From b1d8e49d7263fb6c9025eb3260c2992c4497a9e6 Mon Sep 17 00:00:00 2001
From: Andrew Chen <achen.code@gmail.com>
Date: Wed, 19 Jan 2011 17:05:56 +0000
Subject: [PATCH] Be a little more graceful when scrolling horizontally in a
 (vertical) scroll view. Not quite to the point of diagonal scrolling, but
 hopefully closer.

---
 src/com/fsck/k9/view/ToggleScrollView.java | 42 +++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/com/fsck/k9/view/ToggleScrollView.java b/src/com/fsck/k9/view/ToggleScrollView.java
index 386a6cea6..ba348e9c5 100644
--- a/src/com/fsck/k9/view/ToggleScrollView.java
+++ b/src/com/fsck/k9/view/ToggleScrollView.java
@@ -2,16 +2,19 @@ package com.fsck.k9.view;
 
 import android.content.Context;
 import android.util.AttributeSet;
+import android.view.GestureDetector;
 import android.view.MotionEvent;
 import android.widget.ScrollView;
 
 public class ToggleScrollView extends ScrollView
 {
+    private GestureDetector mDetector;
     private boolean mScrolling = true;
 
     public ToggleScrollView(Context context, AttributeSet attrs)
     {
         super(context, attrs);
+        mDetector = new GestureDetector(new YScrollDetector());
     }
 
     public void setScrolling(boolean enable)
@@ -28,6 +31,43 @@ public class ToggleScrollView extends ScrollView
     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev)
     {
-        return (mScrolling) ? super.onInterceptTouchEvent(ev) : false;
+        if(!mScrolling) {
+            return false;
+        }
+
+        // This doesn't quite get us to diagonal scrolling, but it's somewhat better than what we've
+        // currently got.  This is based on
+        // http://stackoverflow.com/questions/2646028/android-horizontalscrollview-within-scrollview-touch-handling
+        boolean result = super.onInterceptTouchEvent(ev);
+        if (mDetector.onTouchEvent(ev))
+        {
+            return result;
+        }
+
+        return false;
+    }
+
+    // Return false if we're scrolling in the x direction
+    class YScrollDetector extends GestureDetector.SimpleOnGestureListener
+    {
+        @Override
+        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)
+        {
+            try
+            {
+                if (Math.abs(distanceY) > Math.abs(distanceX))
+                {
+                    return true;
+                }
+                else
+                {
+                    return false;
+                }
+            } catch (Exception e)
+            {
+                // nothing
+            }
+            return false;
+        }
     }
 }