From 1d1354e2127af92151857d3dc11010d5839abfd7 Mon Sep 17 00:00:00 2001
From: John McLear <john@mclear.co.uk>
Date: Sat, 26 Mar 2016 10:38:39 +0800
Subject: [PATCH] extend it further so it's exposed to DAM

---
 src/static/js/AttributeManager.js | 71 +++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/src/static/js/AttributeManager.js b/src/static/js/AttributeManager.js
index d4d20a1f7..b559d9e3f 100644
--- a/src/static/js/AttributeManager.js
+++ b/src/static/js/AttributeManager.js
@@ -178,6 +178,77 @@ AttributeManager.prototype = _(AttributeManager.prototype).extend({
     }
     return [];
   },
+  /*
+    Gets a given attribute on a selection
+    @param attributeName
+    @param prevChar
+    returns true or false if an attribute is visible in range
+  */
+  getAttributeOnSelection: function(attributeName, prevChar){
+    var rep = this.rep;
+    if (!(rep.selStart && rep.selEnd)) return
+
+    var withIt = Changeset.makeAttribsString('+', [
+      [attributeName, 'true']
+    ], rep.apool);
+    var withItRegex = new RegExp(withIt.replace(/\*/g, '\\*') + "(\\*|$)");
+    function hasIt(attribs)
+    {
+      return withItRegex.test(attribs);
+    }
+
+    return rangeHasAttrib(rep.selStart, rep.selEnd)
+
+    function rangeHasAttrib(selStart, selEnd) {
+      // if range is collapsed -> no attribs in range
+      if(selStart[1] == selEnd[1] && selStart[0] == selEnd[0]) return false
+
+      if(selStart[0] != selEnd[0]) { // -> More than one line selected
+        var hasAttrib = true
+
+        // from selStart to the end of the first line
+        hasAttrib = hasAttrib && rangeHasAttrib(selStart, [selStart[0], rep.lines.atIndex(selStart[0]).text.length])
+
+        // for all lines in between
+        for(var n=selStart[0]+1; n < selEnd[0]; n++) {
+          hasAttrib = hasAttrib && rangeHasAttrib([n, 0], [n, rep.lines.atIndex(n).text.length])
+        }
+
+        // for the last, potentially partial, line
+        hasAttrib = hasAttrib && rangeHasAttrib([selEnd[0], 0], [selEnd[0], selEnd[1]])
+
+        return hasAttrib
+      }
+
+      // Logic tells us we now have a range on a single line
+
+      var lineNum = selStart[0]
+        , start = selStart[1]
+        , end = selEnd[1]
+        , hasAttrib = true
+
+      // Iterate over attribs on this line
+
+      var opIter = Changeset.opIterator(rep.alines[lineNum])
+        , indexIntoLine = 0
+
+      while (opIter.hasNext()) {
+        var op = opIter.next();
+        var opStartInLine = indexIntoLine;
+        var opEndInLine = opStartInLine + op.chars;
+        if (!hasIt(op.attribs)) {
+          // does op overlap selection?
+          if (!(opEndInLine <= start || opStartInLine >= end)) {
+            hasAttrib = false; // since it's overlapping but hasn't got the attrib -> range hasn't got it
+            break;
+          }
+        }
+        indexIntoLine = opEndInLine;
+      }
+
+      return hasAttrib
+    }
+  },
 
   /*
     Gets all attributes at a position containing line number and column