Merge pull request #517 from MerginMaps/iss_509-measurement-tools

add measurement tools

Author: tomasMizera

src/.vuepress/sidebar/en.js

@@ -96,6 +96,7 @@ module.exports = {
                 '/field/gps_accuracy/',
                 '/field/tracking/',
                 '/field/autosync/',
+                '/field/measure/',
                 '/field/layers/',
                 '/field/mobile-features/',
                 '/field/reuse-last-values/',

src/field/measure/index.md

@@ -0,0 +1,37 @@
+# Measurement Tools
+[[toc]]
+
+## Measure length and area in Mergin Maps mobile app
+In the <MobileAppNameShort />, it is possible to measure length and area on a map window. Measurement tools use the same units as are used by the QGIS project.
+
+To open the measurement tools, tap the **More** button in the bottom navigation panel and use the **Measure** option.
+   ![Mergin Maps mobile app Measurement tools](./mobile-measure.jpg "Mergin Maps mobile app Measurement tools")
+
+Use the **Add Point** button to add points along the line or area you want to measure
+- The *length* between added points is displayed in the **Measure** panel.
+- The current length is displayed near the crosshairs as you move them.
+- Use the **Undo** button to remove the last point.
+- To get the area, add the points along the shape. When you move the crosshairs close to the first point, you will see the **Close shape** option.
+
+When finished with the measurements, tap the **Done** for length measurement or **Close shape** for area measurement. The values of *perimeter* and *area* will be displayed in the **Measure** panel.
+
+![Mergin Maps mobile app measuring length and area](./mobile-measure-length-area.jpg "Mergin Maps mobile app measuring length and area")
+
+Tap **Repeat** to start a new measurement.
+
+Measured values are not saved.
+
+## Changing measurement units in QGIS
+Units that are used when measuring in the <MobileAppNameShort /> are defined (and can be changed) in the project in QGIS:
+
+1. Open your <MainPlatformName /> project in QGIS
+2. Navigate to the **General** tab in the **Project Properties**
+3. In the **Measurements** section, change the *Units for distance measurement* and *Units for area measurement* to the units you want to use when measuring length and area in the <MobileAppNameShort />
+4. Save and synchronise your project
+
+For example, here we switched to length units to feet and area units to acres.
+
+![QGIS length and area units setup](./qgis-project-properties-set-units.jpg "QGIS length and area units setup")
+
+Now, the <MobileAppNameShort /> displays the length/the perimeter in feet and the area in acres.
+![Mergin Maps mobile app measuring length and area in feet and acres](./mobile-measure-length-area-ft-ac.jpg "Mergin Maps mobile app measuring length and area in feet and acres")