From 85c7fc4d6e529ee310a87929409101d08d76d6b2 Mon Sep 17 00:00:00 2001
From: MarekSpodBiedry <73122968+MarekSpodBiedry@users.noreply.github.com>
Date: Mon, 12 Oct 2026 08:32:27 +0200
Subject: [PATCH] Zoom dialog: a Magnification choice sets the percentage to
 store (#521)

---
 crates/ui-egui/src/control.rs       |  2 +-
 crates/ui-egui/src/dialogs.rs       | 13 ++++-
 crates/ui-egui/tests/zoom_dialog.rs | 85 +++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+), 2 deletions(-)
 create mode 100644 crates/ui-egui/tests/zoom_dialog.rs

diff --git a/crates/ui-egui/src/control.rs b/crates/ui-egui/src/control.rs
index 6f6280ef7..ef9dddd6f 100644
--- a/crates/ui-egui/src/control.rs
+++ b/crates/ui-egui/src/control.rs
@@ -232,7 +232,7 @@ pub fn handle(app: &mut SheetApp, ctx: &egui::Context, method: &str, p: &Json) -
                 } else if field == "search" {
                     d.search = s("value").unwrap_or("").to_string();
                 } else {
-                    d.values.insert(field.to_string(), p.get("value").cloned().unwrap_or(Json::Null));
+                    d.set_value(field, p.get("value").cloned().unwrap_or(Json::Null));
                 }
                 ok(json!(d.values))
             }
diff --git a/crates/ui-egui/src/dialogs.rs b/crates/ui-egui/src/dialogs.rs
index 5e859c68e..da6b49748 100644
--- a/crates/ui-egui/src/dialogs.rs
+++ b/crates/ui-egui/src/dialogs.rs
@@ -47,6 +47,17 @@ impl Dialog {
         &self.name
     }
 
+    /// Sets a form value. In Zoom, a Magnification choice is also the percentage `view.zoom` stores.
+    pub(crate) fn set_value(&mut self, key: &str, value: Json) {
+        if self.name == "zoom"
+            && key == "preset"
+            && let Some(p) = value.as_str().and_then(|s| s.parse::<f64>().ok())
+        {
+            self.values.insert("percent".into(), json!(p));
+        }
+        self.values.insert(key.into(), value);
+    }
+
     fn form(name: &str, title: &str, command: &'static str, fields: Vec<Field>, defaults: Json) -> Dialog {
         Dialog {
             name: name.into(),
@@ -1288,7 +1299,7 @@ fn form_fields(ui: &mut egui::Ui, d: &mut Dialog) {
                         let cur = d.values.get(key).and_then(Json::as_str).unwrap_or("").to_string();
                         for (val, text) in options {
                             if ui.radio(cur == val, text).clicked() {
-                                d.values.insert(key.into(), json!(val));
+                                d.set_value(key, json!(val));
                             }
                         }
                     });
diff --git a/crates/ui-egui/tests/zoom_dialog.rs b/crates/ui-egui/tests/zoom_dialog.rs
new file mode 100644
index 000000000..f5be90833
--- /dev/null
+++ b/crates/ui-egui/tests/zoom_dialog.rs
@@ -0,0 +1,85 @@
+//! The Zoom dialog stores the Magnification the user picks.
+
+use egui::vec2;
+use egui_kittest::kittest::Queryable;
+use gridcraft_engine::Session;
+use gridcraft_ui_egui::SheetApp;
+use gridcraft_ui_egui::control::{Outcome, handle};
+use serde_json::{Value as Json, json};
+
+fn harness() -> egui_kittest::Harness<'static, SheetApp> {
+    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 zoom(h: &egui_kittest::Harness<'static, SheetApp>) -> u16 {
+    h.state().session.active().unwrap().wb.active().unwrap().zoom
+}
+
+fn control(h: &mut egui_kittest::Harness<'static, SheetApp>, method: &str, params: Json) -> Json {
+    let ctx = h.ctx.clone();
+    match handle(h.state_mut(), &ctx, method, &params) {
+        Outcome::Done(v) => v,
+        Outcome::Screenshot { .. } => json!(null),
+    }
+}
+
+#[test]
+fn choosing_a_magnification_and_pressing_ok_sets_that_zoom() {
+    let mut h = harness();
+    h.state_mut().run("view.zoom", json!({"percent": 160})).unwrap();
+    h.state_mut().open_dialog("zoom", json!({}));
+    h.run_steps(6);
+    h.get_by_label("50%").click();
+    h.run_steps(6);
+    h.get_by_label("   OK   ").click();
+    h.run_steps(6);
+    assert!(h.state().dialog.is_none());
+    assert_eq!(zoom(&h), 50);
+}
+
+#[test]
+fn choosing_a_magnification_and_confirming_by_command_sets_that_zoom() {
+    let mut h = harness();
+    h.state_mut().run("view.zoom", json!({"percent": 180})).unwrap();
+    h.state_mut().open_dialog("zoom", json!({}));
+    h.run_steps(6);
+    h.get_by_label("75%").click();
+    h.run_steps(6);
+    let r = control(&mut h, "ui.dialog.confirm", json!({}));
+    assert_eq!(r["ok"], json!(true), "{r}");
+    assert_eq!(zoom(&h), 75);
+}
+
+#[test]
+fn setting_the_magnification_over_the_control_channel_sets_that_zoom() {
+    let mut h = harness();
+    h.state_mut().run("view.zoom", json!({"percent": 180})).unwrap();
+    control(&mut h, "ui.dialog", json!({"name": "zoom"}));
+    control(&mut h, "ui.dialog.set", json!({"field": "preset", "value": "25"}));
+    let r = control(&mut h, "ui.dialog.confirm", json!({}));
+    assert_eq!(r["ok"], json!(true), "{r}");
+    assert_eq!(zoom(&h), 25);
+}
+
+#[test]
+fn a_custom_percentage_after_a_magnification_wins_and_an_unedited_ok_keeps_the_zoom() {
+    let mut h = harness();
+    control(&mut h, "ui.dialog", json!({"name": "zoom"}));
+    control(&mut h, "ui.dialog.set", json!({"field": "preset", "value": "25"}));
+    control(&mut h, "ui.dialog.set", json!({"field": "percent", "value": 225}));
+    control(&mut h, "ui.dialog.confirm", json!({}));
+    assert_eq!(zoom(&h), 225);
+    control(&mut h, "ui.dialog", json!({"name": "zoom"}));
+    control(&mut h, "ui.dialog.confirm", json!({}));
+    assert_eq!(zoom(&h), 225);
+}