T14c, T15 review fixes: Tab steps past merges, empty charts lay out nothing, flat domains widen by size, pointed parts let go of shrunk data, signed waterfall totals, sunburst children take their share, today stays on the timeline

src/charts/tiles.rs

@@ -27,6 +27,13 @@ pub(crate) struct Tiles {
     pub hover: Option<usize>,
 }
 
+impl Tiles {
+    /// The part under the pointer, if there are still that many parts.
+    pub(crate) fn pointed(&self, count: usize) -> Option<usize> {
+        self.hover.filter(|ix| *ix < count)
+    }
+}
+
 /// Keeps `tiles` answering the pointer: `find` names the tile at a place in the box.
 pub(crate) fn tracked(
     root: Div,
@@ -120,7 +127,10 @@ impl RenderOnce for Treemap {
     fn render(mut self, window: &mut Window, cx: &mut App) -> impl IntoElement {
         let tiles: Entity<Tiles> =
             window.use_keyed_state((self.id.clone(), "tiles"), cx, |_, _| Tiles::default());
-        let (bounds, hover) = (tiles.read(cx).bounds, tiles.read(cx).hover);
+        let (bounds, hover) = (
+            tiles.read(cx).bounds,
+            tiles.read(cx).pointed(self.tiles.len()),
+        );
         let theme = cx.theme();
         let (colors, sizes, rem) = (theme.colors.clone(), theme.chart(), window.rem_size());
         let pixels = |length: gpui::Rems| f32::from(length.to_pixels(rem));
@@ -296,7 +306,8 @@ impl RenderOnce for HeatmapChart {
     fn render(mut self, window: &mut Window, cx: &mut App) -> impl IntoElement {
         let tiles: Entity<Tiles> =
             window.use_keyed_state((self.id.clone(), "tiles"), cx, |_, _| Tiles::default());
-        let (bounds, hover) = (tiles.read(cx).bounds, tiles.read(cx).hover);
+        let cells = self.rows.len() * self.columns.len();
+        let (bounds, hover) = (tiles.read(cx).bounds, tiles.read(cx).pointed(cells));
         let theme = cx.theme();
         let (colors, sizes, rem) = (theme.colors.clone(), theme.chart(), window.rem_size());
         let pixels = |length: gpui::Rems| f32::from(length.to_pixels(rem));
@@ -307,8 +318,8 @@ impl RenderOnce for HeatmapChart {
             pixels(sizes.foot),
             pixels(sizes.inset),
         );
-        let (columns, rows) = (self.columns.len().max(1), self.rows.len().max(1));
-        let (cell_w, cell_h) = (rect.w / columns as f32, rect.h / rows as f32);
+        let (columns, rows) = (self.columns.len(), self.rows.len());
+        let (cell_w, cell_h) = (rect.w / columns.max(1) as f32, rect.h / rows.max(1) as f32);
         let cell = |row: usize, column: usize| Rect {
             x: rect.x + cell_w * column as f32,
             y: rect.y + cell_h * row as f32,
@@ -402,7 +413,7 @@ impl RenderOnce for HeatmapChart {
             (self.id.clone(), "heatmap").into(),
             &tiles,
             move |at| {
-                rect.contains(at).then(|| {
+                (rect.contains(at) && rows > 0 && columns > 0).then(|| {
                     let (row, column) = (
                         ((at.1 - rect.y) / cell_h) as usize,
                         ((at.0 - rect.x) / cell_w) as usize,