improved shading calculation (6 steps per hour)

app/src/main/java/org/woheller69/weather/SolarPowerPlant.java

@@ -67,12 +67,39 @@ public class SolarPowerPlant {
             efficiency = Math.max(0, efficiency); //scalar product is negative if sun points to back of module. set 0 in this case
 
             if (efficiency > 0) {
-                //Calculate shading  in 10 degree ranges, total 36 ranges
+                double shFactor=0;
-                int shadingIndex = ((((int) Math.round((solarAzimuth + 5) / 10)) - 1) % 36 + 36) % 36;
+                Instant sh;
-                if (shadingElevation[shadingIndex] > solarElevation) {
+                ZonedDateTime shDateTime;
-                    efficiency *= (double) (100 - shadingOpacity[shadingIndex])/100;
+                AzimuthZenithAngle shPosition;
+                double shSolarAzimuth;
+                double shSolarElevation;
+
+                //Calculate shading in 6 intervals per hour -> 10min steps xx:05 / xx:15 / xx:25 / xx:35 / xx:45 / xx:55
+                int numSteps = 6;
+                long interval = 3600 / numSteps;
+                for (int j=0; j<numSteps;j++){
+                    sh = Instant.ofEpochSecond(epochTimeSeconds-(numSteps-1)*interval/2+j*interval);
+                    shDateTime = ZonedDateTime.ofInstant(sh, ZoneId.of("GMT"));  //currentTimeMillis is in GMT
+
+                    shPosition = Grena3.calculateSolarPosition(
+                            shDateTime,
+                            latitude,
+                            longitude,
+                            DeltaT.estimate(shDateTime.toLocalDate())); // delta T (s)
+
+                    shSolarAzimuth = shPosition.getAzimuth();
+                    shSolarElevation = 90 - shPosition.getZenithAngle();
+
+                    //shading values are provided in 10 degree ranges -> total of 36 ranges
+                    int shadingIndex = ((((int) Math.round((shSolarAzimuth + 5) / 10)) - 1) % 36 + 36) % 36;
+                    if (shadingElevation[shadingIndex] > shSolarElevation) {
+                        shFactor += (double) (100 - shadingOpacity[shadingIndex])/(numSteps*100);
+                    } else {
+                        shFactor += (double) 100/(numSteps*100);  //numSteps iterations with no shading give 100%
                     }
                 }
+                efficiency *= shFactor;
+            }
         }
 
         double totalRadiationOnCell = solarPowerNormal * efficiency + solarPowerDiffuse * diffuseEfficiency + shortwaveRadiation * (0.5-0.5*Math.cos(tiltAngle/180*Math.PI)) * albedo;  //flat plate equivalent of the solar irradiance

app/src/main/java/org/woheller69/weather/ui/RecycleList/CityWeatherAdapter.java

@@ -2,7 +2,6 @@ package org.woheller69.weather.ui.RecycleList;
 
 import android.content.Context;
 import androidx.core.content.ContextCompat;
-import androidx.core.content.res.ResourcesCompat;
 import androidx.preference.PreferenceManager;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
@@ -338,20 +337,11 @@ public class CityWeatherAdapter extends RecyclerView.Adapter<CityWeatherAdapter.
                                         mCourseOfDay.getLayoutManager().scrollToPosition(i);
                                     }
 
-                                    highlightSelected(view);
                                 }
 
                             }
                         }
 
-                        private void highlightSelected(View view) {
-                            for (int j=0;j<courseDayList.size();j++){  //reset all items
-                                if (holder.recyclerView.getLayoutManager().getChildAt(j)!=null){
-                                    holder.recyclerView.getLayoutManager().getChildAt(j).setBackground(ResourcesCompat.getDrawable(context.getResources(),R.drawable.rounded_transparent,null));
-                                }
-                            }
-                            view.setBackground(ResourcesCompat.getDrawable(context.getResources(),R.drawable.rounded_highlight,null)); //highlight selected item
-                        }
 
                         public void onLongItemClick(View view, int position) {
 

app/src/main/java/org/woheller69/weather/ui/RecycleList/CourseOfDayAdapter.java

@@ -42,7 +42,7 @@ public class CourseOfDayAdapter extends RecyclerView.Adapter<CourseOfDayAdapter.
         this.courseOfDayList = courseOfDayList;
         this.recyclerViewHeader=recyclerViewHeader;
         this.recyclerView=recyclerView;
-        if (courseOfDayList.size()!=0 && courseOfDayList.get(0)!=null) {
+        if (courseOfDayList!=null && courseOfDayList.size()!=0 && courseOfDayList.get(0)!=null) {
             this.courseOfDayHeaderDate = new Date(courseOfDayList.get(0).getLocalForecastTime(context));
         }else this.courseOfDayHeaderDate=new Date();  //fallback if no data available
     }
@@ -141,7 +141,8 @@ public class CourseOfDayAdapter extends RecyclerView.Adapter<CourseOfDayAdapter.
 
     @Override
     public int getItemCount() {
-        return courseOfDayList.size();
+        if (courseOfDayList==null) return 0;
+        else return courseOfDayList.size();
     }
 
     class CourseOfDayViewHolder extends RecyclerView.ViewHolder {