Small tweaks and fixes 20200305 (#383)

* Ensure up to 5 relevant decimals for float delegates

* Ensure CSMethods table can remove multiple rows without issue

* Expand ViewOnly delegate to handle floats as well

* Set delegate as default for view-only table

activity_browser/app/ui/tables/LCA_setup.py

@@ -184,11 +184,11 @@ def sync(self, name: str = None):
             ], columns=self.HEADERS)
 
     def delete_rows(self):
-        indices = [self.get_source_index(p) for p in self.selectedIndexes()]
+        indices = (self.get_source_index(p) for p in self.selectedIndexes())
         rows = [i.row() for i in indices]
         self.dataframe.drop(rows, axis=0, inplace=True)
-        self.sync()
-        signals.calculation_setup_changed.emit()
+        signals.calculation_setup_changed.emit()  # Trigger update of CS in brightway
+        self.sync(self.current_cs)  # Sync CS from brightway back into table.
 
     def to_python(self):
         return self.dataframe["method"].to_list()

activity_browser/app/ui/tables/delegates/float.py

@@ -13,7 +13,7 @@ def __init__(self, parent=None):
     def displayText(self, value, locale):
         if math.isnan(value):
             return ""
-        return str(value)
+        return "{:.5g}".format(value)
 
     def createEditor(self, parent, option, index):
         editor = QtWidgets.QLineEdit(parent)

activity_browser/app/ui/tables/delegates/viewonly.py

@@ -1,4 +1,6 @@
 # -*- coding: utf-8 -*-
+import math
+
 from PySide2.QtWidgets import QStyledItemDelegate
 
 
@@ -9,5 +11,17 @@ class ViewOnlyDelegate(QStyledItemDelegate):
     def __init__(self, parent=None):
         super().__init__(parent)
 
+    def displayText(self, value, locale):
+        try:
+            value = float(value)
+            if math.isnan(value):
+                return ""
+            return "{:.5g}".format(value)
+        except ValueError:
+            return str(value)
+        except TypeError:
+            # Unexpected object types (eg. parameters)
+            return repr(value)
+
     def createEditor(self, parent, option, index):
         return None

activity_browser/app/ui/tables/views.py

@@ -9,6 +9,7 @@
 from PySide2.QtWidgets import QFileDialog, QTableView, QTreeView
 
 from ...settings import ab_settings
+from .delegates import ViewOnlyDelegate
 from .models import (DragPandasModel, EditableDragPandasModel,
                      EditablePandasModel, PandasModel,
                      SimpleCopyDragPandasModel, SimpleCopyPandasModel)
@@ -52,6 +53,9 @@ def __init__(self, parent=None):
         self.setSortingEnabled(True)
         self.verticalHeader().setDefaultSectionSize(22)  # row height
         self.verticalHeader().setVisible(True)
+        # Use a custom ViewOnly delegate by default.
+        # Can be overridden table-wide or per column in child classes.
+        self.setItemDelegate(ViewOnlyDelegate(self))
 
         self.table_name = 'LCA results'
         self.dataframe = None