Implementing Simple Buffer Searching

Searching the Global Database although is enough but I have felt a need to have a
quick and fast search option to search the current buffer.

Buffer Search is also one of the views It can be only turned on if the File Browser
has focus. ( Thinking of making it global ). The Searching is done
through the fuzzy module. FileNode now implements the Source Interface.
The Changed Function of the Search Bar checks for text changes and then
modifies the Matches Variable which is used by the Update Function to
Draw the Results. The Results have the Matching Characters Highlighted
Differently. Maximum of 15 results are displayed to avoid lag. Upon
Selecting the Result through the Search Bar navigation is possible and
selection of the item is done the same way it works for file Browser.
After Selection the Focus is returned Back to the File Browser. For The
Tracks only the title is used for searching.

utils/utils.go

@@ -1,6 +1,7 @@
 package utils
 
 import (
+	"fmt"
 	"io/ioutil"
 	"strconv"
 	"strings"
@@ -136,3 +137,37 @@ func CheckDirectoryFmt(path string) string {
 		return path + "/"
 	}
 }
+
+func GetMatchedString(s string, color string, nulcol string, matchedIndexes []int) string {
+	// The indexes that we will receive from the matchedIndexes are always sorted so we have to just
+	// add the color string at
+	//           `indexValue + ( len(colorString) * k )`
+	//           where k is the index of the indexValue in the matchedIndexes slice
+	// and we will need to also reset the colors, For that we check if the next indexValue in the matchedIndexes for
+	// the current indexValue is not the consecutive value ( v + 1 ) if yes ( is not consecutive ) then we add the reset
+	// color string at the k + 1 index in the string.
+	// for e.g.
+	//    if we have the following matchedIndexes slice
+	//                        []int{ 1, 3, 4, 6}
+	// During the First Iteration matchedIndexes[k] = 1 and and matchedIndexes[k+1] are not consecutive so the nulcol
+	// string will be added to the matchedIndexes[k] + 1 index of the string
+	// During the Second Iteration as 3, 4 are consecutive the nulcol will be skipped.
+	color = fmt.Sprintf("[%s:-:bi]", color)
+	nulcol = fmt.Sprintf("[%s:-:b]", nulcol)
+	nulc := 0
+	for k := range matchedIndexes {
+		s = InsertAt(s, color, matchedIndexes[k]+(len(color)*k)+nulc)
+		if k < len(matchedIndexes)-1 && matchedIndexes[k]-matchedIndexes[k+1] != 1 {
+			s = InsertAt(s, nulcol, (matchedIndexes[k]+1)+(len(color)*(k+1))+nulc)
+			nulc += len(nulcol)
+		}
+		if k == len(matchedIndexes)-1 {
+			s = InsertAt(s, nulcol, ((matchedIndexes[len(matchedIndexes)-1] + 1) +
+				(len(matchedIndexes) * len(color)) +
+				(len(nulcol) * (len(matchedIndexes) - 1))))
+		}
+	}
+	// Adding the Nulcol at the Start
+	s = nulcol + s
+	return s
+}