diff --git a/lang/gpxsee_cs.ts b/lang/gpxsee_cs.ts
index 221283cf..c053fce8 100644
--- a/lang/gpxsee_cs.ts
+++ b/lang/gpxsee_cs.ts
@@ -15,13 +15,13 @@
     </message>
     <message>
         <location filename="../src/elevationgraph.cpp" line="15"/>
-        <location filename="../src/elevationgraph.cpp" line="81"/>
+        <location filename="../src/elevationgraph.cpp" line="82"/>
         <source>km</source>
         <translation>km</translation>
     </message>
     <message>
         <location filename="../src/elevationgraph.cpp" line="16"/>
-        <location filename="../src/elevationgraph.cpp" line="82"/>
+        <location filename="../src/elevationgraph.cpp" line="83"/>
         <source>m</source>
         <translation>m</translation>
     </message>
@@ -41,12 +41,12 @@
         <translation>Minimum</translation>
     </message>
     <message>
-        <location filename="../src/elevationgraph.cpp" line="86"/>
+        <location filename="../src/elevationgraph.cpp" line="87"/>
         <source>mi</source>
         <translation>mi</translation>
     </message>
     <message>
-        <location filename="../src/elevationgraph.cpp" line="87"/>
+        <location filename="../src/elevationgraph.cpp" line="88"/>
         <source>ft</source>
         <translation>ft</translation>
     </message>
@@ -59,332 +59,355 @@
 <context>
     <name>GUI</name>
     <message>
-        <location filename="../src/gui.cpp" line="137"/>
+        <location filename="../src/gui.cpp" line="139"/>
         <source>About Qt</source>
         <translation>O Qt</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="339"/>
+        <location filename="../src/gui.cpp" line="349"/>
         <source>GPXSee is distributed under the terms of the GNU General Public License version 3. For more info about GPXSee visit the project homepage at </source>
         <translation>Program GPXSee je distribuován pod podmínkami licence GNU General Public License verze 3. Pro více informací navštivte stránky programu na adrese </translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="400"/>
+        <location filename="../src/gui.cpp" line="410"/>
         <source>Open file</source>
         <translation>Otevřít soubor</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="151"/>
+        <location filename="../src/gui.cpp" line="153"/>
         <source>Save as</source>
         <translation>Uložit jako</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="455"/>
+        <location filename="../src/gui.cpp" line="469"/>
         <source>Open POI file</source>
         <translation>Otevřít POI soubor</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="142"/>
+        <location filename="../src/gui.cpp" line="144"/>
         <source>Open</source>
         <translation>Otevřít</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="125"/>
+        <location filename="../src/gui.cpp" line="127"/>
         <source>Quit</source>
         <translation>Ukončit</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="132"/>
-        <location filename="../src/gui.cpp" line="355"/>
-        <location filename="../src/gui.cpp" line="356"/>
+        <location filename="../src/gui.cpp" line="134"/>
+        <location filename="../src/gui.cpp" line="365"/>
+        <location filename="../src/gui.cpp" line="366"/>
         <source>Keyboard controls</source>
         <translation>Ovládací klávesy</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="146"/>
+        <location filename="../src/gui.cpp" line="148"/>
         <source>Save</source>
         <translation>Uložit</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="156"/>
+        <location filename="../src/gui.cpp" line="158"/>
         <source>Close</source>
         <translation>Zavřít</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="161"/>
+        <location filename="../src/gui.cpp" line="163"/>
         <source>Reload</source>
         <translation>Znovu načíst</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="279"/>
+        <location filename="../src/gui.cpp" line="286"/>
         <source>Show</source>
         <translation>Zobrazit</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="229"/>
-        <location filename="../src/gui.cpp" line="270"/>
+        <location filename="../src/gui.cpp" line="236"/>
+        <location filename="../src/gui.cpp" line="277"/>
         <source>File</source>
         <translation>Soubor</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="130"/>
-        <location filename="../src/gui.cpp" line="373"/>
-        <location filename="../src/gui.cpp" line="374"/>
+        <location filename="../src/gui.cpp" line="132"/>
+        <location filename="../src/gui.cpp" line="383"/>
+        <location filename="../src/gui.cpp" line="384"/>
         <source>Data sources</source>
         <translation>Zdroje dat</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="168"/>
+        <location filename="../src/gui.cpp" line="170"/>
         <source>Load POI file</source>
         <translation>Nahrát POI soubor</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="171"/>
+        <location filename="../src/gui.cpp" line="173"/>
         <source>Show POIs</source>
         <translation>Zobrazit POI</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="176"/>
+        <location filename="../src/gui.cpp" line="179"/>
         <source>Show map</source>
         <translation>Zobrazit mapu</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="186"/>
+        <location filename="../src/gui.cpp" line="192"/>
         <source>Show graphs</source>
         <translation>Zobrazovat grafy</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="191"/>
+        <location filename="../src/gui.cpp" line="198"/>
         <source>Show toolbars</source>
         <translation>Zobrazovat nástrojové lišty</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="198"/>
+        <location filename="../src/gui.cpp" line="205"/>
         <source>Metric</source>
         <translation>Metrické</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="204"/>
+        <location filename="../src/gui.cpp" line="211"/>
         <source>Imperial</source>
         <translation>Imperiální</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="211"/>
+        <location filename="../src/gui.cpp" line="218"/>
         <source>Next</source>
         <translation>Následující</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="214"/>
+        <location filename="../src/gui.cpp" line="221"/>
         <source>Previous</source>
         <translation>Předchozí</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="218"/>
+        <location filename="../src/gui.cpp" line="225"/>
         <source>Last</source>
         <translation>Poslední</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="221"/>
+        <location filename="../src/gui.cpp" line="228"/>
         <source>First</source>
         <translation>První</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="243"/>
+        <location filename="../src/gui.cpp" line="250"/>
         <source>Map</source>
         <translation>Mapa</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="248"/>
+        <location filename="../src/gui.cpp" line="255"/>
         <source>POI</source>
         <translation>POI</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="252"/>
+        <location filename="../src/gui.cpp" line="259"/>
         <source>Settings</source>
         <translation>Nastavení</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="253"/>
+        <location filename="../src/gui.cpp" line="260"/>
         <source>Units</source>
         <translation>Jednotky</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="260"/>
+        <location filename="../src/gui.cpp" line="267"/>
         <source>Help</source>
         <translation>Nápověda</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="307"/>
+        <location filename="../src/gui.cpp" line="317"/>
         <source>Elevation</source>
         <translation>Výška</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="308"/>
+        <location filename="../src/gui.cpp" line="318"/>
         <source>Speed</source>
         <translation>Rychlost</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="358"/>
+        <location filename="../src/gui.cpp" line="368"/>
         <source>Next file</source>
         <translation>Následující soubor</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="359"/>
+        <location filename="../src/gui.cpp" line="369"/>
         <source>Previous file</source>
         <translation>Předchozí soubor</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="361"/>
+        <location filename="../src/gui.cpp" line="371"/>
         <source>First file</source>
         <translation>První soubor</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="362"/>
+        <location filename="../src/gui.cpp" line="372"/>
         <source>Last file</source>
         <translation>Poslední soubor</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="363"/>
+        <location filename="../src/gui.cpp" line="373"/>
         <source>Append modifier</source>
         <translation>Modifikátor nahradit/přidat</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="377"/>
+        <location filename="../src/gui.cpp" line="387"/>
         <source>Map (tiles) source URLs are read on program startup from the following file:</source>
         <translation>URL mapových zdrojů (dlaždic) jsou načteny při startu programu z následujícího souboru:</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="381"/>
+        <location filename="../src/gui.cpp" line="391"/>
         <source>The file format is one map entry per line, consisting of the map name and tiles URL delimited by a TAB character. The tile X and Y coordinates are replaced with $x and $y in the URL and the zoom level is replaced with $z. An example map file could look like:</source>
         <translation>Formát souboru je jeden mapový záznam na řádku, kde mapový záznam sestává ze jména mapy a URL dlaždic navzájem oddělených tabulátorem. Souřadnice dlaždice jsou v URL nahrazeny řetězci $x a $y, úroven přiblížení (zoom) pak řetězcem $z. Příklad:</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="389"/>
+        <location filename="../src/gui.cpp" line="399"/>
         <source>To make GPXSee load a POI file automatically on startup, add the file to the following directory:</source>
         <translation>POI soubory, které se mají automaticky nahrát při startu programu jsou načítány z následujícího adresáře:</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="446"/>
-        <location filename="../src/gui.cpp" line="462"/>
+        <location filename="../src/gui.cpp" line="460"/>
+        <location filename="../src/gui.cpp" line="476"/>
         <source>Line: %1</source>
         <translation>Řádka: %1</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="509"/>
-        <location filename="../src/gui.cpp" line="629"/>
+        <location filename="../src/gui.cpp" line="523"/>
+        <location filename="../src/gui.cpp" line="642"/>
         <source>mi</source>
         <translation>mi</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="512"/>
-        <location filename="../src/gui.cpp" line="514"/>
-        <location filename="../src/gui.cpp" line="516"/>
-        <location filename="../src/gui.cpp" line="518"/>
+        <location filename="../src/gui.cpp" line="526"/>
+        <location filename="../src/gui.cpp" line="528"/>
+        <location filename="../src/gui.cpp" line="530"/>
+        <location filename="../src/gui.cpp" line="532"/>
         <source>ft</source>
         <translation>ft</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="515"/>
-        <location filename="../src/gui.cpp" line="527"/>
+        <location filename="../src/gui.cpp" line="529"/>
+        <location filename="../src/gui.cpp" line="541"/>
         <source>Maximum</source>
         <translation>Maximum</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="517"/>
-        <location filename="../src/gui.cpp" line="529"/>
+        <location filename="../src/gui.cpp" line="531"/>
+        <location filename="../src/gui.cpp" line="543"/>
         <source>Minimum</source>
         <translation>Minimum</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="135"/>
-        <location filename="../src/gui.cpp" line="335"/>
+        <location filename="../src/gui.cpp" line="137"/>
+        <location filename="../src/gui.cpp" line="345"/>
         <source>About GPXSee</source>
         <translation>O aplikaci GPXSee</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="286"/>
+        <location filename="../src/gui.cpp" line="293"/>
         <source>Navigation</source>
         <translation>Navigace</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="337"/>
+        <location filename="../src/gui.cpp" line="347"/>
         <source>GPX viewer and analyzer</source>
         <translation>Prohlížeč a analyzátor GPX</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="376"/>
+        <location filename="../src/gui.cpp" line="386"/>
         <source>Map sources</source>
         <translation>Mapové zdroje</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="388"/>
+        <location filename="../src/gui.cpp" line="398"/>
         <source>POIs</source>
         <translation>POI body</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="508"/>
-        <location filename="../src/gui.cpp" line="520"/>
+        <location filename="../src/gui.cpp" line="522"/>
+        <location filename="../src/gui.cpp" line="534"/>
         <source>Distance</source>
         <translation>Vzdálenost</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="510"/>
-        <location filename="../src/gui.cpp" line="522"/>
+        <location filename="../src/gui.cpp" line="524"/>
+        <location filename="../src/gui.cpp" line="536"/>
         <source>Time</source>
         <translation>Čas</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="511"/>
-        <location filename="../src/gui.cpp" line="523"/>
+        <location filename="../src/gui.cpp" line="525"/>
+        <location filename="../src/gui.cpp" line="537"/>
         <source>Ascent</source>
         <translation>Stoupání</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="524"/>
-        <location filename="../src/gui.cpp" line="526"/>
-        <location filename="../src/gui.cpp" line="528"/>
-        <location filename="../src/gui.cpp" line="530"/>
+        <location filename="../src/gui.cpp" line="538"/>
+        <location filename="../src/gui.cpp" line="540"/>
+        <location filename="../src/gui.cpp" line="542"/>
+        <location filename="../src/gui.cpp" line="544"/>
         <source>m</source>
         <translation>m</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="513"/>
-        <location filename="../src/gui.cpp" line="525"/>
+        <location filename="../src/gui.cpp" line="527"/>
+        <location filename="../src/gui.cpp" line="539"/>
         <source>Descent</source>
         <translation>Klesání</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="625"/>
+        <location filename="../src/gui.cpp" line="638"/>
         <source>%1 tracks</source>
         <translation>Počet tras: %1</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="521"/>
-        <location filename="../src/gui.cpp" line="632"/>
+        <location filename="../src/gui.cpp" line="535"/>
+        <location filename="../src/gui.cpp" line="645"/>
         <source>km</source>
         <translation>km</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="448"/>
-        <location filename="../src/gui.cpp" line="463"/>
+        <location filename="../src/gui.cpp" line="462"/>
+        <location filename="../src/gui.cpp" line="477"/>
         <source>Error</source>
         <translation>Chyba</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="443"/>
+        <location filename="../src/gui.cpp" line="457"/>
         <source>Error loading GPX file:
 %1</source>
         <translation>Soubor GPX nelze otevřít:
 %1</translation>
     </message>
     <message>
-        <location filename="../src/gui.cpp" line="459"/>
+        <location filename="../src/gui.cpp" line="473"/>
         <source>Error loading POI file:
 %1</source>
         <translation>Soubor POI nelze otevřít:
 %1</translation>
     </message>
 </context>
+<context>
+    <name>QObject</name>
+    <message>
+        <location filename="../src/scaleitem.cpp" line="75"/>
+        <source>mi</source>
+        <translation>mi</translation>
+    </message>
+    <message>
+        <location filename="../src/scaleitem.cpp" line="75"/>
+        <source>ft</source>
+        <translation>ft</translation>
+    </message>
+    <message>
+        <location filename="../src/scaleitem.cpp" line="77"/>
+        <source>km</source>
+        <translation>km</translation>
+    </message>
+    <message>
+        <location filename="../src/scaleitem.cpp" line="77"/>
+        <source>m</source>
+        <translation>m</translation>
+    </message>
+</context>
 <context>
     <name>SpeedGraph</name>
     <message>
@@ -399,13 +422,13 @@
     </message>
     <message>
         <location filename="../src/speedgraph.cpp" line="11"/>
-        <location filename="../src/speedgraph.cpp" line="70"/>
+        <location filename="../src/speedgraph.cpp" line="71"/>
         <source>km</source>
         <translation></translation>
     </message>
     <message>
         <location filename="../src/speedgraph.cpp" line="12"/>
-        <location filename="../src/speedgraph.cpp" line="71"/>
+        <location filename="../src/speedgraph.cpp" line="72"/>
         <source>km/h</source>
         <translation>km/h</translation>
     </message>
@@ -420,12 +443,12 @@
         <translation>Maximum</translation>
     </message>
     <message>
-        <location filename="../src/speedgraph.cpp" line="75"/>
+        <location filename="../src/speedgraph.cpp" line="76"/>
         <source>mi</source>
         <translation>mi</translation>
     </message>
     <message>
-        <location filename="../src/speedgraph.cpp" line="76"/>
+        <location filename="../src/speedgraph.cpp" line="77"/>
         <source>mi/h</source>
         <translation>mi/h</translation>
     </message>