I just started learning Google Web Toolkit (GWT). How do I make different HTML pages in my GWT application?
For example, I want to create an application for a book store. In this application I'll have three pages:
Home pages where I will welcome the user and offer the user books
Page to browse books by categories and view details (use GWT widgets)
Check out books online.
Of course there could be other pages like the user's details, add new book, etc.
So, what is the best way of making different pages in GWT and how can I make navigation from page to page? Are there any examples or tutorials? Or do I even need to create different pages when I can create a whole application in one page?
What I usually do in situations like this is design the webpage framework first. I'll have a div for the header, side menu and footer. I'll also have a div in my HTML for the main content.
Example:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name='gwt:module' content='org.project.package.Core=org.project.package.Core'>
</head>
<body>
<!-- Load the JavaScript code for GWT -->
<script language="javascript" src="ui/org.project.package.ui.Core.nocache.js"></script>
<!-- For some unknown reason in Internet Explorer you have to have cellpadding/spacing ON THE ELEMENT and not on the STYLE if it is in the body tag like this -->
<table id="wrapper" cellpadding="0" cellspacing="0" style="width: 100%;height: 100%;">
<!-- Header row -->
<tr style="height: 25%;">
<td colspan="2" id="header"></td>
</tr>
<!-- Body row and left nav row -->
<tr style="height: 65%;">
<td id="leftnav"></td>
<td id="content"></td>
</tr>
<!-- Footer row -->
<tr style="height: 10%;">
<td colspan="2" id="footer"></td>
</tr>
</table>
<!-- This iframe handles history -->
<iframe id="__gwt_historyFrame" style="width:0;height:0;border:0"></iframe>
</body>
</html>
(If you like <div> based layouts, feel free to use those instead.)
Then you build your entry point (in my case Core.java) as you normally would, setting each of the elements as need be.
RootPanel.get("header").add(new Header());
RootPanel.get("leftnav").add(new NavigationMenu());
RootPanel.get("footer").add(new Footer());
It is, of course, possible to have a static footer and header, but that's neither here nor there.
I also have an abstract class called "Content". Content objects extend "Composite" and will have various methods for simplifying the creation and layout of a new page. Every page that I build for this application, be it a help screen, search screen, shopping cart, or anything else, is of type Content.
Now, what I do is create a class called "ContentContainer". This is a singleton that is responsible for managing the "content" element. It has one method "setContent" that accepts objects of type "Content". It then basically removes anything within the "content" <td> and replaces it with whatever widget (Composite) you assign via the "setContent" method. The setContent method also handles history and title bar management. Basically the ContentContainer serves to aggregate all the various points of binding that you might have to make if each page content had to "know" about all the functions it must perform.
Finally, you need a way to get to that page, right? That's simple:
ContentContainer.getInstance().setContent(new Search());
Put the above in an on-click event somewhere and you're golden.
The only things that your other widgets need to be bound to is the ContentContainer and the type of Content that they are adding.
The downsides that I can see to ChrisBo's approach are that you've got a list that has to be maintained of tokens -> pages. The other downside I can see is that I don't see how you can have an actual history system with this method.
One thing it does offer over my approach is that all page choices are pretty centralized. I'd use some sort of Enum or at least a static class with String values to prevent myself from mongling up links.
In either case, I think the point can be summed up as this: swap the content of some central page element based on what your user clicks actions your user(s) perform.
I would use the HyperLink and History class. The good thing about the Hyperlink class is, that it sets this token(e.g.#foobar), and all you have to do, is catch the event, that is fired when the value of the token is changed(ValueChangeEvent). In the eventHandler you would then replace the pages.
Example:
address of welcome Page: www.yourpage.com/#home
on this page would be a link to the "browse book"-page, when the link is clicked the new address would be something like this: www.yourpage.com/#browse
And here is the code:
public class MainEntryPoint implements EntryPoint, ValueChangeHandler {
VerticalPanel panel = new VerticalPanel();
Label label=new Label();
public void onModuleLoad() {
Hyperlink link1 = new Hyperlink("books", "browse");
Hyperlink link2 = new Hyperlink("user details", "details");
panel.add(link1);
panel.add(link2);
panel.add(label);
RootPanel.get().add(panel);
History.addValueChangeHandler(this);
//when there is no token, the "home" token is set else changePage() is called.
//this is useful if a user has bookmarked a site other than the homepage.
if(History.getToken().isEmpty()){
History.newItem("home");
} else {
changePage(History.getToken());
}
}
public void onValueChange(ValueChangeEvent event) {
changePage(History.getToken());
}
public void changePage(String token) {
if(History.getToken().equals("browse")) {
label.setText("Here would be some books");
} else if (History.getToken().equals("details")) {
label.setText("Here would be the user details");
} else {
label.setText("Welcome page");
}
}
}
Awesome! I combined Chris R.'s answer with Chris Boesing's to come up with this:
This is the 'index' start page
public class Index implements EntryPoint, ValueChangeHandler<String> {
public void onModuleLoad() {
History.addValueChangeHandler(this);
if (History.getToken().isEmpty()) History.newItem("index");
Composite c = new Login();
FlowControl.go(c);
}
public void onValueChange(ValueChangeEvent<String> e) {
FlowControl.go(History.getToken());
}
}
This is the controller, or ContentContainer according to Chris R.
public class FlowControl {
private static FlowControl instance;
private FlowControl() {}
public static void go(Composite c) {
if (instance == null) instance = new FlowControl(); // not sure why we need this yet since everything is static.
RootPanel.get("application").clear();
RootPanel.get("application").getElement().getStyle().setPosition(Position.RELATIVE); // not sure why, but GWT throws an exception without this. Adding to CSS doesn't work.
// add, determine height/width, center, then move. height/width are unknown until added to document. Catch-22!
RootPanel.get("application").add(c);
int left = Window.getClientWidth() / 2 - c.getOffsetWidth() / 2; // find center
int top = Window.getClientHeight() / 2 - c.getOffsetHeight() / 2;
RootPanel.get("application").setWidgetPosition(c, left, top);
History.newItem(c.getTitle()); // TODO: need to change and implement (or override) this method on each screen
}
public static void go(String token) {
if (token == null) go(new Login());
if (token.equals("cart")) go(new Cart());
if (token.equals("login")) go(new Login());
// Can probably make these constants in this class
}
Then you can pepper Hyperlinks and Buttons anywhere throughout your code. (Have not tried Hyperlinks yet.)
Button submit = new Button("Submit");
submit.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
FlowControl.go(new MyScreen());
}
});
I added a div to my HTML
<!-- This is where the application will reside within. It is controlled by FlowControl class. -->
<div id="application"></div>
And now all screens must call initWidget() in the constructor instead of adding to RootPanel, since it is a Composite class now, like
initWidget(myPanel); // all composites must call this in constructor
If you want it to be FULL AJAXified (like a desktop app) of course you'd only need one page. Then just change the contents of the body depending on the link.
Also, there is a google group for GWT that is very very active, and I know this has been asked before there, you just need to use the "search" feature.
GWT Multipage - simple framework for multi-page-GWT-applications.
You can use MVP patern.
Here is mi simple library https://code.google.com/p/gwt-simple-mvp/wiki/GettingStarted .
And you can split code to more js files. https://code.google.com/p/gwt-spliting/
I used Chloe S. answer (combining Chris R.'s answer with Chris Boesing's) to build this App Controller for a working GWT Web App. The version in production is tested (and working %100) but this redacted version below will need to be modified to integrate with your own app (start by renaming the page keys to your menu items).
AppController.java:
/**
* This App Controller utilizes two static inner-classes (Pages and External)
* to manage and server multiple pages with multiple sub-page (through their presenters)
* via String key constants which also serve as the literal text for the menu items.
*
* Pages are added as menu commands in their respective views:
* // Add menu items to the menu with commands:
* menuItems.put(Pages.PAGE1, mainMenu.addItem(Pages.PAGE1, new Command() {
* public void execute() {
* History.newItem(Pages.PAGE1);
* }
* }));
*
* Pages are fired as History tokens (from entry point java class):
*
* **
* * Receives history events and pushes them to the AppController using a deferred command.
* * Changes the cursor to show waiting.
* * #param the value change token
* *
* public void onValueChange(ValueChangeEvent<String> e) {
* // check token to cover first historical "back" navigation:
* if(!History.getToken().isEmpty()) {
* AppController.waitCursor.execute(); // cursor is reset in page attach method
* }
* Scheduler.get().scheduleDeferred(new ScheduledCommand() {
* public void execute() {
* AppController.go(History.getToken());
* }
* });
* }
*
* Wait cursors are implemented as CSS:
*
* body.wait, body.wait * {
* cursor: wait !important;
* }
*
* NOTE: This page swapping implementation technique (based on the StackOverflow solution
* found here: [http://stackoverflow.com/questions/1061705/multiple-pages-tutorial-in-google-web-toolkit-gwt][1])
* differs from the obtuse and ancient 2010 GWT framework documentation in that the App Controller manages / handles
* adding the widget to the container, and therefore all the Presenters must implement the
* "AppControlPresenter" or "AppControlContainerPresenter" interface to give it access to their containers.
* (thus eliminating "public void go(final HasWidgets container);" method in all presenter architecture except for 'MainAppPresenter')
* There is also no event bus; static method calls are used for any needed interactivity.
*
* Includes a popup for pages still under construction.
*/
package com.;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import java.util.HashMap;
import java.util.Map;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.logical.shared.AttachEvent;
import com.google.gwt.event.logical.shared.ResizeEvent;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.user.client.History;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.DecoratedPopupPanel;
import com.google.gwt.user.client.ui.Frame;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.LayoutPanel;
import com.google.gwt.user.client.ui.RootLayoutPanel;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.UIObject;
/**
*
*/
public class AppController {
/** */
public final static String DEFAULT_INITIAL_PAGE1_SUB_PAGE = Pages.PAGE_1A;
/** Singleton instance for the AppController */
private static AppController instance = new AppController();
/** Presenter for the main app */
private static MainAppPresenter mainAppPresenter;
/** container for the different views */
private static LayoutPanel container;
/** sub-container for the different sub-views */
private static LayoutPanel page1Container;
/** */
private static DecoratedPopupPanel popup;
/** constant for Style-Dependent names for menu items (see menu-style.css) */
public final static String MENU_ACTIVE_STYLE = "active";
/** constant for Style-Dependent class name in css */
public final static String CURSOR_WAIT_CLASS = "wait";
/** */
public final static String POPUP_DEMO_ID = "popupDemo";
/** */
public final static int DEMOP_POPUP_VERTICAL_OFFSET = 0;
/** */
public final static String POPUP_DEMO_STATEMENT = "<span class='text'>This page is under construction</span>"
+ "<span class='char'>…</span>";
/** */
public static ScheduledCommand waitCursor = new ScheduledCommand() {
#Override
public void execute() {
AppController.waitCursor(true);
}
};
/** */
public static ScheduledCommand normalCursor = new ScheduledCommand() {
#Override
public void execute() {
AppController.waitCursor(false);
}
};
/** Flag for determining if the page was reloaded */
private static boolean reloaded = false;
private static final LoginServiceAsync loginRpcService = GWT.create(LoginService.class);
/**
* Called on the resize event to set the position of the demo popup
* window to be adjusted to the correct dimensions (size and positoin)
* regardless of screen size.
*/
private static ScheduledCommand resetPopupDimensions = new ScheduledCommand() {
#Override
public void execute() {
if(!UNDER_CONSTRUCTION || popup == null) {
return;
}
int demoWidth = Math.round(Window.getClientWidth() / MainApp.PHI),
demoYPosition = Window.getClientHeight() / 2 - Math.round(popup.getOffsetHeight() / 2);
popup.setWidth(String.valueOf(demoWidth) + "px");
if(popup.getOffsetWidth() >= Window.getClientWidth()) {
popup.setWidth("100%");
popup.setPopupPosition(0, demoYPosition);
} else {
popup.setPopupPosition(Window.getClientWidth() / 2 - (popup.getOffsetWidth() / 2), demoYPosition);
}
}
};
/** */
private static final String LOGIN_OBJECT_NAME = "Login Presenter Object";
/**
* static inner-class for external websites
*/
public static class External {
/** The frame to contain the website */
private static Frame frame;
/** */
public static final String EXTERNAL_URL_1 = "http://";
/** */
public static final String EXTERNAL_URL_2 = "http://";
/**
* #returns true if the name of the token is equal to one of the URLs
* #param token the name to check
*/
public static boolean has(String token) {
return token.equalsIgnoreCase(EXTERNAL_URL_1) ||
token.equalsIgnoreCase(EXTERNAL_URL_2);
}
/**
* Gets the external Frame object
* #param url
* #return Frame
*/
public static Frame get(String url) {
if(frame == null) {
frame = new Frame(url);
frame.addAttachHandler(new AttachEvent.Handler() {
#Override
public void onAttachOrDetach(AttachEvent event) {
// hide the popup:
showPopup(false);
Scheduler.get().scheduleFinally(resetPopupDimensions);
Scheduler.get().scheduleFinally(normalCursor);
}
});
}
else if(!frame.getUrl().equalsIgnoreCase(url)) {
frame.setUrl(url);
}
return frame;
}
}
/**
* static inner-class for holding pages activated by the app's main menu commands
*/
public static class Pages {
/** */
public static final String PAGE1 = "foo";
/** */
public static final String PAGE2 = "bar";
/** */
public static final String PAGE_1A = "baz";
/** */
public static final String PAGE_1B = "qux";
/** */
public static String lastPage;
/** */
public static String lastPage1SubPage;
/** */
public static String unsavedMessage;
/** */
private static HashMap<String, AppControlPresenter> pageMap;
/** */
private static AppControlPresenter presenter;
/** */
private static Composite view;
/**
* initializes the hashmap of pages
*/
public static void init() {
pageMap = new HashMap<String, AppControlPresenter>();
}
/**
* #returns true if the name of the token is equal to one of the pages
* #param token the name to check
*/
public static boolean has(String token) {
return token.equalsIgnoreCase(PAGE1) ||
token.equalsIgnoreCase(PAGE2) ||
token.equalsIgnoreCase(PAGE_1A);
}
/**
* Gets the correct page container to display as a Composite
* #param page the token name of the page
* #return Composite page
*/
public static Composite get(String page) {
view = null;
presenter = null;
if(page.equalsIgnoreCase(PAGE1)) {
if(pageMap.get(PAGE1) == null) {
pageMap.put(PAGE1, new Page1Presenter(PAGE1));
page1Container = ((AppControlContainerPresenter) pageMap.get(PAGE1)).getContentPane();
}
presenter = pageMap.get(PAGE1);
lastPage = page;
mainAppPresenter.setCurrentMenuItem(page);
}
else if(page.equalsIgnoreCase(PAGE_1A) ||
page.equalsIgnoreCase(PAGE_1B) {
if(pageMap.get(PAGE1) == null) {
pageMap.put(PAGE1, new Page1Presenter(PAGE1));
page1Container = ((AppControlContainerPresenter) pageMap.get(PAGE1)).getContentPane();
}
presenter = pageMap.get(PAGE1);
lastPage1SubPage = page;
view = ((AppControlContainerPresenter)presenter).setCurrentPage(page);
}
else if(page.equalsIgnoreCase(PAGE2)) {
if(pageMap.get(PAGE2) == null) {
pageMap.put(PAGE2, new Page2Presenter(PAGE2));
}
presenter = pageMap.get(PAGE2);
lastPage = PAGE2;
mainAppPresenter.setCurrentMenuItem(page);
}
else if(External.has(page)) {
throw new Error("App Controller Error -- Use 'External' inner-class for: " + page);
}
else {
throw new Error("App Controller Error -- Page name not found: " + page);
}
if(view == null) {
view = (Composite)presenter.view();
}
view.addAttachHandler(new AttachEvent.Handler() {
#Override
public void onAttachOrDetach(AttachEvent event) {
AppController.showPopup(false);
presenter.updateAttachOrDetach(event);
Scheduler.get().scheduleFinally(resetPopupDimensions);
Scheduler.get().scheduleFinally(normalCursor);
}
});
return view;
}
/**
* Gets the current AppControlPresenter for the last page.
* #returns the current AppControlPresenter
*/
public static AppControlPresenter getCurrentPresenter() {
return presenter;
}
/**
* Gets an AppControlPresenter from the pageMap.
* #param token the name of the presenter
* #returns the AppControlPresenter
*/
public static AppControlPresenter getPresenter(String token) {
return pageMap.get(token);
}
/**
* Returns true if the page is already loaded.
* #param token name of the page
*/
public static boolean alreadyLoaded(String token) {
MainApp.debug(1, "[already loaded: " + presenter.toString() + " (token: " + token + ")");
return presenter.toString().equalsIgnoreCase(token);
}
/**
* Returns true if the page is visible
* #param page the token name of the page
*/
public static boolean isVisible(String page) {
UIObject component = pageMap.get(page).view();
return !(component.getOffsetHeight() == 0 && component.getOffsetWidth() == 0);
}
/**
* Returns true if the page is visible
* #param presenter the AppControlPresenter instance
*/
public static boolean isVisible(AppControlPresenter presenter) {
UIObject component = presenter.view();
return !(component.getOffsetHeight() == 0 && component.getOffsetWidth() == 0);
}
/**
* Returns true if the application has unsaved data.
* Iterates through all the pages and checks each presenter.
*/
public static boolean unsavedData() {
if(pageMap.isEmpty()) return false;
boolean unsaved = false;
for(Map.Entry<String, AppControlPresenter> entry : pageMap.entrySet()) {
AppControlPresenter presenter = entry.getValue();
if(presenter != null && presenter.unsavedData()) {
MainApp.debug(1, "(!) " + presenter.toString() + " has unsaved data");
unsavedMessage = presenter.dataDescription();
unsaved = true;
break; // just need to know one exists for now (window closing event)
}
}
return unsaved;
}
/**
* Called on a resize event on the window. Iterates through all the pages
* and tells their presenters to resize their content.
*/
public static void resize() {
for(Map.Entry<String, AppControlPresenter> entry : pageMap.entrySet()) {
AppControlPresenter presenter = entry.getValue();
if(presenter != null && isVisible(presenter)) {
presenter.resize();
}
}
}
} //end class Pages
/**
* #returns true if the history token is equal to any of the pages in the app
*/
public static boolean hasHistory() {
String token = History.getToken();
return External.has(token) || Pages.has(token);
}
/**
* Starts the login view at the root layout level
*/
public static void goLoginScreen() {
//check for reload:
if(hasHistory()) {
MainApp.debug(1, "(!) AppController has History on Login");
reloaded = true;
}
else {
reloaded = false;
}
RootLayoutPanel.get().clear();
RootLayoutPanel.get().add(new LoginPresenter(LOGIN_OBJECT_NAME).view());
}
/**
* #returns the last "Page1" page
*/
public static String getLastPage1Page() {
if(Pages.lastPage1SubPage == null || Pages.lastPage1SubPage.isEmpty()) {
Pages.lastPage1SubPage = DEFAULT_INITIAL_PAGE1_SUB_PAGE;
}
return Pages.lastPage1SubPage;
}
/**
* Tells the app to start with the Page1 page.
* #param username the username of the person logged-in
*/
public static void goMainApp(String username) {
//hide the login background:
RootPanel.getBodyElement().getStyle().setProperty("background", "none");
mainAppPresenter = new MainAppPresenter(username);
RootLayoutPanel.get().clear();
mainAppPresenter.go(RootLayoutPanel.get());
//get the center panel:
container = mainAppPresenter.getContainer();
//check for reload:
//NOTE: the token will be empty if the user refreshes
// and navigates all the way back to the zero-state
// from the login screen.
//NOTE: this logic may change after user-persistence is implemented
if(hasHistory() || History.getToken().isEmpty()) {
// reset the reloaded flag:
reloaded = false;
if(History.getToken().isEmpty()) {
//land on the first page:
History.newItem(AppController.Pages.PAGE1);
}
else {
MainApp.debug(2, "(!) AppController has History on reload: " + History.getToken());
History.fireCurrentHistoryState();
}
}
else {
//land on the first page:
History.newItem(AppController.Pages.PAGE1);
}
}
/**
*
*/
public static void checkIfSessionActive() {
loginRpcService.loginFromSession(new AsyncCallback<LoginSummary>() {
#Override
public void onFailure(Throwable throwable) {
goLoginScreen();
}
#Override
public void onSuccess(LoginSummary loginSummary) {
if (loginSummary.getErrorString() != null)
goLoginScreen();
else
goMainApp(loginSummary.getUser().getName());
}
});
}
/**
*
*/
public static void sessionLogout() {
DialogBoxWidget.confirm(200,
"Logout",
"Are you sure you want to log out?",
new ConfirmDialogCallback() {
#Override
public void onAffirmative() {
loginRpcService.logout(new AsyncCallback<Void>() {
#Override
public void onFailure(Throwable throwable) {
goLoginScreen();
}
#Override
public void onSuccess(Void aVoid) {
goLoginScreen();
}
});
}
#Override
public void onCancel() {
}
});
}
/**
* Shows or hides the "Under Construction" popup if UNDER_CONSTRUCION is true.
* #param show true to show and false to hide
*/
public static void showPopup(boolean show) {
if(MainApp.UNDER_CONSTRUCTION && popup != null) {
if(show) {
popup.show();
}
else {
popup.hide();
}
}
}
/**
* Called by every history event fired (including the back and forward buttons).
* Ignores the login and empty index historically.
* #param token the name of the page to load
*/
public static void go(String token) {
if(reloaded) {
normalCursor.execute();
}
if(token == null || token.isEmpty() || reloaded == true) return;
MainApp.debug("<history changed> - AppController.go()-> " + token);
// build the popup message for all unfinished pages:
if(MainApp.UNDER_CONSTRUCTION) {
if(popup == null) {
popup = new DecoratedPopupPanel(false);
popup.ensureDebugId(POPUP_DEMO_ID);
popup.addStyleDependentName(POPUP_DEMO_ID);
popup.setWidget(new HTML(new Image("images/workingman.png") + POPUP_DEMO_STATEMENT + new Image("images/workingmanFLIP.png")));
}
}
// check token for which page to return:
if(token.equalsIgnoreCase(External.EXTERNAL_URL_1)) {
MainAppPresenter.clearActiveMenuItems();
setExternalContentURL(External.get(token));
}
else if(token.equalsIgnoreCase(External.EXTERNAL_URL_2)) {
MainAppPresenter.clearActiveMenuItems();
setExternalContentURL(External.get(token));
}
else if(token.equalsIgnoreCase(Pages.PAGE1)) {
setContent(Pages.get(Pages.PAGE1));
setPage1Content(Pages.get(getLastPage1Page()));
}
else if(token.equalsIgnoreCase(Pages.PAGE_1A) ||
token.equalsIgnoreCase(Pages.PAGE_1B)) {
setContent(Pages.get(Pages.PAGE1));
setPage1Content(Pages.get(token));
}
else if(token.equalsIgnoreCase(Pages.PAGE2)) {
setContent(Pages.get(Pages.PAGE2));
}
else { // default behavior for a page not described:
MainApp.debug(2, "(!) Unknown page: " + token);
setContent(Pages.get(token));
}
}
/**
* Called by MainApp on a window resize event.
* #param e the ResizeEvent
*/
public static void resize(ResizeEvent e) {
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
#Override
public void execute() {
if(mainAppPresenter != null) {
mainAppPresenter.resize();
}
Pages.resize();
Scheduler.get().scheduleFinally(resetPopupDimensions);
}
});
}
/**
* Changes the cursor to "wait" or "auto" depending on the parameter
* #param wait true to set the cursor to waiting
*/
private static void waitCursor(Boolean wait) {
if(wait) {
RootPanel.getBodyElement().addClassName(CURSOR_WAIT_CLASS);
}
else {
RootPanel.getBodyElement().removeClassName(CURSOR_WAIT_CLASS);
}
}
/**
* Private Constructor which initializes the Pages object.
*/
private AppController() {
Pages.init();
}
/**
* Sets the content of the main app container to one of the "Pages."
* #param c the Composite widget to be added
*/
private static void setContent(Composite c) {
container.clear();
container.add(c.asWidget());
}
/**
* Sets the content of the main app container an external URL.
* #param f the Frame by which external web sites are added
*/
private static void setExternalContentURL(Frame f) {
container.clear();
container.add(f);
// must reset the width and height every time:
f.getElement().getStyle().setWidth(100, Unit.PCT);
f.getElement().getStyle().setHeight(100, Unit.PCT);
}
/**
* Sets the content of the Page1 container to one of the sub pages.
* #param c the Composite widget to be added
*/
private static void setPage1Content(Composite c) {
page1Container.clear();
page1Container.add(c.asWidget());
}
}
AppControlPresenter.java:
package com.*;
import com.google.gwt.event.logical.shared.AttachEvent;
import com.google.gwt.user.client.ui.Composite;
/**
* Base interface for all 'Presenters' used by AppController.java
* NOTE: classes that implement this interface do not launch the presenter's view
* into the provided container; rather, the view is retrieved and used by the
* AppController instance by calling the 'view()' method
*/
public interface AppControlPresenter {
/**
* Gets the view (for use in AppController.java)
*/
public Composite view();
/**
* Indicates if current search data is present and unsaved.
* #returns true to if a search is still active
*/
public boolean unsavedData();
/**
* Called on resize event to notify presenters with visible
* components that need resizing for different screen sizes.
* #returns true if elements were resized
*/
public boolean resize();
/**
* Called on attachEvents to tell the presenter to update.
* #param event the AttachEvent
*/
public void updateAttachOrDetach(AttachEvent event);
/**
* Gets the message to display for unsaved data.
* #returns a message String describing the data
*/
public String dataDescription();
/**
* Gets a fully qualified name for use in comparisons
* #return the name of this presenter used by the <code>AppController</code>
*/
public String toString();
}
AppControlContainerPresenter.java:
package com.*;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.LayoutPanel;
/**
*/
public interface AppControlContainerPresenter extends AppControlPresenter {
/**
*
* #return
*/
public LayoutPanel getContentPane();
/**
*
* #param pageName
* #return
*/
public Composite setCurrentPage(String pageName);
}
Add a module for each page you have that needs the GWT functionality. Reuse your components.
Related
I convert HTML to PDF using iText7 and need to add Text Markup Annotations for specific text in the HTML. I am using CustomTagWorkers as explained in this link and then I am using the annotation examples given here.
I am able to successfully add Link Annotation by replacing the qr tag with a link annotation. However my requirement is to add a Text Markup Annotation. The Text Markup annotation can only be drawn by giving the specific coordinates of the page (rectangle object) which I do not know in the code. I tried to give Rectangle(0, 0) hoping that iText will render this in place of tag. However I am unable to add the Text Markup Annotation to paragraph object which is the return object of public IPropertyContainer getElementResult() {.
Here is my entire code:
/**
* Converts an HTML file to a PDF document, introducing a custom tag to create a
* QR Code involving a custom TagWorker and a custom CssApplier.
*/
public class C05E04_QRCode2 {
/**
* The path to the resulting PDF file.
*/
public static final String DEST = "C:\\Samples\\itext-annotation\\qrcode.pdf";
/**
* The path to the source HTML file.
*/
public static final String SRC = "C:\\Samples\\itext-annotation\\qrcode.html";
/**
* The main method of this example.
*
* #param args no arguments are needed to run this example.
* #throws IOException signals that an I/O exception has occurred.
*/
public static void main(String[] args) throws IOException {
File file = new File(DEST);
file.getParentFile().mkdirs();
C05E04_QRCode2 app = new C05E04_QRCode2();
System.out.println("pdf");
app.createPdf(SRC, DEST);
}
/**
* Creates the PDF file.
*
* #param src the path to the source HTML file
* #param dest the path to the resulting PDF
* #throws IOException signals that an I/O exception has occurred.
*/
public void createPdf(String src, String dest) throws IOException {
ConverterProperties properties = new ConverterProperties();
properties.setCssApplierFactory(new QRCodeTagCssApplierFactory())
.setTagWorkerFactory(new QRCodeTagWorkerFactory());
HtmlConverter.convertToPdf(new File(src), new File(dest), properties);
}
/**
* A factory for creating QRCodeTagCssApplier objects.
*/
class QRCodeTagCssApplierFactory extends DefaultCssApplierFactory {
/**
* Gets the custom css applier.
*
* #param tag the tag
* #return the custom css applier
*/
/*
* (non-Javadoc)
*
* #see com.itextpdf.html2pdf.css.apply.impl.DefaultCssApplierFactory#
* getCustomCssApplier(com.itextpdf.html2pdf.html.node.IElementNode)
*/
#Override
public ICssApplier getCustomCssApplier(IElementNode tag) {
if (tag.name().equals("qr")) {
return new BlockCssApplier();
}
return null;
}
}
/**
* A factory for creating QRCodeTagWorker objects.
*/
class QRCodeTagWorkerFactory extends DefaultTagWorkerFactory {
/**
* Gets the custom tag worker.
*
* #param tag the tag
* #param context the context
* #return the custom tag worker
*/
#Override
public ITagWorker getCustomTagWorker(IElementNode tag, ProcessorContext context) {
if (tag.name().equals("qr")) {
return new QRCodeTagWorker(tag, context);
}
return null;
}
}
/**
* The custom ITagWorker implementation for the qr-tag.
*/
static class QRCodeTagWorker implements ITagWorker {
/** The p. */
private Paragraph p;
/** The annotation. */
private PdfLinkAnnotation linkAnnotation;
/**
* Instantiates a new QR code tag worker.
*
* #param element the element
* #param context the context
*/
public QRCodeTagWorker(IElementNode element, ProcessorContext context) {
}
/**
* Process content.
*
* #param content the content
* #param context the context
* #return true, if successful
*/
#Override
public boolean processContent(String content, ProcessorContext context) {
return true;
}
/**
* Process tag child.
*
* #param childTagWorker the child tag worker
* #param context the context
* #return true, if successful
*/
#Override
public boolean processTagChild(ITagWorker childTagWorker, ProcessorContext context) {
return false;
}
/**
* Process end.
*
* #param element the element
* #param context the context
*/
#Override
public void processEnd(IElementNode element, ProcessorContext context) {
//Link Annotation
linkAnnotation = new PdfLinkAnnotation(new Rectangle(0, 0)).setAction(PdfAction.createURI(
"https://kb.itextpdf.com/"));
Link link = new Link("here", linkAnnotation);
p = new Paragraph("The example of link annotation. Click ").add(link.setUnderline())
.add(" to learn more...");
//Line Annotation
float[] floatArray = new float[] { 169, 790, 105, 790, 169, 800, 105, 800 };
PdfAnnotation lineAnnotation = PdfTextMarkupAnnotation.createHighLight(new Rectangle(0, 0), floatArray);
lineAnnotation.setTitle(new PdfString("You are here:"));
lineAnnotation.setContents("Cambridge Innovation Center");
lineAnnotation.setColor(ColorConstants.YELLOW);
//Text Markup Annotation
PdfAnnotation ann = PdfTextMarkupAnnotation.createHighLight(
new Rectangle(105, 790, 64, 10),
new float[]{169, 790, 105, 790, 169, 800, 105, 800})
.setColor(Color.YELLOW)
.setTitle(new PdfString("Hello!"))
.setContents(new PdfString("I'm a popup."))
.setTitle(new PdfString("iText"))
.setOpen(true)
.setRectangle(new PdfArray(new float[]{100, 600, 200, 100}));
}
/**
* Gets the element result.
*
* #return the element result
*/
#Override
public IPropertyContainer getElementResult() {
return p;
}
}
}
HTML File:
<html>
<head>
<meta charset="UTF-8">
<title>QRCode Example</title>
<link rel="stylesheet" type="text/css" href="css/qrcode.css"/>
</head>
<body>
<span> The example of <qr> text markup </qr> annotation. </span>
</body>
</html>
CSS File:
qr {
border: solid 1px red;
height: 200px;
width: 200px;
}
Illustration of the final output
The easiest pragmatic way to proceed is make your <qr> tag behave as inline-block. This will make sure that we will not have the text from the tag wrap to the next line (in this case annotation is tricky to define), and also we will have a natural grouping element that we will be able to fetch the coordinates from.
I have modified the input HTML slightly, to get rid of <qr> tag in favor of <annot> and add the above mentioned display: inline-block behavior:
<html>
<head>
<style>
annot {
display: inline-block;
}
</style>
</head>
<body>
<span> The example of <annot> text markup </annot> annotation. </span>
</body>
</html>
We proceed with the definition of the custom tag worker factory and custom tag worker in the similar fashion as in the original post:
private static class CustomTagWorkerFactory extends DefaultTagWorkerFactory {
#Override
public ITagWorker getCustomTagWorker(IElementNode tag, ProcessorContext context) {
if ("annot".equals(tag.name())) {
return new AnnotTagWorker(tag, context);
}
return super.getCustomTagWorker(tag, context);
}
}
private static class AnnotTagWorker extends PTagWorker {
public AnnotTagWorker(IElementNode element, ProcessorContext context) {
super(element, context);
}
#Override
public IPropertyContainer getElementResult() {
IPropertyContainer baseResult = super.getElementResult();
if (baseResult instanceof Paragraph) {
((Paragraph) baseResult).setNextRenderer(new AnnotTagRenderer((Paragraph) baseResult));
}
return baseResult;
}
}
Now the meaty part will be implemented in AnnotTagRenderer. Notice how we set the renderer to the resultant element in AnnotTagWorker. The renedrer implementation is aware of the physical coordinates of the text block corresponding to our <annot> tag on the PDF page. We can now fetch the coordinates from this.getOccupiedArea() in draw() method and this does the main trick for us - all we need to do as a remainder is create the right annotation object and add it to the page. Here is the implementation:
private static class AnnotTagRenderer extends ParagraphRenderer {
public AnnotTagRenderer(Paragraph modelElement) {
super(modelElement);
}
#Override
public IRenderer getNextRenderer() {
return new AnnotTagRenderer((Paragraph) modelElement);
}
#Override
public void draw(DrawContext drawContext) {
super.draw(drawContext);
Rectangle occupiedArea = this.getOccupiedAreaBBox();
float[] quadPoints = new float[] {occupiedArea.getLeft(), occupiedArea.getTop(), occupiedArea.getRight(), occupiedArea.getTop(),
occupiedArea.getLeft(), occupiedArea.getBottom(), occupiedArea.getRight(), occupiedArea.getBottom()};
PdfAnnotation ann = PdfTextMarkupAnnotation.createHighLight(
new Rectangle(occupiedArea), quadPoints)
.setColor(ColorConstants.YELLOW)
.setTitle(new PdfString("Hello!"))
.setContents(new PdfString("I'm a popup."))
.setTitle(new PdfString("iText"));
drawContext.getDocument().getPage(this.getOccupiedArea().getPageNumber()).addAnnotation(ann);
}
}
Visual result looks as follows:
Finally, don't forget to plug the custom tag worker factory into the converter properties:
ConverterProperties properties = new ConverterProperties().setTagWorkerFactory(new CustomTagWorkerFactory());
HtmlConverter.convertToPdf(new File(sourceHTML), new File(targetPDF), properties);
I'm developing an Eclipse plugin, where I need every editor of the application to be readonly, depending on the path of the contained file (relative to the project).
I've made my own editor class, and been able to override some method to get what I want:
public class MyTextEditor extends TextEditor {
/**
* Overridden to inhibit the replace action in find&replace dialog.
*/
#Override
public boolean isEditorInputModifiable() {
if (!super.isEditorInputModifiable()) {
return false;
}
return Utils.checkEditorInputModifiable(getEditorInput());
}
/**
* Overridden to inhibit any user edit in the editor input.
*/
#Override
public boolean isEditable() {
if (!super.isEditable()) {
return false;
}
return Utils.checkEditorInputModifiable(getEditorInput());
}
How to make read only editor in Eclipse (Eclipse Plugin Development)
But the question is: how to do that on the compare editor??
The editor used by eclipse in each compare dialog is a different editor, I can use my content ContentMergeViewer and set the compareConfiguration as readonly (on one side or both) but this is not sufficient. The compareInput on each side should be made readonly!
Or is there any other more convenient way to achive what I want??
Thank you!
I have a possible solution: you can extend the TextMergeViewer and override some method to check the file path "on the fly":
public abstract class AbstractMergeViewer extends TextMergeViewer {
/**
* Overridden to check if the editor input is modifiable.
*
* #see {#link TextMergeViewer#setEditable(ISourceViewer sourceViewer, boolean state)}
*/
#Override
protected void setEditable(ISourceViewer sourceViewer, boolean state) {
if (!Utils.checkEditorInputModifiable(getEditorInput(sourceViewer))) {
state = false;
}
super.setEditable(sourceViewer, state);
}
/**
* Return a custom implementation of a {#link MergeViewerContentProvider},
* to check if the content is modifiable.
*/
public IContentProvider getContentProvider() {
return new MASMergeViewerContentProvider(getCompareConfiguration());
}
}
The contentProvider has to be extended too:
public class MyMergeViewerContentProvider extends MergeViewerContentProvider {
/**
* Check if the left content is modifiable, with
* {#link Utils#checkResourceModifiable}.
*
* #see org.eclipse.compare.internal.MergeViewerContentProvider#isLeftEditable(java.lang.Object)
*/
#Override
public boolean isLeftEditable(Object element) {
if (element instanceof ICompareInput) {
Object left = ((ICompareInput) element).getLeft();
if (left instanceof LocalResourceTypedElement) {
LocalResourceTypedElement res = (LocalResourceTypedElement) left;
if (!Utils.checkResourceModifiable(res.getResource())) {
return false;
}
}
}
return super.isLeftEditable(element);
}
/**
* Check if the right content is modifiable, with
* {#link Utils#checkResourceModifiable}.
*
* #see org.eclipse.compare.internal.MergeViewerContentProvider#isRightEditable(java.lang.Object)
*/
#Override
public boolean isRightEditable(Object element) {
if (element instanceof ICompareInput) {
Object right = ((ICompareInput) element).getRight();
if (right instanceof LocalResourceTypedElement) {
LocalResourceTypedElement res = (LocalResourceTypedElement) right;
if (!Utils.checkResourceModifiable(res.getResource())) {
return false;
}
}
}
return super.isRightEditable(element);
}
This way all the graphic element in the compare dialog have the right state (disabled if the file is readonly).
MergeViewerContentProvider is an internal class, and should not be extended.. but I haven't found another solution.
The MergeViewer can be applied to a contentType via the extension point
org.eclipse.compare.contentMergeViewers
Now I have another problem: if the contentType is not one that I have defined, Eclipse uses its own implementation of the compare editor, and not mine.
Should I open a new question?
I can open a generated jasper pdf report, in new tab with Window.open():
Window.open("report.pdf?traceCode=" + traceCode, "_BLANK", "");
If i want print the pdf file by clicking a button, what should i do? (Window.print() will print the entire page)
You can create your own class and on click of Print button in your application, by using native print method you can call Window.Print().
GWT UIObject can be used for this purpose and the method and it will be converted into string.
public class NTPrint {
/**
* If true, use a Timer instead to print the internal frame
*/
public static boolean USE_TIMER = true;
/**
* Time in seconds to wait before printing the internal frame when using Timer
*/
public static int TIMER_DELAY = 1;
public static native void it() /*-{
$wnd.print();
}-*/;
public static void it(String html) {
try{
buildFrame(html);
if (USE_TIMER) {
Timer timer = new Timer() {
public void run() {
printFrame();
}
};
timer.schedule(TIMER_DELAY * 1000);
} else {
printFrame();
}
}
catch (Throwable exc) {
CommonUtil.printStackTrace(exc);
Window.alert(exc.getMessage());
}
}
/**
* This method will be called when you pass Widget without style.
* #param uiObjects
*/
public static void it( UIObject...uiObjects) {
StringBuffer objString= new StringBuffer();
for(UIObject obj: uiObjects)
objString.append(obj.toString());
it("", objString.toString());
}
}
OnClick of Print button,
/**
* prints all forms
* #param documentInfo
*/
public static void printForms(List<FormTransaction> formTransactions, String documentInfo, List<CellTransaction> cellTransactionList, boolean isComment, Document document) {
String style = "<link rel='styleSheet' type='text/css' href='v4workflow/css/style.css'>"
+ "<link rel='styleSheet' type='text/css' href='v4workflow/css/gwtcontrols.css'>"
+ "<style type='text/css' media='print'>"
+ "#media print {"
+ ".footerText{font-size:13px; font-weight:normal;margin-top:0px;}"
+ ".break {page-break-after:always}"
+ "}" + "</style>";
List<UIObject> uiObjects = new ArrayList<UIObject>();
NTPrintLayout printLayout = new NTPrintLayout();
printLayout.setSelectedDocument(null);
uiObjects.add(createHeader());
NTPrint.it(style,uiObjects);
}
public static FlexTable createHeader(){
FlexTable flexTable = new FlexTable();
flexTable.setWidth("100%");
return flexTable;
}
You won't be able to call the print() method (or any other method for that matter) of the window object if that window contains non-HTML page.
Let the user download the file.
Refer this also
I am trying to figure out how to propagate events for components inside google maps InfoWindow.
I create anchor or a button and want to handle click event on any of those.
I have found solutions described here
and
here
but those both are using google maps wrappers for gwt.
I would like to avoid those libraries.
QUESTION:
Do you know any way how can I propagate those events from info window to some GWT panel which wraps google maps?
Based on code found here:
http://gwt-maps3.googlecode.com/svn/trunk/src/com/googlecode/maps3/client/
I have created this class that solves problem with using no external library (you have to take Only InfoWindowJSO source from link given)
And then instead passing InnerHtml as string to setContent... you just pass Widget element.
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.ui.ComplexPanel;
import com.google.gwt.user.client.ui.Widget;
public class InfoWindow
{
static class FakePanel extends ComplexPanel
{
public FakePanel(Widget w)
{
w.removeFromParent();
getChildren().add(w);
adopt(w);
}
#Override
public boolean isAttached()
{
return true;
}
public void detachWidget()
{
this.remove(0);
}
}
/** */
InfoWindowJSO jso;
/** If we have a widget, this will exist so we can detach later */
FakePanel widgetAttacher;
/** Keep track of this so we can get it again later */
Widget widgetContent;
/** */
public InfoWindow()
{
this.jso = InfoWindowJSO.newInstance();
}
/** */
public InfoWindow(InfoWindowOptions opts)
{
this.jso = InfoWindowJSO.newInstance(opts);
}
/** Detaches the handler and closes */
public void close()
{
this.detachWidget();
this.jso.close();
}
/** Detaches the content widget, if it exists */
private void detachWidget()
{
if (this.widgetAttacher != null)
{
this.widgetAttacher.detachWidget();
this.widgetAttacher = null;
}
}
/** */
public void open(JavaScriptObject map)
{
this.jso.open(map);
}
public void open(JavaScriptObject map, JavaScriptObject marker)
{
this.jso.open(map, marker);
}
/** */
public void setOptions(InfoWindowOptions value)
{
this.jso.setOptions(value);
}
/** */
public void setContent(String value)
{
this.widgetContent = null;
this.detachWidget();
this.jso.setContent(value);
}
/** */
public void setContent(Element value)
{
this.widgetContent = null;
this.detachWidget();
this.jso.setContent(value);
}
/** */
public void setContent(Widget value)
{
this.widgetContent = value;
this.detachWidget();
this.jso.setContent(value.getElement());
if (this.widgetAttacher == null)
{
// Add a hook for the close button click
this.jso.addListener("closeclick", new Runnable() {
#Override
public void run()
{
detachWidget();
}
});
this.widgetAttacher = new FakePanel(value);
}
else if (this.widgetAttacher.getWidget(0) != value)
{
this.widgetAttacher.detachWidget();
this.widgetAttacher = new FakePanel(value);
}
}
/** #return the widget, if a widget was set */
public Widget getContentWidget()
{
return this.widgetContent;
}
/** */
public JavaScriptObject getPosition()
{
return this.jso.getPosition();
}
/** */
public void setPosition(JavaScriptObject value)
{
this.jso.setPosition(value);
}
/** */
public int getZIndex()
{
return this.jso.getZIndex();
}
/** */
public void setZIndex(int value)
{
this.jso.setZIndex(value);
}
/** */
public void addListener(String whichEvent, Runnable handler)
{
this.jso.addListener(whichEvent, handler);
}
}
A. Browser events bubble all the way to the top of the DOM tree. You can attach your click handlers to a widget that is parent to both the maps InfoWindow and your widget. Then, when a user clicks on your button, you need to check for the source of event to make sure it came from your button.
public void onClick(final ClickEvent event) {
Element e = Element.as(event.getNativeEvent().getEventTarget());
// check if e is your button
}
B. You can create a regular GWT button, attach a ClickHandler to it. Do not put it inside the InfoWindow: place it on top it using absolute positioning and a higher z-index.
I use the static value nextAnchorId to uniquely generate IDs for each InfoWindow, and when the InfoWindow is ready (usually when you call infoWindow.open(map);), I get the anchor by element ID and add my click handler to it. This is kind of what Manolo is doing, but this implementation doesn't require gwtquery, which means that I can run my code in Super Dev Mode.
private static int nextAnchorId = 1;
public InfoWindow makeInfo() {
InfoWindowOptions infoWindowOptions = InfoWindowOptions.create();
FlowPanel infoContentWidget = new FlowPanel();
final String theAnchorId_str = "theAnchor" + nextAnchorId;
HTML theAnchor = new HTML("<a id=\"" + theAnchorId_str + "\">Click me!</a>");
infoContentWidget.add(theAnchor);
infoWindowOptions.setContent(infoContentWidget.getElement());
InfoWindow infoWindow = InfoWindow.create(infoWindowOptions);
infoWindow.addDomReadyListenerOnce(new InfoWindow.DomReadyHandler() {
#Override
public void handle() {
com.google.gwt.user.client.Element muffinButton = (com.google.gwt.user.client.Element) Document.get().getElementById(theAnchorId_str);
DOM.sinkEvents(muffinButton, Event.ONCLICK);
DOM.setEventListener(muffinButton, new EventListener() {
#Override
public void onBrowserEvent(Event event) {
Window.alert("You clicked on the anchor!");
// This is where your click handling for the link goes.
}
});
}
});
nextAnchorId++;
return infoWindow
}
A very simple solution is to use gwtquery:
Identify the anchor in the map you want to add the click handler and define a css selector for that (for instance id=my_link)
Use gquery to locate it and to add the event.
$('#my_link').click(new Function() {
public boolean f(Event e) {
[...]
return false; //false means stop propagation and prevent default
}
});
Note that gwtquery is not a wrapper of jquery but an entire gwt implementation of its api, so including it in your project will not overload it, and the compiler will pick up just the stuff you use.
I have following problems with layout settings in the FieldEditorPreferencePage.
My code is something like this:
public void createFieldEditors () {
Group pv = new group(getfieldEditorParent(), SWT.SHADOW_OUT);
Group of = new group(getfieldEditorParent(), SWT.SHADOW_OUT);
pv.setText(“pv”);
of.setText(“of”);
GridLayout layout = new GridLayout(2,false);
pv.setLayout(layout);
of.setLayout(layout);
addField(new StringFieldEditor(“PreferenceStore name”,“Text:”, pv);
addField(new StringFieldEditor(“PreferenceStore name”,“Text:”, pv);
addField(new StringFieldEditor(“PreferenceStore name”,“Text:”, of);
addField(new StringFieldEditor(“PreferenceStore name”,“Text:”, of);
and so on.
}
The problem is that it does not work with GridLayout.
The StringFieldEditors are not parallel. The number of columns is always 1. Also when I try to change the size of StringFieldEditors in the groups, it doesn’t work too.
Anybody have any ideas?
Thanks.
The problem is that when you are using FieldEditorPreferencePage, you can use only FieldEditor subclasses as components. Here's a snippet from a documentation:
FieldEditorPreferencePage implements a
page that uses these field editors to
display and store the preference
values on the page. Instead of
creating SWT controls to fill its
contents, a FieldEditorPreferencePage
subclass creates field editors to
display the contents. All of the
fields on the page must be implemented
as field editors.
That means you have two options how to achieve what you want:
Implement your own subclass of FieldEditor, which would represent the Group widget.
Do not extend FieldEditorPreferencePage, but only a PreferencePage instead. Then you have to implement createContents method instead of createFieldEditors. You will also have to manage loading and saving of the properties.
I think the second way might be easier if you want to provide some complex layout. You may find some information more here
Another (easy) workaround:
You can also create new Composites to create more columns. The problem is that these FieldEditors communicate with their parent and mess up your layout. So, by creating an "empty" composite, they can communicate as much as they want :)
someGroup = new Group(..., SWT.NONE);
someGroup .setLayout(new GridLayout(16, false));
Composite myC1= new Composite(someGroup,SWT.NONE);
addField(new BooleanFieldEditor(...,C1);
Composite myC2= new Composite(someGroup,SWT.NONE);
addField(new BooleanFieldEditor(...,C2);
Two things to understand about FieldEditorPreferencePage (with GRID style):
The layout of field editor parents is always set to GridLayout even for "custom" components like Groups;
The number of columns in layout is adjusted according to the maximum number of components in any of the field editors (which is 2 in case of StringFieldEditor).
In the above example, the layout data of Groups should take this into account:
GridDataFactory.defaultsFor(pv).grab(true, false).span(2, 1).applyTo(pv);
GridDataFactory.defaultsFor(of).grab(true, false).span(2, 1).applyTo(of);
I implementer the Group-FieldEditor which can contain other FieldEditors and layout them as a Group.
import java.util.Collection;
import org.eclipse.jface.preference.FieldEditor;
import org.eclipse.jface.preference.FieldEditorPreferencePage;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Group;
/**
* Class is intended to create a Group Widgets, inside of the {#link FieldEditorPreferencePage}
* objects.
* This class should be used as following:
*
* use the {#link #getFieldEditorParent()} to as a parent, while creating new Field Editors.
* use {#link #setFieldEditors(Collection)} to add the collection of FieldEditors to the
* {#link GroupFieldEditor}.
*
*
* #author alf
*
*/
public class GroupFieldEditor extends FieldEditor {
private String name;
private Collection members;
private int numcolumns;
private Group group;
private Composite parent;
/**
* The gap outside, between the group-frame and the widgets around the group
*/
private static final int GROUP_PADDING = 5; // px
/**
* The gap inside, between the group-frame and the content
*/
private static final int GROUP_VERTICAL_MARGIN = 5; // px
/**
* The inside-distance creates a new boolean field editor
*/
protected GroupFieldEditor() {
}
/**
* Creates a Group of {#link FieldEditor} objects
*
* #param name
* - name
* #param fieldEditorParent
* - parent
*/
public GroupFieldEditor(String name, Composite fieldEditorParent) {
this.name = name;
// the parent is a Composite, which is contained inside of the preference page. Initially it
// does not have any layout.
this.parent = fieldEditorParent;
FillLayout fillLayout = new FillLayout();
fillLayout.marginHeight = GROUP_VERTICAL_MARGIN;
this.parent.setLayout(fillLayout);
this.group = new Group(parent, SWT.DEFAULT);
this.group.setText(this.name);
}
/**
* The parent for all the FieldEditors inside of this Group.
*
* #return - the parent
*/
public Composite getFieldEditorParent() {
return group;
}
/**
* Sets the FieldeditorChildren for this {#link GroupFieldEditor}
*
* #param membersParam
*/
public void setFieldEditors(Collection membersParam) {
this.members = membersParam;
doFillIntoGrid(getFieldEditorParent(), numcolumns);
}
/*
* (non-Javadoc) Method declared on FieldEditor.
*/
#Override
protected void adjustForNumColumns(int numColumns) {
this.numcolumns = numColumns;
}
/*
* (non-Javadoc) Method declared on FieldEditor.
*/
#Override
protected void doFillIntoGrid(Composite parentParam, int numColumns) {
GridLayout gridLayout = new GridLayout();
gridLayout.marginLeft = GROUP_PADDING;
gridLayout.marginRight = GROUP_PADDING;
gridLayout.marginTop = GROUP_PADDING;
gridLayout.marginBottom = GROUP_PADDING;
this.group.setLayout(gridLayout);
this.parent.layout();
this.parent.redraw();
if (members != null) {
for (FieldEditor editor : members) {
editor.fillIntoGrid(getFieldEditorParent(), 1);
}
}
}
/*
* (non-Javadoc) Method declared on FieldEditor. Loads the value from the
* preference store and sets it to the check box.
*/
#Override
protected void doLoad() {
if (members != null) {
for (FieldEditor editor : members) {
editor.load();
}
}
}
/*
* (non-Javadoc) Method declared on FieldEditor. Loads the default value
* from the preference store and sets it to the check box.
*/
#Override
protected void doLoadDefault() {
if (members != null) {
for (FieldEditor editor : members) {
editor.loadDefault();
}
}
}
/*
* (non-Javadoc) Method declared on FieldEditor.
*/
#Override
protected void doStore() {
if (members != null) {
for (FieldEditor editor : members) {
editor.store();
}
}
}
#Override
public void store() {
super.store();
doStore();
}
/*
* (non-Javadoc) Method declared on FieldEditor.
*/
#Override
public int getNumberOfControls() {
return 1;
}
/*
* (non-Javadoc) Method declared on FieldEditor.
*/
#Override
public void setFocus() {
if (members != null && !members.isEmpty()) {
members.iterator().next().setFocus();
}
}
/*
* #see FieldEditor.setEnabled
*/
#Override
public void setEnabled(boolean enabled, Composite parentParam) {
if (members != null) {
for (FieldEditor editor : members) {
editor.setEnabled(enabled, parentParam);
}
}
}
#Override
public void setPreferenceStore(IPreferenceStore store) {
super.setPreferenceStore(store);
if (members != null) {
for (FieldEditor editor : members) {
editor.setPreferenceStore(store);
}
}
}
}
Yet another workaround:
Use Labels to separate groups of fields.
The following creates a vertical line separator and puts text directly beneath it:
new Label(getFieldEditorParent(), SWT.SEPARATOR | SWT.HORIZONTAL)
.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false, 2, 1));
new Label(getFieldEditorParent(), SWT.NONE).setText("My Group Title");