documents and editor: a writing view - measure, font, scale, focus fading, typewriter centering

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/documents/document/tests/look.rs

@@ -0,0 +1,108 @@
+use gpui::{TestAppContext, px, rems};
+
+use super::{MarkdownMode, frames, open};
+use crate::documents::DocumentLook;
+
+/// Sixty short paragraphs, each its own block.
+fn long() -> String {
+    (0..60).map(|n| format!("Paragraph {n}.\n\n")).collect()
+}
+
+#[gpui::test]
+fn the_measure_narrows_the_column(cx: &mut TestAppContext) {
+    let (document, cx) = open("A paragraph.\n", MarkdownMode::Visual, cx);
+    let look = DocumentLook {
+        measure: Some(rems(20.)),
+        ..DocumentLook::default()
+    };
+    document.update(cx, |document, cx| document.set_look(look, cx));
+    frames(cx);
+    let block = cx.debug_bounds("markdown-block-0").expect("drawn");
+    assert!(block.size.width <= px(320.0), "{:?}", block.size);
+}
+
+#[gpui::test]
+fn typewriter_keeps_the_open_block_mid_view(cx: &mut TestAppContext) {
+    let (document, cx) = open(&long(), MarkdownMode::Visual, cx);
+    let look = DocumentLook {
+        typewriter: true,
+        ..DocumentLook::default()
+    };
+    document.update_in(cx, |document, window, cx| {
+        document.set_look(look, cx);
+        document.open(Some(40), false, window, cx);
+        document.list.scroll_to_reveal_item(40);
+    });
+    frames(cx);
+    let (block, view) = document.read_with(cx, |document, _| {
+        (
+            document.list.bounds_for_item(40),
+            document.list.viewport_bounds(),
+        )
+    });
+    let block = block.expect("block 40 is laid out");
+    let off = (block.center().y - view.center().y).abs();
+    assert!(off < px(4.0), "{off:?} from the middle");
+}
+
+#[gpui::test]
+fn typewriter_keeps_the_source_caret_mid_view(cx: &mut TestAppContext) {
+    let (document, cx) = open(&long(), MarkdownMode::Source, cx);
+    let look = DocumentLook {
+        typewriter: true,
+        ..DocumentLook::default()
+    };
+    document.update(cx, |document, cx| {
+        document.set_look(look, cx);
+        document.set_caret(90, 0, cx);
+    });
+    frames(cx);
+    let before = document.read_with(cx, |document, cx| document.top_line(cx));
+    let editor = document.read_with(cx, |document, _| document.editor().clone());
+    let focus = editor.read_with(cx, gpui::Focusable::focus_handle);
+    cx.update(|window, cx| window.focus(&focus, cx));
+    cx.simulate_input(
+        "
+
+
+
+
+
+
+
+
+
+",
+    );
+    frames(cx);
+    let after = document.read_with(cx, |document, cx| document.top_line(cx));
+    assert_eq!(after, before + 10, "the view follows the caret");
+}
+
+#[gpui::test]
+fn the_scale_sizes_source_lines(cx: &mut TestAppContext) {
+    let (document, cx) = open("a\n", MarkdownMode::Source, cx);
+    let editor = document.read_with(cx, |document, _| document.editor().clone());
+    frames(cx);
+    let plain = editor.read_with(cx, |editor, _| editor.metrics.line);
+    let look = DocumentLook {
+        scale: 2.0,
+        ..DocumentLook::default()
+    };
+    document.update(cx, |document, cx| document.set_look(look, cx));
+    frames(cx);
+    let large = editor.read_with(cx, |editor, _| editor.metrics.line);
+    assert!(large > plain * 1.8, "{plain:?} to {large:?}");
+}
+
+#[gpui::test]
+fn focus_counts_the_open_block_as_the_readers(cx: &mut TestAppContext) {
+    let (document, cx) = open(&long(), MarkdownMode::Visual, cx);
+    document.update_in(cx, |document, window, cx| {
+        document.open(Some(3), false, window, cx)
+    });
+    assert_eq!(
+        document.read_with(cx, |document, cx| document.current_block(cx)),
+        3
+    );
+}