fix: add hand tool scale buttons

crates/ui-egui/src/brush_panel_tests.rs

@@ -620,3 +620,38 @@ fn options_bar_reaches_brush_settings_and_the_preset_library() {
     h.run_steps(3);
     assert!(h.state().ui.panels.brush_settings && h.state().ui.brush_tab == 0);
 }
+
+#[test]
+fn hand_tool_offers_scale_buttons_and_requests_the_right_view() {
+    use egui_kittest::kittest::Queryable;
+
+    let mut app = app();
+    app.run("file.new", json!({"width": 400, "height": 200})).unwrap();
+    app.sync_views();
+    app.ui.tool = crate::state::Tool::Hand;
+    app.ui.views[0].zoom = 2.0;
+    let mut h = Harness::builder().with_size(vec2(1400.0, 60.0)).build_ui_state(
+        |ui, app: &mut PhotocraftApp| {
+            if ui.ctx().fonts(|f| f.families().contains(&egui::FontFamily::Name("medium".into()))) {
+                crate::panels::options_bar(app, ui);
+            }
+        },
+        app,
+    );
+    PhotocraftApp::setup_context(&h.ctx, crate::theme::ThemeKind::Studio);
+    h.run_steps(4);
+
+    h.get_by_label("100%").click();
+    h.run_steps(1);
+    assert_eq!(h.state().ui.views[0].zoom, 1.0);
+
+    h.get_by_label("Fit Screen").click();
+    h.run_steps(1);
+    assert!(h.state().ui.views[0].fit_pending);
+    assert!(!h.state().ui.views[0].fill_pending);
+
+    h.get_by_label("Fill Screen").click();
+    h.run_steps(1);
+    assert!(h.state().ui.views[0].fill_pending);
+    assert!(!h.state().ui.views[0].fit_pending);
+}

crates/ui-egui/src/canvas.rs

@@ -394,6 +394,18 @@ pub fn fit_view(view: &mut View, doc: &Document, area: Vec2) {
     view.zoom = zoom;
     view.center = [w / 2.0, h / 2.0];
     view.fit_pending = false;
+    view.fill_pending = false;
+}
+
+/// Centre the document and zoom until it fills the canvas. One axis can extend beyond the
+/// viewport, matching the Hand tool's Fill Screen action.
+pub fn fill_view(view: &mut View, doc: &Document, area: Vec2) {
+    let (w, h) = (doc.size.width as f32, doc.size.height as f32);
+    let zoom = (area.x / w).max(area.y / h).clamp(0.01, 32.0);
+    view.zoom = zoom;
+    view.center = [w / 2.0, h / 2.0];
+    view.fit_pending = false;
+    view.fill_pending = false;
 }
 
 /// Zoom steps like Photoshop's (⌘+ / ⌘−).
@@ -1545,6 +1557,9 @@ pub fn canvas_view(app: &mut PhotocraftApp, ui: &mut egui::Ui, idx: usize, rect:
     if view.fit_pending && rect.width() > 50.0 {
         fit_view(&mut view, &doc, rect.size());
     }
+    if view.fill_pending && rect.width() > 50.0 {
+        fill_view(&mut view, &doc, rect.size());
+    }
     // Preferences › Tools › Overscroll off: clamp before anything is drawn (scrollbars.rs).
     if !app.session.prefs().tools.overscroll && crate::scrollbars::clamp_view(&mut view, rect.size()) {
         ctx.request_repaint();
@@ -3534,6 +3549,20 @@ mod tests {
         assert_eq!(zoom_step(32.0, 1), 32.0);
     }
 
+    #[test]
+    fn fill_view_covers_the_canvas_and_centres_the_document() {
+        let mut app = PhotocraftApp::new(photocraft_engine::Session::new(), crate::Services::default());
+        app.run("file.new", json!({"width": 400, "height": 200})).unwrap();
+        let doc = app.session.active().unwrap().doc.clone();
+        let mut view = View { fill_pending: true, ..View::default() };
+
+        fill_view(&mut view, &doc, vec2(600.0, 600.0));
+
+        assert_eq!(view.zoom, 3.0, "the short edge fills the available height");
+        assert_eq!(view.center, [200.0, 100.0]);
+        assert!(!view.fill_pending);
+    }
+
     #[test]
     fn damage_grows_by_nested_effect_reach() {
         use photocraft_doc::{Effect, Layer};

crates/ui-egui/src/control.rs

@@ -295,15 +295,18 @@ fn dispatch(app: &mut PhotocraftApp, ctx: &egui::Context, req: &ControlRequest)
                 if let Some(z) = p.get("zoom").and_then(Value::as_f64) {
                     app.ui.views[i].zoom = (z as f32).clamp(0.01, 64.0);
                     app.ui.views[i].fit_pending = false;
+                    app.ui.views[i].fill_pending = false;
                 }
                 if let Some(c) = p.get("center").and_then(Value::as_array)
                     && c.len() == 2
                 {
                     app.ui.views[i].center = [c[0].as_f64().unwrap_or(0.0) as f32, c[1].as_f64().unwrap_or(0.0) as f32];
                     app.ui.views[i].fit_pending = false;
+                    app.ui.views[i].fill_pending = false;
                 }
                 if p.get("fit").and_then(Value::as_bool) == Some(true) {
                     app.ui.views[i].fit_pending = true;
+                    app.ui.views[i].fill_pending = false;
                 }
             }
             if let Some(name) = s("theme") {

crates/ui-egui/src/crop_ui.rs

@@ -447,7 +447,7 @@ mod tests {
     fn space_on_the_canvas_moves_the_frame_not_the_view() {
         use egui::{Event, Key, PointerButton, pos2};
         let mut a = app(SampleType::U8);
-        let view = crate::state::View { zoom: 2.0, center: [100.0, 50.0], fit_pending: false, doc_size: [200, 100] };
+        let view = crate::state::View { zoom: 2.0, center: [100.0, 50.0], fit_pending: false, fill_pending: false, doc_size: [200, 100] };
         a.ui.views = vec![view.clone()];
         let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(600.0, 400.0)).build_ui_state(
             |ui, app: &mut PhotocraftApp| {

crates/ui-egui/src/menus.rs

@@ -268,6 +268,12 @@ pub(crate) fn invoke_unguarded(app: &mut PhotocraftApp, ctx: &egui::Context, id:
                 "view.fitOnScreen" => v.fit_pending = true,
                 _ => v.zoom = 1.0,
             }
+            if id == "view.fitOnScreen" {
+                v.fill_pending = false;
+            } else {
+                v.fit_pending = false;
+                v.fill_pending = false;
+            }
             Ok(Value::Null)
         }
         "window.newWindowForDocument" => {

crates/ui-egui/src/panels.rs

@@ -883,7 +883,28 @@ pub fn options_bar(app: &mut PhotocraftApp, ui: &mut egui::Ui) {
                             app.ui.views[i].zoom = 1.0;
                         }
                     }
-                    Tool::Hand => hint(ui, tl!("Drag to pan  ·  hold Space with any tool")),
+                    Tool::Hand => {
+                        hint(ui, tl!("Drag to pan  ·  hold Space with any tool"));
+                        if widgets::secondary_button(ui, "100%", 0.0).clicked()
+                            && let Some(i) = app.session.active_index()
+                        {
+                            app.ui.views[i].zoom = 1.0;
+                            app.ui.views[i].fit_pending = false;
+                            app.ui.views[i].fill_pending = false;
+                        }
+                        if widgets::secondary_button(ui, tl!("Fit Screen"), 0.0).clicked()
+                            && let Some(i) = app.session.active_index()
+                        {
+                            app.ui.views[i].fit_pending = true;
+                            app.ui.views[i].fill_pending = false;
+                        }
+                        if widgets::secondary_button(ui, tl!("Fill Screen"), 0.0).clicked()
+                            && let Some(i) = app.session.active_index()
+                        {
+                            app.ui.views[i].fill_pending = true;
+                            app.ui.views[i].fit_pending = false;
+                        }
+                    }
                     Tool::Lasso | Tool::PolygonLasso => hint(
                         ui,
                         &crate::i18n::fmt(

crates/ui-egui/src/scrollbars.rs

@@ -280,7 +280,7 @@ mod tests {
         assert_eq!(clamp_axis(600.0, 1000.0, 500.0, 1.0), 600.0);
         // Smaller than the view: centred.
         assert_eq!(clamp_axis(-90.0, 1000.0, 500.0, 0.2), 500.0);
-        let mut v = View { zoom: 1.0, center: [-500.0, 20.0], fit_pending: false, doc_size: [1000, 800] };
+        let mut v = View { zoom: 1.0, center: [-500.0, 20.0], fit_pending: false, fill_pending: false, doc_size: [1000, 800] };
         assert!(clamp_view(&mut v, vec2(500.0, 400.0)));
         assert_eq!(v.center, [250.0, 200.0]);
         assert!(!clamp_view(&mut v, vec2(500.0, 400.0)), "stable: no repaint loop");
@@ -299,7 +299,7 @@ mod tests {
         let (at, len) = s.thumb((0.0, 1000.0), 0.0);
         assert!(at.is_finite() && len.is_finite());
         assert_eq!(s.doc_per_point((0.0, 1000.0), 0.0), 0.0);
-        let mut v = View { zoom: 1.0, center: [0.0, 0.0], fit_pending: false, doc_size: [0, 0] };
+        let mut v = View { zoom: 1.0, center: [0.0, 0.0], fit_pending: false, fill_pending: false, doc_size: [0, 0] };
         assert!(!clamp_view(&mut v, vec2(500.0, 400.0)));
     }
 

crates/ui-egui/src/state.rs

@@ -367,6 +367,9 @@ pub struct View {
     pub center: [f32; 2],
     /// Recompute fit-to-screen on next frame.
     pub fit_pending: bool,
+    /// Recompute fill-screen on next frame. Unlike fit, this may crop an edge of the document.
+    #[serde(default)]
+    pub fill_pending: bool,
     /// Document size this view last showed; a change (Image/Canvas Size, crop) re-centres it.
     #[serde(default)]
     pub doc_size: [u32; 2],
@@ -374,7 +377,7 @@ pub struct View {
 
 impl Default for View {
     fn default() -> Self {
-        Self { zoom: 1.0, center: [0.0, 0.0], fit_pending: true, doc_size: [0, 0] }
+        Self { zoom: 1.0, center: [0.0, 0.0], fit_pending: true, fill_pending: false, doc_size: [0, 0] }
     }
 }