1 files changed, 80 insertions, 0 deletions
diff --git a/WordPress/src/main/java/org/wordpress/android/widgets/WPScrollView.java b/WordPress/src/main/java/org/wordpress/android/widgets/WPScrollView.java
new file mode 100644
index 000000000..0133b6529
--- /dev/null
+++ b/WordPress/src/main/java/org/wordpress/android/widgets/WPScrollView.java
@@ -0,0 +1,80 @@
+package org.wordpress.android.widgets;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+import android.widget.ScrollView;
+
+/**
+ * ScrollView which reports when user has scrolled up or down, and when scrolling has completed
+ */
+public class WPScrollView extends ScrollView {
+
+    public interface ScrollDirectionListener {
+        void onScrollUp(float distanceY);
+        void onScrollDown(float distanceY);
+        void onScrollCompleted();
+    }
+
+    private ScrollDirectionListener mScrollDirectionListener;
+    private int mInitialScrollCheckY;
+    private static final int SCROLL_CHECK_DELAY = 250;
+
+    public WPScrollView(Context context) {
+        this(context, null);
+    }
+
+    public WPScrollView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public WPScrollView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+    }
+
+    public void setScrollDirectionListener(ScrollDirectionListener listener) {
+        mScrollDirectionListener = listener;
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        if (mScrollDirectionListener != null
+                && event.getActionMasked() == MotionEvent.ACTION_MOVE
+                && event.getHistorySize() > 0) {
+            float initialY = event.getHistoricalY(event.getHistorySize() - 1);
+            float distanceY = initialY - event.getY();
+            if (distanceY < 0) {
+                mScrollDirectionListener.onScrollUp(distanceY);
+                startScrollCheck();
+            } else if (distanceY > 0) {
+                mScrollDirectionListener.onScrollDown(distanceY);
+                startScrollCheck();
+            }
+        }
+        return super.onTouchEvent(event);
+    }
+
+    private void startScrollCheck() {
+        mInitialScrollCheckY = getScrollY();
+        post(mScrollTask);
+    }
+
+    private final Runnable mScrollTask = new Runnable() {
+        @Override
+        public void run() {
+            if (mInitialScrollCheckY == getScrollY()) {
+                mScrollDirectionListener.onScrollCompleted();
+            } else {
+                mInitialScrollCheckY = getScrollY();
+                postDelayed(mScrollTask, SCROLL_CHECK_DELAY);
+            }
+        }
+    };
+
+    public boolean canScrollUp() {
+        return canScrollVertically(-1);
+    }
+    public boolean canScrollDown() {
+        return canScrollVertically(1);
+    }
+}