Warn user and avoid crash when trying to add qlr which does not exist

Fixes #18

src/QlrBrowser/core/qlrmanager.py

@@ -125,8 +125,10 @@ def browser_itemclicked(self, fileinfo, newState):
                     QCoreApplication.processEvents()
                     # Load qlr
                     QgsLayerDefinition.loadLayerDefinition(path, self.layer_insertion_point())
-                    # This is backwards, but qlr is always loaded at the bottom of the TOC
-                    self._move_qlr_to_top(path)
+                    # Lets see if we catched the loaded layer. If not - it could be because the qlrfile was moved
+                    if path in self.fileSystemItemToLegendNode:
+                        # This is backwards, but qlr is always loaded at the bottom of the TOC
+                        self._move_qlr_to_top(path)
                     # Remove message
                     self.iface.messageBar().popWidget(msgItem)
                 finally:
@@ -139,6 +141,8 @@ def layer_insertion_point(self):
 
     def _move_qlr_to_top(self, qlrpath):
         """Moves the layers added to the TOC from the given QLR file. For now always to the top of the TOC"""
+        if not qlrpath in self.fileSystemItemToLegendNode:
+            return
         # Only supports moving layer to the top of the TOC.
         for nodeinfo in self.fileSystemItemToLegendNode[qlrpath]:
             node = self._getlayerTreeNode(nodeinfo)

src/QlrBrowser/i18n/da.ts

@@ -29,10 +29,20 @@
 <context>
     <name>DockWidget</name>
     <message>
-        <location filename="dockwidget.py" line="51"/>
+        <location filename="dockwidget.py" line="55"/>
         <source>Filter</source>
         <translation>Filtrér</translation>
     </message>
+    <message>
+        <location filename="dockwidget.py" line="197"/>
+        <source>Qlr Browser Error</source>
+        <translation>Qlr Browser fejl</translation>
+    </message>
+    <message>
+        <location filename="dockwidget.py" line="197"/>
+        <source>The selected path does not exist anymore</source>
+        <translation>Den valgte sti eksisterer ikke længere</translation>
+    </message>
 </context>
 <context>
     <name>QlrBrowser</name>

src/QlrBrowser/qlrbrowser.py

@@ -188,7 +188,7 @@ def initGui(self):
         #    removed on close (see self.onClosePlugin method)
         if self.dockwidget is None:
             # Create the dockwidget (after translation) and keep reference
-            self.dockwidget = DockWidget( self.iface.mainWindow())
+            self.dockwidget = DockWidget( self.iface)
             self.dockwidget.addRootPath(self.settings.value("baseDirectory"))
             self.qlrmanager = QlrManager(self.iface, self.dockwidget)
 

src/QlrBrowser/ui/dockwidget.py

@@ -24,6 +24,7 @@
 import os
 from PyQt4 import QtGui, uic
 from PyQt4.QtCore import QFileInfo, QDir, pyqtSignal, pyqtSlot, Qt, QTimer
+from qgis._gui import QgsMessageBar
 from ..core.filesystemmodel import FileSystemModel
 
 FORM_CLASS, _ = uic.loadUiType(os.path.join(
@@ -37,8 +38,9 @@ class DockWidget(QtGui.QDockWidget, FORM_CLASS):
 
     itemStateChanged = pyqtSignal(object, bool)
 
-    def __init__(self, parent=None):
+    def __init__(self, iface=None):
         """Constructor."""
+        parent = None if iface is None else iface.mainWindow()
         super(DockWidget, self).__init__(parent)
         # Set up the user interface from Designer.
         # After setupUI you can access any designer object by doing
@@ -47,6 +49,8 @@ def __init__(self, parent=None):
         # #widgets-and-dialogs-with-auto-connect
         self.setupUi(self)
 
+        self.iface = iface
+
         # UI
         self.filterLineEdit.setPlaceholderText( self.trUtf8(u'Filter'))
         self.treeWidget.setColumnCount(1)
@@ -112,6 +116,12 @@ def _treeitem_doubleclicked(self, item, column):
     def _treeitem_changed(self, item, column):
         checked = item.checkState(column) == Qt.Checked
         path = item.fullpath
+        if checked:
+            # Dont try to turn on a non-existing qlr
+            if not self._checkFileItemExists(path):
+                # Path no longer exists. Reload filesystem
+                self.reloadFileSystemInfo()
+                return
         self.setPathCheckState(path, checked)
         self.itemStateChanged.emit(item.fileitem, checked)
 
@@ -180,6 +190,16 @@ def _createWidgetItem(self, fileitem):
             num_checked_sub_paths = self.getNumCheckedSubPaths(fileitem.fullpath)
         return TreeWidgetItem(fileitem, checked, num_checked_sub_paths)
 
+    def _checkFileItemExists(self, path):
+        if os.path.exists(path):
+            return True
+        else:
+            self.iface.messageBar().pushMessage(
+                    self.trUtf8("Qlr Browser Error"),
+                    self.trUtf8("The selected path does not exist anymore"),
+                    level=QgsMessageBar.CRITICAL)
+            return False
+
     #
     # Events
     #