function to move to previous entry

sahli.coffee

@@ -146,6 +146,27 @@ class @Sahli
     $('body').stop()
     @loadinfopanel i
 
+  @prevpic = =>
+    viewbox = $('div#sahliviewer')
+    viewbox.children().remove()
+    $('#panel').empty()
+    @scroll_direction = 1
+    @scroll_speed = 5
+    filedata = @filedata
+    i = @currentpic-2
+    if i < 0
+      i = i + filedata.length
+    filedata[i].pic = $('<h6>' + filedata[i].file + '</h6>')
+    viewbox.append filedata[i].pic
+    @loadpic filedata[i], filedata[i].pic
+    @currentpic = i + 1
+    if @currentpic > filedata.length - 1
+      @currentpic = 0
+    $('#panel').hide()
+    $('#outbox').show()
+    $('body').stop()
+    @loadinfopanel i
+
   @togglefullscreen = ->
     docElm = document.documentElement
     if @fullscreen
@@ -315,6 +336,8 @@ class @Sahli
       switch ev.which
         when @keycode ' '
           @nextpic()
+        when @keycode 'p'
+          @prevpic()
         when @keycode 'f'
           @togglefullscreen()
         when @keycode 's'