Zoom buttons

app/static/app/js/components/GCPPopup.jsx

@@ -166,6 +166,10 @@ class GCPPopup extends React.Component {
                 </div> : ""}
             </div>
 
+            <div className="btn-group zoom-buttons">
+                <button onClick={this.zoomOut} disabled={!this.canZoomOut()} type="button" className="btn btn-xs btn-default" title="-">-</button>
+                <button onClick={this.zoomIn} disabled={!this.canZoomIn()} type="button" className="btn btn-xs btn-default" title="+">+</button>
+            </div>
 
             <div>
                 <strong>{_("Horizontal error:")}</strong> {Math.abs(Math.max(feature.properties.error[0], feature.properties.error[1])).toFixed(3)} {_("(meters)")}

app/static/app/js/css/GCPPopup.scss

@@ -21,6 +21,10 @@
         }
     }
 
+    .zoom-buttons{
+        float: right; 
+    }
+
     div.image{
         overflow: hidden;
         a{