Apps horozontal scroll view not accurate

I have an xml layout with my custom view (bottom horizontal scroll view).


In the middle of the view there is a small tirangle showing which is the currently selected box.

The user can move these boxes (buttons) with his finger to the right and to the left.

However the white small arrow doesn't reach to the middle of the box


I have tried to add/remove margine to its left.

But it didn't help.

Where should I look around?



part of the xml:

Code (Text):

1.      <com.w.n.SearchButtonsBarHorizontalScrollView
2.             android:id="@+id/searchButtonBar"
3.             android:layout_width="wrap_content"
4.             android:layout_height="wrap_content"
5.             android:layout_alignParentBottom="true"
6.             android:background="@drawable/engines_bg"
7.             android:fadingEdge="horizontal"
8.             android:gravity="center"
9.             android:padding="0dp"
10.             android:scrollbars="none" >
11.    
12.             <LinearLayout
13.                 android:layout_width="wrap_content"
14.                 android:layout_height="wrap_content"
15.                 android:gravity="center_horizontal"
16.                 android:orientation="horizontal"
17.                 android:paddingTop="25dp" >
18.    
19.                 <ImageButton
20.                     android:id="@+id/leftMargin"
21.                     android:layout_width="110dp"
22.                     android:layout_height="wrap_content"
23.                     android:layout_weight="1"
24.                     android:background="@drawable/search_engine_button"
25.                     android:visibility="invisible" />
26.    
27.                 <ImageButton
28.                     android:id="@+id/searchButton1"
29.                     android:layout_width="wrap_content"
30.                     android:layout_height="wrap_content"
31.                     android:layout_weight="1"
32.                     android:background="@drawable/search_engine_button"
33.                     android:onClick="engineClicked" />
34.    
35.                 <ImageButton
36.                     android:id="@+id/searchButton2"
37.                     android:layout_width="wrap_content"
38.                     android:layout_height="wrap_content"
39.                     android:layout_weight="1"
40.                     android:background="@drawable/search_engine_button"
41.                     android:onClick="engineClicked" />
42.    
43.                 <ImageButton
44.                     android:id="@+id/searchButton3"
45.                     android:layout_width="wrap_content"
46.                     android:layout_height="wrap_content"
47.                     android:layout_weight="1"
48.                     android:background="@drawable/search_engine_button"
49.                     android:onClick="engineClicked" />
50.        </com.w.n.SearchButtonsBarHorizontalScrollView>

Maybe the fix should be in the code of my SearchButtonsBarHorizontalScrollView

Code (Text):

1.     public boolean onTouchEvent(MotionEvent event) {
2.         super.onTouchEvent(event);
3.         Log.d("w","ontouchevent");     
4.         if (event.getAction()==MotionEvent.ACTION_UP) {
5.             Log.d("WAZE","action up");
6.             Integer min_dist=null;
7.             SearchEngine min_se=null;
8.             @SuppressWarnings("unchecked")
9.             Map<Object, SearchEngine> engines=(Map<Object, SearchEngine>)getTag(R.id.searchEngines);
10.             Iterator<SearchEngine> i=engines.values().iterator();
11.             while (i.hasNext()) {
12.                 SearchEngine tmp_se=(SearchEngine)i.next();
13.                 int tmp_dist=Math.abs(tmp_se.getButton().getButtonXPosition()-getScrollX()-getWidth()/2);
14.                 if (min_dist==null || tmp_dist<min_dist) {
15.                     min_dist=tmp_dist;
16.                     min_se=tmp_se;
17.                 }
18.             }
19.             ((SearchActivity)getTag(R.id.searchActivity)).setActiveEngine(min_se);
20.         }
21.         return true;
22.        
23.     }