feat: style output layers of plugin GUI (#188)

Style was chosen to follow the ors maps client.
Style is only overwritten on GUI usage, not for anything else. See discussion in the PR.

Fixes #149 

Co-authored-by: Jakob Schnell <Jakob.Schnell@heigit.org>

CHANGELOG.md

@@ -46,6 +46,7 @@ RELEASING:
 - Additional parameter for the "smoothing factor" to isochrones processing algorithms ([#172](https://github.com/GIScience/orstools-qgis-plugin/issues/172))
 - Mention omission of configuration options when using traveling salesman
 - option to set location type for isochrones ([#191](https://github.com/GIScience/orstools-qgis-plugin/pull/191))
+- Add styling of routing output in main plugin ([#149](https://github.com/GIScience/orstools-qgis-plugin/issues/149))
 - make items in centroid list drag and droppable ([#144](https://github.com/GIScience/orstools-qgis-plugin/issues/144))
 - Add save button for vertices ([#144](https://github.com/GIScience/orstools-qgis-plugin/issues/144))
 

ORStools/gui/ORStoolsDialog.py

@@ -45,7 +45,7 @@
 )
 from qgis.gui import QgsMapCanvasAnnotationItem
 
-from PyQt5.QtCore import QSizeF, QPointF, QCoreApplication
+from PyQt5.QtCore import QSizeF, QPointF, QCoreApplication, QSettings
 from PyQt5.QtGui import QIcon, QTextDocument
 from PyQt5.QtWidgets import QAction, QDialog, QApplication, QMenu, QMessageBox, QDialogButtonBox
 
@@ -243,6 +243,20 @@ def run_gui_control(self):
         layer_out.dataProvider().addAttributes(directions_core.get_fields())
         layer_out.updateFields()
 
+        basepath = os.path.dirname(__file__)
+
+        # add ors svg path
+        my_new_path = os.path.join(basepath, "img/svg")
+        svg_paths = QSettings().value("svg/searchPathsForSVG")
+        if my_new_path not in svg_paths:
+            svg_paths.append(my_new_path)
+            QSettings().setValue("svg/searchPathsForSVG", svg_paths)
+
+        # style output layer
+        qml_path = os.path.join(basepath, "linestyle.qml")
+        layer_out.loadNamedStyle(qml_path, True)
+        layer_out.triggerRepaint()
+
         # Associate annotations with map layer, so they get deleted when layer is deleted
         for annotation in self.dlg.annotations:
             # Has the potential to be pretty cool: instead of deleting, associate with mapLayer