Custom left button fixes (#1205)

* navBarButtonColor was not applied to custom initial left button
* Dynamic custom button didn’t work
* Setting default icon (like menu or back button) after a custom icon was used didn’t work

android/app/src/main/java/com/reactnativenavigation/views/LeftButton.java

         this.navigatorEventId = navigatorEventId;
         this.overrideBackPressInJs = overrideBackPressInJs;
         setInitialState();
+        setColor();
     }
 
     void setIconState(TitleBarLeftButtonParams params) {
         this.params = params;
-        if (params.color.hasColor()) {
-            setColor(params.color.getColor());
-        }
+        setColor();
         animateIconState(params.iconState);
     }
 
+    void setCustomIcon(TitleBarLeftButtonParams params) {
+        this.params = params;
+        setColor();
+    }
+
     @Override
     public void onClick(View v) {
         if (isBackButton()) {
         }
     }
 
+    private void setColor() {
+        if (!params.color.hasColor()) {
+            return;
+        }
+        if (params.hasDefaultIcon()) {
+            setColor(params.color.getColor());
+        } else if (params.hasCustomIcon()) {
+            ViewUtils.tintDrawable(params.icon, params.color.getColor(), true);
+        }
+    }
+
     @Override
     public void setColor(int color) {
         if (params.hasDefaultIcon()) {

android/app/src/main/java/com/reactnativenavigation/views/TitleBar.java

         if (shouldSetLeftButton(leftButtonParams)) {
             createAndSetLeftButton(leftButtonParams, leftButtonOnClickListener, navigatorEventId, overrideBackPressInJs);
         } else if (hasLeftButton()) {
-            if (leftButtonParams.hasDefaultIcon()) {
+            if (leftButtonParams.hasDefaultIcon() || leftButtonParams.hasCustomIcon()) {
                 updateLeftButton(leftButtonParams);
             } else {
                 removeLeftButton();
     }
 
     private void updateLeftButton(TitleBarLeftButtonParams leftButtonParams) {
-        leftButton.setIconState(leftButtonParams);
+        if (leftButtonParams.hasDefaultIcon()) {
+            leftButton.setIconState(leftButtonParams);
+            setNavigationIcon(leftButton);
+        } else if (leftButtonParams.hasCustomIcon()) {
+            leftButton.setCustomIcon(leftButtonParams);
+            setNavigationIcon(leftButtonParams.icon);
+        }
     }
 
     private boolean shouldSetLeftButton(TitleBarLeftButtonParams leftButtonParams) {
                 overrideBackPressInJs);
         setNavigationOnClickListener(leftButton);
 
-        if (leftButtonParams.icon != null) {
+        if (leftButtonParams.hasCustomIcon()) {
             setNavigationIcon(leftButtonParams.icon);
         } else {
             setNavigationIcon(leftButton);