ElyTable: the wheel scrolls past the data without waiting for the kernel (T-06)

crates/ely-lok/src/view/scroll.rs

@@ -113,7 +113,18 @@ impl LokView {
         }
         // The kernel sizes a sheet in tile twips already.
         let reach = self.tile_of(self.reach);
-        (self.doc_size.0.max(reach.0), self.doc_size.1.max(reach.1))
+        let (w, h) = (self.doc_size.0.max(reach.0), self.doc_size.1.max(reach.1));
+        let Some(sheet) = &self.sheet else {
+            return (w, h);
+        };
+        // Sheets scroll ahead of the kernel, to their end.
+        let end = self.tile_of((sheet.columns.start(sheet.columns.count()), sheet.rows.start(sheet.rows.count())));
+        let (fx, fy) = self.frozen_tiles();
+        let ahead = (
+            fx + self.scroll.0 + 2 * self.geom.twips_of(self.viewport.0),
+            fy + self.scroll.1 + 2 * self.geom.twips_of(self.viewport.1),
+        );
+        (w.max(ahead.0.min(end.0)), h.max(ahead.1.min(end.1)))
     }
 
     /// The print-twips document point under a view position (LOK-04).

crates/ely-lok/src/view/tests/large.rs

@@ -202,7 +202,8 @@ fn a_sheet_brings_far_cut_and_frozen_cells_into_view() {
             assert_eq!(view.spare, (0.0, 0.0), "and stays left after it");
             let size = view.doc_size;
             view.doc_size = view.tile_of((view.print_of(size).0 + 20 * 1280, size.1));
-            assert_eq!(view.extent(), view.doc_size, "the kernel's size is the extent, uncut");
+            let extent = view.extent();
+            assert!(extent.0 >= view.doc_size.0 && extent.1 >= view.doc_size.1, "the kernel's size is uncut");
             view.doc_size = size;
             view.viewport = (800.0, 200.0);
             let (width, height) = (view.geom.twips_of(view.viewport.0), view.geom.twips_of(view.viewport.1));
@@ -440,3 +441,30 @@ fn the_first_size_has_a_scale_and_keeps_the_row() {
     let after = middle(&mut cx);
     assert!(before.abs_diff(after) <= 1, "row {before} became {after} when the first size landed");
 }
+
+#[test]
+fn an_empty_sheet_scrolls_on_without_waiting() {
+    let Some(install) = crate::client::tests::install() else {
+        eprintln!("SKIP: no pinned LOK build");
+        return;
+    };
+    let mut cx = gpui::TestAppContext::single();
+    let (view, worker) = cx.update(|app| live_view_of(app, &install, "short.fods", SHORT_ROWS));
+    let json = cx.update(|app| worker.lock().expect("the worker lock").values(&view.read(app).doc, crate::sheet::GEOMETRY).expect("geometry"));
+    let geometry = crate::sheet::geometry(&json).expect("parsed");
+    let bounds = Bounds { origin: point(px(0.0), px(0.0)), size: size(px(400.0), px(200.0)) };
+    cx.update(|app| view.update(app, |view, cx| {
+        view.set_geometry(geometry.clone(), cx);
+        view.prepare(bounds);
+    }));
+    // Each step a viewport down, before the kernel answers.
+    for step in 1..=20 {
+        let moved = cx.update(|app| view.update(app, |view, cx| {
+            let from = view.scroll.1;
+            view.scroll_by(0.0, -200.0, cx);
+            view.scroll.1 - from
+        }));
+        let full = cx.update(|app| view.read(app).geom.twips_of(200.0));
+        assert_eq!(moved, full, "step {step} went the whole way");
+    }
+}

tasks/BUGS.md

@@ -13,7 +13,7 @@
 - [x] T-03 视口比工作表宽时网格先居中再左移一次 — 载入回复带文档种类，表格不居中；R1 测试漏几何到达前的首帧；R2 PASS
 - [x] T-04 从不调用 `setClientZoom`，内核命中与几何按默认缩放算 — R2.16 已修（worker 每次报可见区前 setClientZoom）
 - [x] T-05 文档尺寸按内核像素取整，表尾被裁 — 内核尺寸按其测量时的比例换到当前比例（加载即设比例、缩放即改比例并重测、迟到的测量也换算）；R1–R4 缩放后未重测、表尾锚点被截、连续缩放迟到、首次测量无比例与文件超行；R5 PASS
-- [ ] T-06 滚轮向下被内核平铺区卡住
+- [x] T-06 滚轮向下被内核平铺区卡住 — 表格的可滚范围先行两屏、止于表尾；R1 PASS
 - [x] T-07 表头点选、行高列宽拖动是“按编号的命令”，而每次点击与拖选都推进修订，紧接着的表头操作被当作过期拒绝 — 行列号不再算作按编号的命令；R1 PASS
 - [ ] T-08 自动筛选的列菜单对光标所在的表而不是按钮所在的表筛选、排序
 - [ ] T-09 导入文本文件时整文件的 UTF-8 校验在界面线程跑

tasks/reviews/T-06-r1.md

@@ -0,0 +1 @@
+PASS