Issue #28: Improve Auto complete vertical offset calculation to work correctly on android 6 and below too

Author: AmrDeveloper

codeview/src/main/java/com/amrdeveloper/codeview/CodeView.java

@@ -682,7 +682,8 @@ public void showDropDown() {
         }
 
         final Rect displayFrame = new Rect();
-        getWindowVisibleDisplayFrame(displayFrame);
+        getGlobalVisibleRect(displayFrame);
+
         int displayFrameHeight = displayFrame.height();
 
         int verticalOffset = lineButton + dropDownHeight;
@@ -691,7 +692,7 @@ public void showDropDown() {
         }
 
         setDropDownHeight(dropDownHeight);
-        setDropDownVerticalOffset(verticalOffset);
+        setDropDownVerticalOffset(verticalOffset - displayFrameHeight - dropDownHeight);
         setDropDownHorizontalOffset((int) layout.getPrimaryHorizontal(position));
 
         super.showDropDown();