Merge PR #3862: M7: open the paragraph editor without a fade-in

crates/ui-egui/src/edit_text_ui.rs: #3862's Area builder with fade_in(false), keeping the reveal/look locals and their uses after the Area (#3952, #3863).
crates/ui-egui/tests/editing.rs: kept all new tests.

crates/ui-egui/src/content_ui.rs

@@ -523,7 +523,9 @@ pub(crate) fn editor(ctx: &egui::Context, view: &mut DocView, info: &DocInfo, ad
     let (mut commit, mut cancel, mut done) = (false, false, false);
     let mut undrawable = None;
     let memo = &view.content.undrawable;
-    egui::Area::new(egui::Id::new(("added-text", view.id.0))).order(egui::Order::Foreground).fixed_pos(r.min).constrain(false).show(ctx, |ui| {
+    // Shown at once, like the paragraph editor: a fade-in shows the page's copy through it.
+    let area = egui::Area::new(egui::Id::new(("added-text", view.id.0))).fade_in(false);
+    area.order(egui::Order::Foreground).fixed_pos(r.min).constrain(false).show(ctx, |ui| {
         let Some(t) = view.content.draft.as_mut() else { return };
         ui.set_width(r.width() + 64.0);
         if let Some(source_rect) = source_rect.filter(|_| !background_ready) {

crates/ui-egui/src/edit_text_ui.rs

@@ -1531,9 +1531,12 @@ pub(crate) fn overlay(ctx: &egui::Context, view: &mut DocView, info: &DocInfo) -
     let mut done = None;
     let mut reveal = false;
     let mut look = None;
-    egui::Area::new(egui::Id::new("edit-text-line")).order(egui::Order::Foreground).fixed_pos(Pos2::new(ed.rect.left(), ed.rect.top())).show(
-        ctx,
-        |ui| {
+    // No fade-in: while it faded, the page's own copy of the text showed through the cover.
+    egui::Area::new(egui::Id::new("edit-text-line"))
+        .order(egui::Order::Foreground)
+        .fade_in(false)
+        .fixed_pos(Pos2::new(ed.rect.left(), ed.rect.top()))
+        .show(ctx, |ui| {
             // The editor opens at the source size. Once text changes, show the real draft
             // extent: single rows grow toward the page edge, paragraphs rewrap at their
             // source width, and the visible frame grows/shrinks vertically with their rows.
@@ -1626,8 +1629,7 @@ pub(crate) fn overlay(ctx: &egui::Context, view: &mut DocView, info: &DocInfo) -
                     done = Some(true);
                 }
             });
-        },
-    );
+        });
     if reveal {
         view.text_background.reveal();
     }

crates/ui-egui/src/fill_sign.rs

@@ -706,7 +706,9 @@ pub(crate) fn type_box(ctx: &egui::Context, view: &mut DocView, info: &DocInfo,
     let zoom = xf.rect.width() / xf.pw.max(1.0);
     let mut commit = false;
     let mut cancel = false;
-    egui::Area::new(egui::Id::new(("fill-text", view.id.0))).order(egui::Order::Foreground).fixed_pos(pos).show(ctx, |ui| {
+    // Shown at once, like the paragraph editor: a fade-in shows the page's copy through it.
+    let area = egui::Area::new(egui::Id::new(("fill-text", view.id.0))).fade_in(false);
+    area.order(egui::Order::Foreground).fixed_pos(pos).show(ctx, |ui| {
         let Some(t) = view.fill_text.as_mut() else { return };
         // The box is white in every theme, so the caret must not follow the theme (pale in dark mode) (#655).
         ui.visuals_mut().text_cursor.stroke.color = crate::edit_text_ui::caret_color_on(Color32::WHITE);

crates/ui-egui/src/forms_ui.rs

@@ -503,7 +503,9 @@ pub(crate) fn overlay(ctx: &egui::Context, view: &mut DocView, info: &DocInfo, f
     match f.kind {
         FormFieldKind::Text => {
             let multiline = f.has(field_flags::MULTILINE);
-            egui::Area::new(egui::Id::new(("form-editor", view.id.0))).order(egui::Order::Foreground).fixed_pos(rect.min).show(ctx, |ui| {
+            // Shown at once, like the paragraph editor: a fade-in shows the field's value through it.
+            let area = egui::Area::new(egui::Id::new(("form-editor", view.id.0))).fade_in(false);
+            area.order(egui::Order::Foreground).fixed_pos(rect.min).show(ctx, |ui| {
                 ui.set_min_size(rect.size());
                 let Some(fx) = view.forms.focus.as_mut() else { return };
                 // Sized from the text being typed, so an auto-sized field shrinks to keep it in view.

crates/ui-egui/tests/editing.rs

@@ -2996,6 +2996,62 @@ fn a_paragraph_whose_edit_fails_stays_open_with_its_typing() {
     assert_eq!(doc.text_blocks(0).iter().map(|b| b.text.clone()).collect::<Vec<_>>(), ["Top edited", "Bottom"]);
 }
 
+/// Two boxes, "Top" and "Bottom", in Edit text, with egui's animations on: the window animates
+/// unless the system asks for less motion, and the test harness turns them off.
+fn two_boxes_animated() -> (Harness<'static, PdfCraftApp>, [egui::Rect; 2]) {
+    let bytes = source_font_fixture_with_text("BT /F1 24 Tf 20 220 Td (Top) Tj ET BT /F2 24 Tf 20 120 Td (Bottom) Tj ET");
+    let mut h = Harness::builder().with_size(egui::vec2(1400.0, 900.0)).with_step_dt(1.0 / 60.0).build_eframe(move |_cc| {
+        let mut app = PdfCraftApp::new();
+        app.set_option("language", "en").unwrap();
+        app.open_bytes("boxes.pdf", None, bytes).expect("opens");
+        app
+    });
+    h.ctx.all_styles_mut(|s| s.animation_time = 0.2);
+    h.run_steps(4);
+    assert!(h.state_mut().execute("edit.edit_text"));
+    h.run_steps(2);
+    let r = h.state().views[0].page_screen_rect(0).expect("on screen");
+    let k = r.width() / 300.0;
+    let mut blocks = {
+        let s = h.state();
+        s.session.get(s.views[0].id).unwrap().text_blocks(0)
+    };
+    blocks.sort_by(|a, b| b.rect[1].partial_cmp(&a.rect[1]).unwrap_or(std::cmp::Ordering::Equal));
+    let on_screen = |b: &pdfcraft_engine::TextBlock| {
+        egui::Rect::from_min_max(
+            egui::pos2(r.left() + b.rect[0] as f32 * k, r.top() + (300.0 - b.rect[3] as f32) * k),
+            egui::pos2(r.left() + b.rect[2] as f32 * k, r.top() + (300.0 - b.rect[1] as f32) * k),
+        )
+    };
+    (h, [on_screen(&blocks[0]), on_screen(&blocks[1])])
+}
+
+/// The colour of the editor's frame (the accent stroke around `r`) this frame, if it is painted.
+fn editor_frame_color(h: &Harness<'static, PdfCraftApp>, r: egui::Rect) -> Option<egui::Color32> {
+    h.output().shapes.iter().find_map(|shape| match &shape.shape {
+        egui::Shape::Rect(rect) if rect.stroke.width == 1.5 && rect.rect.contains(r.center()) => Some(rect.stroke.color),
+        _ => None,
+    })
+}
+
+/// A paragraph opens at once: it used to fade in over a fifth of a second, its frame dimmed and
+/// the page's own copy of the text showing through the editor's cover.
+#[test]
+fn a_paragraph_editor_opens_at_full_opacity() {
+    let (mut h, [top, _]) = two_boxes_animated();
+    h.hover_at(top.center());
+    h.run_steps(1);
+    h.drag_at(top.center());
+    h.run_steps(1);
+    h.drop_at(top.center());
+    let accent = egui::Color32::from_rgb(0x14, 0x73, 0xE6);
+    for frame in 0..8 {
+        h.step();
+        // The click's own frame opens it: the editor's frame is there from then on, at full colour.
+        assert_eq!(editor_frame_color(&h, top), Some(accent), "frame {frame} after the click");
+    }
+}
+
 #[test]
 fn editing_existing_text_in_place() {
     let mut h = harness(1, |_| {});