I have a chat activity and trying to inflate different layouts for the sender and receiver. so far I can retrieve data for the firebase realtime database but sender and receiver have the same layout, I have created layout second layout and tried with viewType but can't figure out how to assign the current user to a cretin layout, please help :(
chat activity
if (!employee)
{
FirebaseRecyclerOptions options = new FirebaseRecyclerOptions.Builder<ChatMessageModel>()
.setQuery(FirebaseDatabase.getInstance().getReference().child("client_emp_messages")
.child(formattedDate+uid), ChatMessageModel.class)
.build();
}
else
{
// employee
Bundle bundle = getIntent().getExtras();
String d = bundle.getString("path_to_client_realtime_db");
options = new FirebaseRecyclerOptions.Builder<ChatMessageModel>()
.setQuery(FirebaseDatabase.getInstance().getReference().child("client_emp_messages")
.child(d), ChatMessageModel.class)
.build();
}
adapter = new ChatAdapter(options);
nMessageList.setAdapter(adapter);
chat adapter
public class ChatAdapter extends FirebaseRecyclerAdapter<ChatMessageModel, ChatAdapter.ChatViewHolder>
{
public ChatAdapter(#NonNull FirebaseRecyclerOptions<ChatMessageModel> options) {
super(options);
}
#Override
protected void onBindViewHolder(#NonNull ChatViewHolder holder, int i, #NonNull ChatMessageModel model) {
holder.nMessage_text_view.setText(model.getMessage());
}
#NonNull
#Override
public ChatViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.message_single_layout, parent, false);
return new ChatViewHolder(view);
}
class ChatViewHolder extends RecyclerView.ViewHolder
{
TextView nMessage_text_view;
public ChatViewHolder(#NonNull View itemView) {
super(itemView);
nMessage_text_view = itemView.findViewById(R.id.message_text_view);
}
}
}
What I suggest you is to make one layout. like the sender on the right side and receiver on the left side. you can use it with the help of a linear layout or relative layout. and set their visibility Invisible.
So download the message data from the database and check it by user id token. If it data matches with the current user token then display it in the right column and set visibility Visible and vice versa.
For that, you just need to store the user token with the message in the database.
Hope you understand it. Thanks
Related
MainView include InformationCOmponent:
#Push
#Route
public class MainView extends VerticalLayout {
InformationComponent infoComponent;
public MainView(#Autowired StudentRepository studentRepo, #Autowired Job jobImportCsv, #Autowired JobLauncher jobLauncher, #Value("${file.local-tmp-file}") String inputFile) {
[...] // some stuffs
infoComponent = new InformationComponent(studentRepo);
add(infoComponent);
}
//update when job process is over
private void uploadFileSuccceed() {
infoComponent.update(myUploadComponent.getFile());
}
InformationComponent:
public class InformationComponent extends HorizontalLayout {
StudentRepository studentRepo;
Label nbLineInFile = new Label();
VerticalLayout componentLeft = new VerticalLayout();;
VerticalLayout componentRight = new VerticalLayout();;
public InformationComponent(StudentRepository studentRepo) {
[...] // some init and style stuff
addLine("Nombre de lignes dans le fichier", nbLineInFile);
}
private void addLine(String label, Label value) {
componentLeft.add(new Label(label));
componentRight.add(value);
}
public void update(File file) {
try {
long nbLines = Files.lines(file.toPath(), Charset.defaultCharset()).count();
System.out.println("UPDATED! " +nbLines); // value is display in console ok!
UI.getCurrent().access(() -> nbLineInFile.setText(nbLines)); // UI is not updated!!
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
When I call InformationComponent from MainView the Label is not update in the browser.
UI.getCurrent().access(() -> nbLineInFile.setText(nbLines))
also try wwith #Push(PushMode.MANUAL) and ui.push(); but doesn't work either...
Complete source code is here: https://github.com/Tyvain/ProcessUploadedFile-Vaadin_SpringBatch/tree/push-not-working
I suspect the problem here is that uploadFileSuccceed() is run from a background thread, in which case UI.getCurrent() will return null. This would cause a NullPointerException that either kills the background thread or alternatively the exception is caught and silently ignored by the caller. Another alternative is that uploadFileSuccceed() happens through a different browser window and thus also a different UI instance, which means that the changes would be pushed in the context of the wrong UI.
For exactly these reasons, UI.getCurrent().access(...) is generally an anti pattern, even though it's unfortunately quite widely used in old examples.
You can check whether this is the cause of your problem by logging the value of UI.getCurrent() in the beginning of the update method, and comparing that to the value of UI.getCurrent() e.g. in the constructor of InformationComponent.
To properly fix the problem, you should pass the correct UI instance through the entire chain of events originating from whatever triggers the background processing to start. You should also note that it might be tempting to use the getUI() method that is available in any Component subclass, but that method is not thread safe and should thus be avoided in background threads.
As a final notice, I would recommend using the Span or Text component instead of Label in cases like this. In Vaadin 10, the Label component has been changed to use the <label> HTML element, which means that it's mainly intended to be used as the label of an input component.
Based on information provided by Leif you should do something like the following example.
At runtime, when this HorizontalLayout subclass object is attached to a parent UI object, its onAttach method is called. At that point we can remember the UI by storing its reference is a member variable named ui. Actually, an Optional<UI> is returned rather than a UI object, so we need to test for null, though it should never be null at point of onAttach.
public class InformationComponent extends HorizontalLayout {
UI ui;
StudentRepository studentRepo;
Label nbLineInFile = new Label();
VerticalLayout componentLeft = new VerticalLayout();;
VerticalLayout componentRight = new VerticalLayout();;
public InformationComponent(StudentRepository studentRepo) {
[...] // some init and style stuff
addLine("Nombre de lignes dans le fichier", nbLineInFile);
}
private void addLine(String label, Label value) {
componentLeft.add(new Label(label));
componentRight.add(value);
}
public void update(File file) {
try {
long nbLines = Files.lines(file.toPath(), Charset.defaultCharset()).count();
System.out.println("UPDATED! " +nbLines); // value is display in console ok!
this.ui.access(() -> nbLineInFile.setText(nbLines)); // UI is not updated!!
} catch (IOException e) {
throw new RuntimeException(e);
} catch (UIDetachedException e) {
// Do here what is needed to do if UI is no longer attached, user has closed the browser
}
#Override // Called when this component (this `HorizontalLayout`) is attached to a `UI` object.
public void onAttach() {
ui = this.getUI().orElseThrow( () -> new IllegalStateException("No UI found, which should be impossible at point of `onAttach` being called.") );
}
Vaadin 8.1 introduced the TreeGrid component. It does not have the collapseItemsRecursively and expandItemsRecursively methods anymore (as available in the now legacy Tree component). Do i miss something or do you need to develop your own implementation? If so, what is a recommended way of doing this?
As I'm sure you've noticed, the TreeGrid is a rather new component, currently being developed and available starting with v8.1.alphaX (current stable version is v8.0.6). As such, it probably has only some basic functionalities for the time being, with the rest to follow sometime in the future, although there are no guarantee. For example this similar feature request for the older TreeTable component has been in open state since 2011.
Either way, even if they're probably not the optimum solutions, there are a couple of work-arounds that you can use to achieve this behavior. I'm shamelessly using as a base sample, a slightly modified version of the code currently available in the vaadin-sampler for TreeGrid.
public class RecursiveExpansionTreeGrid extends VerticalLayout {
private Random random = new Random();
public RecursiveExpansionTreeGrid() {
// common setup with some dummy data
TreeGrid<Project> treeGrid = new TreeGrid<>();
treeGrid.setItems(generateProjectsForYears(2010, 2016), Project::getSubProjects);
treeGrid.addColumn(Project::getName).setCaption("Project Name").setId("name-column");
treeGrid.addColumn(Project::getHoursDone).setCaption("Hours Done");
treeGrid.addColumn(Project::getLastModified).setCaption("Last Modified");
addComponent(treeGrid);
}
// generate some dummy data to display in the tree grid
private List<Project> generateProjectsForYears(int startYear, int endYear) {
List<Project> projects = new ArrayList<>();
for (int year = startYear; year <= endYear; year++) {
Project yearProject = new Project("Year " + year);
for (int i = 1; i < 2 + random.nextInt(5); i++) {
Project customerProject = new Project("Customer Project " + i);
customerProject.setSubProjects(Arrays.asList(
new LeafProject("Implementation", random.nextInt(100), year),
new LeafProject("Planning", random.nextInt(10), year),
new LeafProject("Prototyping", random.nextInt(20), year)));
yearProject.addSubProject(customerProject);
}
projects.add(yearProject);
}
return projects;
}
// POJO for easy binding
public class Project {
private List<Project> subProjects = new ArrayList<>();
private String name;
public Project(String name) {
this.name = name;
}
public String getName() {
return name;
}
public List<Project> getSubProjects() {
return subProjects;
}
public void setSubProjects(List<Project> subProjects) {
this.subProjects = subProjects;
}
public void addSubProject(Project subProject) {
subProjects.add(subProject);
}
public int getHoursDone() {
return getSubProjects().stream().map(project -> project.getHoursDone()).reduce(0, Integer::sum);
}
public Date getLastModified() {
return getSubProjects().stream().map(project -> project.getLastModified()).max(Date::compareTo).orElse(null);
}
}
// Second POJO for easy binding
public class LeafProject extends Project {
private int hoursDone;
private Date lastModified;
public LeafProject(String name, int hoursDone, int year) {
super(name);
this.hoursDone = hoursDone;
lastModified = new Date(year - 1900, random.nextInt(12), random.nextInt(10));
}
#Override
public int getHoursDone() {
return hoursDone;
}
#Override
public Date getLastModified() {
return lastModified;
}
}
}
Next, recursively expanding or collapsing the nodes depends a bit on your scenario, but basically it breaks down to the same thing: making sure each node from the root to the deepest leaf is expanded/collapsed.The simplest way of doing it is to flatten your hierarchy into a list of nodes, and call the appropriate method, expand(List<T> items) or expand(T ... items) (the second delegates to the first and is probably a convenience method eg expand(myItem)).
For simplicity, I've added a flatten method in our Project implementation. If you can't do that for some reason, then create a recursive method that creates a list starting with the selected node and includes all the children, of the children, of the children.... well, you get the idea.
public Stream<Project> flatten() {
return Stream.concat(Stream.of(this), getSubProjects().stream().flatMap(Project::flatten));
}
Possible scenarios:
Automatically expand the entire hierarchy when expanding the root - add listeners, and expand/collapse the whole flattened hierarchy:
treeGrid.addCollapseListener(event -> {
if (event.isUserOriginated()) {
// event is triggered by all collapse calls, so only do it the first time, when the user clicks in the UI
// and ignore the programmatic calls
treeGrid.collapse(event.getCollapsedItem().flatten().collect(Collectors.toList()));
}
});
treeGrid.addExpandListener(event -> {
if (event.isUserOriginated()) {
// event is triggered by all expand calls, so only do it the first time, when the user clicks in the UI
// and ignore the programmatic calls
treeGrid.expand(event.getExpandedItem().flatten().collect(Collectors.toList()));
}
});
Expanding the hierarchy or part of it with a custom action, such as a context menu
GridContextMenu<Project> contextMenu = new GridContextMenu<>(treeGrid);
contextMenu.addGridBodyContextMenuListener(contextEvent -> {
contextMenu.removeItems();
if (contextEvent.getItem() != null) {
Project project = (Project) contextEvent.getItem();
// update selection
treeGrid.select(project);
// show option for expanding
contextMenu.addItem("Expand all", VaadinIcons.PLUS, event -> treeGrid.expand((project).flatten().collect(Collectors.toList())));
// show option for collapsing
contextMenu.addItem("Collapse all", VaadinIcons.MINUS, event -> treeGrid.collapse((project).flatten().collect(Collectors.toList())));
}
});
In the end, you should be getting this effect:
From the docs for treegrid, you can use the methods, collapse and expand, by passing a list or array of the treegrid's data items to expand or collapse:
treeGrid.expand(someTreeGridItem1, someTreeGridItem2);
treeGrid.collapse(someTreeGridItem1);
Also worthy of note, is a section showing the ability to prevent certain items from ever being collapsed
I have a gwt and grails legacy app that I'm upgrading and modifying.. Its a reservation calendar basically with different "views".. the problem I'm having is I want the user to be able to choose a default view for themselves upon logging in..I've done this with a grails only application before but gwt is much different..how can I pass something from config.groovy to the gwt part that select which view to show..and this view isn't a view like a grails view..think of it like restaurants..and a user may only want to see the reservations for a particular restaurant instead of the default of all restaurants
Maybe not a direct answer to your question but you can just make a ordinary GWT remote service UserPreferencesService which will store user preferences
public interface UserPreferencesService extends RemoteService {
List<Restaurant> getRestaurants(Account user);
void setRestaurants(Account user, List<Restaurant> restaurants);
}
In your entry point you can then make a decision on what kind of view you'll show to user
public final class Application implements EntryPoint {
private AuthServiceAsync authService =
GWT.create(AuthService.class);
private UserPreferencesAsync preferencesService =
GWT.create(UserPreferencesService.class);
#Override
public void onModuleLoad() {
// handle login
authService.getAccount(new Callback<Account>() {
#Override
public void onSuccess(final Account account) {
// check if user have a preferred restourants
preferencesService.getRestaurants(account,
new Callback<Account>() {
#Override
public void onSuccess(final List<Restaurant> restaurants) {
// user did not select any restaurants yet.
// Show a selection widget
if (restaurants.isEmpty) {
RestaurantSelectorWidget widget =
new RestaurantSelectorWidget();
// your custom handler here
widget.addHandler(new Handler() {
#Override
public void onSelected(/*...*/) {
// save user preferences
// and switch to normal view
}
})
RootPanel.get("container")
.add(widget);
} else {
// show normal view
}
}
}
}
}
}
}
}
Also you may take look to this plugin which is adds GWT support to grails.
Good day! I would like to ask how these particular situation is done in JAVAFX.
I have made a layout as being pointed out here (link to layout question)
My question is since the keyboard layout is from a different FXML with a different Controller class and with the mainLayout having a different FXML with its own controller class, , how do you code such thing that when I press key 'A', it will display on the textfield found in the mainLayout? Does it have to do with bindings? If so, how? Please?
bear in mind that JavaFX and FXML follow the MVC principle.
an easy (although perhaps not optimal) solution would look like this:
public class Main extends Application {
#Override
public void start(Stage stage) throws Exception {
FXMLLoader layout1Loader = new FXMLLoader(getClass().getResource("layout1.fxml"));
FXMLLoader layout2loader = new FXMLLoader(getClass().getResource("layout2.fxml"));
Node layout1 = (Node) layout1Loader.load();
Node layout2 = (Node) layout2loader.load();
final Layout1Controller l1Controller = layout1Loader.getController();
final Layout2Controller l2Controller = layout2loader.getController();
l2Controller.but2.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent actionEvent) {
l1Controller.toggleStatus(actionEvent);
}
});
Parent root = (Parent) layout1;
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
...
}
I have developed an application. I want to display a message before the user starts implementing my application. Like when it is used first time i want to show "Count = 1". And when app is visited second time, "Count = 2".
How can i achieve it? I had done such thing in android using sharedperferences. But how can i do it in blackberry. I had tried something with PersistentStore. But cant achieve that, for i dont know anything about the Persistance in BB.
Also i would wish to restrict the use for 100. Is it possible?
sample codes for this will be appreciable, since i am new to this environment..
You can achieve it with Persistent Storage.
Check this nice tutorial about storing persistent data.
Also you can use SQLite. Link to a development guide which describes how to use SQLite databases in Java® applications: Storing data in SQLite databases.
You can restrict user for trying your application at most 100 times using your own logic with the help of persistent data. But I think there may be some convention, so try Google for that.
got it...
I created a new class which implements Persistable. In that class i had created an integer variable and set an getter and setter function for that integer...
import net.rim.device.api.util.Persistable;
public class Persist implements Persistable
{
private int first;
public int getCount()
{
return first;
}
public void setCount()
{
this.first += 1;
}
}
Then in the class which initializes my screen, i had declared persistence variables and 3 functions to use my Persist.java, initStore(), savePersist(), and getPersist()
public final class MyScreen extends MainScreen implements FieldChangeListener
{
/*
* Declaring my variables...
*/
private static PersistentObject store;
public Persist p;
public MyScreen()
{
//my application codes
//here uses persistence
initStore();
p = getPersist();
if(p.getCount()<100)
{
savePersist();
UiApplication.getUiApplication().invokeLater(new Runnable()
{
public void run()
{
Dialog.alert(p.getCount.toString());
}
});
}
else
{
close();
System.exit(0);
}
}
//three function....
public static void initStore()
{
store = PersistentStore.getPersistentObject(0x4612d496ef1ecce8L);
}
public void savePersist()
{
synchronized (store)
{
p.setCount();
store.setContents(p);
store.commit();
}
}
public Persist getPersist()
{
Persist p = new Persist();
synchronized(store)
{
p = (Persist)store.getContents();
if(p==null)
{
p = new Persist();
}
}
return p;
}
}
I hope u all will get it right now....
If there are another simple way, plz let me know...
Thanks