add tab functionality to pastebin (resolves #48)

The tab key now inserts a tab instead of changing the focus.

static/js/bin.js

@@ -5,7 +5,6 @@ var navlist = document.getElementById("info").getElementsByClassName("right")[0]
 init();
 
 function init() {
-
     var editA = document.createElement('a');
 
     editA.setAttribute("href", "#");
@@ -23,8 +22,8 @@ function init() {
     document.getElementById('wordwrap').addEventListener('click', wrap);
 }
 
-
 function edit(ev) {
+    ev.preventDefault();
 
     navlist.remove();
     document.getElementById("filename").remove();
@@ -35,9 +34,9 @@ function edit(ev) {
 
     var editordiv = document.getElementById("editor");
     editordiv.style.display = "block";
+    editordiv.addEventListener('keydown', handleTab);
 }
 
-
 function paste(ev) {
     var editordiv = document.getElementById("editor");
     document.getElementById("newcontent").value = editordiv.value;

static/js/paste.js

@@ -0,0 +1,3 @@
+// @license magnet:?xt=urn:btih:1f739d935676111cfff4b4693e3816e664797050&dn=gpl-3.0.txt GPL-v3-or-Later
+document.getElementById('content').addEventListener('keydown', handleTab);
+// @license-end

static/js/util.js

@@ -0,0 +1,18 @@
+// @license magnet:?xt=urn:btih:1f739d935676111cfff4b4693e3816e664797050&dn=gpl-3.0.txt GPL-v3-or-Later
+
+function handleTab(ev) {
+    // change tab key behavior to insert tab instead of change focus
+    if(ev.keyCode == 9) {
+        ev.preventDefault();
+
+        var val = this.value;
+        var start = this.selectionStart;
+        var end = this.selectionEnd;
+
+        this.value = val.substring(0, start) + '\t' + val.substring(end);
+        this.selectionStart = start + 1;
+        this.selectionEnd = end + 1;
+    }
+}
+
+// @license-end

templates/display/bin.html

@@ -52,5 +52,6 @@
 <script src="/static/js/bin_hljs.js"></script>
 {% endif %}
 
+<script src="/static/js/util.js"></script>
 <script src="/static/js/bin.js"></script>
 {% endblock %}

templates/paste.html

@@ -33,4 +33,7 @@
             </div>
         </div>
     </form>        
+
+<script src="/static/js/util.js"></script>
+<script src="/static/js/paste.js"></script>
 {% endblock %}