#14 Fixed no slides library crash

app/src/main/java/agency/tango/materialintro/MainActivity.java

@@ -19,7 +19,7 @@ public void onCreate(Bundle savedInstanceState) {
             @Override
             public void onClick(View v) {
                 Intent intent = new Intent(MainActivity.this, IntroActivity.class);
-                MainActivity.this.startActivity(intent);
+                startActivity(intent);
             }
         });
     }

material-intro-screen/src/main/java/agency/tango/materialintroscreen/MaterialIntroActivity.java

@@ -102,9 +102,13 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
         viewPager.post(new Runnable() {
             @Override
             public void run() {
-                int currentItem = viewPager.getCurrentItem();
-                messageButtonBehaviourOnPageSelected.pageSelected(currentItem);
-                nextButtonBehaviour(currentItem, adapter.getItem(currentItem));
+                if (adapter.slidesCount() == 0) {
+                    finish();
+                } else {
+                    int currentItem = viewPager.getCurrentItem();
+                    messageButtonBehaviourOnPageSelected.pageSelected(currentItem);
+                    nextButtonBehaviour(currentItem, adapter.getItem(currentItem));
+                }
             }
         });
     }
@@ -113,7 +117,7 @@ public void run() {
     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         SlideFragment fragment = adapter.getItem(viewPager.getCurrentItem());
         boolean hasPermissionToGrant = fragment.hasNeededPermissionsToGrant();
-        if (hasPermissionToGrant == false) {
+        if (!hasPermissionToGrant) {
             viewPager.setAllowedSwipeDirection(SwipeableViewPager.SwipeDirection.all);
             nextButtonBehaviour(viewPager.getCurrentItem(), fragment);
             messageButtonBehaviourOnPageSelected.pageSelected(viewPager.getCurrentItem());
@@ -170,7 +174,7 @@ public void pageScrolled(final int position, float offset) {
                         viewPager.post(new Runnable() {
                             @Override
                             public void run() {
-                                if (adapter.getItem(position).hasNeededPermissionsToGrant() || adapter.getItem(position).canMoveFurther() == false) {
+                                if (adapter.getItem(position).hasNeededPermissionsToGrant() || !adapter.getItem(position).canMoveFurther()) {
                                     viewPager.setCurrentItem(position);
                                     pageIndicator.clearJoiningFractions();
                                 }
@@ -237,6 +241,7 @@ private int color(@ColorRes int color) {
      *
      * @param slideFragment Fragment to add
      */
+    @SuppressWarnings("unused")
     public void addSlide(SlideFragment slideFragment) {
         adapter.addItem(slideFragment);
     }
@@ -247,6 +252,7 @@ public void addSlide(SlideFragment slideFragment) {
      * @param slideFragment          Fragment to add
      * @param messageButtonBehaviour Add behaviour for message button
      */
+    @SuppressWarnings("unused")
     public void addSlide(SlideFragment slideFragment, MessageButtonBehaviour messageButtonBehaviour) {
         adapter.addItem(slideFragment);
         messageButtonBehaviours.put(adapter.getLastItemPosition(), messageButtonBehaviour);
@@ -263,8 +269,8 @@ public void setSkipButtonVisible() {
         skipButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                for (int position = viewPager.getCurrentItem(); position < adapter.getCalculatedCount(); position++) {
-                    if (adapter.getItem(position).canMoveFurther() == false) {
+                for (int position = viewPager.getCurrentItem(); position < adapter.slidesCount(); position++) {
+                    if (!adapter.getItem(position).canMoveFurther()) {
                         viewPager.setCurrentItem(position);
                         showError(adapter.getItem(position).cantMoveFurtherErrorMessage());
                         return;
@@ -313,6 +319,7 @@ public ViewTranslationWrapper getNextButtonTranslationWrapper() {
      *
      * @return ViewTranslationWrapper
      */
+    @SuppressWarnings("unused")
     public ViewTranslationWrapper getBackButtonTranslationWrapper() {
         return backButtonTranslationWrapper;
     }
@@ -322,6 +329,7 @@ public ViewTranslationWrapper getBackButtonTranslationWrapper() {
      *
      * @return ViewTranslationWrapper
      */
+    @SuppressWarnings("unused")
     public ViewTranslationWrapper getPageIndicatorTranslationWrapper() {
         return pageIndicatorTranslationWrapper;
     }
@@ -331,6 +339,7 @@ public ViewTranslationWrapper getPageIndicatorTranslationWrapper() {
      *
      * @return ViewTranslationWrapper
      */
+    @SuppressWarnings("unused")
     public ViewTranslationWrapper getViewPagerTranslationWrapper() {
         return viewPagerTranslationWrapper;
     }
@@ -340,6 +349,7 @@ public ViewTranslationWrapper getViewPagerTranslationWrapper() {
      *
      * @return ViewTranslationWrapper
      */
+    @SuppressWarnings("unused")
     public ViewTranslationWrapper getSkipButtonTranslationWrapper() {
         return skipButtonTranslationWrapper;
     }

material-intro-screen/src/main/java/agency/tango/materialintroscreen/MessageButtonBehaviour.java

@@ -2,6 +2,7 @@
 
 import android.view.View;
 
+@SuppressWarnings("unused")
 public class MessageButtonBehaviour {
     private View.OnClickListener clickListener;
     private String messageButtonText;

material-intro-screen/src/main/java/agency/tango/materialintroscreen/MoveUpBehaviour.java

@@ -7,6 +7,7 @@
 import android.view.View;
 import android.widget.LinearLayout;
 
+@SuppressWarnings("unused")
 public class MoveUpBehaviour extends CoordinatorLayout.Behavior<LinearLayout> {
     public MoveUpBehaviour(Context context, AttributeSet attrs) {
         super(context, attrs);

material-intro-screen/src/main/java/agency/tango/materialintroscreen/SlideFragment.java

@@ -56,7 +56,7 @@ public static SlideFragment createInstance(SlideFragmentBuilder builder) {
     }
 
     public static boolean isNotNullOrEmpty(String string) {
-        return string != null && string.isEmpty() == false;
+        return string != null && !string.isEmpty();
     }
 
     @Nullable
@@ -93,7 +93,7 @@ public int buttonsColor() {
 
     public boolean hasAnyPermissionsToGrant() {
         boolean hasPermissionToGrant = hasPermissionsToGrant(neededPermissions);
-        if (hasPermissionToGrant == false) {
+        if (!hasPermissionToGrant) {
             hasPermissionToGrant = hasPermissionsToGrant(possiblePermissions);
         }
         return hasPermissionToGrant;
@@ -144,14 +144,14 @@ public void askForPermissions() {
         }
 
         String[] permissionsToGrant = removeEmptyAndNullStrings(notGrantedPermissions);
-        ActivityCompat.requestPermissions(this.getActivity(), permissionsToGrant, PERMISSIONS_REQUEST_CODE);
+        ActivityCompat.requestPermissions(getActivity(), permissionsToGrant, PERMISSIONS_REQUEST_CODE);
     }
 
     private boolean hasPermissionsToGrant(String[] permissions) {
         if (permissions != null) {
-            for (int i = 0; i < permissions.length; i++) {
-                if (isNotNullOrEmpty(permissions[i])) {
-                    if (ContextCompat.checkSelfPermission(getContext(), permissions[i]) != PackageManager.PERMISSION_GRANTED) {
+            for (String permission : permissions) {
+                if (isNotNullOrEmpty(permission)) {
+                    if (ContextCompat.checkSelfPermission(getContext(), permission) != PackageManager.PERMISSION_GRANTED) {
                         return true;
                     }
                 }
@@ -160,6 +160,7 @@ private boolean hasPermissionsToGrant(String[] permissions) {
         return false;
     }
 
+    @SuppressWarnings("SuspiciousMethodCalls")
     private String[] removeEmptyAndNullStrings(final ArrayList<String> permissions) {
         List<String> list = new ArrayList<>(permissions);
         list.removeAll(Collections.singleton(null));

material-intro-screen/src/main/java/agency/tango/materialintroscreen/SlideFragmentBuilder.java

@@ -3,6 +3,7 @@
 import android.support.annotation.ColorRes;
 import android.support.annotation.DrawableRes;
 
+@SuppressWarnings({"unused", "WeakerAccess"})
 public class SlideFragmentBuilder {
     int backgroundColor;
     int buttonsColor;

material-intro-screen/src/main/java/agency/tango/materialintroscreen/adapter/SlidesAdapter.java

@@ -28,12 +28,18 @@ public Object instantiateItem(ViewGroup container, int position) {
         return fragment;
     }
 
+    /**
+     * @return Returns count of fragments in adapter
+     */
     @Override
     public int getCount() {
         return fragments.size();
     }
 
-    public int getCalculatedCount() {
+    /**
+     * @return Returns count of fragments in adapter WITHOUT empty slide if is available
+     */
+    public int slidesCount() {
         if (isLastItemEmptySlide()) {
             return fragments.size() - 1;
         } else {
@@ -42,25 +48,25 @@ public int getCalculatedCount() {
     }
 
     public void addItem(SlideFragment fragment) {
-        fragments.add(getCalculatedCount(), fragment);
-        this.notifyDataSetChanged();
+        fragments.add(slidesCount(), fragment);
+        notifyDataSetChanged();
     }
 
     public void addEmptySlide(LastEmptySlideFragment fragment) {
         fragments.add(fragment);
-        this.notifyDataSetChanged();
+        notifyDataSetChanged();
     }
 
     public int getLastItemPosition() {
-        return getCalculatedCount() - 1;
+        return slidesCount() - 1;
     }
 
     public boolean isLastSlide(int position) {
-        return position == getCalculatedCount() - 1;
+        return position == slidesCount() - 1;
     }
 
     public boolean shouldFinish(int position) {
-        return position == getCalculatedCount();
+        return position == slidesCount();
     }
 
     private boolean isLastItemEmptySlide() {

material-intro-screen/src/main/java/agency/tango/materialintroscreen/animations/ViewTranslationWrapper.java

@@ -19,13 +19,14 @@ public class ViewTranslationWrapper {
     public ViewTranslationWrapper(View view) {
         this.view = view;
 
-        this.enterTranslation = new NoTranslation();
-        this.exitTranslation = new NoTranslation();
-        this.setErrorAnimation(0);
+        enterTranslation = new NoTranslation();
+        exitTranslation = new NoTranslation();
+        setErrorAnimation(0);
     }
 
     /**
      * Set translation after passing first slide
+     *
      * @param enterTranslation new translation
      */
     public ViewTranslationWrapper setEnterTranslation(IViewTranslation enterTranslation) {
@@ -35,6 +36,7 @@ public ViewTranslationWrapper setEnterTranslation(IViewTranslation enterTranslat
 
     /**
      * Set translation after passing last slide
+     *
      * @param exitTranslation new translation
      */
     public ViewTranslationWrapper setExitTranslation(IViewTranslation exitTranslation) {
@@ -44,6 +46,7 @@ public ViewTranslationWrapper setExitTranslation(IViewTranslation exitTranslatio
 
     /**
      * Set default translation
+     *
      * @param defaultTranslation new translation
      */
     public ViewTranslationWrapper setDefaultTranslation(IViewTranslation defaultTranslation) {
@@ -53,6 +56,7 @@ public ViewTranslationWrapper setDefaultTranslation(IViewTranslation defaultTran
 
     /**
      * Set view on error animation
+     *
      * @param errorAnimation new animation
      */
     public ViewTranslationWrapper setErrorAnimation(@AnimRes int errorAnimation) {
@@ -63,20 +67,20 @@ public ViewTranslationWrapper setErrorAnimation(@AnimRes int errorAnimation) {
     }
 
     public void enterTranslate(float percentage) {
-        this.enterTranslation.translate(view, percentage);
+        enterTranslation.translate(view, percentage);
     }
 
     public void exitTranslate(float percentage) {
-        this.exitTranslation.translate(view, percentage);
+        exitTranslation.translate(view, percentage);
     }
 
     public void defaultTranslate(float percentage) {
-        this.defaultTranslation.translate(view, percentage);
+        defaultTranslation.translate(view, percentage);
     }
 
     public void error() {
         if (errorAnimation != null) {
-            this.view.startAnimation(errorAnimation);
+            view.startAnimation(errorAnimation);
         }
     }
 }

material-intro-screen/src/main/java/agency/tango/materialintroscreen/animations/wrappers/BackButtonTranslationWrapper.java

@@ -11,7 +11,7 @@ public class BackButtonTranslationWrapper extends ViewTranslationWrapper {
     public BackButtonTranslationWrapper(View view) {
         super(view);
 
-        this.setEnterTranslation(new EnterDefaultTranslation())
+        setEnterTranslation(new EnterDefaultTranslation())
                 .setDefaultTranslation(new DefaultPositionTranslation())
                 .setExitTranslation(new ExitDefaultTranslation());
     }

material-intro-screen/src/main/java/agency/tango/materialintroscreen/animations/wrappers/NextButtonTranslationWrapper.java

@@ -11,7 +11,7 @@ public class NextButtonTranslationWrapper extends ViewTranslationWrapper {
     public NextButtonTranslationWrapper(View view) {
         super(view);
 
-        this.setExitTranslation(new ExitDefaultTranslation())
+        setExitTranslation(new ExitDefaultTranslation())
                 .setDefaultTranslation(new DefaultPositionTranslation())
                 .setErrorAnimation(R.anim.shake_it);
     }

material-intro-screen/src/main/java/agency/tango/materialintroscreen/animations/wrappers/PageIndicatorTranslationWrapper.java

@@ -10,7 +10,7 @@ public class PageIndicatorTranslationWrapper extends ViewTranslationWrapper {
     public PageIndicatorTranslationWrapper(View view) {
         super(view);
 
-        this.setDefaultTranslation(new DefaultPositionTranslation())
+        setDefaultTranslation(new DefaultPositionTranslation())
                 .setExitTranslation(new ExitDefaultTranslation());
     }
 }

material-intro-screen/src/main/java/agency/tango/materialintroscreen/animations/wrappers/SkipButtonTranslationWrapper.java

@@ -1,17 +1,17 @@
 package agency.tango.materialintroscreen.animations.wrappers;
 
-        import android.view.View;
+import android.view.View;
 
-        import agency.tango.materialintroscreen.animations.ViewTranslationWrapper;
-        import agency.tango.materialintroscreen.animations.translations.DefaultPositionTranslation;
-        import agency.tango.materialintroscreen.animations.translations.EnterDefaultTranslation;
-        import agency.tango.materialintroscreen.animations.translations.ExitDefaultTranslation;
+import agency.tango.materialintroscreen.animations.ViewTranslationWrapper;
+import agency.tango.materialintroscreen.animations.translations.DefaultPositionTranslation;
+import agency.tango.materialintroscreen.animations.translations.EnterDefaultTranslation;
+import agency.tango.materialintroscreen.animations.translations.ExitDefaultTranslation;
 
 public class SkipButtonTranslationWrapper extends ViewTranslationWrapper {
     public SkipButtonTranslationWrapper(View view) {
         super(view);
 
-        this.setEnterTranslation(new EnterDefaultTranslation())
+        setEnterTranslation(new EnterDefaultTranslation())
                 .setDefaultTranslation(new DefaultPositionTranslation())
                 .setExitTranslation(new ExitDefaultTranslation());
     }

material-intro-screen/src/main/java/agency/tango/materialintroscreen/animations/wrappers/ViewPagerTranslationWrapper.java

@@ -10,7 +10,7 @@ public class ViewPagerTranslationWrapper extends ViewTranslationWrapper {
     public ViewPagerTranslationWrapper(View view) {
         super(view);
 
-        this.setDefaultTranslation(new DefaultAlphaTranslation())
+        setDefaultTranslation(new DefaultAlphaTranslation())
                 .setExitTranslation(new AlphaTranslation());
     }
 }

material-intro-screen/src/main/java/agency/tango/materialintroscreen/listeners/SwipeStateTouchListener.java

@@ -17,7 +17,7 @@ public SwipeStateTouchListener(SwipeableViewPager viewPager, SlidesAdapter adapt
     @Override
     public void process() {
         SlideFragment fragment = adapter.getItem(viewPager.getCurrentItem());
-        if (fragment.canMoveFurther() == false || fragment.hasNeededPermissionsToGrant()) {
+        if (!fragment.canMoveFurther() || fragment.hasNeededPermissionsToGrant()) {
             viewPager.setAllowedSwipeDirection(SwipeableViewPager.SwipeDirection.left);
         } else {
             viewPager.setAllowedSwipeDirection(SwipeableViewPager.SwipeDirection.all);

material-intro-screen/src/main/java/agency/tango/materialintroscreen/listeners/scrollListeners/ParallaxScrollListener.java

@@ -18,7 +18,7 @@ public ParallaxScrollListener(SlidesAdapter adapter) {
     @SuppressWarnings("ConstantConditions")
     @Override
     public void pageScrolled(int position, float offset) {
-        if (position != adapter.getCalculatedCount()) {
+        if (position != adapter.slidesCount()) {
             Fragment fragment = adapter.getItem(position);
             Fragment fragmentNext = getNextFragment(position);
 

material-intro-screen/src/main/java/agency/tango/materialintroscreen/parallax/ParallaxFragment.java

@@ -19,12 +19,11 @@ public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
         parallaxLayout = findParallaxLayout(view);
     }
 
-    @SuppressWarnings("PointlessBooleanExpression")
     public Parallaxable findParallaxLayout(View root) {
         Queue<View> queue = new LinkedList<>();
         queue.add(root);
 
-        while (queue.isEmpty() == false) {
+        while (!queue.isEmpty()) {
             View child = queue.remove();
 
             if (child instanceof Parallaxable) {