i have two classes, one named Main other is Results
(a) the Main class screen have 2 fields:
1- EditField
2- ButtonField
(b) Result class: in this class there is url connection
i want once i click on the ButtonField it go to the other screen with the data i entred in the EditField to parse the xml accourding to my submit text
like this :
http://www.test.com/search.php?q=[ i want the text in the EditField to be here ]
pleaase i have been trying for 2 weeks
i'm very very new at BlackBerry development
okkk you can make one constructor having parameter is of String type of the Resultclass. Get the String from EditField in Button Click From your Main class like this way
Strnig urlString = youreditfield.getText();//this will be in fieldChanged or any method
you have used for pushing the Screen
and pass this String to that class which you are pushing from the button click like this way
UiApplication.getUiApplication().pushScreen(new Result(urlString));
And yourclass constructor would be
Result(String yourEditfieldurl) {
Assign this url to a variable and use it in Result class that's it
}
Or you can make a Static variable
like this
In main class make a varible like this
public static String editFieldUrl;
assign the value in ButtonField click method
editFieldUrl = yourEditfield.getText();
and use this variable in the other class.
I think this may help you.
Related
In Vaadin, when you scroll down or up in tables (com.vaadin.ui.Table) there is no event that will be fired to tell you that user is now scrolling.
Why would we need scroll event in table?
Let's first take a look at this example of Vaadin (Dashboard Demo) after you open the link just click sign in, and you'll be automatically redirected to the transactions page, this page shows a table of financial transactions, these transactions will show a batch after another while you are scrolling, what actually happened is that the data was loaded on UI initiation (all the transactions).
Now, let's assume that we have thousands or say millions of transactions. Is it logic to load them all together when the UI is initiated? isn't it of wisdom to load them bit by bit to prevent slowing down the UI while it waits for all transactions to load?.
The best solution to this problem is to get the first (say 100 transactions) then get more transactions while scrolling down, but this solution have only one problem, that is Vaadin does not support Scroll Event Handling in com.vaadin.ui.Table !!
According to your question you are looking for lazy loading.
If you connect your table with a container which supports lazy loading your items are loaded from it's data source lazily. This means when you scroll and get out of the buffered items the table "asks" the container for more items. The container then loads more items from it's data source.
For example the JPAContainer from Vaadin supports that feature. This container connects to a data source using JPA. More information here.
Vaadin Table's Scrolling Event
The Dashboard Demo (GitHub repo) project actually depends on Vaadin tables as you see in the code in this file in line 53, what we are going to do is to extend com.vaadin.ui.Table and implement our own behavior that will support scrolling Vaadin tables from now on.
First of all, let's create new simple interface ScrollingTableScrollListener this interface will be responsible for implementing scroll events and its code will look like this:
package com.vaadin.demo.dashboard.scrolling;
public interface ScrollingTableScrollListener {
public void doTableScroll();
}
This interface should be implemented whenever you have a table in your view and you want to add a scroll event handler for it. But wait a minute this is not applicable to any kind of tables, this is only applicable to our own table.
Now, let's create our table, our table's name is (ScrollingTable) and it extends (com.vaadin.ui.Table) this class code is:
package com.vaadin.demo.dashboard.scrolling;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.vaadin.ui.Table;
public class ScrollingTable extends Table {
private static final long serialVersionUID = 5007124121625961567L;
List listeners = new ArrayList();
private void fireSrollEvent() {
for (ScrollingTableScrollListener listener : listeners) {
listener.doTableScroll();
}
}
public void addScrollListener(ScrollingTableScrollListener listener) {
listeners.add(listener);
}
#Override
public void changeVariables(Object source, Map variables) {
super.changeVariables(source, variables);
fireSrollEvent();
}
}
Actually, this table is the same as Vaadin's one, but it has the following differences:
It overrides the method changeVariables() of the super class (Vaadin Table : com.vaadin.ui.Table), actually here lays our core business that will initiate the Scrolling Behavior. What we did here is that we invoked the changeVariables() of the super class and then we invoked the fireSrollEvent() method.
Another difference is that it has two more members:
public void addScrollListener(ScrollingTableScrollListener listener) this method will take care of adding new listeners to table's scrolling event.
private void fireSrollEvent() this method is the one that will be invoked by changeVariables() method and will invoke the method doTableScroll() on every registered listener that this table has added by invoking the method addScrollListener().
Now to make use of the new stuff that we have added, we will change the original code of the aforementioned Dashboard demo (specifically the file TransactionsView.java). In this file there are only few lines to add and modify.
First, we will modify the line 49 by adding new interface that this class will implement, which is our new interface (ScrollingTableScrollListener) and implement its single method by adding the following lines in the end of this class:
#Override
public void doTableScroll() {
// TODO Auto-generated method stub
Notification.show("You are scrolling!\nYou can add your own behavior here!");
}
Then, we will change both lines 53 and 66 to use the new inherited class (ScrollingTable) rather than the super class (Table):
//Line 53 in the original class
Table t;
//Line 55 in our class
ScrollingTable t;
....
....
....
//line 66 in the original class
t = new Table() {
//line 68 in our class
t = new ScrollingTable() {
Finally, we should add the listener to our ScrollingTable's scrolls :) , this is done by invoking the method addScrollListener on the table (t) after defining the table (line 89 of our new class):
t.addScrollListener(this);
this line means that this class (TransactionView) is listening on the ScrollingTable (t) scroll event, and it will invoke the method doTableScroll whenever the user scrolls down/up the ScrollingTable (t).
Here you go, you have now a table that will tell you whenever the user is scrolling, your task now is to do what you want when the table fires scrolling event and put your stuff between the curly brackets {} of the method that we defined in the first step:
#Override
public void doTableScroll() {
// Put your own code here ...
}
Here is the link of the new Dashboard on GitHub.
The answer on my blog
Hm, event fires on EVERY action with table (such as row select, etc.). More appropricate solution is additional checking variable changing in table state.
Here example:
public class ScrollingTable extends Table {
// ...
#Override
public void changeVariables(Object source, Map<String, Object> variables) {
super.changeVariables(source, variables);
handleScrollEvent(variables);
}
private void handleScrollEvent(Map<String, Object> variables) {
if (variables.containsKey("firstvisible")) {
for (TableScrollListener listener : listeners) {
listener.doTableScroll();
}
}
}
'm trying to create a reusable link class that extends Link. I have a webpage with about 7 menu items and I'm using inheritance for my application. I want to create a reusable link class to shorten the length of my code..
As of now the link creates and runs fine when I add(new Link....) as an anonymous class inside oninitialize().
The custom link class (which is an inner class of the base page) works fine when I hard code the instance of the new page to go to, and assign it to a "Page" reference, then pass it into setResponsePage();
The problem is, I'm passing trying to be able to pass object through the constructor generically. When I pass it through the constructor, and try to travel to the new page, I get a session has expired.
I've tried using generics for the class, and I've also tried just declaring a Page reference as a parameter value. Am I supposed to use some sort of Model? Or can someone provide an example of how to do this? I want to be able to use this custom link class to add new links for the 7 menu items, which each have there own class...
Code that works:
add(new Link("userPageLink")
{
public void onClick()
{
pageTitle = "User";
Page next = new UserPage();
setResponsePage(next);
}
});
Modified code that gives page expired upon click:
public class CustomLinkToNewPage extends Link
{
private String title;
private Page next;
public CustomLinkToNewPage(String id, String title, Page newPage)
{
super(id);
next = newPage;
this.title = title;
}
#Override
public void onClick()
{
SSAPage.pageTitle = title;
setResponsePage(next);
}
}
This might be due to the fact that in the first version you crate the Page object when the onClick method of the Link object is called and in the second version, the Page object is created on Page-construction (way earlier).
You might get the result if you pass the Pageclass of the responsepage instead on an instance.
Component features setters for these either with
public final <C extends IRequestablePage> void setResponsePage(java.lang.Class<C> cls, PageParameters parameters)
or without parameters.
public final <C extends IRequestablePage> void setResponsePage(java.lang.Class<C> cls)
See Javadoc for more information.
I ended up doing:
public class CustomLinkToNewPage<T extends SSAPage> extends Link
SSAPage is my base page that extends WebPage... So any object passed in to this class's constructor must extend SSAPage as well.
public CustomLinkToNewPage(String id, Class<T> name)
Then I passed in the .class reference to the object, and created a new instance of the object using reflection.. then set that instance to Page, and passed it to setResponsePage in my onClick. Worked nicely, as I couldn't figure out how to do Nicktar's way. So this an alternative in case anyone else runs into this issue.
I'm doing a project in Vaadin 7.
In my project, I need to disable column reordering feature for particular columns in Treetable?
I'm really searching for function like this 'setColumnReorderIds()'.
Is it possible to do it in Vaadin 7.
Or else I need to write some code with 'ColumnReorderListener()'?
Update
This code is to set the first column fixed in a TreeTable. I want to disable reordering in Hierarchy column in the tree table.
public class CustomTreeTable extends TreeTable {
private static final long serialVersionUID = 1L;
private Object[] visibleColumns;
private KeyMapper<Object> columnIdMap = new KeyMapper<Object>();
#Override
public void paintContent(PaintTarget target) throws PaintException {
super.paintContent(target);
paintColumnOrder(target);
}
private void paintColumnOrder(PaintTarget target) throws PaintException {
visibleColumns = this.getVisibleColumns();
final String[] colorder = new String[visibleColumns.length];
int i = 0;
colorder[i++] = columnIdMap.key("Column 1"); // Logic to keep the first column fixed
for (Object colId : visibleColumns) {
if(!colId.equals("Column 1")) {
colorder[i++] = columnIdMap.key(colId);
}
}
target.addVariable(this, "columnorder", colorder);
}
}
Update 2
I tried what Oskar said..
In addition to
paintColumnOrder(target).
I'm calling
paintVisibleColumnOrder(target),
paintAvailableColumns(target),
paintVisibleColumns(target).
i'm able to stop reordering only for the table headers. But, the body is still reordering. Any guesses on this issue?
In the documentation there is only setColumnReorderingAllowed() which allows to control reordering of all columns. So if your case is to control particular ones it looks to me as a very custom behaviour and I would go with own implementation. Also ColumnReorderEvent is generated after processing the action itself therefore implementing own ColumnReorederListener won't help us here I think.
All actual magic which we want to change happens in private Table.paintColumnOrder() called from public Table.paintContent(), called from public TreeTable.paintContent() (see sources of Table and TreeTable). The solution would be:
extend TreeTable
override paintContent() with merged copies of Table.paintContent() and TreeTable.paintContent()
replace paintColumnOrder() call with your custom logic.
Update
Ok, now I see it's more tricky then I thought at the beginnig, since there is no easy way to access most of required fields and methods after subclassing TreeTable... Moreover, columns are reorered on the client side and only the change event status is sent to inform the server. I don't know how to handle custom reordering without creating custom gwt widget :(
I have a BlackBerry application that starts (App load) with a Registration screen when the App is first installed. Later, the App will load with the home screen. Registration screen only appears on first load. I am achieving this by storing a boolean value in PersistentStore. If the value exists, then Registration screen will not appear.
PersistentStoreHelper.persistentHashtable.put("flagged",Boolean.TRUE);
PersistentStoreHelper.persistentObject.commit();
UiApplication.getUiApplication().pushScreen(new MyScreen());
I am aware of the fact that in order to delete the Persistent Store on deleting/uninstalling the App, I have to make the Hashtable a subclass of my own and therefore I have declared the Hashtable in a separate class:
public class PersistentStoreHelper extends Hashtable implements Persistable{
public static PersistentObject persistentObject;
public static final long KEY = 0x9df9f961bc6d6daL;
public static Hashtable persistentHashtable;
}
However this has not helped and the boolean value of flag is not cleared from PersistentStore. Please advice.
EDIT: When I change the above PersistentStoreHelper class to
public static PersistentObject persistentObject =
PersistentStore.getPersistentObject(KEY);
and remove
PersistentStoreHelper.persistentObject =
PersistentStore.getPersistentObject(PersistentStoreHelper.KEY);
from class B where boolean value is being saved, I observe that the boolean value is removed every time the App is closed. This should not happen and the value should only be removed in case the App is deleted/uninstalled. Any pointers?
The way this works is that the BlackBerry OS looks at the objects you are storing in the PersistentStore. If it recognizes that those objects can only be used by your app, then it will delete them when you uninstall the app. However, if the classes of the stored objects are classes that are used by other apps, then your data will not be deleted.
You have declared your helper class like this:
public class PersistentStoreHelper extends Hashtable implements Persistable{
but the helper class is not what is being stored. Your helper class is just a helper, that stores other things for you. In your case, it is storing this:
public static Hashtable persistentHashtable;
but, that object is of type java.util.Hashtable, which is a class used by many apps. So, it won't be deleted when you uninstall your app. What you should do is something like this:
public class PersistentStoreHelper implements Persistable { // so inner class = Persistable
public static PersistentObject persistentObject;
public static final long KEY = 0x9df9f961bc6d6daL;
/**
* persistentHashtable is now an instance of a class that
* only exists in your app
*/
public static MyAppsHashtable persistentHashtable;
private class MyAppsHashtable extends Hashtable implements Persistable {
// don't need anything else ... the declaration does it all!
}
}
I can't see it here, but I'm assuming that somewhere you have this code:
persistentObject = PersistentStore.getPersistentObject(KEY);
and then when you want to save the data back to the store, you're doing something like this;
persistentHashtable.put("SomeKey", someNewData);
persistentObject.setContents(persistentHashtable);
persistentObject.commit();
just adding data to the persistentHashtable doesn't save it (permanently). Hopefully, you already had that part somewhere.
Note: if you make these changes, don't expect this line of code to work, the next time you run your app:
persistentHashtable = (MyAppsHashtable)persistentObject.getContents();
because the last version of your code did not use the MyAppsHashtable class, so the loaded data won't be of that type. This is one reason that it's important to get this right the first time. In general, I always wind up saving data in the PersistentStore that's contained in one top level Hashtable subclass, that implements Persistable. I may later change what goes in it, but I won't ever change the signature of that top-level storage object. Hopefully, you haven't released your app already.
Update: In response to your comment/question below:
if (PersistentStoreHelper.persistentObject.getContents() == null) {
PersistentStoreHelper.persistentHashtable = new MyAppsHashtable();
PersistentStoreHelper.persistentObject.setContents(PersistentStoreHelper.persistentHashtable);
} else {
PersistentStoreHelper.persistentHashtable =
(MyAppsHashtable)PersistentStoreHelper.persistentObject.getContents();
}
We are currently facing one problem in our portlet-environment using JSF2.
The application is creating dynamic portal-pages for the actual user session...think of it as Eclipse editor-views where the user can edit entities. So for now I call the dynamic-views editors :-)
The problem we are facing now, is following. The user navigates to a editor and works on the portlet(s). The displayed views in each portlet change over time of course. Now he wants to have a look on another entity which is displayed in another editor. But when he navigates back to the first editor, the state of portlets changes back to the default views.
In the portlet-world each portlet each portlet gets the view it should display via a parameter which is stored in the PortletSession and I can easily change that parameter as well. I know that this parameter is causing the trouble because when the changes the editors, the portlets will always check this parameter to decide which view to show.
request.getPortletSession().setAttribute("com.ibm.faces.portlet.page.view", "/MyPage.xhtml");
My idea was, to somehow add a callback to each JSF-navigation which will set this parameter to the view the navigation is going to display (possibly including view-params).
Is it possible to have a standard callback? If not, would be possible to execute some kind of EL in the navigation-rule that will set this parameter?
somehow add a callback to each JSF-navigation
You could perform the job in a custom ConfigurableNavigationHandler. Here's a kickoff example:
public class MyNavigationHandler extends ConfigurableNavigationHandler {
private NavigationHandler parent;
public MyNavigationHandler(NavigationHandler parent) {
this.parent = parent;
}
#Override
public void handleNavigation(FacesContext context, String from, String outcome) {
// TODO: Do your job here.
// Keep the following line untouched. This will perform the actual navigation.
parent.handleNavigation(context, from, outcome);
}
#Override
public NavigationCase getNavigationCase(FacesContext context, String fromAction, String outcome) {
return (parent instanceof ConfigurableNavigationHandler)
? ((ConfigurableNavigationHandler) parent).getNavigationCase(context, fromAction, outcome)
: null;
}
#Override
public Map<String, Set<NavigationCase>> getNavigationCases() {
return (parent instanceof ConfigurableNavigationHandler)
? ((ConfigurableNavigationHandler) parent).getNavigationCases()
: null;
}
}
To get it to run, register it as follows in faces-config.xml:
<application>
<navigation-handler>com.example.MyNavigationHandler</navigation-handler>
</application>