Auto adjust widget text color

app/src/main/java/eu/faircode/email/ActivityWidget.java

@@ -31,11 +31,13 @@ import android.widget.ArrayAdapter;
 import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.CompoundButton;
+import android.widget.ImageView;
 import android.widget.RadioButton;
 import android.widget.Spinner;
 import android.widget.TextView;
 
 import androidx.constraintlayout.widget.Group;
+import androidx.core.graphics.ColorUtils;
 import androidx.preference.PreferenceManager;
 
 import com.flask.colorpicker.ColorPickerView;
@@ -230,6 +232,16 @@ public class ActivityWidget extends ActivityBase {
         } else {
             inOld.setBackgroundColor(background);
             inNew.setBackgroundColor(background);
+            float lum = (float) ColorUtils.calculateLuminance(background);
+            int color = (lum > 0.7 ? Color.BLACK : getResources().getColor(R.color.colorWidgetForeground));
+
+            ((ImageView) inOld.findViewById(R.id.ivMessage)).setColorFilter(color);
+            ((TextView) inOld.findViewById(R.id.tvCount)).setTextColor(color);
+            ((TextView) inOld.findViewById(R.id.tvAccount)).setTextColor(color);
+
+            ((ImageView) inNew.findViewById(R.id.ivMessage)).setColorFilter(color);
+            ((TextView) inNew.findViewById(R.id.tvCount)).setTextColor(color);
+            ((TextView) inNew.findViewById(R.id.tvAccount)).setTextColor(color);
         }
     }
 }

app/src/main/java/eu/faircode/email/Widget.java

@@ -31,6 +31,7 @@ import android.text.TextUtils;
 import android.view.View;
 import android.widget.RemoteViews;
 
+import androidx.core.graphics.ColorUtils;
 import androidx.preference.PreferenceManager;
 
 import java.text.NumberFormat;
@@ -118,6 +119,15 @@ public class Widget extends AppWidgetProvider {
                         views.setViewVisibility(R.id.tvAccount, ViewStripe.VISIBLE);
                     }
 
+                    if (!semi && background != Color.TRANSPARENT) {
+                        float lum = (float) ColorUtils.calculateLuminance(background);
+                        if (lum > 0.7f) {
+                            views.setInt(R.id.ivMessage, "setColorFilter", Color.BLACK);
+                            views.setTextColor(R.id.tvCount, Color.BLACK);
+                            views.setTextColor(R.id.tvAccount, Color.BLACK);
+                        }
+                    }
+
                     appWidgetManager.updateAppWidget(appWidgetId, views);
                 }
             }

app/src/main/java/eu/faircode/email/WidgetUnified.java

@@ -31,6 +31,7 @@ import android.net.Uri;
 import android.util.TypedValue;
 import android.widget.RemoteViews;
 
+import androidx.core.graphics.ColorUtils;
 import androidx.preference.PreferenceManager;
 
 public class WidgetUnified extends AppWidgetProvider {
@@ -69,6 +70,10 @@ public class WidgetUnified extends AppWidgetProvider {
                 views.setViewPadding(R.id.title, px, px, px, px);
             }
 
+            float lum = (float) ColorUtils.calculateLuminance(background);
+            if (lum > 0.7f)
+                views.setTextColor(R.id.title, Color.BLACK);
+
             if (name == null)
                 views.setTextViewText(R.id.title, context.getString(R.string.title_folder_unified));
             else

app/src/main/java/eu/faircode/email/WidgetUnifiedRemoteViewsFactory.java

@@ -23,6 +23,7 @@ import android.appwidget.AppWidgetManager;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.graphics.Color;
 import android.graphics.Typeface;
 import android.text.SpannableString;
 import android.text.Spanned;
@@ -34,6 +35,7 @@ import android.widget.RemoteViews;
 import android.widget.RemoteViewsService;
 
 import androidx.core.content.ContextCompat;
+import androidx.core.graphics.ColorUtils;
 import androidx.preference.PreferenceManager;
 
 import java.util.ArrayList;
@@ -51,6 +53,8 @@ public class WidgetUnifiedRemoteViewsFactory implements RemoteViewsService.Remot
     private long account;
     private boolean unseen;
     private boolean flagged;
+    private boolean semi;
+    private int background;
     private int font;
     private int padding;
     private int colorWidgetForeground;
@@ -85,12 +89,20 @@ public class WidgetUnifiedRemoteViewsFactory implements RemoteViewsService.Remot
         folder = prefs.getLong("widget." + appWidgetId + ".folder", -1L);
         unseen = prefs.getBoolean("widget." + appWidgetId + ".unseen", false);
         flagged = prefs.getBoolean("widget." + appWidgetId + ".flagged", false);
+        semi = prefs.getBoolean("widget." + appWidgetId + ".semi", true);
+        background = prefs.getInt("widget." + appWidgetId + ".background", Color.TRANSPARENT);
         font = prefs.getInt("widget." + appWidgetId + ".font", 0);
         padding = prefs.getInt("widget." + appWidgetId + ".padding", 0);
         colorWidgetForeground = ContextCompat.getColor(context, R.color.colorWidgetForeground);
         colorWidgetRead = ContextCompat.getColor(context, R.color.colorWidgetRead);
         colorSeparator = ContextCompat.getColor(context, R.color.lightColorSeparator);
 
+        float lum = (float) ColorUtils.calculateLuminance(background);
+        if (lum > 0.7f) {
+            colorWidgetForeground = ColorUtils.blendARGB(colorWidgetForeground, Color.BLACK, 1.0f);
+            colorWidgetRead = ColorUtils.blendARGB(colorWidgetRead, Color.BLACK, 1.0f);
+        }
+
         pro = ActivityBilling.isPro(context);
 
         DB db = DB.getInstance(context);

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

@@ -21,9 +21,10 @@
         android:textStyle="bold" />
 
     <FrameLayout
+        android:id="@+id/separator"
         android:layout_width="match_parent"
         android:layout_height="1dp"
-        android:background="@color/colorWidgetForeground" />
+        android:background="@color/colorWidgetRead" />
 
     <ListView
         android:id="@+id/lv"