I've created a custom InputHandler for Ant in order to get some input using a GUI. The issue is that the JFrame created immediately closes after the call to setVisible() instead of waiting for input.
Below is the simple code for the InputHandler and the frame it creates.
public class GUIInputHandler implements InputHandler
{
public GUIInputHandler()
{
super();
}
public void handleInput(InputRequest input) throws BuildException
{
GUIFrame frame = new GUIFrame(input.getDefaultValue());
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
Now if I just create a main and create the frame and show it, everything is fine. I could rig it to have some sort of loop with the frame triggering the exit condition but that is a hack. Any ideas?
Related
Using Vaadin 14.0.13 without compatibility mode.
I use a view to create a Dialog with dynamic content:
#Route("")
public class MainView extends VerticalLayout {
public MainView(DialogContentProvider contentProvider) {
this.add(new Button("Click me!", event -> new Dialog(contentProvider.create()).open()));
}
}
The contentProvider is an interface
public interface DialogContentProvider {
Component create();
}
with this implementation:
public class CheckBoxContentProvider implements DialogContentProvider {
#Override
public Component create() {
return new Checkbox("My checkbox", true);
}
}
instantiated by Spring Boot (version 2.2.1.RELEASE) with a bean:
#Bean
public DialogContentProvider contentProvier() {
return new CheckBoxContentProvider();
}
When I click on the button, the dialog is opened but the checkbox haven't the box:
The source code is on github: https://github.com/gronono/bug-vaadin-checkbox
I don't understand why and how I can fix it. If I include the checkbox creation inside the main view, it works fine:
#Route("")
public class MainView extends VerticalLayout {
public MainView(DialogContentProvider contentProvider) {
// this.add(new Button("Click me!", event -> new Dialog(contentProvider.create()).open()));
this.add(new Button("Click me!", event -> new Dialog(new Checkbox("My checkbox", true)).open()));
}
}
This sound an awful lot like this (related github issue)
Basically, this happens when you don't have any View that uses a Checkbox directly, but through other means like reflection or in your case the contentProvider, because in no view of your app there is any import statement of Checkbox (--> therefore, vaadins scan during the installation will not detect usages of Checkbox, so it will not download npm stuff for checkbox).
in the github it says this will be fixed in 14.1
If you need a fix now, for me it worked when I declared a field of that type in any view with a #Route. That field doesn't have to be used.
#Route("")
public class MainView extends VerticalLayout {
private Checkbox unusedCheckbox; // this line fixes it.
public MainView(DialogContentProvider contentProvider) {
this.add(new Button("Click me!", event -> new Dialog(contentProvider.create()).open()));
}
}
Addendum: This is not related to the Checkbox component specifically, it happens with any vaadin component that isn't initially scanned in a route, but used anyway through reflective-, provider-, or generic means.
Edit: You can also work around this currently by adding a #Route(registerAtStartup = false) to your provider that uses the Checkbox directly. This will make vaadins scan see the checkbox usage (therefore importing its npm package), but will not actually register the provider as a real route..
Another way which I prefer if you need this for multiple components is to create a new View with a #Route(registerAtStartup = false) which only defines private variables for each component that you'll need in the application (and arent already used directly in some view of yours). This has the advantage of all these component usage definitions in one place, and once the official fix is released, you need only to delete one class and the deprecated workaround is gone.
#Route(registerAtStartup = false)
public class ComponentImportView extends VerticalLayout {
private Checkbox checkBox;
private Upload upload;
private ProgressBar progressBar;
}
I have a Vaadin Navigator with multiple View elements. Each view has a different purpose however some also contain common traits that I have put inside custom components.
One of those custom components is the menu - it is positioned at the top and allows navigation between the different views. I create and add this component inside the constructor of each view (if you are interested in the menu's implementation see the end of this post). Here is a skeleton for each custom view:
class MyViewX implements View {
MenuViewComponent mvc;
public MyViewX() {
mvc = new MenuViewComponent();
addComponent(mvc);
}
#Override
public void enter(ViewChangeEvent event) {
}
}
So far, so good. In order to make things simple I will explain my problem using a simple label and not one of my other custom components but the dependency that I will describe here is the same for those components just like with the label.
Let's say I have a label which sole purpose is to display a greeting with the user's username. In order to do that I use VaadinSession where I store the attribute. This is done by my LoginController, which validates the user by looking into a database and if the user is present, the attribute is set and one of the views is opened automatically. The problem is that VaadinSession.getCurrent().getAttribute("username") returns null when called inside the constructor. This of course makes sense omho because a constructor should not be bound by a session-attribute.
So far I have managed to use the enter() method where there is no problem in retrieving session attributes:
class MyViewX implements View {
MenuViewComponent mvc;
public MyViewX() {
mvc = new MenuViewComponent();
addComponent(mvc);
}
#Override
public void enter(ViewChangeEvent event) {
String username = (String)VaadinSession.getCurrent().getAttribute("username");
Label greeting = new Label("Hello " + username);
addComponent(greeting);
}
}
The issue that comes from this is obvious - whenever I open the view where this label is present, a new label is added so if I re-visit the view 10 times, I will get 10 labels. Even if I move the label to be a class member variable the addComponent(...) is the one that screws things up. Some of my custom components really depend on the username attribute (in order to display user-specific content) hence I also have to place those in the enter(...) method. The addComponent(...) makes a mess out of it. I even tried the dirty way of removing a component and then re-adding it alas! in vain:
class MyViewX implements View {
MenuViewComponent mvc;
Label greeting;
public MyViewX() {
mvc = new MenuViewComponent();
addComponent(mvc);
}
#Override
public void enter(ViewChangeEvent event) {
String username = (String)VaadinSession.getCurrent().getAttribute("username");
greeting = new Label("Hello " + username);
// Remove if present
try { removeComponent(greeting); }
catch(Exception ex) { }
// Add again but with new content
addComponent(greeting);
}
}
but it's still not working. So my question is: what is the simplest way of updating a component that requires session-bound attributes?
The navigation via the menu custom component is omho not the issue here since all components of the menu are loaded in it's constructor. That's why it's also load that component in particular in a view's own constructor. Here is an example of a button in my menu that opens a view:
#SuppressWarnings("serial")
#PreserveOnRefresh
public class MenuViewComponent extends CustomComponent {
public MenuViewComponent(boolean adminMode) {
HorizontalLayout layout = new HorizontalLayout();
Label title = new Label("<h2><b>Vaadin Research Project</b></h2>");
title.setContentMode(ContentMode.HTML);
layout.addComponent(title);
layout.setComponentAlignment(title, Alignment.TOP_LEFT);
Button personalDashboardButton = new Button("Personal dashboard", new Button.ClickListener() {
#Override
public void buttonClick(ClickEvent event) {
getUI().getNavigator().navigateTo(MainController.PERSONALDASHBOARDVIEW);
}
});
personalDashboardButton.setStyleName(BaseTheme.BUTTON_LINK);
layout.addComponent(personalDashboardButton);
layout.setComponentAlignment(personalDashboardButton, Alignment.TOP_CENTER);
// Add other buttons for other views
layout.setSizeUndefined();
layout.setSpacing(true);
setSizeUndefined();
setCompositionRoot(layout);
}
}
PERSONALDASHBOARDVIEW is just one of the many views I have.
It may be worth considering how long should your view instances "live", just as long they're displayed, until the session ends or a mix of the two. With this in mind and depending on what needs to happen when you enter/re-enter a view, you have at least the following 3 options:
1) Recreate the whole view (allowing for early view garbage-collection)
first register a ClassBasedViewProvider (instead of a StaticViewProvider) which does not hold references to the created views:
navigator = new Navigator(this, viewDisplay);
navigator.addProvider(new Navigator.ClassBasedViewProvider(MyView.NAME, MyView.class));
simple view implementation
public class MyView extends VerticalLayout implements View {
public static final String NAME = "myViewName";
#Override
public void enter(ViewChangeListener.ViewChangeEvent event) {
// initialize tables, charts and all the other cool stuff
addComponent(new SweetComponentWithLotsOfStuff());
}
}
2) Keep some already created components and replace others
public class MyView extends VerticalLayout implements View {
private MySweetComponentWithLotsOfStuff mySweetComponentWithLotsOfStuff;
public MyView() {
// initialize only critical stuff here or things that don't change on enter
addComponent(new MyNavigationBar());
}
#Override
public void enter(ViewChangeListener.ViewChangeEvent event) {
// oh, so the user does indeed want to see stuff. great, let's do some cleanup first
removeComponent(mySweetComponentWithLotsOfStuff);
// initialize tables, charts and all the other cool stuff
mySweetComponentWithLotsOfStuff = new SweetComponentWithLotsOfStuff();
// show it
addComponent(mySweetComponentWithLotsOfStuff);
}
}
3) Lazy creating and updating (or not) the content when entering
public class MyView extends VerticalLayout implements View {
private boolean isFirstDisplay = true;
private MySweetComponentWithLotsOfStuff mySweetComponentWithLotsOfStuff;
public MyView() {
// initialize only critical stuff here, as the user may not even see this view
}
#Override
public void enter(ViewChangeListener.ViewChangeEvent event) {
// oh, so the user does indeed want to see stuff
if (isFirstDisplay) {
isFirstDisplay = false;
// lazily initialize tables, charts and all the other cool stuff
mySweetComponentWithLotsOfStuff = new SweetComponentWithLotsOfStuff();
addComponent(mySweetComponentWithLotsOfStuff);
} else {
// maybe trigger component updates, or simply don't do anything
mySweetComponentWithLotsOfStuff.updateWhateverIsRequired();
}
}
}
I'm sure (and curious) that there may be other options, but I've mainly used a variation of 1) using spring with prototype views and component tabs.
I have the following code:
public class FileLoader extends SwingWorker(Void, Void) {
#Override
private Void doInBackground() {
loadFiles();
}
}
public class LogInPage {
private FileLoader fileLoader = new FileLoader();
public LogInPage() {
fileLoader.execute();
}
loginButtonActionPerformed(ActionEvent evt) {
//wait for files to finish loading
//while displaying a waiting cursor
showMainForm();
}
}
My question would be:
After clicking the button, I would want all the files to be loaded first (while displaying an hourglass cursor and progress bar) before showing the main form.
I have done this before with Thread's join() but was not able to do the same with SwingWorker.
I have read about overriding done() and implementing listeners but I can't apply it here.
Any help?
Thanks.
From what you're saying and contrary to what you think, I think you can actually use SwingWorker's done() method. Before execute(), disable the button, start a busy animation, whatever, then in the done() method, do whatever it is you need to do to continue the program. That's what it's for :-)
You should also look at the SwingWorker.publish() and process() to send and receive the progress bar events.
See also: How do I wait for a SwingWorker's doInBackground() method?
My app has has an option to show screen-B instead of screen-A (default main) at app start up.
First I tried pushScreen(screen-B) in screen-A's constructor which resulted in display stack has screen-A on top and then screen-B..
What I want to do is:
At start up if the option is on, show screen-B (stack has screen-B then screen-A so that Escape key would lead to screen-A)
What would be the right way to acheive this?
You might consider pushing B a little bit later in the process, in the onUiEngineAttached method:
class ScreenA extends Screen {
...
protected void onUiEngineAttached(boolean attached) {
if (attached) {
// check condition and push B as appropriate
}
}
}
When the application starts, in the UiApplication class make the following:
class UiApp extends UiApplication {
UiApp() {
if (yourCondition)
//start A
else
//start B
}
public static void main (String[] args) {
UiApp app = new UiApp();
app.enterEventDispatcher();
}
}
HI, I try to detect reterning to screen after closing another screen,
should work when returning from my application screens, but also returning from device camera
after shooting video. In overriden method onExposed() I'm able to detect this situation,
but it's called too many times, and also called when dialog was shown (alert).
Is there better way to detect return to screen?
protected void onExposed() {
// return to screen detected
MainApp.addLog("onExposed");
}
returning from device camera after
shooting video
Check the Application.activate()
The system invokes this method when it
brings this application to the
foreground. By default, this method
does nothing. Override this method to
perform additional processing when
being brought to the foreground.
If you override the Screen.onUiEngineAttached(boolean) method, you can be notified when the screen is attached or detached from the UI --- basically when it's pushed or popped from the screen stack.
I had to do a similar thing and found it's very confusing because onExposed() can be called multiple times in uncertain timing.
To detect returning from screen B in screen A (main screen), I used screen B's onUiEngineAttached(false) which is called when it is popped.
To use callback:
public interface Ievent {
public void backFromScreenBEvent();
}
Screen A:
public class ScreenA extends MainScreen implements Ievent
{
private ScreenB screenB;
// constructor
public ScreenA()
{
screenB = new ScreenB(this); // pass over Ievent
// ....
}
public void backFromScreenBEvent()
{
// screen B is returning, do something
}
Screen B:
public final class ScreenB extends MainScreen
{
private Ievent event;
// constructor
public ScreenB(final Ievent event)
{
this.event = event;
// ...
}
protected void onUiEngineAttached(boolean attached) {
super.onUiEngineAttached(attached);
if (!attached) {
event.backFromScreenBEvent(); // notify event
}
}