Add distance remaining buffer to show first instruction immediately

libandroid-navigation/src/main/java/com/mapbox/services/android/navigation/v5/utils/RouteUtils.java

@@ -29,6 +29,8 @@ public class RouteUtils {
 
   private static final String FORCED_LOCATION = "Forced Location";
   private static final int FIRST_COORDINATE = 0;
+  private static final int ZERO_INSTRUCTIONS = 0;
+  private static final int ONE_METER_BUFFER = 1;
   private static final Set<String> VALID_PROFILES = new HashSet<String>() {
     {
       add(DirectionsCriteria.PROFILE_DRIVING_TRAFFIC);
@@ -177,6 +179,7 @@ public boolean isValidRouteProfile(String routeProfile) {
   @Nullable
   public BannerInstructions findCurrentBannerInstructions(LegStep currentStep, double stepDistanceRemaining) {
     if (isValidStep(currentStep) && hasInstructions(currentStep.bannerInstructions())) {
+      stepDistanceRemaining = stepDistanceRemaining - ONE_METER_BUFFER; // For showing first banner immediately
       List<BannerInstructions> instructions = new ArrayList<>(currentStep.bannerInstructions());
       Iterator<BannerInstructions> instructionsIterator = instructions.iterator();
       while (instructionsIterator.hasNext()) {
@@ -187,7 +190,7 @@ public BannerInstructions findCurrentBannerInstructions(LegStep currentStep, dou
         }
       }
       int instructionIndex = checkValidIndex(instructions);
-      if (instructions.size() > 0) {
+      if (instructions.size() > ZERO_INSTRUCTIONS) {
         return instructions.get(instructionIndex);
       }
     }
@@ -238,7 +241,7 @@ public VoiceInstructions findCurrentVoiceInstructions(LegStep currentStep, doubl
         }
       }
       int instructionIndex = checkValidIndex(instructions);
-      if (instructions.size() > 0) {
+      if (instructions.size() > ZERO_INSTRUCTIONS) {
         return instructions.get(instructionIndex);
       }
     }