Merge PR #1252: Dialogs move by their title bar instead of staying pinned to the centre (fixes #1250)

docs/ui-parity.md: status line combined (newest date, both change notes)

crates/ui-egui/src/dialogs.rs

@@ -1044,7 +1044,9 @@ pub fn show(app: &mut SheetApp, ctx: &egui::Context) {
         .collapsible(false)
         .resizable(false)
         .default_width(width)
-        .anchor(egui::Align2::CENTER_CENTER, vec2(0.0, -40.0))
+        // A default position, not an anchor: egui anchors can't be dragged, and dialogs move by their title bar.
+        .pivot(egui::Align2::CENTER_CENTER)
+        .default_pos(ctx.content_rect().center() + vec2(0.0, -40.0))
         .open(&mut win_open);
     let window = if d.name == "insertPicture" { window.default_height(240.0) } else { window };
     window.show(ctx, |ui| {

crates/ui-egui/tests/dialog_move.rs

@@ -0,0 +1,70 @@
+//! Dialogs can be dragged by their title bar, like Excel's, and stay where they are dropped.
+
+use egui::{Event, Modifiers, PointerButton, vec2};
+use gridcraft_engine::Session;
+use gridcraft_ui_egui::SheetApp;
+use serde_json::json;
+
+type Harness = egui_kittest::Harness<'static, SheetApp>;
+
+fn harness() -> Harness {
+    let mut session = Session::new();
+    session.new_workbook();
+    let mut h = egui_kittest::Harness::builder().with_size(vec2(1200.0, 800.0)).build_ui_state(
+        |ui, app: &mut SheetApp| {
+            app.logic(&ui.ctx().clone());
+            app.ui(ui);
+        },
+        SheetApp::new(session, Default::default()),
+    );
+    h.run_steps(6);
+    h
+}
+
+fn dialog_rect(h: &Harness, name: &str) -> egui::Rect {
+    h.ctx.memory(|m| m.area_rect(egui::Id::new("dialog").with(name))).unwrap()
+}
+
+fn button(h: &mut Harness, pos: egui::Pos2, pressed: bool) {
+    h.input_mut().events.push(Event::PointerButton { pos, button: PointerButton::Primary, pressed, modifiers: Modifiers::NONE });
+    h.run_steps(2);
+}
+
+fn drag_title_bar(h: &mut Harness, name: &str, by: egui::Vec2) {
+    let start = dialog_rect(h, name).center_top() + vec2(0.0, 10.0);
+    h.input_mut().events.push(Event::PointerMoved(start));
+    h.run_steps(2);
+    button(h, start, true);
+    for step in 1..=4 {
+        h.input_mut().events.push(Event::PointerMoved(start + by * (step as f32 / 4.0)));
+        h.run_steps(1);
+    }
+    button(h, start + by, false);
+}
+
+#[test]
+fn dragging_the_find_and_replace_title_bar_moves_the_dialog_and_it_stays_there() {
+    let mut h = harness();
+    h.state_mut().open_dialog("find", json!({}));
+    h.run_steps(6);
+    let before = dialog_rect(&h, "find");
+    drag_title_bar(&mut h, "find", vec2(120.0, 80.0));
+    h.run_steps(10);
+    let after = dialog_rect(&h, "find");
+    assert_eq!(after.min - before.min, vec2(120.0, 80.0), "dialog went from {before:?} to {after:?}");
+    assert!(h.state().dialog.is_some(), "the drag does not close the dialog");
+}
+
+#[test]
+fn go_to_format_cells_and_sort_can_be_dragged_too() {
+    for name in ["goTo", "formatCells", "sort"] {
+        let mut h = harness();
+        h.state_mut().open_dialog(name, json!({}));
+        h.run_steps(6);
+        let before = dialog_rect(&h, name);
+        drag_title_bar(&mut h, name, vec2(-100.0, 60.0));
+        h.run_steps(10);
+        let after = dialog_rect(&h, name);
+        assert_eq!(after.min - before.min, vec2(-100.0, 60.0), "{name} went from {before:?} to {after:?}");
+    }
+}