Merge pull request #2970 from davep/unbork-selection-list

Fix a crash caused by a prompt being wider than a `SelectionList`

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [0.31.0] - Unreleased
+
+### Fixed
+
+- Fixed a crash when a `SelectionList` had a prompt wider than itself https://github.com/Textualize/textual/issues/2900
+
 ## [0.30.0] - 2023-07-17
 
 ### Added

src/textual/widgets/_option_list.py

@@ -298,6 +298,7 @@ def __init__(
         id: str | None = None,
         classes: str | None = None,
         disabled: bool = False,
+        wrap: bool = True,
     ):
         """Initialise the option list.
 
@@ -307,13 +308,20 @@ def __init__(
             id: The ID of the option list in the DOM.
             classes: The CSS classes of the option list.
             disabled: Whether the option list is disabled or not.
+            wrap: Should prompts be auto-wrapped?
         """
         super().__init__(name=name, id=id, classes=classes, disabled=disabled)
 
         # Internal refresh trackers. For things driven from on_idle.
         self._needs_refresh_content_tracking = False
         self._needs_to_scroll_to_highlight = False
 
+        self._wrap = wrap
+        """Should we auto-wrap options?
+
+        If `False` options wider than the list will be truncated.
+        """
+
         self._contents: list[OptionListContent] = [
             self._make_content(item) for item in content
         ]
@@ -449,6 +457,14 @@ def _clear_content_tracking(self) -> None:
         # bit.
         self._option_ids.clear()
 
+    def _left_gutter_width(self) -> int:
+        """Returns the size of any left gutter that should be taken into account.
+
+        Returns:
+            The width of the left gutter.
+        """
+        return 0
+
     def _refresh_content_tracking(self, force: bool = False) -> None:
         """Refresh the various forms of option list content tracking.
 
@@ -477,13 +493,18 @@ def _refresh_content_tracking(self, force: bool = False) -> None:
 
         # Set up for doing less property access work inside the loop.
         lines_from = self.app.console.render_lines
-        options = self.app.console.options.update_width(
-            self.scrollable_content_region.width
-        )
         add_span = self._spans.append
         option_ids = self._option_ids
         add_lines = self._lines.extend
 
+        # Adjust the options for our purposes.
+        options = self.app.console.options.update_width(
+            self.scrollable_content_region.width - self._left_gutter_width()
+        )
+        options.no_wrap = not self._wrap
+        if not self._wrap:
+            options.overflow = "ellipsis"
+
         # Create a rule that can be used as a separator.
         separator = Strip(lines_from(Rule(style=""))[0])
 

src/textual/widgets/_selection_list.py

@@ -256,6 +256,7 @@ def __init__(
             id=id,
             classes=classes,
             disabled=disabled,
+            wrap=False,
         )
 
     @property
@@ -484,6 +485,19 @@ def _toggle_highlighted_selection(self) -> None:
         if self.highlighted is not None:
             self.toggle(self.get_option_at_index(self.highlighted))
 
+    def _left_gutter_width(self) -> int:
+        """Returns the size of any left gutter that should be taken into account.
+
+        Returns:
+            The width of the left gutter.
+        """
+        return len(
+            ToggleButton.BUTTON_LEFT
+            + ToggleButton.BUTTON_INNER
+            + ToggleButton.BUTTON_RIGHT
+            + " "
+        )
+
     def render_line(self, y: int) -> Strip:
         """Render a line in the display.
 

tests/selection_list/test_over_wide_selections.py

@@ -0,0 +1,29 @@
+"""See https://github.com/Textualize/textual/issues/2900 for the reason behind these tests."""
+
+from textual.app import App, ComposeResult
+from textual.widgets import SelectionList
+
+
+class SelectionListApp(App[None]):
+    """Test selection list application."""
+
+    CSS = """
+    OptionList {
+        width: 20;
+    }
+    """
+
+    def compose(self) -> ComposeResult:
+        yield SelectionList[int](*[(f"{n} " * 100, n) for n in range(10)])
+
+
+async def test_over_wide_options() -> None:
+    """Options wider than the widget should not be an issue."""
+    async with SelectionListApp().run_test() as pilot:
+        assert pilot.app.query_one(SelectionList).highlighted == 0
+        await pilot.pause()
+        assert pilot.app.query_one(SelectionList).highlighted == 0
+
+
+if __name__ == "__main__":
+    SelectionListApp().run()