animation

android/app/src/main/java/com/reactnativenavigation/animation/HideOnScrollAnimator.java

+package com.reactnativenavigation.animation;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ObjectAnimator;
+import android.support.annotation.NonNull;
+import android.support.v4.view.animation.LinearOutSlowInInterpolator;
+import android.view.View;
+
+import com.reactnativenavigation.views.ScrollDirectionListener;
+
+public class HideOnScrollAnimator {
+
+    public enum HideDirection {
+        Up, Down
+    }
+
+    private enum State {
+        Hidden, AnimateHide, Shown, AnimateShow
+    }
+
+    private static final int DURATION = 300;
+    private final View view;
+    private final HideDirection hideDirection;
+    private final int hiddenEndValue;
+    private final int shownEndValue = 0;
+    private State state = State.Shown;
+
+    public HideOnScrollAnimator(View view, HideDirection hideDirection, int height) {
+        this.view = view;
+        this.hideDirection = hideDirection;
+        this.hiddenEndValue = hideDirection == HideDirection.Up ? -height : height;
+    }
+
+    public void onScrollChanged(ScrollDirectionListener.Direction scrollDirection) {
+        if (hideDirection == HideDirection.Down) {
+            handleDownHidingViews(scrollDirection); //TODO better name
+        } else {
+            handleUpHidingViews(scrollDirection);
+        }
+    }
+
+    public void show() {
+        ObjectAnimator animator = createAnimator(true);
+        animator.start();
+    }
+
+    public void hide() {
+        ObjectAnimator animator = createAnimator(false);
+        animator.start();
+    }
+
+    private void handleUpHidingViews(ScrollDirectionListener.Direction scrollDirection) {
+        if (scrollUp(scrollDirection) && !hiding()) {
+            hide();
+        } else if (scrollDown(scrollDirection) && !showing()) {
+            show();
+        }
+    }
+
+    private void handleDownHidingViews(ScrollDirectionListener.Direction scrollDirection) {
+        if (scrollDown(scrollDirection) && !hiding()) {
+            hide();
+        } else if (scrollUp(scrollDirection) && !showing()) {
+            show();
+        }
+    }
+
+    private boolean scrollUp(ScrollDirectionListener.Direction scrollDirection) {
+        return scrollDirection == ScrollDirectionListener.Direction.Up;
+    }
+
+    private boolean scrollDown(ScrollDirectionListener.Direction scrollDirection) {
+        return scrollDirection == ScrollDirectionListener.Direction.Down;
+    }
+
+    private boolean showing() {
+        return state == State.Shown || state == State.AnimateShow;
+    }
+
+    private boolean hiding() {
+        return state == State.Hidden || state == State.AnimateHide;
+    }
+
+    @NonNull
+    private ObjectAnimator createAnimator(final boolean show) {
+        ObjectAnimator animator = ObjectAnimator.ofFloat(view, View.TRANSLATION_Y, show ? shownEndValue : hiddenEndValue);
+        animator.setDuration(DURATION);
+        animator.setInterpolator(new LinearOutSlowInInterpolator());
+        animator.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animation) {
+                state = show ? State.AnimateShow : State.AnimateHide;
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                state = show ? State.Shown : State.Hidden;
+            }
+        });
+        return animator;
+    }
+
+}

android/app/src/main/java/com/reactnativenavigation/core/Button.java

 package com.reactnativenavigation.core;
 
-import android.app.Activity;
 import android.graphics.drawable.Drawable;
 import android.support.annotation.ColorInt;
 import android.support.annotation.NonNull;
             WithText(MenuItem.SHOW_AS_ACTION_WITH_TEXT);
 
             int action;
+
             ShowAsAction(int action) {
                 this.action = action;
             }
         @ColorInt
         int color;
         ShowAsAction showAsAction;
+        boolean enabled = true;
     }
 
-    private final Activity activity;
     private final Menu menu;
     private final ActionMenuView parent;
     private Params buttonParams;
 
-    public Button(Activity activity, Menu menu, ActionMenuView parent, Params buttonParams) {
-        this.activity = activity;
+    public Button(Menu menu, ActionMenuView parent, Params buttonParams) {
         this.menu = menu;
         this.parent = parent;
         this.buttonParams = buttonParams;
     public MenuItem addToMenu(int index) {
         MenuItem item = menu.add(Menu.NONE, Menu.NONE, index, buttonParams.label);
         item.setShowAsAction(buttonParams.showAsAction.action);
+        item.setEnabled(buttonParams.enabled);
         setIcon(item);
         setColor();
         return item;
     }
 
+
     private void setIcon(MenuItem item) {
         if (hasIcon()) {
             item.setIcon(buttonParams.icon);
             @Override
             public void run() {
                 ArrayList<View> outViews = findActualTextViewInMenuByLabel();
-                setTextColorInternal(outViews);
+                setTextColorForFoundButtonViews(outViews);
             }
         });
     }
         return outViews;
     }
 
-    private void setTextColorInternal(ArrayList<View> outViews) {
+    private void setTextColorForFoundButtonViews(ArrayList<View> outViews) {
         for (View button : outViews) {
             ((TextView) button).setTextColor(buttonParams.color);
         }

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

 
     private Menu menu;
     private ActionMenuView actionMenuView;
+    private boolean hideOnScroll = false;
 
     public TitleBar(Context context) {
         super(context);
     public void setButtons(List<Button.Params> buttons) {
         menu.clear();
 
-        Activity context = (Activity) getContext();
         for (int i = 0; i < buttons.size(); i++) {
-            final Button button = new Button(context, buttons.get(i));
-            // Add button in reverse order because in iOS, index 0 starts at right
+            final Button button = new Button(menu, actionMenuView, buttons.get(i));
+            // Add button in reverse order because in iOS index 0 starts at right
             final int index = buttons.size() - i - 1;
-            button.addToMenu(context, menu, index);
+            button.addToMenu(index);
+        }
+    }
+
+    public void setHideOnScroll(boolean hideOnScroll) {
+        this.hideOnScroll = hideOnScroll;
+    }
+
+    public void onScrollChanged(ScrollDirectionListener.Direction direction) {
+        if (hideOnScroll) {
+            //TODO animate hide/show
         }
     }
 }