How do I know which widget fired an event (GWT) - events

I have modified the onValueChange method of the class ValueChangeHandler, so that I can use it in all the DatePicker that I have in my application, but I would like to know which DatePicker fired the event. How do I get that information?
here is the code of my ValueChangeHandler custom class:
class calendarChangeHandler implements ValueChangeHandler<Date>{
#Override
public void onValueChange(ValueChangeEvent<Date> event) {
endCalendar.hideDatePicker();
initCalendar.hideDatePicker();
Date initDate = initCalendar.getValue();
Date endDate = endCalendar.getValue();
int numDias = 0;
if (initDate != null && endDate != null && (endDate.after(initDate))){
numDias = (int)((endDate.getTime()-initDate.getTime())/MILLSECS_PER_DAY);
createTable(numDias+2);
}
}
}
Thank you very much :)

If you only have a few widgets attached to the handler, it's probably easier to use an if statement:
ValueChangeHandler<Date> handler = new ValueChangeHandler<Date>() {
#Override
public void onValueChange(ValueChangeEvent<Date> event) {
if (box1.equals(event.getSource())) {
//It was box1.
} else {
//It was box2.
}
}
};
Otherwise, just use event.getSource() and cast the result to the desired type:
ValueChangeHandler<Date> handler = new ValueChangeHandler<Date>() {
#Override
public void onValueChange(ValueChangeEvent<Date> event) {
DateBox srouce = (DateBox) event.getSource();
//Do something with the source.
}
};

The getSource() method of ValueChangeEvent should give you who fired the event.

Related

Can a BindingContext object data binding object directly be changed on changing of an entry field?

I am new to xamarin, i hope someone can help me with this:
I have a sinple page with entry fields and data binding.
I have page A with a listview. When I click on an item, I get redirected to page B which has the form elements.
async void LvData_ItemSelected(object sender, SelectedItemChangedEventArgs e)
{
if (e.SelectedItem != null)
{
var secondPage = new ProfileDataPage();
secondPage.BindingContext = e.SelectedItem;
await Navigation.PushAsync(secondPage);
}
}
This works, and in page B the fields are filled with the right data.
So now I change the value of an entry field. Then I click on the Save Button and I do something like this (profileData = BindingContext object):
profileData.Height = Functions.ToNullableDouble(Height.Text);
profileData.Weight = Functions.ToNullableDouble(Weight.Text);
etc...
Doesn't the BindingContext know somehow that the value of the entry has changed, and I can just send the BindingContext object to my web api for save, update and so on?
Thank you very much.
for example,here is a mode:
class MyData : INotifyPropertyChanged
{
string height;
string weight;
public MyData(string height,string weight)
{
this.height= height;
this.weight= weight;
}
public string Height
{
set
{
if (height!= value)
{
height= value;
OnPropertyChanged("Height");
}
}
get
{
return height;
}
}
public string Weight
{
set
{
if (weight!= value)
{
weight= value;
OnPropertyChanged("Weight");
}
}
get
{
return weight;
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
you could refer to Binding Mode
So I tried your solutions, which helped, but only after I have update my VS, all the nuget packages and so on..
came to this idea by this post: Link
I have no idea why this was necessary, but it works now!
Thank you!

Xamarin Forms MessagingCenter Subscribe called two times

I'm clicking on a product item in listview in product page viewmodel to show a popup(using rg.plugin popup) for selecting one of the product variants.After selecting variant,i am sending the selected variant to product page using messagingcenter from variant popup page viewmodel,subscribed in product page viewmodel constructor. working fine there.when i navigate to the previous page and then came back to this product page for adding one or more variant to the
same previously selected product,Messagingcenter subscribe called twice and product value increased twice.Tried to subscribe in the product page onappearing and unsubscribe in disappearing method.still calling two times? How to solve this issue?
calling popup:
var result = await dataService.Get_product_variant(store_id, product_id);
if (result.status == "success")
{
ind_vis = false;
OnPropertyChanged("ind_vis");
App.Current.Properties["product_variant_result"] = result;
App.Current.Properties["cartitems"] = purchaselist;
App.Current.Properties["selected_product"] = product_List2 ;
await PopupNavigation.Instance.PushAsync(new Popup_variant());
}
popup viewmodel: sending message
public Popup_variant_vm()
{
Radio_btn = new Command<Product_variant_list2>(Radio_stk_tapped);
product_variant_list = new List<Product_variant_list2>();
purchaselist = new ObservableCollection<Product_list2>();
show_variants();
}
internal void Confirm_variant()
{
if(App.Current.Properties.ContainsKey("selected_variant"))
{
MessagingCenter.Send<Popup_variant_vm, object>(this, "selected_variant", App.Current.Properties["selected_variant"]); //Message send from popup to product page
}
else
{
DependencyService.Get<IToast>().LongAlert("Please select any size");
}
}
product page viewmodel: subscribed here..called twice when navigating from previous page to this
public Store_page()
{
InitializeComponent();
}
protected override void OnAppearing()
{
base.OnAppearing();
var vm = new store_page_vm();
vm.Navigation = Navigation;
BindingContext = vm;
MessagingCenter.Unsubscribe<Popup_variant_vm, object>(this, "selected_variant");
MessagingCenter.Subscribe<Popup_variant_vm, object>(this, "selected_variant",async (sender, selected_variant) =>
{
var vm1 = BindingContext as store_page_vm;
vm1?.Addcart2(selected_variant);// called twice
});
}
unsubscribed in product cs page
protected override void OnDisappearing()
{
var vm = BindingContext as store_page_vm;
vm?.Save_cart();
MessagingCenter.Unsubscribe<Popup_variant_vm>(this, "selected_variant");
}
Your unsubscription should look something like below and it should work :
MessagingCenter.Unsubscribe<Popup_variant_vm, object>(this, "selected_variant");
https://stackoverflow.com/a/44753021/10937160
try this, and make sure you do not call Subscribe more than once.
My solution:
put unsubscribe sentence into subscribe body !!
MessagingCenter.Subscribe<object, string>(this, "IdSearch", (sender, arg) =>
{
listView.ItemsSource = arg;
MessagingCenter.Unsubscribe<object, string>(this, "IdSearch");
}, BindingContext);
I have created static counter variable in my app the in subscriber I have done this:
public static class Constants
{
public static int msgCenterSubscribeCounter { get; set; } = 0;
}
MessagingCenter.Subscribe<object, string>(this, "hello", (sender, arg) =>
{
Constants.msgCenterSubscribeCounter++;
if (arg.Equals("hello") && Constants.msgCenterSubscribeCounter == 1)
{
// handle your logic here
}
});
Reset counter in OnDisappearing() method from where you have called Send.
Changing Messagingcenter in to single subscription.
public class Messagingcenter_singleton
{
private static Messagingcenter_singleton _instance;
private bool isActivated = false;
private Action<string> callBackFun = null;
public static Messagingcenter_singleton Instance()
{
if (_instance == null)
{
_instance = new Messagingcenter_singleton();
}
return _instance;
}
public void setCallBack(Action<string> eventCallBack)
{
callBackFun = eventCallBack;
}
public void startSubscribe()
{
if (!isActivated)
{
isActivated = true;
MessagingCenter.Subscribe<string, string>(this, "Name", eventCallBack);
}
}
private void eventCallBack(string arg1, string arg2)
{
if (callBackFun != null)
{
InvokeMethod(new Action<string>(callBackFun), arg2);
}
}
public static object InvokeMethod(Delegate method, params object[] args)
{
return method.DynamicInvoke(args);
}
}
Use Below Code in you view model class
public void initSubscribe()
{
Messagingcenter_singleton.Instance().startSubscribe();
Messagingcenter_singleton.Instance().setCallBack(eventCallBack)
}
public void eventCallBack(string arg2)
{
// write your code here
}

Fragment with update of detail layout

I have programmed an Android App with fragments. A ListView fragment and a detail fragment.
What I wanna do is, if someone clicks inside the detail activity, a layout which is "View.Gone" should be "View.Visible". The code works without errors but nothing changed on the screen.
You can see it in Detail fragment code where a clik event on the ImageButton btn is.
What do i wrong?
What is the best way to update the detail screen? If someone has a small example or could write me where in my code I have to change what, it makes me happy :-)
Thanks a lot
Tom
The FragmentActivity:
public class CacheFragment extends SherlockFragmentActivity {
CacheListFragment f;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.list_cachelist);
f = new CacheListFragment();
// Supply index input as an argument.
Bundle args = new Bundle();
f.setArguments(args);
}
Here's the Detail Fragment, where you can see whatt should happen if someone clicks on the Imagebutton:
public class CacheDetailsFragment extends SherlockFragment implements OnClickListener {
private CacheDetailsLoading cdLoad= new CacheDetailsLoading();
private static GeocacheDetails _cacheDetails = new GeocacheDetails();
private static GCRatingTyp _cacheVote = new GCRatingTyp();
private CacheDetailsUsing cdUsing = new CacheDetailsUsing();
private Activity _context;
private static CacheDetailsFragment f;
private View view;
/**
* Create a new instance of DetailsFragment, initialized to
* show the text at 'index'.
*/
public static CacheDetailsFragment newInstance(int index ) {
f = new CacheDetailsFragment();
// Supply index input as an argument.
Bundle args = new Bundle();
args.putInt("index", index);
f.setArguments(args);
return f;
}
public int getShownIndex() {
return getArguments().getInt("index", 0);
}
public void setCacheDetail(GeocacheDetails cacheDetails)
{
_cacheDetails = cacheDetails;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if (container == null) {
return null;
}
Bundle bundle=getArguments();
_cacheVote= bundle.getParcelable("cacheVote");
int index = bundle.getInt("index");
_cacheDetails=StaticCacheListByGroup.getCacheList().get(index);
_context = getActivity();
_context.setTheme(R.style.Theme_Sherlock_Light_DarkActionBar);
view = inflater.inflate(R.layout.list_cachedetails, container,false);
((RelativeLayout) view.findViewById(R.id.relativeLoggingInfo)).setVisibility(View.GONE);
((RelativeLayout) view.findViewById(R.id.relativeKategorienInfo)).setVisibility(View.GONE);
ImageButton btn = (ImageButton) view.findViewById(R.id.description_expand);
btn.setOnClickListener(new OnClickListener() {
public void onClick(View v)
{
if(((RelativeLayout) getActivity().findViewById(R.id.relativeDescriptionInfo)).getVisibility() == View.GONE)
{
((ImageButton) getActivity().findViewById(R.id.description_expand)).setBackgroundResource(R.drawable.navigation_collapse_dark);
((RelativeLayout) getActivity().findViewById(R.id.relativeDescriptionInfo)).setVisibility(View.VISIBLE);
}
else
{
((ImageButton) getActivity().findViewById(R.id.description_expand)).setBackgroundResource(R.drawable.navigation_expand_dark);
((RelativeLayout) getActivity().findViewById(R.id.relativeDescriptionInfo)).setVisibility(View.GONE);
}
});
return view;
}
}
Now the Listfragment:
public class CacheListFragment extends SherlockListFragment {
boolean isDualPane;
int mCurCheckPosition = 0;
private CacheListArrayAdapter _adapter;
private SharedPrefs _sp= new SharedPrefs();
private double latitude=0;
private double longitude=0;
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
latitude =Double.parseDouble(_sp.getSharedPrefs(getActivity(), LibraryDefaults.PROGRAMMNAME, "Latitude", "0"));
longitude =Double.parseDouble(_sp.getSharedPrefs(getActivity(), LibraryDefaults.PROGRAMMNAME, "Longitude", "0"));
// Check to see if we have a frame in which to embed the details
// fragment directly in the containing UI.
View detailsFrame = getActivity().findViewById(R.id.details);
isDualPane = detailsFrame != null && detailsFrame.getVisibility() == View.VISIBLE;
if(!isDualPane)
{
Bundle bundle = getActivity().getIntent().getExtras();
if(bundle != null && bundle.containsKey("Titel"))
((TextView) getActivity().findViewById(R.id.listtitle)).setText(bundle.getString("Titel"));
else
((TextView) getActivity().findViewById(R.id.listtitle)).setText(this.getResources().getString(R.string.caches_listtitle));
}
if (StaticCacheListByGroup.getCacheList() != null)
{
GeocachingCompass gc = new GeocachingCompass(getActivity());
_adapter = new CacheListArrayAdapter(getActivity(), StaticCacheListByGroup.getCacheList(), longitude,latitude);
_adapter.setActualCoordinates(new LatLng(latitude,longitude));
_adapter.setActualHeading(gc.getBearing(latitude,longitude));
if (_adapter != null)
setListAdapter(_adapter);
if (savedInstanceState != null) {
// Restore last state for checked position.
mCurCheckPosition = savedInstanceState.getInt("curChoice", 0);
}
getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
getListView().setSoundEffectsEnabled(true);
getListView().setSmoothScrollbarEnabled(true);
getListView().setDrawSelectorOnTop(false);
getListView().setCacheColorHint(R.color.transparentBlack);
getListView().setDivider(getResources().getDrawable( R.color.divider));
getListView().setDividerHeight(5);
if (isDualPane) {
// In dual-pane mode, the list view highlights the selected item.
getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
showDetails(mCurCheckPosition);
}
}
}
#Override
public void onResume() {
super.onResume();
GeocachingCompass gc = new GeocachingCompass(getActivity());
_adapter = new CacheListArrayAdapter(getActivity(), StaticCacheListByGroup.getCacheList(), longitude,latitude);
_adapter.setActualCoordinates(new LatLng(latitude,longitude));
_adapter.setActualHeading(gc.getBearing(latitude,longitude));
if (_adapter != null)
setListAdapter(_adapter);
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("curChoice", mCurCheckPosition);
}
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
showDetails(position);
}
/**
* Helper function to show the details of a selected item, either by
* displaying a fragment in-place in the current UI, or starting a
* whole new activity in which it is displayed.
*/
void showDetails(int index) {
mCurCheckPosition = index;
ReadGCVote getVote = new ReadGCVote();
GeocacheDetails cacheDetails = new GeocacheDetails();
cacheDetails=StaticCacheListByGroup.getCacheList().get(index);
if (isDualPane) {
// We can display everything in-place with fragments, so update
// the list to highlight the selected item and show the data.
getListView().setItemChecked(index, true);
// Check what fragment is currently shown, replace if needed.
CacheDetailsFragment details = (CacheDetailsFragment)
getActivity().getSupportFragmentManager().findFragmentById(R.id.details);
if (details == null || details.getShownIndex() != index) {
// Make new fragment to show this selection.
details = CacheDetailsFragment.newInstance(index);
// Execute a transaction, replacing any existing fragment
// with this one inside the frame.
FragmentTransaction ft = getActivity().getSupportFragmentManager().beginTransaction();
ft.replace(R.id.details, details);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.commit();
}
} else {
// Otherwise we need to launch a new activity to display
Intent intent = new Intent();
intent.setClass(getActivity(), CacheDetailsActivity.class);
intent.putExtra("index", index);
intent.putExtra("cacheDetails",cacheDetails);
intent.putExtra("cacheVote",getVote.getGCVoteByCacheGuid( StaticGCVoteList.getCacheList(), cacheDetails.GetGUID()));
startActivity(intent);
}
}
}
I found the bug :-)
In the code snippet of the Detail Fragment ...
public void onClick(View v)
{
if(((RelativeLayout) getActivity().findViewById(R.id.relativeDescriptionInfo)).getVisibility() == View.GONE)
}
...you shouldn't use "getActivity()" use "view" from "view = inflater.inflate(R.layout.list_cachedetails, container,false);"
Then it will work

Method as Event Handler

can anyone help with my problem ?
I have 2 classes.
public partial class StationTabItem : UserControl
{
SessionServiceClass.Instance.getHistoricalStationData(Convert.ToUInt32(station.stationNumber), setHistoricalStationData);
public void setHistoricalStationData(object sender, readStationDataHistoryCompletedEventArgs e)
{
if (!e.Cancelled && (e.Error == null))
{
historicalStationData = new List<StationData>();
historicalStationData = e.Result.ToList();
fillHistoricalData(historicalStationData);
InitializeComponent();
ComboBox_Left.SelectedIndex = leftIndex;
ComboBox_Right.SelectedIndex = rightIndex;
TextBlock_StationName.Text = stationName;
TextBox_DetailsInfo.Text = evidUdajeStanice;
fillStationData(station);
updateDataGrids(localDynamicData_weatherData.variables, localDynamicData_alignedSurfaceData.variables, localDynamicData_oppositeSurfaceData.variables);
}
}
and second class
public class SessionServiceClass
{
public void getHistoricalStationData(uint stationID, EventHandler<readStationDataHistoryCompletedEventArgs> setHistoricalStationData)
{
rwisClient.readStationDataHistoryAsync(stationID, System.DateTime.Today.AddHours(System.DateTime.Now.Hour).AddMinutes(System.DateTime.Now.Minute), -86400);
rwisClient.readStationDataHistoryCompleted -= setHistoricalStationData;
rwisClient.readStationDataHistoryCompleted += setHistoricalStationData;
}
}
The problem is, if I create more instances of StationTabItem, allways is called every method setHistricalStationData in every instance but with result ,,e.result,, of last istances. It means my variable historicalStationData is overwrite as is last value of it.
Thanks in advance for any ideas.

adding Double click event in CellTable cell - GWT

I am unable to figure out how could I add a double click event to the cell of the CellTable.
Is it possible with GWT CellTable or not?
Is there any workaround
thank you..
al
BTW, i saw this post but there is no reply...
http://www.devcomments.com/Adding-DoubleClicks-and-OnContextMenu-to-CellTable-at1066168.htm
I crafted something different that just fit my needs:
cellTable.addCellPreviewHandler(new Handler<TitoloProxy>() {
long lastClick=-1000;
#Override
public void onCellPreview(CellPreviewEvent<TitoloProxy> event) {
long clictAt = System.currentTimeMillis();
GWT.log("clickAt: "+(clictAt));
GWT.log("lastClick: "+(lastClick));
if(event.getNativeEvent().getType().contains("click")){
GWT.log(""+(clictAt-lastClick));
if(clictAt-lastClick < 300) { // dblclick on 2 clicks detected within 300 ms
Window.alert("I am a double click crafted event!");
}
lastClick = System.currentTimeMillis();
}
}
});
cellTable.addDomHandler(new DoubleClickHandler() {
#Override
public void onDoubleClick(DoubleClickEvent event) {
Window.alert("That's it!");
}
}, DoubleClickEvent.getType());
Integer row=0;// to hold row index
Integer column=0;// to hold column index
_Grid.addCellPreviewHandler(new CellPreviewEvent.Handler<Model>() {
// this is to handle row id
#Override
public void onCellPreview(final CellPreviewEvent<Model> event) {
if (BrowserEvents.CLICK.equalsIgnoreCase(event.getNativeEvent().getType())) {
row = event.getIndex();
column=event.getColumn();
}
}
});
// because Doubleclick handler doesn't give row index or column index we will use addCellPreviewHandler to return row index or column index.
_Grid.addDomHandler(new DoubleClickHandler() {
#Override
public void onDoubleClick(final DoubleClickEvent event) {
System.out.println(" You clicked row = " + row);
System.out.println(" You clicked column = " + column);
}
}, DoubleClickEvent.getType());
For cell lists, this code works ok:
cellList.addDomHandler(new DoubleClickHandler() {
#Override
public void onDoubleClick(DoubleClickEvent event) {
// do the stuff
}
}, DoubleClickEvent.getType());
I'm not sure about table cells
Because the CellPreview interface does not natively capture double click events you will need add event logic into the Overriden onCellPreview method. First you would think the best way would be to check the click time differences. However it is much more efficient and elegant to use a state machine and count clicks. This is more robust and allows you to deal with multiple event cases - Such as mouse hover, single, and double clicks. The code is pretty straightforward. So enjoy!
public class CellHoverHandler implements Handler<T> {
Timer singleClickTimer;
int clickCount = 0;
int clickDelay = 300;
#Override
public void onCellPreview(final CellPreviewEvent<T> event) {
if (Event.getTypeInt(event.getNativeEvent().getType()) == Event.ONMOUSEOVER) {
handleOnMouseOver(event);
} else if (Event.getTypeInt(event.getNativeEvent().getType()) == Event.ONCLICK) {
clickCount++;
if (clickCount == 1) {
singleClickTimer = new Timer() {
#Override
public void run() {
clickCount = 0;
handleOnClick(event);
}
};
singleClickTimer.schedule(clickDelay);
} else if (clickCount == 2) {
singleClickTimer.cancel();
clickCount = 0;
handleOnDblClick(event);
}
}
}
private void handleOnMouseOver(CellPreviewEvent<T> event) {
Element cell = event.getNativeEvent().getEventTarget().cast();
GWT.log("mouse over event");
}
private void handleOnClick(CellPreviewEvent<T> event) {
Element cell = event.getNativeEvent().getEventTarget().cast();
GWT.log("click event");
}
private void handleOnDblClick(CellPreviewEvent<T> event) {
Element cell = event.getNativeEvent().getEventTarget().cast();
GWT.log("double click event");
}
OPTIMIZATION: feel free to stick the count, timer, and delay as static class members or global members to reuse. Also check to see if the timer is null before making a new instance. I had omitted this for simplicity. Unlike a lot of other techniques this way still provides you with easy and direct access to the cell event. The technique with overloading the AbstractCell works well too, however sometimes you really don't have custom cells or want to make a custom cell to just handle events on the cell.
Leaving this here for future reference
private Set<GenericEventHandler<T>> dblClickHandlers = new HashSet<>(4);
dblClickHandlers simply maps interface implementations of my choice
table.addCellPreviewHandler(event -> {
if (BrowserEvents.DBLCLICK.equalsIgnoreCase(event.getNativeEvent().getType())) {
LOGGER.info("dblclick (native) " + event.getIndex() + " " + event.getColumn() + "; " + event.getValue());
dblClickHandlers.forEach(handler -> {
handler.onEvent(event.getValue());
});
}
});
table.sinkBitlessEvent(BrowserEvents.DBLCLICK);
The trick is to sink the 'dblclick' event.
If you wanted a text cell that allows you to support your own chosen list of events, you can use this:
public class EventfulTextCell extends AbstractSafeHtmlCell`<String`> {
private static final String[] NO_CONSUMED_EVENTS = null;
public EventfulTextCell() {
this(NO_CONSUMED_EVENTS);
}
public EventfulTextCell(String... consumedEvents) {
super(SimpleSafeHtmlRenderer.getInstance(), consumedEvents);
}
#Override
public void render(Context context, SafeHtml value, SafeHtmlBuilder sb) {
if (value != null) {
sb.append(value);
}
}
}
Then you instantiate it:
new EventfulTextCell("click", "dblclick")
Then override the onBrowserEvent() method to process your events.

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