--- a/templates/results.html	Wed May 27 18:57:30 2015 +0800
+++ b/templates/results.html	Thu May 28 15:11:01 2015 +0800
@@ -34,14 +34,18 @@
     <header>
       <a href="/results.html">back to tip</a>
       {% set prevrev = changesets[0]['rev'] + 120 if changesets else None %}
-      {% if prevrev %}<a href="?rev=rev({{ prevrev }})">prev page</a>{% end %}
+      {% if prevrev %}<a href="{{ setrev(prevrev) }}">prev page</a>{% end %}
       {% set nextrev = changesets[-1]['rev'] - 1 if changesets else None %}
-      {% if nextrev > -1 %}<a href="?rev=rev({{ nextrev }})">next page</a>{% end %}
+      {% if nextrev > -1 %}<a href="{{ setrev(nextrev) }}">next page</a>{% end %}
       <span style="color: #777;">
-        hover things for a tooltip; red means slowest ever, green means fastest
-        ever; first color and time means without .hg/cache, second means with
-        .hg/cache.
+        hover things for a tooltip; red means slow, green means fast; first
+        color and time means without .hg/cache, second means with .hg/cache.
       </span>
+      {% if local %}
+        local colors (<a href="{{ setlocal(None) }}">switch to global colors</a>)
+      {% else %}
+        global colors (<a href="{{ setlocal(1) }}">switch to local colors</a>)
+      {% end %}
     </header>
     <table>
       <thead>
@@ -85,8 +89,8 @@
     </table>
     <footer>
       <a href="/results.html">back to tip</a>
-      {% if prevrev %}<a href="?rev=rev({{ prevrev }})">prev page</a>{% end %}
-      {% if nextrev > -1 %}<a href="?rev=rev({{ nextrev }})">next page</a>{% end %}
+      {% if prevrev %}<a href="{{ setrev(prevrev) }}">prev page</a>{% end %}
+      {% if nextrev > -1 %}<a href="{{ setrev(nextrev) }}">next page</a>{% end %}
     </footer>
   </body>
 </html>

--- a/viewer.py	Wed May 27 18:57:30 2015 +0800
+++ b/viewer.py	Thu May 28 15:11:01 2015 +0800
@@ -5,6 +5,7 @@
 import re
 import sqlite3
 import subprocess
+from urllib import quote_plus
 
 from tornado.ioloop import IOLoop
 from tornado.options import define, options
@@ -133,10 +134,40 @@
             self.write(line)
         self.finish()
 
+    def urlencode(self, **kwargs):
+        def joinparams(params):
+            return ','.join(quote_plus(i, '()') for i in params)
+        return '&'.join(quote_plus(k) + '=' + joinparams(v) for k, v in kwargs.items())
+
+    def setlocal(self, value=None):
+        kwargs = self.request.arguments.copy()
+        if value is None:
+            try:
+                kwargs.pop('local')
+            except KeyError:
+                pass
+        else:
+            kwargs['local'] = [str(value)]
+        return '?' + self.urlencode(**kwargs)
+
+    def setrev(self, value):
+        kwargs = self.request.arguments.copy()
+        kwargs['rev'] = ['rev({})'.format(value)]
+        return '?' + self.urlencode(**kwargs)
+
     def results_html(self):
         changesets = self.getchangesets()
-        results = self.getresults(changesets, self.get_argument('local', False))
-        self.render('results.html', changesets=changesets, marks=MARKS, results=results)
+        local = self.get_argument('local', False)
+        results = self.getresults(changesets, local)
+        context = {
+            'changesets': changesets,
+            'marks': MARKS,
+            'results': results,
+            'local': local,
+            'setlocal': self.setlocal,
+            'setrev': self.setrev
+        }
+        self.render('results.html', **context)
 
 
 def green_to_red((low, high), value):