Roundabout maneuver icon depicts counterclockwise movement when driving on the left

[1ec5]

A roundabout icon in a region that drives on the left should depict a clockwise movement, but instead it always depicts a counterclockwise movement; the icon is horizontally flipped.

#2044 attempted to fix this and some related issues by flipping the icon when the maneuver modifier is slight left, left, or sharp left:

mapbox-navigation-android/libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/instruction/maneuver/ManeuverView.java

Lines 238 to 244 in 2aa1316

	boolean flip = SHOULD_FLIP_MODIFIERS.contains(maneuverModifier);
	if (STEP_MANEUVER_MODIFIER_LEFT.equals(drivingSide) && STEP_MANEUVER_MODIFIER_UTURN.contains(maneuverModifier)) {
	setScaleX(flip ? 1 : -1);
	} else {
	setScaleX(flip ? -1 : 1);
	}
	}

While this heuristic is correct for most maneuver types, it’s incorrect for roundabout maneuvers. By default, the navigation SDK sets roundabout_exits=true in the Directions API request, producing two maneuvers, one for entering the roundabout and the other for exiting it. In a region that drives on the left, you make a slight left turn to enter the roundabout and another slight left turn to exit it. These slight left turns are reflected in the two maneuvers’ modifiers.

On iOS, we use this heuristic that works well: for a roundabout, rotary, or roundabout turn maneuver, flip the image horizontally if and only if the driving side is left. The driving side is the only determining factor for circular junctions; the modifier is irrelevant.

/ref #396
/cc @mapbox/navigation-android

[1ec5]

For the purposes of adapting the MapboxDirections.swift logic in this library:

• Translation of maneuver types from Swift names to their JSON equivalents
• Translation of maneuver modifiers from Swift names to their JSON equivalents

The types and modifiers are described in comments above that chunk of code, or you can consult the Directions API documentation.

[1ec5]

A fix could look something like this, though there may be an opportunity to reorganize the logic:

diff --git a/libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/instruction/maneuver/ManeuverView.java b/libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/instruction/maneuver/ManeuverView.java
index 218fd058..d3f57369 100644
--- a/libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/instruction/maneuver/ManeuverView.java
+++ b/libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/instruction/maneuver/ManeuverView.java
@@ -236,6 +236,9 @@ public class ManeuverView extends View {
       maneuverViewUpdate.updateManeuverView(canvas, primaryColor, secondaryColor, size, roundaboutAngle);
     }
     boolean flip = SHOULD_FLIP_MODIFIERS.contains(maneuverModifier);
+    if (ROUNDABOUT_MANEUVER_TYPES.contains(maneuverType)) {
+      flip = STEP_MANEUVER_MODIFIER_LEFT.equals(drivingSide);
+    }
     if (STEP_MANEUVER_MODIFIER_LEFT.equals(drivingSide) && STEP_MANEUVER_MODIFIER_UTURN.contains(maneuverModifier)) {
       setScaleX(flip ? 1 : -1);
     } else {