make star icon clickable

app/src/main/java/de/westnordost/streetcomplete/MainActivity.java

@@ -44,6 +44,7 @@
 import android.widget.CheckBox;
 import android.widget.ImageView;
 import android.widget.ProgressBar;
+import android.widget.RelativeLayout;
 import android.widget.TextView;
 import android.widget.Toast;
 
@@ -247,6 +248,9 @@ public void onServiceDisconnected(ComponentName className)
 		downloadProgressBar = findViewById(R.id.download_progress);
 		downloadProgressBar.setMax(1000);
 
+		RelativeLayout starMenu = findViewById(R.id.uploadedAnswersContainer);
+		starMenu.setOnClickListener(this::starInfoMenu);
+
 		mapFragment = (QuestsMapFragment) getSupportFragmentManager().findFragmentById(R.id.map_fragment);
 		mapFragment.getMapAsync(BuildConfig.MAPZEN_API_KEY);
 		updateMapQuestOffsets();
@@ -1120,6 +1124,20 @@ private void onLocationRequestFinished(LocationState withLocationState)
 		}
 	}
 
+	// ---------------------------------------------------------------------------------------------
+
+	/** Menu raised by clicking on the star icon */
+	public void starInfoMenu(View view) {
+		String message = getString(R.string.about_contributing) + "\n\n" + getString(R.string.about_missing_stars);
+		if(answersCounter.waitingForUpload() + answersCounter.uploaded() == 0){
+			message = getString(R.string.how_to_get_stars) + "\n\n" + getString(R.string.about_contributing);
+		}
+		new AlertDialog.Builder(MainActivity.this)
+			.setMessage(message)
+			.show();
+	}
+
+
 	// ---------------------------------------------------------------------------------------------
 
 	/** Does not necessarily mean that the user has internet. But if he is not connected, he will

app/src/main/java/de/westnordost/streetcomplete/statistics/AnswersCounter.java

@@ -90,6 +90,10 @@ public Integer waitingForUpload(){
 		return unsynced;
 	}
 
+	public Integer uploaded(){
+		return unsynced;
+	}
+
 	@SuppressLint("StaticFieldLeak") public void update()
 	{
 		new AsyncTask<Void, Void, Void>()

app/src/main/res/layout/activity_main.xml

@@ -42,7 +42,8 @@
                 android:paddingEnd="12dp"
                 android:clipChildren="false"
                 android:minWidth="84dp"
-                android:gravity="center_vertical">
+                android:gravity="center_vertical"
+                android:clickable="true">
 
                 <ProgressBar
                     android:id="@+id/uploadedAnswersProgress"

app/src/main/res/values/strings.xml

@@ -661,4 +661,7 @@ Otherwise, you can download another keyboard in the app store. Popular keyboards
     <string name="quest_ferry_motor_vehicle_name_title">Does %s transport motor vehicles?</string>
     <string name="quest_ferry_motor_vehicle_title">Does this ferry route transport motor vehicles?</string>
     <string name="create_new_note_hint">Best write the note in the locally spoken language or otherwise in English.</string>
+    <string name="about_contributing">Your answers are directly improving OpenStreetMap. Contributed data is open, everyone can use it. Many great projects are already using it.</string>
+    <string name="about_missing_stars">Currently star count is not shared across devices, but answers are added directly to the OpenStreetMap database.</string>
+    <string name="how_to_get_stars">Select one of markers on the map and answer the question. This way you will improve OpenStreetMap data and get stars. If you see no markers you may need to zoom out map.</string>
 </resources>