From f0869f218de23a946d634c4146d9a6e0f5a0b480 Mon Sep 17 00:00:00 2001
From: Dave Pearson <davep@davep.org>
Date: Tue, 28 Feb 2023 10:05:32 +0000
Subject: [PATCH] :sparkles: Added test code for
 https://github.com/Textualize/textual/issues/1897

---
 scroll_api_test.py | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 scroll_api_test.py

diff --git a/scroll_api_test.py b/scroll_api_test.py
new file mode 100644
index 0000000..00df645
--- /dev/null
+++ b/scroll_api_test.py
@@ -0,0 +1,39 @@
+"""https://github.com/Textualize/textual/issues/1897"""
+
+from rich.segment        import Segment
+from textual.app         import App, ComposeResult
+from textual.widgets     import Header, Footer
+from textual.scroll_view import ScrollView
+from textual.geometry    import Size
+from textual.strip       import Strip
+
+class ScrollViewTest( ScrollView, can_focus=True ):
+
+    def __init__( self, height: int ) -> None:
+        super().__init__()
+        self.virtual_size = Size( 0, height )
+
+    def render_line( self, y: int ) -> Strip:
+        return Strip( [
+            Segment( f"{self.scroll_offset.y + y:10}" ),
+            Segment( f"{y:10}" ),
+            *(
+                [ Segment( f"{' ' * 10}scroll_offset.y == {self.scroll_offset.y}") ]
+                if y == 0 else []
+            )
+        ] )
+
+class ScrollTestApp( App[ None ] ):
+
+    def compose( self ) -> ComposeResult:
+        yield Header()
+        yield ScrollViewTest( 1000 )
+        yield Footer()
+
+    def on_mount( self ) -> None:
+        self.query_one( ScrollViewTest ).focus()
+
+if __name__ == "__main__":
+    ScrollTestApp().run()
+
+### scroll_api_test.py ends here