implement scale bar plugin (fix #291)

plugins/README.md

@@ -18,6 +18,8 @@ Available Plugins
 - [**Render Limit Increase**](https://raw.github.com/breunigs/ingress-intel-total-conversion/gh-pages/plugins/render-limit-increase.user.js) increases render limits. Good for high density areas (e.g. London, UK) and faster PCs.
 - [**Resonator Display Zoom Level Decrease**](https://raw.github.com/breunigs/ingress-intel-total-conversion/gh-pages/plugins/resonator-display-zoom-level-decrease.user.js) Resonator start displaying earlier.
 - [**Resonator Energy in Portal Detail**](https://raw.github.com/breunigs/ingress-intel-total-conversion/gh-pages/plugins/reso-energy-pct-in-portal-detail.user.js) Resonator energy in percent is displayed in the portal detals.
+- [**Scale Bar**](https://raw.github.com/breunigs/ingress-intel-total-conversion/gh-pages/plugins/scale-bar.user.js) Shows a scale bar in the top left corner. [View screenshot](http://breunigs.github.com/ingress-intel-total-conversion/scre
+enshots/plugin_scale_bar.png)
 - [**Show Portal Address**](https://raw.github.com/breunigs/ingress-intel-total-conversion/gh-pages/plugins/show-address.user.js) Shows portal address in the side panel.
 
 ### available only with the development version

plugins/scale-bar.user.js

@@ -0,0 +1,48 @@
+// ==UserScript==
+// @id             iitc-plugin-scale-bar@breunigs
+// @name           iitc: scale bar
+// @version        0.1
+// @namespace      https://github.com/breunigs/ingress-intel-total-conversion
+// @updateURL      https://raw.github.com/breunigs/ingress-intel-total-conversion/gh-pages/plugins/scale-bar.user.js
+// @downloadURL    https://raw.github.com/breunigs/ingress-intel-total-conversion/gh-pages/plugins/scale-bar.user.js
+// @description    shows scale bar on the map
+// @include        https://www.ingress.com/intel*
+// @match          https://www.ingress.com/intel*
+// ==/UserScript==
+
+function wrapper() {
+// ensure plugin framework is there, even if iitc is not yet loaded
+if(typeof window.plugin !== 'function') window.plugin = function() {};
+
+
+// PLUGIN START ////////////////////////////////////////////////////////
+
+
+// use own namespace for plugin
+window.plugin.scaleBar = function() {};
+
+window.plugin.scaleBar.setup  = function() {
+  $('head').append('<style>.leaflet-control-scale { position: absolute; top: 2px; left: 40px; } </style>');
+  // Before you ask: yes, I explicitely turned off imperial units. Imperial units
+  // are worse than Internet Explorer 6 whirring fans combined. Upgrade to the metric
+  // system already.
+  window.map.addControl(new L.Control.Scale({position: 'topleft', imperial: false}));
+};
+
+var setup =  window.plugin.scaleBar.setup;
+
+// PLUGIN END //////////////////////////////////////////////////////////
+
+if(window.iitcLoaded && typeof setup === 'function') {
+  setup();
+} else {
+  if(window.bootPlugins)
+    window.bootPlugins.push(setup);
+  else
+    window.bootPlugins = [setup];
+}
+} // wrapper end
+// inject code into site context
+var script = document.createElement('script');
+script.appendChild(document.createTextNode('('+ wrapper +')();'));
+(document.body || document.head || document.documentElement).appendChild(script);