From 3625e110e4844ed232f2a235d34410ba3c3770a8 Mon Sep 17 00:00:00 2001
From: Santhosh Thottingal <santhosh.thottingal@gmail.com>
Date: Thu, 9 Aug 2012 21:17:32 +0530
Subject: [PATCH] Visual prefix

Make sure that suggestion is not only prefix but also visually prefix.
Checks the ending character is pre-base vowel.
There might be characters with this property in non-indic languages, but
I am not aware of now.

Change-Id: I91abd4dee6c4349e901777ebd6972731808daf45
---
 .../src/jquery.uls.languagefilter.js          | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/lib/jquery.uls/src/jquery.uls.languagefilter.js b/lib/jquery.uls/src/jquery.uls.languagefilter.js
index ee28065e..a7809c9c 100644
--- a/lib/jquery.uls/src/jquery.uls.languagefilter.js
+++ b/lib/jquery.uls/src/jquery.uls.languagefilter.js
@@ -186,6 +186,10 @@
 					suggestion = "";
 				}
 			}
+			// Make sure that it is a visual prefix.
+			if ( !isVisualPrefix( userInput, suggestion ) ) {
+				suggestion = "";
+			}
 			this.$suggestion.val( suggestion );
 		},
 
@@ -355,5 +359,20 @@
 	};
 
 	$.fn.regionselector.Constructor = RegionSelector;
+	/**
+	 * Check if a prefix is visually prefix of a string
+	 * @param String prefix
+	 * @param String string
+	 */
+	function isVisualPrefix( prefix, string ) {
+		// Pre-base vowel signs of Indic languages. A vowel sign is called pre-base if
+		// consonant + vowel becomes [vowel][consonant] when rendered. Eg:  ക + െ => കെ
+		var prebases = "െേൈൊോൌெேைொோௌେୈୋୌિਿिিেৈোৌෙේෛොෝෞ";
+		if ( prebases.indexOf( string[prefix.length] ) > 0 ) {
+			return false;
+		} else {
+			return true;
+		}
+	}
 
 } )( jQuery );