Develop Reference

How do I use the toast feature?

I just started learning Android Studio. I want to display a toast notification by pressing a button on the widget. However, there is an error when using the getApplicationContext() function. Can you tell me how to fix it? Other things, including getBaseContext(), were the same..... The error message was "Cannot resolve method" getApplicationContext () "" I didn't speak English, so I used Google Translator.... I'm so sorry if you can't understand...
package com.jhjsapp.widget;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.Context;
import android.view.View;
import android.widget.RemoteViews;
import android.widget.Toast;
/**
* Implementation of App Widget functionality.
*/
public class TestWidget extends AppWidgetProvider {
static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
int appWidgetId) {
CharSequence widgetText = context.getString(R.string.appwidget_text);
// Construct the RemoteViews object
RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.test_widget);
views.setTextViewText(R.id.appwidget_text, widgetText);
// Instruct the widget manager to update the widget
appWidgetManager.updateAppWidget(appWidgetId, views);
}
#Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
// There may be multiple widgets active, so update all of them
for (int appWidgetId : appWidgetIds) {
updateAppWidget(context, appWidgetManager, appWidgetId);
}
}
#Override
public void onEnabled(Context context) {
// Enter relevant functionality for when the first widget is created
}
#Override
public void onDisabled(Context context) {
// Enter relevant functionality for when the last widget is disabled
}
public void butcli(View view){
Toast.makeText(getApplicationContext(),"버튼 눌림", Toast.LENGTH_SHORT).show();
}
}
This is JAVA code
enter image description here

You cannot show Toast message using getApplicationContext() because the Widget extends AppWidgetProvider. So you cannot get the current context.
You can try something like this :
public class testWidget extends AppWidgetProvider{
#Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
final int N = appWidgetIds.length;
for (int i=0; i<N; i++) {
int appWidgetId = appWidgetIds[i];
Intent intent = new Intent(context, MainPage.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, 0);
RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.widgetlayout);
views.setOnClickPendingIntent(R.id.button1, pendingIntent);
appWidgetManager.updateAppWidget(appWidgetId, views);
}
}
#Override
public void onReceive(Context context, Intent intent) {
super.onReceive(context, intent);
Toast.makeText(context, "Button Clicked", Toast.LENGTH_SHORT).show();
}

create a global variable first
private Context context;
then initialize context by adding this line to updateAppWidget() and onUpdate() and onEnabled() and onDisabled();
this.context=context;
then use toast like :
Toast.makeText(context,"버튼 눌림", Toast.LENGTH_SHORT).show();

Widget not responding on tapping

I am trying to create a simple widget. I wanted that, when touchet, to show a toast. But it does not show anything. I don't know where I'm wrong, it looks quite well(maybe i have forgotten something i didn't notice).
Code:
static String clAc = "CLICKED";
static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
int appWidgetId) {
Intent intent = new Intent(context, LocationWidget.class);
intent.setAction(clAc);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context,0, intent,0);
Paper.init(context);
String title = Paper.book().read("content");
RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.location_widget);
views.setTextViewText(R.id.appwidget_text, title);
views.setOnClickPendingIntent(R.id.layout_wrapper, pendingIntent);
appWidgetManager.updateAppWidget(appWidgetId, views);
}
#Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
for (int appWidgetId : appWidgetIds) {
updateAppWidget(context, appWidgetManager, appWidgetId);
}
}
#Override
public void onEnabled(Context context) {
// Enter relevant functionality for when the first widget is created
}
#Override
public void onDisabled(Context context) {
// Enter relevant functionality for when the last widget is disabled
}
#Override
public void onReceive(Context context, Intent intent) {
super.onReceive(context, intent);
if(intent.getAction().contentEquals(clAc))
Toast.makeText(context, "clicked",Toast.LENGTH_LONG).show();
}

Try to update not each appWidgetId, but all appWidgetIds with your logic.

notifyappwidgetviewdatachanged not working on a listview on my widget

I tried lots of solutions but after weeks i have not been able to solve this issue: why "notifyappwidgetviewdatachanged" doesn't work? how can i update a listview placed on my widget? Where am i wrong?
Here are my classes.
Widget Provider:
public class Widget_Provider extends AppWidgetProvider
{
public static final String ACTION_MOSTRAORARI = "fACTION_TOAST";
public static final String EXTRA_STRING = "EXTRA_STRING";
#Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
// There may be multiple widgets active, so update all of them
for (int appWidgetId : appWidgetIds)
{
RemoteViews views = updateWidgetListView(context, appWidgetId);
final Intent onItemClick = new Intent(context, Widget_Provider.class);
onItemClick.setAction(ACTION_MOSTRAORARI);
onItemClick.setData(Uri.parse(onItemClick.toUri(Intent.URI_INTENT_SCHEME)));
final PendingIntent onClickPendingIntent = PendingIntent.getBroadcast(context, 0, onItemClick, PendingIntent.FLAG_UPDATE_CURRENT);
views.setPendingIntentTemplate(R.id.myStopList, onClickPendingIntent);
appWidgetManager.updateAppWidget(appWidgetId, views);
}
super.onUpdate(context, appWidgetManager, appWidgetIds);
}
public RemoteViews updateWidgetListView(Context context, int appWidgetId)
{
RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget);
Intent svcIntent = new Intent(context, Widget_Service.class);
svcIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
svcIntent.setData(Uri.parse(svcIntent.toUri(Intent.URI_INTENT_SCHEME)));
remoteViews.setRemoteAdapter(R.id.myStopList, svcIntent);
return remoteViews;
}
#Override
public void onReceive(Context context, Intent intent)
{
if (intent.getAction().equals(ACTION_MOSTRAORARI)) {
if (MainUtils.isNewtworkAvailable(context))
{
String item = intent.getExtras().getString(EXTRA_STRING);
Intent intentOrari = new Intent(context, Diag_MostraOrari.class);
intentOrari.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
context.startActivity(intentOrari);
}
}
super.onReceive(context, intent);
}
#Override
public void onDeleted(Context context, int[] appWidgetIds) {}
#Override
public void onEnabled(Context context) {}
#Override
public void onDisabled(Context context) {}
}
Widget Service:
public class Widget_Service extends RemoteViewsService
{
#Override
public RemoteViewsFactory onGetViewFactory(Intent intent)
{
Map<String, ArrayList<String>> map = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
/* ---
* Here i fetch data from a local db and store it on "map"
*/ ---
return (new Widget_ListProvider(this.getApplicationContext(), intent, map));
}
}
ListProvider:
public class Widget_ListProvider implements RemoteViewsFactory
{
private Map<String, ArrayList<String>> map = new HashMap<>();
private ArrayList<ListItem_Widget> listItemList = new ArrayList<>();
private Context context = null;
private int appWidgetId;
public Widget_ListProvider(Context context, Intent intent, Map<String, ArrayList<String>> map)
{
this.map = map;
this.context = context;
appWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
populateListItem();
}
//This function populate the arraylist "listItemList" by the data stored on "map"
private void populateListItem() { [...] }
#Override
public int getCount() {
return listItemList.size();
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public RemoteViews getViewAt(int position)
{
final RemoteViews remoteView = new RemoteViews(context.getPackageName(), R.layout.listitem_widget);
ListItem_Widget listItem = listItemList.get(position);
remoteView.setTextViewText(R.id.heading, listItem.heading);
remoteView.setTextViewText(R.id.content, listItem.content);
final Intent fillInIntent = new Intent();
fillInIntent.setAction(Widget.ACTION_MOSTRAORARI);
final Bundle bundle = new Bundle();
bundle.putString(Widget.EXTRA_STRING, listItem.heading);
fillInIntent.putExtras(bundle);
remoteView.setOnClickFillInIntent(R.id.listrow, fillInIntent);
return remoteView;
}
#Override
public RemoteViews getLoadingView() {
return null;
}
#Override
public int getViewTypeCount() {
return 1;
}
#Override
public boolean hasStableIds() {
return true;
}
#Override
public void onCreate() {}
#Override
public void onDataSetChanged() {}
#Override
public void onDestroy() {}
}
The xml of my listview custom item contains just two textviews: "heading" and "content".
Where am i wrong? why when i call "notifyappwidgetviewdatachanged" from another activity nothing happens?
[EDIT]
That's the activity where i need to update my widget.
public class Diag_Line extends AppCompatActivity
{
//[...]
#Override
protected void onCreate(Bundle savedInstanceState)
{
//[...]
AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(getApplicationContext());
ComponentName thisAppWidget = new ComponentName(getApplicationContext().getPackageName(), Widget.class.getName());
int[] appWidgetIds = appWidgetManager.getAppWidgetIds(thisAppWidget);
appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.myStopList);
//"myStopList" is the id of my listview inside the widget xml.
//[...]
}
}

Well, the problem is a quite obvious: In your RemoteViewsFactory you have an empty method onDataSetChanged(). But when you're triggering notifyAppWidgetViewDataChanged(), you're getting callback in onDataSetChanged(). For better understanding check this pic.
If Diag_Line is a Configuration Activity just make something like this:
appWidgetManager.updateAppWidget(appWidgetIds, views); // views is a RemoteViews that you need to build
appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.myStopList);
Also check official documentation here
UPDATE
Some hints for you. If you're working with widget, make all fetching data and fillings RemoteViews on background (IntentService is a nice approach). So just make IntentService and make logic for widget here. Don't forget to make him foreground (only for Android O), if you're triggering your updates by broadcasts. Also you can check library that makes all for you.

In order for notifyAppWidgetViewDataChanged() to work properly
we need to retreive the data in onDataSetChanged() method of RemoteViewSourceFactory
like this:
override fun onDataSetChanged() {
listOfArticles = newsDatabaseRepo.getSynchronouslySavedNews() as ArrayList<Articles>
}
as suggested in here
And have a method to refresh the widget if a change occured:
private fun refreshWidget() {
val appWidgetManager =
AppWidgetManager.getInstance(applicationContext)
val thisAppWidget = ComponentName(
applicationContext.packageName,
MyAppWidgetProvider::class.java.name
)
val appWidgetIds = appWidgetManager.getAppWidgetIds(thisAppWidget)
appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.stack_view)
}
After calling the above method and once I come out of my App I am able to notice the changes in My Widget
So in order to check if onDataSetChanged is called after notifyAppWidgetViewDataChanged()
I kept a debug point and onDataSetChanged() was called and the list was updated as suggested in here here

Had a similar problem updating my widget, it was calling onDataSetChanged but not refreshing the layout. So in my case I had to set updateAppWidget to null before updating with remoteviews like this:
appWidgetManager.updateAppWidget(appWidgetId, null);
appWidgetManager.updateAppWidget(appWidgetId, remoteViews);
Looks like there is some sort of caching happening here.

Multiple widgets giving same appWidgetId on click on each widgets

I need to create Widgets in my android app similar work flow of contact widgets in android. But the problem facing is if there are n widgets of the same application each widgets have different functionality. how to differentiate the button click on each widgets.?
public class MyWidgetActivity extends AppWidgetProvider {
private static final String MyOnClick = "myOnClickTag";
static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
int appWidgetId) {
CharSequence widgetText = MyWidgetActivityConfigureActivity.loadTitlePref(context, appWidgetId);
// Construct the RemoteViews object
RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.simple_widget);
views.setTextViewText(R.id.appwidget_text, widgetText);
views.setOnClickPendingIntent(R.id.actionButton, getPendingSelfIntent(context, MyOnClick,views.getLayoutId()));
// Instruct the widget manager to update the widget
appWidgetManager.updateAppWidget(appWidgetId, views);
}
#Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
// There may be multiple widgets active, so update all of them
for (int appWidgetId : appWidgetIds) {
updateAppWidget(context, appWidgetManager, appWidgetId);
// Tell the AppWidgetManager to perform an update on the current app
// widget
}
}
#Override
public void onDeleted(Context context, int[] appWidgetIds) {
// When the user deletes the widget, delete the preference associated with it.
for (int appWidgetId : appWidgetIds) {
MyWidgetActivityConfigureActivity.deleteTitlePref(context, appWidgetId);
}
}
#Override
public void onEnabled(Context context) {
// Enter relevant functionality for when the first widget is created
}
#Override
public void onDisabled(Context context) {
// Enter relevant functionality for when the last widget is disabled
}
#Override
public void onReceive(Context context, Intent intent) {
super.onReceive(context, intent);
if (MyOnClick.equals(intent.getAction()))
{
int appWidgetId = intent.getIntExtra(EXTRA_APPWIDGET_ID,0);
Log.e("KOKOKOKO :: ",""+appWidgetId);
MyWidgetActivityConfigureActivity.loadIdPrefCallQuick(context,appWidgetId);
//your onClick action is here
Toast.makeText(context,"Quick Action Triggered",Toast.LENGTH_SHORT).show();
}
super.onReceive(context, intent);
}
static PendingIntent getPendingSelfIntent(Context context, String action, int appWidgtId)
{
// if we brodcast than definetly we have to define ONRECEIVE
Intent intent = new Intent(context, MyWidgetActivity.class);
intent.putExtra(EXTRA_APPWIDGET_ID,appWidgtId);
intent.setAction(action);
return PendingIntent.getBroadcast(context, 0, intent, 0);
}
}

Instead of this code (static PendingIntent getPendingSelfIntent) :
return PendingIntent.getBroadcast(context, 0, intent, 0);
You should do this :
return PendingIntent.getBroadcast(context, appWidgtId, intent, PendingIntent.FLAG_UPDATE_CURRENT);
This way you should get unique intent and also unique appWidgtId.
It is important to set requestCode (2nd attribute of getBroadcast), so it wouldn't conflict.

TextView Widget Not Updating

My TextView Widget is not updating on the home screen.
The new value of the text does not appear on the widget but the old value still remains as it was. This is my code for the widget class and activity that calls the widget update:
public class MotivappWidget extends AppWidgetProvider {
#Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
int[] appWidgetIds) {
super.onUpdate(context, appWidgetManager, appWidgetIds);
Intent intent = new Intent(context, ViewAll.class);
PendingIntent pending = PendingIntent
.getActivity(context, 0, intent, 0);
RemoteViews updateViews = new RemoteViews(context.getPackageName(),
R.layout.widget);
// updateViews.setTextViewText(R.id.widget_text, input);
updateViews.setOnClickPendingIntent(R.id.widget_text, pending);
appWidgetManager.updateAppWidget(appWidgetIds, updateViews);
}
public class ViewAll extends Activity implements OnClickListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_view);
}
protected void onResume() {
super.onResume();
updateWidgetText();
}
private void updateWidgetText() {
LayoutInflater inflater = (LayoutInflater) getApplicationContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View vi_widgy = inflater.inflate(R.layout.widget, null); //there is a layout xml file called widget.xml already made
TextView tv_widgy = (TextView) vi_widgy.findViewById(R.id.widget_text); //in widget.xml, there is a text view called widget_text
tv_widgy.setText("Text has just changed."); //this text never appears on the widget home even after updating
updateAllWidgets();
}
private void updateAllWidgets(){
AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(getApplicationContext());
int[] appWidgetIds = appWidgetManager.getAppWidgetIds(new ComponentName(this, MotivappWidget.class));
if (appWidgetIds.length > 0) {
new MotivappWidget().onUpdate(this, appWidgetManager, appWidgetIds);
}
}
}