Align title after left button is set (#5129)

When setting left button and the title was centred, it got an undesired offset.
Now whenever left button is set we make sure to realign the title.

lib/android/app/src/main/java/com/reactnativenavigation/utils/StringUtils.java

 package com.reactnativenavigation.utils;
 
+import android.support.annotation.Nullable;
+
 public class StringUtils {
 
 	@SuppressWarnings("StringEquality")
 		}
 		return s1.equals(s2);
 	}
+
+    public static boolean isEmpty(@Nullable CharSequence s) {
+        return s == null || s.length() == 0;
+    }
 }

lib/android/app/src/main/java/com/reactnativenavigation/utils/UiUtils.java

 import android.os.Handler;
 import android.os.Looper;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.util.DisplayMetrics;
 import android.view.View;
 import android.view.ViewTreeObserver;
     private static int statusBarHeight = -1;
     private static int topBarHeight = -1;
 
-    public static void runOnPreDrawOnce(final View view, final Runnable task) {
+    public static <T extends View> void runOnPreDrawOnce(@Nullable final T view, final Functions.Func1<T> task) {
+        if (view == null) return;
+        runOnPreDrawOnce(view, () -> task.run(view));
+    }
+
+    public static void runOnPreDrawOnce(@Nullable final View view, final Runnable task) {
+        if (view == null) return;
         view.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
             @Override
             public boolean onPreDraw() {

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

 
 import com.reactnativenavigation.parse.Alignment;
 import com.reactnativenavigation.parse.params.Colour;
+import com.reactnativenavigation.utils.StringUtils;
 import com.reactnativenavigation.utils.UiUtils;
 import com.reactnativenavigation.utils.ViewUtils;
 import com.reactnativenavigation.viewcontrollers.TitleBarButtonController;
 
 import javax.annotation.Nullable;
 
+import static com.reactnativenavigation.utils.UiUtils.runOnPreDrawOnce;
+
 @SuppressLint("ViewConstructor")
 public class TitleBar extends Toolbar {
     public static final int DEFAULT_LEFT_MARGIN = 16;
         return super.getTitle() == null ? "" : (String) super.getTitle();
     }
 
-    public void setTitleTextColor(Colour color) {
-        if (color.hasValue()) setTitleTextColor(color.get());
-    }
-
     public void setComponent(View component) {
         clearTitle();
         clearSubtitle();
         subtitleAlignment = alignment;
     }
 
-    private void alignTextView(Alignment alignment, TextView view) {
+    public void alignTextView(Alignment alignment, TextView view) {
+        if (StringUtils.isEmpty(view.getText())) return;
         Integer direction = view.getParent().getLayoutDirection();
-        Boolean isRTL = direction == View.LAYOUT_DIRECTION_RTL;
+        boolean isRTL = direction == View.LAYOUT_DIRECTION_RTL;
 
         if (alignment == Alignment.Center) {
             //noinspection IntegerDivisionInFloatingPointContext
 
     private void setLeftButton(TitleBarButtonController button) {
         leftButtonController = button;
+        runOnPreDrawOnce(findTitleTextView(), title -> alignTextView(titleAlignment, title));
         button.applyNavigationIcon(this);
     }
 

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/TitleBarTest.java

 package com.reactnativenavigation.viewcontrollers;
 
-import android.app.*;
-import android.support.v7.widget.*;
-import android.view.*;
-
-import com.reactnativenavigation.*;
-import com.reactnativenavigation.parse.params.*;
-import com.reactnativenavigation.react.*;
-import com.reactnativenavigation.utils.*;
-import com.reactnativenavigation.views.titlebar.*;
-
-import org.junit.*;
-
-import java.util.*;
-
-import static com.reactnativenavigation.utils.TitleBarHelper.*;
-import static org.assertj.core.api.Java6Assertions.*;
-import static org.mockito.Mockito.*;
+import android.app.Activity;
+import android.support.v7.widget.ActionMenuView;
+import android.view.View;
+import android.widget.TextView;
+
+import com.reactnativenavigation.BaseTest;
+import com.reactnativenavigation.parse.params.Button;
+import com.reactnativenavigation.parse.params.Text;
+import com.reactnativenavigation.react.Constants;
+import com.reactnativenavigation.react.ReactView;
+import com.reactnativenavigation.utils.CollectionUtils;
+import com.reactnativenavigation.views.titlebar.TitleBar;
+
+import org.junit.Test;
+import org.mockito.Mockito;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import static com.reactnativenavigation.utils.TitleBarHelper.createButtonController;
+import static org.assertj.core.api.Java6Assertions.assertThat;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 public class TitleBarTest extends BaseTest {
 
         assertThat(uut.getNavigationIcon()).isNull();
     }
 
+    @Test
+    public void setLeftButton_titleIsAligned() {
+        uut.setTitle("Title");
+        TextView title = new TextView(activity);
+        uut.addView(title);
+        when(uut.findTitleTextView()).thenReturn(title);
+
+        uut.setLeftButtons(Collections.singletonList(Mockito.mock(TitleBarButtonController.class)));
+        dispatchPreDraw(title);
+        verify(uut).alignTextView(any(), eq(title));
+    }
+
     @Test
     public void setRightButtons_buttonsAreAddedInReverseOrderToMatchOrderOnIOs() {
         uut.setLeftButtons(new ArrayList<>());