Datatable labelling rows (#1868)

* Renaming some component classes in DataTable

* Some more renaming of DataTable component classes

* Separate styling for fixed rows/columns from labels

* Highlight fixed rows/cols affected by colour differently

* Tweaking styles for fixed data in DataTable

* Update DataTable snapshots

* Add row label to Row metadata

* Wiring up some labelled row logic behind flags

* Renaming variable in DataTable

* Variable renaming in DataTable

* [no ci] Labelling rows progress

* Add RenderedRow abstraction to DataTable

* Computing label widths

* Use the Column object to represent row label column

* Ability to toggle row labels reactively

* Adjust width calculation for label widths

* Add DataTable.RowLabelSelected

* Posting the RowLabelClick message

* Hovering of row labels applies new style

* Remove a print

* Ensure horizontal scrolling with column cursor accounts for row label column

* Account for possible row labels in cell cursor horizontal scrolling

* Ensure cursor highlighting is correct on row label cells

* Document component class for DataTable label hover

* Test to ensure clicking row label emits correct event

* Add snapshot test for DataTable with fixed rows/cols and row labels

* Using pilot pause instead of wait_for_idle directly

* Update CHANGELOG

* Add a docstring

* Add a note to CHANGELOG.md about RowLabelSelected

tests/snapshot_tests/snapshot_apps/data_table_column_cursor.py

@@ -21,6 +21,7 @@ class TableApp(App):
         table.focus()
         table.cursor_type = "column"
         table.fixed_columns = 1
+        table.fixed_rows = 1
         yield table
 
     def on_mount(self) -> None:

tests/snapshot_tests/snapshot_apps/data_table_row_cursor.py

@@ -20,6 +20,8 @@ class TableApp(App):
         table = DataTable()
         table.focus()
         table.cursor_type = "row"
+        table.fixed_columns = 1
+        table.fixed_rows = 1
         yield table
 
     def on_mount(self) -> None:

tests/snapshot_tests/snapshot_apps/data_table_row_labels.py

@@ -0,0 +1,37 @@
+from textual.app import App, ComposeResult
+from textual.widgets import DataTable
+
+ROWS = [
+    ("lane", "swimmer", "country", "time"),
+    (5, "Chad le Clos", "South Africa", 51.14),
+    (4, "Joseph Schooling", "Singapore", 50.39),
+    (2, "Michael Phelps", "United States", 51.14),
+    (6, "László Cseh", "Hungary", 51.14),
+    (3, "Li Zhuhao", "China", 51.26),
+    (8, "Mehdy Metella", "France", 51.58),
+    (7, "Tom Shields", "United States", 51.73),
+    (10, "Darren Burns", "Scotland", 51.84),
+    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
+]
+
+
+class TableApp(App):
+    def compose(self) -> ComposeResult:
+        yield DataTable()
+
+    def on_mount(self) -> None:
+        table = self.query_one(DataTable)
+        table.fixed_rows = 1
+        table.fixed_columns = 1
+        table.focus()
+        rows = iter(ROWS)
+        column_labels = next(rows)
+        for column in column_labels:
+            table.add_column(column, key=column)
+        for index, row in enumerate(rows):
+            table.add_row(*row, label=str(index))
+
+
+app = TableApp()
+if __name__ == "__main__":
+    app.run()