gwt get array button value - gwt

My gwt project have flexTable show data of image and button on each row and coll.
But my button won't work properly. this is my current code:
private Button[] b = new Button[]{new Button("a"),...,new Button("j")};
private int z=0;
...
public void UpdateTabelGallery(JsArray str){
for(int i=0; i str.length(); i++){
b[i].setText(str.gettitle());
UpdateTabelGallery(str.get(i));
}
}
public void UpdateTabelGallery(GalleryData str){
Image img = new Image();
img.setUrl(str.getthumburl());
HTML himage= new HTML("a href="+str.geturl()+">"+ img +"/a>" + b[z] );
TabelGaleri.setWidget(y, x, himage);
//is here th right place?
b[z].addClickHandler(new ClickHandler(){
#Override
public void onClick(ClickEvent event) {
Window.alert("I wan to show the clicked button text" + b[z].getText());
}
});
z++;
}
I'm still confuse where I should put my button handler. With this current code seems the clickhandler didn't work inside a looping. And if I put it outside loop its not working because I need to know which button clicked. I need to get my index button.but how? Is there any option than array button?
thanks

I was using this method me too, then I've created a new Button with an additional argument.
When I add the ButtonArg I set also the argument:
Panel.add(new ButtonArg("B1", i));
...
// Create a handler for the A-Z buttons
class MyHandler implements ClickHandler {
public void onClick(ClickEvent e) {
ButtonArg btn=(ButtonArg) e.getSource();
Window.alert("Button Text="+btn.getArgument());
}
}
public class ButtonArg extends Button {
int argument;
public ButtonArg(String html, int arg) {
super(html);
setArgument(arg);
}
public int getArgument() {
return argument;
}
public void setArgument(int argument) {
this.argument = argument;
}
[...]

The problem is that you refer to 'z' in your click handler, but the value of z changes, so that when your click handler is actually called the value of z is wrong.
You need a local final variable in UpdateTabelGallery which you assign the current value of z to to allow it to be captured by the handler you create. Even better, get rid of z entirely and pass i to UpdateTableGallery:
public void updateTableGallery(GalleryData str, final int i){
Image img = new Image();
img.setUrl(str.getthumburl());
HTML himage= new HTML("a href="+str.geturl()+">"+ img +"/a>" + b[i] );
TabelGaleri.setWidget(y, x, himage);
//is here th right place?
b[i].addClickHandler(new ClickHandler(){
#Override
public void onClick(ClickEvent event) {
Window.alert("I wan't to show the clicked button text" + b[i].getText());
}
});
}
But what do you expect:
HTML himage= new HTML("a href="+str.geturl()+">"+ img +"/a>" + b[i] );
to do? Aside from the incorrect HTML syntax, I don't think adding ypur button to the string will work.

I know this is old, but it didn't look answered and I was looking to do the same thing. Here's one solution:
public void onModuleLoad() {
Button[] b=new Button[26];
RootPanel rp=RootPanel.get("body");
// Create a handler for the A-Z buttons
class MyHandler implements ClickHandler {
public void onClick(ClickEvent e) {
Button btn=(Button) e.getSource();
Window.alert("Button Text="+btn.getText());
}
}
MyHandler handler = new MyHandler();
for(int i=0;i<26;i++) {
b[i] = new Button(String.valueOf((char)(65+i)));
b[i].addStyleName("sendButton");
rp.add(b[i]);
b[i].addClickHandler(handler);
}
SimplePanel sPanel = new SimplePanel();
}

Related

CellTable click swallowed

I've an combo box which is composed of a text field and a popup with a CellTable showing the suggestion items. The text field has a change handler that updates the CellTable's selection.
When typing a character and clicking an already selected suggestion, the first click is swallowed. The second click works and triggers the selection via the CellTable.addDomHandler(...).
Any idea why first click is swallowed?
Example code:
private static class SuggestFieldTextAndPopupSandbox extends SimplePanel {
private final TextField mText;
private CellTable<Handle<String>> mTable;
private SingleSelectionModel<Handle<String>> mTableSelection;
private SingleSelectionModel<Handle<String>> mSelection;
private ProvidesKey<Handle<String>> mKeyProvider = new SimpleKeyProvider<Handle<String>>();
private PopupPanel mPopup;
private List<Handle<String>> mData;
public SuggestFieldTextAndPopupSandbox() {
mData = Lists.newArrayList(new Handle<String>("AAA"), new Handle<String>("AAB"), new Handle<String>("ABB"));
mSelection = new SingleSelectionModel<Handle<String>>();
mText = new TextField();
mText.addKeyPressHandler(new KeyPressHandler() {
#Override
public void onKeyPress(KeyPressEvent pEvent) {
mPopup.showRelativeTo(mText);
}
});
mText.addBlurHandler(new BlurHandler() {
#Override
public void onBlur(BlurEvent pEvent) {
mTableSelection.setSelected(startsWith(mText.getValue()), true);
}
});
mText.addChangeHandler(new ChangeHandler() {
#Override
public void onChange(ChangeEvent pEvent) {
mText.setText(mText.getText().toUpperCase());
}
});
mTable = new CellTable<Handle<String>>(0, GWT.<TableResources>create(TableResources.class));
mTable.setTableLayoutFixed(false);
mTableSelection = new SingleSelectionModel<Handle<String>>(mKeyProvider);
mTable.setSelectionModel(mTableSelection);
mTable.addDomHandler(new ClickHandler() {
#Override
public void onClick(final ClickEvent pEvent) {
Scheduler.get().scheduleFinally(new ScheduledCommand() {
#Override
public void execute() {
mSelection.setSelected(mTableSelection.getSelectedObject(), true);
mText.setFocus(true);
mPopup.hide();
}
});
}
}, ClickEvent.getType());
mTable.addColumn(new TextColumn<Handle<String>>() {
#Override
public String getValue(Handle<String> pObject) {
return pObject.get();
}
});
mTable.setRowData(mData);
mPopup = new PopupPanel();
mPopup.setAutoHideEnabled(true);
mPopup.setWidget(mTable);
mPopup.setWidth("200px");
mPopup.setHeight("200px");
VerticalPanel p = new VerticalPanel();
p.add(mText);
setWidget(p);
}
private Handle<String> startsWith(final String pValue) {
final String val = nullToEmpty(pValue).toLowerCase();
int i = 0;
for (Handle<String> item : mData) {
String value = item.get();
if (value != null && value.toLowerCase().startsWith(val)) {
return item;
}
i++;
}
return null;
}
}
I reproduced your issue and here is the problem:
when you click on the suggestions the following is happening:
The text field is loosing focus which causes the corresponding ChangeEvent to be dealt with followed by the BlurEvent.
The click causes the popup to get the focus now which is why it is swallowed.
If you remove the ChangeHandler and the BlurHandler of the text field the issue disappears. But I think I found another solution
Try replacing the DOM handler of the mTable with a selection handler relative to the mTableSelection as follows:
mTableSelection.addSelectionChangeHandler(new Handler(){
#Override
public void onSelectionChange(SelectionChangeEvent event) {
Scheduler.get().scheduleFinally(new ScheduledCommand() {
#Override
public void execute() {
mSelection.setSelected(mTableSelection.getSelectedObject(), true);
mText.setFocus(true);
mPopup.hide();
}
});
}
});
Found a way how to properly solve this.
Skipping the blur handler when user hovers the suggestion list area seemed to fix that issue, at least from the tests that were done didn't see any more issues.
This was necessary because just before the user clicks a suggestion item, the text is blurred and it fires a selection change. This in turn cancels the selection made when user clicks an item.

Add ClickHandler to every button

I am trying to implement a click logging system in GWT, so I know where people are going around my app.
I want to be able to do this automatically with out adding the handler to every single Button?
I tried in a Composite class:
this.addDomHandler(new ClickHandler() {...}, ClickEvent.getType());
But the ClickEvent didn't give me any specifics on what had been clicked. The below didn't work as well.
NodeList<Element> elements = Document.get().getElementsByTagName("a");
EventListener el = new EventListener() {
#Override
public void onBrowserEvent(Event event) {
System.out.println(event.toString());
}
};
for (int i = 0; i < elements.getLength(); i++) {
Element e = elements.getItem(i);
com.google.gwt.user.client.Element castedElem = (com.google.gwt.user.client.Element) e;
DOM.sinkEvents(castedElem, Event.ONCLICK);
DOM.setEventListener(castedElem, el);
}
Any tips?
Take a look here:
Notice every click in a gwt application
This will be called on every click in your applilcation.
So, if you have this code:
Event.addNativePreviewHandler(new NativePreviewHandler() {
#Override
public void onPreviewNativeEvent(NativePreviewEvent event) {
if (event.getNativeEvent().getType().equals("click")) {
Element eventTarget = DOM.eventGetTarget(Event.as(event.getNativeEvent()));
// check if eventTarget is an a-tag
}
}
});
Any time the mouse is clicked, you will get an event. Exame the event to see, if an a-tag is clicked.
Hope that helps.

Double Click event for DataGrid

I added double click event for DataGrid, but it doesn't work correctly. The code handles a single click, but it does not handle double click.
Please help.
private DataGrid<Contract> table = new DataGrid<Contract>();
table.addCellPreviewHandler(new Handler<Contract>() {
#Override
public void onCellPreview(final CellPreviewEvent<Contract> event) {
if (BrowserEvents.DBLCLICK.equals(event.getNativeEvent().getType())) {
//it doesn't handle
Window.alert("Tro-lo-lo");
}
if (BrowserEvents.CLICK.equals(event.getNativeEvent().getType())) {
//it handles
Window.alert("Tru-la-la");
}
}
});
DataGrid has many things in common with CellTable. So solutions from this question must work for you too:
Using CellPreviewHandler count time between two clicks
Or you can add DoubleClickHandler using addDomHandler method
dataGrid.addDomHandler(new DoubleClickHandler() {
#SuppressWarnings("unchecked")
#Override
public void onDoubleClick(DoubleClickEvent event) {
DataGrid<YourDataProviderType> grid = (DataGrid<YourDataProviderType>) event.getSource();
int row = grid.getKeyboardSelectedRow();
YourDataProviderType item = grid.getVisibleItem(row);
Window.alert("Do Something Here");
}
}, DoubleClickEvent.getType());

GWT - Reference to a global variable set by callback method

Please help me, as I will go mad with this soon:
When I run the code, on first occasion loadNewPoint() is executed and displays some data from global variable - allPointsAndPlaces
However when I click a button (from a child class), the same method loadNewPoint() gives me null pointer for allPointsAndPlaces.
I have changed the code structure a lot from an original trying to solve this issue, and moved this method (loadNewPoint()) to a parent class to see, if it would solve the issue.
Parent class:
public class CabbieApp implements EntryPoint {
private GetLocationsServiceAsync getAllLocationsService = GWT.create(GetLocationsService.class);
CabbiePoint[] allPointsAndPlaces;
PointsQuiz quiz;
/**
* Entry point method.
*/
public void onModuleLoad() {
//Get all the required data from DB
getAllPointsAndLocations();
}
private void loadAppPages(){
// Associate the Main panel with the HTML host page.
RootPanel rootPanel = RootPanel.get("pointsList");
quiz = new PointsQuiz();
rootPanel.setStyleName("GWTapp");
rootPanel.add(quiz.getMainPanel());
loadNewPoint();
}
private void getAllPointsAndLocations() {
// Initialize the service proxy.
if (getAllLocationsService == null) {
getAllLocationsService = GWT.create(GetLocationsService.class);
}
// Set up the callback object.
AsyncCallback<CabbiePoint[]> callback = new AsyncCallback<CabbiePoint[]>() {
public void onFailure(Throwable caught) {
System.out.println(caught.getMessage());
}
public void onSuccess(CabbiePoint[] result) {
//allPointsAndPlaces = result;
System.out.println(result.length);
allPointsAndPlaces = result;
loadAppPages();
}
};
// Make the call to the service.
getAllLocationsService.getLocations(callback);
}
void loadNewPoint(){
int r = Random.nextInt(allPointsAndPlaces.length);
quiz.CurrentPlace = allPointsAndPlaces[r].getPlaceName();
quiz.CurrentLocation = allPointsAndPlaces[r].getPlaceLocation();
quiz.point.setText(quiz.CurrentPlace);
quiz.location.setText(quiz.CurrentLocation);
quiz.location.setStyleName("invisibleText");
}
}
Child class:
public class PointsQuiz extends CabbieApp{
VerticalPanel mainPanel = new VerticalPanel();
HorizontalPanel navigation = new HorizontalPanel();
TextBox point = new TextBox();
TextBox location = new TextBox();
Button showLocation = new Button("Show Location");
Button nextPoint = new Button("Next Point");
String CurrentPlace, CurrentLocation;
public PointsQuiz() {
// Assemble Add Stock panel.
navigation.add(showLocation);
navigation.add(nextPoint);
navigation.setCellHorizontalAlignment(nextPoint, HasHorizontalAlignment.ALIGN_RIGHT);
navigation.addStyleName("addPanel");
mainPanel.setSpacing(5);
mainPanel.setStyleName("body");
mainPanel.setVerticalAlignment(HasVerticalAlignment.ALIGN_MIDDLE);
mainPanel.setHorizontalAlignment(HasHorizontalAlignment.ALIGN_CENTER);
// Assemble Main panel.
mainPanel.add(point);
point.setWidth("200px");
mainPanel.add(location);
location.setWidth("200px");
mainPanel.add(navigation);
navigation.setWidth("200px");
// Move cursor focus to the input box.
showLocation.setFocus(true);
// Listen for mouse events on the show location button.
showLocation.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
showCurrentLocation();}
});
// Listen for mouse events on the next point button.
nextPoint.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
loadNewPoint();
}
});
}
private void showCurrentLocation(){
location.setStyleName("visibleText");
}
public VerticalPanel getMainPanel() {
return mainPanel;
}
}
I managed to find a solution to this problem with Bhumika's help.
To make this work I had to change CabbiePoint[] allPointsAndPlaces to static.
This would solve the reference problem one way - from child to parent.
Also I managed to find out trough debugging, that this reference
quiz = new PointsQuiz();
is also null on a second run of loadNewPoint(). So this child reference (PointsQuiz quiz;) and any other references to children were set also to static.
You are getting null pointer error because of allPointsAndPlaces is null. As per your coding The value of allPointsAndPlaces is assigned after completion of RPC call in getAllPointsAndLocations() method. so the allPointsAndPlaces has some assigned values.
Here you try to directly access loadNewPoint() method in child class. At a time, allPointsAndPlaces is not assigned.

GWT FlexTable - drag selection how?

I am trying to get a proper method for days to select multiple cells in a flextable's column.
So far i only managed to do it with clicks which works well, but a drag selection would be much better. I have been reading docs and searching, but all the stuff i found was based on deprecated code. I use GWT 2.0 .
I know i need some event handler which would run when drag selection mouse gesture occurs, and that handler needs to know the cell's index where the selection start and of course the cell's index where the selection ends.
Any advice || code would be much appreciated.
This needs to be improved but it should give you the basic idea. First you need to create a CustomTable that listens to MouseEvents. You can do this by extending composite to wrap a focuspanel and a flextable as such :
public class CustomTable extends Composite implements MouseDownHandler, MouseMoveHandler, MouseUpHandler{
List<CellWidget> widgets = new ArrayList<CellWidget>();
FlexTable table = new FlexTable();
FocusPanel focusPanel = new FocusPanel();
boolean selecting= false;
Point selectStart,selectEnd;
public CustomTable(){
focusPanel.setWidget(table);
focusPanel.addMouseDownHandler(this);
focusPanel.addMouseMoveHandler(this);
focusPanel.addMouseUpHandler(this);
initWidget(focusPanel);
}
public void setWidget(int row, int column, CellWidget widget){
widgets.add(widget);
table.setWidget(row, column, widget);
}
#Override
public void onMouseUp(MouseUpEvent event) {
event.preventDefault();
if (selecting){
selecting=false;
DOM.releaseCapture(this.getElement());
selectEnd = new Point(event.getClientX(),event.getClientY());
for (CellWidget widget : widgets){
if (widget.isIn(selectStart,selectEnd))
widget.say();
}
selectStart = selectEnd = null;
}
}
#Override
public void onMouseMove(MouseMoveEvent event) {
event.preventDefault();
if (selecting){
//do some fancy layout
}
}
#Override
public void onMouseDown(MouseDownEvent event) {
event.preventDefault();
selecting = true;
DOM.setCapture(this.getElement());
selectStart = new Point(event.getClientX(),event.getClientY());
}
}
Next you define a CellWidget which basically encapsulates what you would like to add to your cells. When added to DOM, CellWidget calculates and stores its position later to determine if it is in the selected area :
public class CellWidget extends Composite{
Widget content;
Point topLeft,topRight,bottomLeft,bottomRight;
public CellWidget(Widget w){
this.content = w;
initWidget(w);
}
#Override
protected void onLoad() {
topLeft = new Point(getAbsoluteLeft(),getAbsoluteTop());
topRight = new Point(getAbsoluteLeft()+getOffsetWidth(),getAbsoluteTop());
bottomLeft = new Point(getAbsoluteLeft(),getAbsoluteTop()+getOffsetHeight());
bottomRight = new Point(getAbsoluteLeft()+getOffsetWidth(),getAbsoluteTop()+getOffsetHeight());
}
public void say(){
Window.alert(content + " is selected!");
}
public boolean isIn(Point start, Point end){
if (topLeft.isBetween(start, end) || topRight.isBetween(start, end)
|| bottomLeft.isBetween(start, end) || bottomRight.isBetween(start, end))
return true;
else
return false;
}
}
A simple point implementation to make things easier :
public class Point {
int x,y;
public Point(int x,int y){
this.x=x;
this.y=y;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
#Override
public String toString() {
return x+","+y;
}
public boolean isBetween(Point p1,Point p2){
if (p1.getX() < x && p2.getX() > x && p1.getY() < y && p2.getY() > y)
return true;
return false;
}
}
Finally at your EntryPoint module you wrap things up by :
public void onModuleLoad() {
RootPanel rootPanel = RootPanel.get();
CustomTable table = new CustomTable();
table.setWidget(0, 0, new CellWidget(new Label("hello 0,0")));
table.setWidget(0, 1, new CellWidget(new Label("hello 0,1")));
table.setWidget(1, 0, new CellWidget(new Label("hello 1,0")));
table.setWidget(1, 1, new CellWidget(new Label("hello 1,1")));
rootPanel.add(table);
}
I know that the actual logic to determine if the widgets fall within the selected area is incomplete and needs to be improved but i think this solution is clear enough to give the basic idea. Cheers