.getTaskListView());
    contentContainer.add(clientFactory.getTaskEditView());
    contentContainer.setAnimationDuration(500);
  }

  public boolean isTaskListIncluded() {
    return false;
  }

  /**
   * Set the handler to invoke when the add button is pressed. If no handler is
   * specified, the button is hidden.
   * 
   * @param handler the handler to add to the button, or null to hide
   */
  public void setAddButtonHandler(ClickHandler handler) {
    // Clear the old handler.
    if (addButtonHandler != null) {
      addButtonHandler.removeHandler();
      addButtonHandler = null;
    }

    if (handler == null) {
      // Hide the button.
      addButton.setVisible(false);
    } else {
      // Show the button and add the handler.
      addButton.setVisible(true);
      addButtonHandler = addButton.addClickHandler(handler);
    }
  }

  /**
   * Set the widget to display in content area.
   * 
   * @param content the {@link Widget} to display
   */
  public void setWidget(IsWidget content) {
    contentContainer.setWidget(content);

    // Do not animate the first time we show a widget.
    if (firstContentWidget) {
      firstContentWidget = false;
      contentContainer.animate(0);
    }
  }

  @Override
  protected void adjustOrientation(boolean isPortrait) {
    if (isPortrait) {
      // Portrait.
      layoutPanel.setWidgetTopHeight(titleBar, 0, Unit.PX, PORTRAIT_MENU_HEIGHT_PT, Unit.PT);
      layoutPanel.setWidgetLeftRight(titleBar, 0, Unit.PX, 0, Unit.PX);
      titleElem.getStyle().clearDisplay();

      layoutPanel
          .setWidgetTopBottom(contentContainer, PORTRAIT_MENU_HEIGHT_PT, Unit.PT, 0, Unit.PX);
      layoutPanel.setWidgetLeftRight(contentContainer, 0, Unit.EX, 0, Unit.PX);

      layoutPanel.setWidgetTopHeight(addButtonContainer, 0, Unit.PX, PORTRAIT_MENU_HEIGHT_PT,
          Unit.PT);
      layoutPanel.setWidgetRightWidth(addButtonContainer, 8, Unit.PX, 3, Unit.EX);

      layoutPanel.setWidgetTopHeight(backButtonContainer, 0, Unit.PX, PORTRAIT_MENU_HEIGHT_PT,
          Unit.PT);
      layoutPanel.setWidgetLeftWidth(backButtonContainer, 8, Unit.PX, 6, Unit.EX);
    } else {
      // Landscape.
      layoutPanel.setWidgetTopBottom(titleBar, 0, Unit.PX, 0, Unit.PX);
      layoutPanel.setWidgetLeftWidth(titleBar, 0, Unit.PX, LANDSCAPE_MENU_WIDTH_EX, Unit.EX);
      titleElem.getStyle().setDisplay(Display.NONE);

      layoutPanel.setWidgetTopBottom(contentContainer, 0, Unit.PX, 0, Unit.PX);
      layoutPanel
          .setWidgetLeftRight(contentContainer, LANDSCAPE_MENU_WIDTH_EX, Unit.EX, 0, Unit.PX);

      layoutPanel.setWidgetTopHeight(addButtonContainer, 5, Unit.PX, 4, Unit.EX);
      layoutPanel.setWidgetLeftWidth(addButtonContainer, 0, Unit.PX, LANDSCAPE_MENU_WIDTH_EX,
          Unit.EX);

      layoutPanel.setWidgetBottomHeight(backButtonContainer, 5, Unit.PX, 4, Unit.EX);
      layoutPanel.setWidgetLeftWidth(backButtonContainer, 0, Unit.PX, LANDSCAPE_MENU_WIDTH_EX,
          Unit.EX);
    }
  }
}