Raster calc: refresh layers list if a layer is renamed or added/removed

Fixes #20601 - bug: Raster calculator produces empty results layer and no error message if input layer is one that has been renamed in QGIS layers panel

Author: elpaso

python/plugins/processing/algs/qgis/ui/RasterCalculatorWidgets.py

@@ -28,10 +28,13 @@
 import re
 import json
 
+from qgis.utils import iface
 from qgis.PyQt import uic
+from qgis.PyQt.QtCore import Qt
 from qgis.PyQt.QtGui import QTextCursor
 from qgis.PyQt.QtWidgets import (QLineEdit, QPushButton, QLabel,
-                                 QComboBox, QSpacerItem, QSizePolicy)
+                                 QComboBox, QSpacerItem, QSizePolicy,
+                                 QListWidgetItem)
 
 from qgis.core import (QgsProcessingUtils,
                        QgsProcessingParameterDefinition,
@@ -187,8 +190,20 @@ def fillPredefined(self):
     def setList(self, options):
         self.options = options
         self.listWidget.clear()
-        for opt in options.keys():
-            self.listWidget.addItem(opt)
+        entries = QgsRasterCalculatorEntry.rasterEntries()
+
+        def _find_source(name):
+            for entry in entries:
+                if entry.ref == name:
+                    return entry.raster.source()
+            return ''
+
+        for name in options.keys():
+            item = QListWidgetItem(name, self.listWidget)
+            tooltip = _find_source(name)
+            if tooltip:
+                item.setData(Qt.ToolTipRole, tooltip)
+            self.listWidget.addItem(item)
 
     def setValue(self, value):
         self.text.setPlainText(value)
@@ -202,28 +217,28 @@ class ExpressionWidgetWrapper(WidgetWrapper):
     def _panel(self, options):
         return ExpressionWidget(options)
 
+    def _get_options(self):
+        entries = QgsRasterCalculatorEntry.rasterEntries()
+        options = {}
+        for entry in entries:
+            options[entry.ref] = entry.ref
+        return options
+
     def createWidget(self):
         if self.dialogType == DIALOG_STANDARD:
-            entries = QgsRasterCalculatorEntry.rasterEntries()
-            options = {}
-            for entry in entries:
-                options[entry.ref] = entry.ref
-            return self._panel(options)
+            if iface is not None and iface.layerTreeView() is not None and iface.layerTreeView().layerTreeModel() is not None:
+                iface.layerTreeView().layerTreeModel().dataChanged.connect(self.refresh)
+            return self._panel(self._get_options())
         elif self.dialogType == DIALOG_BATCH:
             return QLineEdit()
         else:
             layers = self.dialog.getAvailableValuesOfType([QgsProcessingParameterRasterLayer], [QgsProcessingOutputRasterLayer])
             options = {self.dialog.resolveValueDescription(lyr): "{}@1".format(self.dialog.resolveValueDescription(lyr)) for lyr in layers}
-            return self._panel(options)
+            self.widget = self._panel(options)
+            return self.widget
 
-    def refresh(self):
-        # TODO: check if avoid code duplication with self.createWidget
-        layers = QgsProcessingUtils.compatibleRasterLayers(QgsProject.instance())
-        options = {}
-        for lyr in layers:
-            for n in range(lyr.bandCount()):
-                options[lyr.name()] = '{:s}@{:d}'.format(lyr.name(), n + 1)
-        self.widget.setList(options)
+    def refresh(self, *args):
+        self.widget.setList(self._get_options())
 
     def setValue(self, value):
         if self.dialogType == DIALOG_STANDARD:

src/app/qgsrastercalcdialog.cpp

@@ -153,6 +153,7 @@ QVector<QgsRasterCalculatorEntry> QgsRasterCalcDialog::rasterEntries() const
   return entries;
 }
 
+
 void QgsRasterCalcDialog::setExtentSize( int width, int height, QgsRectangle bbox )
 {
   mNColumnsSpinBox->setValue( width );
@@ -168,6 +169,7 @@ void QgsRasterCalcDialog::setExtentSize( int width, int height, QgsRectangle bbo
 void QgsRasterCalcDialog::insertAvailableRasterBands()
 {
   mAvailableRasterBands = QgsRasterCalculatorEntry::rasterEntries().toList();
+  mRasterBandsListWidget->clear();
   for ( const auto &entry : qgis::as_const( mAvailableRasterBands ) )
   {
     QgsRasterLayer *rlayer = entry.raster;