Java tutorial
/* * Copyright (c) 2010 Zhihua (Dennis) Jiang * * 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.gwtmobile.ui.client.page; import com.google.gwt.core.client.Scheduler; import com.google.gwt.core.client.Scheduler.ScheduledCommand; import com.google.gwt.dom.client.Document; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.event.logical.shared.ResizeEvent; import com.google.gwt.event.logical.shared.ResizeHandler; import com.google.gwt.user.client.Timer; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.ui.RootLayoutPanel; import com.google.gwt.user.client.ui.Widget; import com.gwtmobile.ui.client.CSS.StyleNames.Primary; import com.gwtmobile.ui.client.page.PageHistory.NavigateInfo; import com.gwtmobile.ui.client.utils.Utils; import com.gwtmobile.ui.client.widgets.HeaderPanel; import com.gwtmobile.ui.client.widgets.IsGwtMobilePanel; import com.gwtmobile.ui.client.widgets.PagePanel; import com.gwtmobile.ui.client.widgets.WidgetBase; public abstract class Page extends WidgetBase implements IsGwtMobilePanel { final static private String CONSUMED_TOKEN = "#?#"; private Transition _transition = Transition.SLIDE; // assume SLIDE as default transition protected String _tokenStateInfo = CONSUMED_TOKEN; protected static boolean _inTransition = false; static { if (!Utils.isDesktop() && !Utils.hasPhoneGap()) { hideAddressBar(); Window.addResizeHandler(new ResizeHandler() { @Override public void onResize(ResizeEvent event) { hideAddressBar(); scrollToHideAddressBar(); } }); } } public static boolean isInTransition() { return _inTransition; }; @Override protected void initWidget(Widget widget) { super.initWidget(widget); setStyleName(Primary.PagePanel); // we might need to assert that the given widget has to be a PagePanel if (widget.getClass().getName().endsWith("PagePanel")) setTransition(((PagePanel) widget).getTransitionFlavor().getTransition()); // TODO: use permutation instead? if (Utils.isAndroid()) { addStyleName("Android"); } else if (Utils.isIOS()) { addStyleName("iOS"); } else { addStyleName("Desktop"); } } private static void hideAddressBar() { int barHeight = Utils.isIOS() ? 60 : Utils.isAndroid() ? 1 : 0; if (barHeight > 0) { RootLayoutPanel.get().setHeight(Window.getClientHeight() + barHeight + "px"); } } private static void scrollToHideAddressBar() { Scheduler.get().scheduleDeferred(new ScheduledCommand() { @Override public void execute() { Window.scrollTo(0, 1); } }); } @Override public void onLoad() { super.onLoad(); if (!Utils.isDesktop() && !Utils.hasPhoneGap()) { scrollToHideAddressBar(); } } /** * Gives the page an opportunity to load state that was sent as part of the * history token prior to display. * * @see PageHistory#navigateTo(String, String) * @see BrowserPageHistory#onValueChange(com.google.gwt.event.logical.shared.ValueChangeEvent) * * @param stateInfo */ protected void initNavigationalState(String stateInfo) { } @Override public void onTransitionEnd(TransitionDirection direction) { if (direction != TransitionDirection.To) { return; } final Page to; final PageHistory pageHistory = PageHistory.Instance; final NavigateInfo info = pageHistory.getNavigateInfo(); if (false == info.isGoBack()) { // goto to = this; // TODO: change to use scheduler deferred command. Timer timer = new Timer() { @Override public void run() { to.onNavigateTo(info.getFromPage(), info.getValue()); to.initNavigationIfRequired(); } }; timer.schedule(1); } else { // goback to = pageHistory.current(); Timer timer = new Timer() { @Override public void run() { to.onNavigateBack(info.getFromPage(), info.getValue()); to.initNavigationIfRequired(); } }; timer.schedule(1); } _inTransition = false; } protected void initNavigationIfRequired() { if (!CONSUMED_TOKEN.equals(_tokenStateInfo)) { initNavigationalState(_tokenStateInfo); _tokenStateInfo = CONSUMED_TOKEN; } } protected void onNavigateTo(Page from, Object object) { } protected void onNavigateBack(Page from, Object object) { } public void goTo(final Page toPage) { goTo(toPage, toPage.getTransition()); } public void goTo(final Page toPage, Object params) { goTo(toPage, params, toPage.getTransition()); } public void goTo(final Page toPage, final Transition transition) { goTo(toPage, null, transition); } public void goTo(final Page toPage, Object params, final Transition transition) { if (_inTransition) { return;//can't start a new page transition until last one is complete. } _inTransition = true; PageHistory.Instance.goTo(toPage, params, transition); } public void goBack(Object returnValue) { if (_inTransition) { return;//can't start a new page transition until last one is complete. } _inTransition = true; PageHistory.Instance.goBack(returnValue); } public void setTransition(Transition transition) { this._transition = transition; } public Transition getTransition() { return _transition; } public static void load(Page mainPage) { setPageResolution(); PageHistory.Instance.startUp(mainPage); } // public static void setDefaultTransition(Transition transition) { // _defaultTransition = transition; // } @Override public Widget getWidget() { // make getWidget() public return super.getWidget(); } private static void setPageResolution() { int clientWidth = Window.getClientWidth(); if (Utils.isDesktop()) { Document.get().getDocumentElement().setClassName("HVGA"); } else if (clientWidth < 320) { Document.get().getDocumentElement().setClassName("QVGA"); } else if (clientWidth < 480) { Document.get().getDocumentElement().setClassName("HVGA"); } else if (clientWidth < 560) { Document.get().getDocumentElement().setClassName("WVGA"); } else { Document.get().getDocumentElement().setClassName("WXGA"); } } public static native double getDevicePixelRatio() /*-{ return $wnd.devicePixelRatio; }-*/; /** * Adds a home button handler. It assumes the right button in the header is * the home button. * </br> * By Frank Mena 2012-04-11 * * @param header the header */ //FIXME: remove "right button" assumption public void addHomeHandler(HeaderPanel header) { header.setRightButtonClickHandler(new ClickHandler() { @Override public void onClick(ClickEvent event) { goHome(); } }); } /** * Go home. Only works if you are using {@link SerialPageHistory}. * </br> * By Frank Mena 2012-04-11 */ public void goHome() { if (PageHistory.Instance instanceof SerialPageHistory) { SerialPageHistory history = (SerialPageHistory) PageHistory.Instance; history.goHome(this); } } /** * Push a page into the stack. Only works if you are using * {@link SerialPageHistory}. * * By Frank Mena 2012-04-11 * * @param page the page to push */ public static void push(Page page) { if (PageHistory.Instance instanceof SerialPageHistory) { SerialPageHistory history = (SerialPageHistory) PageHistory.Instance; history.add(page); } } /** * Exposes the onNavigate method of a page. Useful when restoring from * passivated state. * * By Frank Mena 2012-04-11 */ public void doOnNavigateTo() { this.onNavigateTo(null, null); } }