Create AppStyle and set button color from screen

android/app/src/main/java/com/reactnativenavigation/params/AppStyle.java

+package com.reactnativenavigation.params;
+
+import android.os.Bundle;
+
+import com.reactnativenavigation.params.parsers.StyleParamsParser;
+
+public class AppStyle {
+    public static StyleParams appStyle;
+
+    public static void setAppStyle(Bundle params) {
+        appStyle = new StyleParamsParser(params.getBundle("appStyle")).parse();
+    }
+}

android/app/src/main/java/com/reactnativenavigation/params/TitleBarButtonParams.java

     public StyleParams.Color color;
     public ShowAsAction showAsAction;
     public boolean enabled = true;
+
+    public void setColorFromScreenStyle(StyleParams.Color titleBarButtonColor) {
+        if (!color.hasColor() && titleBarButtonColor.hasColor()) {
+            color = titleBarButtonColor;
+        }
+    }
 }

android/app/src/main/java/com/reactnativenavigation/params/parsers/ActivityParamsParser.java

 import android.os.Bundle;
 
 import com.reactnativenavigation.params.ActivityParams;
+import com.reactnativenavigation.params.AppStyle;
 
 public class ActivityParamsParser extends Parser {
     public static ActivityParams parse(Bundle params) {
         ActivityParams result = new ActivityParams();
 
-        StyleParamsParser.setAppStyle(params);
+        AppStyle.setAppStyle(params);
 
         if (hasKey(params, "screen")) {
             result.type = ActivityParams.Type.SingleScreen;

android/app/src/main/java/com/reactnativenavigation/params/parsers/StyleParamsParser.java

 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
+import com.reactnativenavigation.params.AppStyle;
 import com.reactnativenavigation.params.StyleParams;
 
 public class StyleParamsParser {
-    private static StyleParams appStyle;
     private Bundle params;
 
-    public static void setAppStyle(Bundle params) {
-        StyleParamsParser.appStyle = new StyleParamsParser(params.getBundle("appStyle")).parse();
-    }
-
     public StyleParamsParser(Bundle params) {
         this.params = params;
     }
 
     @Nullable
     private StyleParams.Color getDefaultNavigationColor() {
-        return appStyle == null ? new StyleParams.Color() : appStyle.navigationBarColor;
+        return AppStyle.appStyle == null ? new StyleParams.Color() : AppStyle.appStyle.navigationBarColor;
     }
 
     @Nullable
     private StyleParams.Color getDefaultSelectedBottomTabsButtonColor() {
-        return appStyle == null ? new StyleParams.Color() : appStyle.selectedBottomTabsButtonColor;
+        return AppStyle.appStyle == null ? new StyleParams.Color() : AppStyle.appStyle.selectedBottomTabsButtonColor;
     }
 
     @Nullable
     private StyleParams.Color getDefaultBottomTabsButtonColor() {
-        return appStyle == null ? new StyleParams.Color() : appStyle.bottomTabsButtonColor;
+        return AppStyle.appStyle == null ? new StyleParams.Color() : AppStyle.appStyle.bottomTabsButtonColor;
     }
 
     @Nullable
     private StyleParams.Color getDefaultBottomTabsColor() {
-        return appStyle == null ? new StyleParams.Color() : appStyle.bottomTabsColor;
+        return AppStyle.appStyle == null ? new StyleParams.Color() : AppStyle.appStyle.bottomTabsColor;
     }
 
     private boolean isDefaultBottomTabsHiddenOnScroll() {
-        return appStyle != null && appStyle.bottomTabsHiddenOnScroll;
+        return AppStyle.appStyle != null && AppStyle.appStyle.bottomTabsHiddenOnScroll;
     }
 
     private boolean isDefaultBottomTabsHidden() {
-        return appStyle != null && appStyle.bottomTabsHidden;
+        return AppStyle.appStyle != null && AppStyle.appStyle.bottomTabsHidden;
     }
 
     private boolean isDefaultScreenBelowTopBar() {
-        return appStyle == null || appStyle.drawScreenBelowTopBar;
+        return AppStyle.appStyle == null || AppStyle.appStyle.drawScreenBelowTopBar;
     }
 
     private boolean isDefaultTopTabsHidden() {
-        return appStyle != null && appStyle.topTabsHidden;
+        return AppStyle.appStyle != null && AppStyle.appStyle.topTabsHidden;
     }
 
     private boolean isDefaultBackButtonHidden() {
-        return appStyle != null && appStyle.backButtonHidden;
+        return AppStyle.appStyle != null && AppStyle.appStyle.backButtonHidden;
     }
 
     @Nullable
     private StyleParams.Color getDefaultTitleBarColor() {
-        return appStyle == null ? new StyleParams.Color() : appStyle.titleBarTitleColor;
+        return AppStyle.appStyle == null ? new StyleParams.Color() : AppStyle.appStyle.titleBarTitleColor;
     }
 
     @Nullable
     private StyleParams.Color getTitleBarButtonColor() {
-        return appStyle == null ? new StyleParams.Color() : appStyle.titleBarButtonColor;
+        return AppStyle.appStyle == null ? new StyleParams.Color() : AppStyle.appStyle.titleBarButtonColor;
     }
 
     private boolean isDefaultTopBarHidden() {
-        return appStyle != null && appStyle.titleBarHidden;
+        return AppStyle.appStyle != null && AppStyle.appStyle.titleBarHidden;
     }
 
     @Nullable
     private StyleParams.Color getDefaultTopBarColor() {
-        return appStyle == null ? new StyleParams.Color() : appStyle.topBarColor;
+        return AppStyle.appStyle == null ? new StyleParams.Color() : AppStyle.appStyle.topBarColor;
     }
 
     @Nullable
     private StyleParams.Color getDefaultStatusBarColor() {
-        return appStyle == null ? new StyleParams.Color() : appStyle.statusBarColor;
+        return AppStyle.appStyle == null ? new StyleParams.Color() : AppStyle.appStyle.statusBarColor;
     }
 
     private boolean getBoolean(String titleBarHidden, boolean defaultValue) {

android/app/src/main/java/com/reactnativenavigation/params/parsers/TitleBarButtonParamsParser.java

 
 import android.os.Bundle;
 
+import com.reactnativenavigation.params.AppStyle;
 import com.reactnativenavigation.params.StyleParams;
 import com.reactnativenavigation.params.TitleBarButtonParams;
 import com.reactnativenavigation.react.ImageLoader;
         if (hasKey(bundle,"icon")) {
             result.icon = ImageLoader.loadImage(bundle.getString("icon"));
         }
-        result.color = StyleParams.Color.parse(bundle.getString("color"));
+        result.color = getColor(bundle, AppStyle.appStyle.titleBarButtonColor);
         result.showAsAction = parseShowAsAction(bundle.getString("showAsAction"));
         result.enabled = bundle.getBoolean("enabled", true);
         result.eventId = bundle.getString("id");
         return result;
     }
 
+    private StyleParams.Color getColor(Bundle bundle, StyleParams.Color defaultColor) {
+        StyleParams.Color color = StyleParams.Color.parse(bundle.getString("color"));
+        return color.hasColor() || defaultColor == null ? color : defaultColor;
+    }
+
     private static TitleBarButtonParams.ShowAsAction parseShowAsAction(String showAsAction) {
         if (showAsAction == null) {
             return TitleBarButtonParams.ShowAsAction.IfRoom;

android/app/src/main/java/com/reactnativenavigation/screens/Screen.java

     }
 
     public void setTitleBarRightButtons(String navigatorEventId, List<TitleBarButtonParams> titleBarButtons) {
+        setButtonColorFromScreen(titleBarButtons);
         topBar.setTitleBarRightButtons(navigatorEventId, titleBarButtons);
     }
 
     public StyleParams getStyleParams() {
         return screenParams.styleParams;
     }
+
+    private void setButtonColorFromScreen(List<TitleBarButtonParams> titleBarButtonParamses) {
+        for (TitleBarButtonParams titleBarButtonParamse : titleBarButtonParamses) {
+            titleBarButtonParamse.setColorFromScreenStyle(screenParams.styleParams.titleBarButtonColor);
+        }
+    }
 }