🔀 Merge pull request #121 from davep/better-raindrops-messaging

Tidy up the way the highlighted raindrop is handled

src/braindrop/app/screens/main.py

@@ -176,6 +176,9 @@ class Main(Screen[None]):
     active_collection: var[Raindrops] = var(Raindrops, always_update=True)
     """The currently-active collection."""
 
+    highlighted_raindrop: var[Raindrop | None] = var(None)
+    """The currently-highlighted raindrop."""
+
     def __init__(self, api: API) -> None:
         """Initialise the main screen.
 
@@ -205,7 +208,9 @@ def compose(self) -> ComposeResult:
             yield RaindropsView(classes="focus").data_bind(
                 raindrops=Main.active_collection
             )
-            yield RaindropDetails(classes="focus")
+            yield RaindropDetails(classes="focus").data_bind(
+                raindrop=Main.highlighted_raindrop
+            )
         yield Footer()
 
     @work
@@ -367,12 +372,15 @@ def command_show_tagged(self, command: ShowTagged) -> None:
         """
         self.active_collection = self.active_collection.tagged(command.tag)
 
-    @on(RaindropsView.OptionHighlighted)
-    def update_details(self) -> None:
-        """Update the details panel to show the current raindrop."""
-        self.query_one(RaindropDetails).raindrop = self.query_one(
-            RaindropsView
-        ).highlighted_raindrop
+    @on(RaindropsView.Empty)
+    def deselect_raindrop(self) -> None:
+        """Handle that there is no selected Raindrop."""
+        self.highlighted_raindrop = None
+
+    @on(RaindropsView.Highlighted)
+    def highlight_raindrop(self, message: RaindropsView.Highlighted) -> None:
+        """Handle the highlighted raindrop changing."""
+        self.highlighted_raindrop = message.raindrop
 
     @on(Redownload)
     def action_redownload_command(self) -> None:
@@ -502,7 +510,7 @@ def _current_raindrop(self, action: str) -> Raindrop | None:
         Returns:
             The highlighted raindrop, or `None`.
         """
-        if (raindrop := self.query_one(RaindropsView).highlighted_raindrop) is None:
+        if (raindrop := self.highlighted_raindrop) is None:
             self.notify(
                 f"No Raindrop is highlighted, there is nothing to {action}!",
                 title="No Raindrop",

src/braindrop/app/widgets/raindrops_view.py

@@ -2,6 +2,7 @@
 
 ##############################################################################
 # Python imports.
+from dataclasses import dataclass
 from typing import Final, cast
 
 ##############################################################################
@@ -17,7 +18,9 @@
 
 ##############################################################################
 # Textual imports.
+from textual import on
 from textual.binding import Binding
+from textual.message import Message
 from textual.reactive import var
 from textual.widgets.option_list import Option, OptionDoesNotExist
 
@@ -140,6 +143,9 @@ class RaindropsView(OptionListEx):
     compact: var[bool] = var(False)
     """Toggle to say if we should use a compact view or not."""
 
+    class Empty(Message):
+        """A message sent if the view becomes empty."""
+
     def _add_raindrops(self) -> None:
         """Add the current raindrops to the display."""
         with self.preserved_highlight:
@@ -149,6 +155,8 @@ def _add_raindrops(self) -> None:
                     for raindrop in self.raindrops
                 ]
             )
+        if not self.option_count:
+            self.post_message(self.Empty())
 
     def watch_data(self) -> None:
         """React to the data being changed."""
@@ -162,24 +170,23 @@ def watch_compact(self) -> None:
         """React to the compact setting being toggled."""
         self._add_raindrops()
 
-    @property
-    def highlighted_raindrop(self) -> Raindrop | None:
-        """The currently-highlighted Raindrop, if there is one, or `None`."""
-        if self.highlighted is not None:
-            return cast(
-                RaindropView, self.get_option_at_index(self.highlighted)
-            ).raindrop
-        return None
-
-    @highlighted_raindrop.setter
-    def highlighted_raindrop(self, raindrop: Raindrop | None) -> None:
-        if raindrop is None:
-            self.highlighted = None
-        else:
-            try:
-                self.highlighted = self.get_option_index(RaindropView.id_of(raindrop))
-            except OptionDoesNotExist:
-                pass
+    @dataclass
+    class Highlighted(Message):
+        """Message sent when a new Raindrop is highlighted."""
+
+        raindrop: Raindrop
+        """The raindrop that was highlighted."""
+
+    @on(OptionListEx.OptionHighlighted)
+    def raindrop_highlighted(self, message: OptionListEx.OptionHighlighted) -> None:
+        """Handle a raindrop being highlighted.
+
+        Args:
+            message: The message to handle.
+        """
+        message.stop()
+        assert isinstance(message.option, RaindropView)
+        self.post_message(self.Highlighted(message.option.raindrop))
 
     def action_visit(self) -> None:
         """Action that visits the currently-selected raindrop link, if there is one."""