Grid: an armed Format Painter pastes onto the next cells clicked or dragged (fixes #1211)

crates/ui-egui/src/grid.rs

@@ -2258,10 +2258,22 @@ fn interact(app: &mut SheetApp, ui: &mut egui::Ui, resp: &egui::Response, geo: &
     // Release.
     if resp.drag_stopped() || (!pointer.any_down() && app.grid.drag != Drag::None && !resp.dragged()) {
         match std::mem::take(&mut app.grid.drag) {
-            Drag::Select if resp.drag_stopped() => {
-                if let Some(p) = pos {
+            Drag::Select => {
+                if resp.drag_stopped()
+                    && let Some(p) = pos
+                {
                     select_to_pointer(app, geo, sh, wb, p);
                 }
+                // An armed Format Painter pastes onto the cells just clicked or dragged over
+                // (not while pointing a formula reference, which also drags a Select).
+                if app.session.format_painter.is_some() && !app.editor.as_ref().is_some_and(|ed| ed.can_point()) {
+                    let dest = app.session.active().map(|d| d.selection.current().a1());
+                    if let Some(dest) = dest
+                        && let Err(e) = app.run("edit.formatPainter", json!({"apply": dest}))
+                    {
+                        app.message = Some(("GridCraft".into(), crate::clean_error(&e)));
+                    }
+                }
             }
             Drag::Fill { target: Some(t) } => {
                 let src = sel.current();

crates/ui-egui/src/ribbon.rs

@@ -569,6 +569,7 @@ fn home(app: &mut SheetApp, ui: &mut Ui) {
         }
         let fp_on = app.session.format_painter.is_some();
         let fp = toggle_button(ui, Icon::Brush, fp_on, "Format Painter (double-click to keep it on)");
+        fp.widget_info(|| egui::WidgetInfo::selected(egui::WidgetType::Button, ui.is_enabled(), fp_on, "Format Painter"));
         control_keytip(app, ui, &fp, "edit.formatPainter");
         if fp.double_clicked() {
             act(app, "edit.formatPainter", json!({"sticky": true}));

crates/ui-egui/tests/format_painter.rs

@@ -0,0 +1,78 @@
+//! Format Painter through the real ribbon button and a click on the grid.
+
+use egui::accesskit::Toggled;
+use egui::{Event, Modifiers, PointerButton, Pos2};
+use egui_kittest::kittest::{NodeT, Queryable};
+use gridcraft_engine::Session;
+use gridcraft_engine::core::CellRef;
+use gridcraft_engine::model::Style;
+use gridcraft_ui_egui::{SheetApp, grid::Geo};
+use serde_json::json;
+
+type Harness = egui_kittest::Harness<'static, SheetApp>;
+
+fn harness() -> Harness {
+    let mut session = Session::new();
+    session.new_workbook();
+    session.execute("range.setValues", json!({"range": "A1", "values": [["source"]]})).unwrap();
+    session.execute("home.bold", json!({"range": "A1", "on": true})).unwrap();
+    session.execute("home.fillColor", json!({"range": "A1", "color": "#FFFF00"})).unwrap();
+    session.execute("selection.set", json!({"cell": "A1"})).unwrap();
+    let mut h = Harness::builder().with_size(egui::vec2(1200.0, 800.0)).build_ui_state(
+        |ui, app: &mut SheetApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        SheetApp::new(session, Default::default()),
+    );
+    h.run_steps(4);
+    h
+}
+
+fn style(h: &Harness, a1: &str) -> Style {
+    let doc = h.state().session.active().unwrap();
+    let sheet = doc.wb.active().unwrap();
+    doc.wb.styles.get(sheet.style_id(CellRef::parse(a1).unwrap())).clone()
+}
+
+fn point(h: &Harness, a1: &str) -> Pos2 {
+    let app = h.state();
+    let sheet = app.session.active().unwrap().wb.active().unwrap();
+    Geo::new(sheet, app.grid.rect.unwrap(), app.view().scroll).cell_rect(sheet, CellRef::parse(a1).unwrap()).center()
+}
+
+fn pressed(h: &Harness) -> bool {
+    h.get_by_label("Format Painter").accesskit_node().toggled() == Some(Toggled::True)
+}
+
+fn click_cell(h: &mut Harness, a1: &str) {
+    let at = point(h, a1);
+    for event in [
+        Event::PointerMoved(at),
+        Event::PointerButton { pos: at, button: PointerButton::Primary, pressed: true, modifiers: Modifiers::NONE },
+        Event::PointerButton { pos: at, button: PointerButton::Primary, pressed: false, modifiers: Modifiers::NONE },
+    ] {
+        h.input_mut().events.push(event);
+        h.run_steps(1);
+    }
+    h.run_steps(2);
+}
+
+#[test]
+fn ribbon_button_picks_up_the_format_and_a_click_on_a_cell_pastes_it() {
+    let mut h = harness();
+    let source = style(&h, "A1");
+    assert!(source.font.bold);
+    assert_ne!(style(&h, "C3"), source);
+
+    h.get_by_label("Format Painter").click();
+    h.run_steps(2);
+    assert!(h.state().session.format_painter.is_some(), "the button must arm the painter");
+    assert!(pressed(&h), "the armed button must show as pressed");
+
+    click_cell(&mut h, "C3");
+    assert_eq!(style(&h, "C3"), source, "clicking C3 must paste A1's format");
+    assert!(h.state().session.format_painter.is_none(), "a single-click painter disarms after one use");
+    assert!(!pressed(&h));
+}