Merge 1734-fxdrag

crates/engine/src/layer_menu_cmds.rs

@@ -5,7 +5,7 @@
 
 use photocraft_algo::selection::Region;
 use photocraft_color::{BlendMode, ColorMode};
-use photocraft_doc::{BlendIf, BlendRange, Document, Effect, Knockout, Layer, LayerContent, LayerId, LayerMask, SmartSource, StackMode};
+use photocraft_doc::{BlendIf, BlendRange, Document, Effect, Effects, Knockout, Layer, LayerContent, LayerId, LayerMask, SmartSource, StackMode};
 use photocraft_geom::Rect;
 use photocraft_raster::{Surface, from_rgba_into, to_rgba};
 use serde_json::{Value, json};
@@ -605,6 +605,68 @@ fn scale_effects(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(Value::Null)
 }
 
+/// Dragging a layer's fx onto another layer in the Layers panel: all its effects (or just the one
+/// at `effect`) move there, or with `copy` are copied. Moving all effects replaces the target's
+/// style, as pasting a layer style does; a single effect replaces the target's effect of the same
+/// kind, else is added.
+fn transfer_effects(s: &mut Session, p: &Value) -> Result<Value> {
+    const CMD: &str = "layer.layerStyle.transferEffects";
+    let id_of = |key: &str| p.get(key).and_then(Value::as_u64).map(LayerId).ok_or_else(|| bad(CMD, format!("`{key}` must be a layer id")));
+    let from = id_of("from")?;
+    let to = id_of("to")?;
+    if from == to {
+        return Err(bad(CMD, "the effects are already on that layer"));
+    }
+    let copy = p.get("copy").and_then(Value::as_bool).unwrap_or(false);
+    let index = match p.get("effect") {
+        None | Some(Value::Null) => None,
+        Some(v) => Some(v.as_u64().and_then(|i| usize::try_from(i).ok()).ok_or_else(|| bad(CMD, "`effect` must be an effect index"))?),
+    };
+    let d = s.active().ok_or(EngineError::NoDocument)?;
+    let src = d.doc.layer(from).ok_or(EngineError::NoLayer(from))?;
+    d.doc.layer(to).ok_or(EngineError::NoLayer(to))?;
+    let payload = match index {
+        Some(i) => {
+            let e = src.effects.items.get(i).cloned().ok_or_else(|| bad(CMD, format!("the layer has no effect {i}")))?;
+            Effects { enabled: true, items: vec![e], psd_raw: None, reference: None }
+        }
+        None => Effects { psd_raw: None, ..src.effects.clone() },
+    };
+    if payload.items.is_empty() {
+        return Err(bad(CMD, "the layer has no layer effects"));
+    }
+    let label = if copy { "Copy Layer Effects" } else { "Move Layer Effects" };
+    s.edit(label, |doc, _| {
+        let dst = doc.layer_mut(to).ok_or(EngineError::NoLayer(to))?;
+        dst.effects.psd_raw = None;
+        if index.is_some() {
+            dst.effects.enabled = true;
+            for e in payload.items {
+                let same = dst.effects.items.iter().position(|x| std::mem::discriminant(x) == std::mem::discriminant(&e));
+                match same.and_then(|i| dst.effects.items.get_mut(i)) {
+                    Some(slot) => *slot = e,
+                    None => dst.effects.items.push(e),
+                }
+            }
+        } else {
+            dst.effects = payload;
+        }
+        if !copy {
+            let src = doc.layer_mut(from).ok_or(EngineError::NoLayer(from))?;
+            match index {
+                Some(i) if i < src.effects.items.len() => {
+                    src.effects.items.remove(i);
+                    src.effects.psd_raw = None;
+                }
+                Some(_) => {}
+                None => src.effects = Effects::default(),
+            }
+        }
+        Ok(())
+    })?;
+    Ok(json!({"from": from.0, "to": to.0}))
+}
+
 /// Effects drawn beneath the layer (they become separate layers below it, unclipped).
 fn is_below(e: &Effect) -> bool {
     match e {
@@ -861,6 +923,14 @@ pub fn specs() -> Vec<CommandSpec> {
         ),
         spec!("layer.layerStyle.createLayer", "Create Layer", ["Layer", "Layer Style"], r##"{"layer":id?}"##, has_effects, create_layer),
         spec!("layer.layerStyle.scaleEffects", "Scale Effects…", ["Layer", "Layer Style"], r##"{"scale":1..1000=100}"##, has_effects, scale_effects),
+        spec!(
+            "layer.layerStyle.transferEffects",
+            "Move Layer Effects",
+            [],
+            r##"{"from":id,"to":id,"effect":index? (default: all effects),"copy":bool=false}"##,
+            has_doc,
+            transfer_effects
+        ),
         CommandSpec {
             id: "layer.layerContentOptions",
             label: "Layer Content Options…",

crates/engine/src/layer_menu_cmds/tests.rs

@@ -526,3 +526,56 @@ fn load_files_into_stack_as_smart_object_then_median() {
     assert!((px[0] - 0.2).abs() < 2.0 / 255.0, "{px:?}");
     let _ = std::fs::remove_dir_all(&dir);
 }
+
+#[test]
+fn transfer_effects_moves_or_copies_between_layers() {
+    let mut s = session(8, "rgb");
+    s.execute("layer.new.layer", json!({})).unwrap();
+    let a = active(&s).id;
+    s.execute("layer.layerStyle.dropShadow", json!({})).unwrap();
+    s.execute("layer.layerStyle.colorOverlay", json!({"color": "#ff8000"})).unwrap();
+    s.execute("layer.new.layer", json!({})).unwrap();
+    let b = active(&s).id;
+    let layer = |s: &Session, id| s.active().unwrap().doc.layer(id).unwrap().clone();
+    let labels = |l: &Layer| l.effects.items.iter().map(Effect::label).collect::<Vec<_>>();
+    let both = labels(&layer(&s, a));
+    assert_eq!(both.len(), 2);
+
+    // Alt-drag of the whole fx row copies: both layers have the style.
+    s.execute("layer.layerStyle.transferEffects", json!({"from": a.0, "to": b.0, "copy": true})).unwrap();
+    assert_eq!(labels(&layer(&s, a)), both);
+    assert_eq!(labels(&layer(&s, b)), both);
+
+    // Dragging one effect row moves just that effect.
+    s.execute("layer.new.layer", json!({})).unwrap();
+    let c = active(&s).id;
+    s.execute("layer.layerStyle.transferEffects", json!({"from": a.0, "to": c.0, "effect": 1})).unwrap();
+    assert_eq!(labels(&layer(&s, a)), both[..1]);
+    assert_eq!(labels(&layer(&s, c)), both[1..]);
+
+    // Dragging the whole fx row moves everything and leaves the source without a style.
+    s.execute("layer.layerStyle.transferEffects", json!({"from": b.0, "to": a.0})).unwrap();
+    assert!(layer(&s, b).effects.items.is_empty());
+    assert_eq!(labels(&layer(&s, a)), both);
+
+    // One history step per drop.
+    let steps = s.active().unwrap().history.past_len();
+    s.execute("layer.layerStyle.transferEffects", json!({"from": a.0, "to": b.0})).unwrap();
+    assert_eq!(s.active().unwrap().history.past_len(), steps + 1);
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(labels(&layer(&s, a)), both);
+    assert!(layer(&s, b).effects.items.is_empty());
+
+    // Bad input is an error and changes nothing.
+    for bad in [
+        json!({"from": a.0, "to": a.0}),
+        json!({"from": a.0}),
+        json!({"from": a.0, "to": 9999}),
+        json!({"from": a.0, "to": b.0, "effect": 7}),
+        json!({"from": a.0, "to": b.0, "effect": -1}),
+        json!({"from": b.0, "to": a.0}),
+    ] {
+        assert!(s.execute("layer.layerStyle.transferEffects", bad.clone()).is_err(), "{bad}");
+    }
+    assert_eq!(s.active().unwrap().history.past_len(), steps);
+}

crates/ui-egui/src/fx_drag_tests.rs

@@ -0,0 +1,86 @@
+//! #1719: layer effects are dragged onto another layer in the Layers panel, as in Photoshop: an
+//! effect row or the fx badge moves its effects there, ⌥-drag copies them.
+
+use egui::{Modifiers, PointerButton, Pos2, Rect, accesskit::Role, vec2};
+use egui_kittest::Harness;
+use egui_kittest::kittest::{NodeT, Queryable};
+use photocraft_doc::LayerId;
+use serde_json::json;
+
+use crate::PhotocraftApp;
+use crate::layer_row_ui::{Indicator, RowRects, recorded};
+
+/// `a` with a Drop Shadow and a Color Overlay, and `b` above it without effects.
+fn harness() -> (Harness<'static, PhotocraftApp>, LayerId, LayerId) {
+    let mut s = photocraft_engine::Session::new();
+    s.execute("file.new", json!({"width": 64, "height": 48})).unwrap();
+    let a = s.execute("layer.new.layer", json!({"name": "a"})).unwrap()["layer"].as_u64().unwrap();
+    s.execute("layer.layerStyle.dropShadow", json!({})).unwrap();
+    s.execute("layer.layerStyle.colorOverlay", json!({"color": "#ff8000"})).unwrap();
+    let b = s.execute("layer.new.layer", json!({"name": "b"})).unwrap()["layer"].as_u64().unwrap();
+    let mut h = Harness::builder().with_size(vec2(1440.0, 900.0)).with_max_steps(64).build_eframe(move |cc| {
+        PhotocraftApp::setup_context(&cc.egui_ctx, Default::default());
+        PhotocraftApp::new(s, crate::Services::default())
+    });
+    h.run_steps(8);
+    (h, LayerId(a), LayerId(b))
+}
+
+fn row(h: &Harness<'_, PhotocraftApp>, id: LayerId) -> RowRects {
+    recorded(&h.ctx).into_iter().find(|r| r.layer == id.0).unwrap()
+}
+
+/// The effect row `name` under layer `id`'s row.
+fn effect_row(h: &Harness<'_, PhotocraftApp>, id: LayerId, name: &str) -> Rect {
+    let layer = row(h, id).row;
+    h.query_all_by_role(Role::Button)
+        .filter(|n| n.accesskit_node().label().as_deref() == Some(name))
+        .map(|n| n.rect())
+        .find(|r| r.top() >= layer.bottom() - 1.0 && r.left() < layer.center().x && r.right() > layer.center().x)
+        .unwrap_or_else(|| panic!("no {name} row under the layer"))
+}
+
+fn effects(h: &Harness<'_, PhotocraftApp>, id: LayerId) -> Vec<&'static str> {
+    h.state().session.active().unwrap().doc.layer(id).unwrap().effects.items.iter().map(photocraft_doc::Effect::label).collect()
+}
+
+/// A real press, drag and release, `modifiers` held throughout.
+fn drag(h: &mut Harness<'_, PhotocraftApp>, from: Pos2, to: Pos2, modifiers: Modifiers) {
+    h.event(egui::Event::ModifiersChanged(modifiers));
+    h.hover_at(from);
+    h.run_steps(1);
+    h.event(egui::Event::PointerButton { pos: from, button: PointerButton::Primary, pressed: true, modifiers });
+    h.run_steps(1);
+    for i in 1..=6 {
+        h.hover_at(from + (to - from) * (i as f32 / 6.0));
+        h.run_steps(1);
+    }
+    h.event(egui::Event::PointerButton { pos: to, button: PointerButton::Primary, pressed: false, modifiers });
+    h.run_steps(1);
+    h.event(egui::Event::ModifiersChanged(Modifiers::NONE));
+    h.run_steps(3);
+}
+
+#[test]
+fn dragging_effects_onto_a_layer_moves_them_and_alt_copies() {
+    let (mut h, a, b) = harness();
+    assert_eq!(effects(&h, a), ["Drop Shadow", "Color Overlay"]);
+    let steps = h.state().session.active().unwrap().history.past_len();
+
+    // ⌥-drag one effect row onto `b`: just that effect is copied.
+    let from = effect_row(&h, a, "Color Overlay").center();
+    let to = row(&h, b).row.center();
+    drag(&mut h, from, to, Modifiers::ALT);
+    assert_eq!(effects(&h, a), ["Drop Shadow", "Color Overlay"]);
+    assert_eq!(effects(&h, b), ["Color Overlay"]);
+    assert_eq!(h.state().session.active().unwrap().history.past_len(), steps + 1, "one history step");
+
+    // Drag the fx badge onto `b`: all of `a`'s effects move there, replacing `b`'s.
+    let badge = row(&h, a).indicators.into_iter().find(|(k, _)| *k == Indicator::Fx).unwrap().1;
+    let to = row(&h, b).row.center();
+    drag(&mut h, badge.center(), to, Modifiers::NONE);
+    assert!(effects(&h, a).is_empty(), "the effects moved off `a`");
+    assert_eq!(effects(&h, b), ["Drop Shadow", "Color Overlay"]);
+    // The drag moved effects, not the layer: `b` is still above `a`.
+    assert!(row(&h, b).row.top() < row(&h, a).row.top());
+}

crates/ui-egui/src/panels.rs

@@ -1587,9 +1587,14 @@ fn layers(app: &mut PhotocraftApp, ui: &mut egui::Ui) {
         .min_scrolled_height(if fill { rows_h } else { 0.0 })
         .auto_shrink([false, !fill])
         .show(ui, |ui| {
-            // The drag key is set only by actual layer-row drags, not clicks or
+            // The drag keys are set only by actual layer-row and fx drags, not clicks or
             // ordinary scrolling. The ScrollArea applies this to its own content.
-            let dragging = ctx.data(|d| d.get_temp::<u64>(egui::Id::new("layer-drag"))).is_some() && ctx.input(|i| i.pointer.primary_down());
+            // An fx drag that never saw its release (the panel was hidden) must not outlive the button.
+            if !ctx.input(|i| i.pointer.primary_down() || i.pointer.any_released()) {
+                ctx.data_mut(|d| d.remove::<FxDrag>(fx_drag_key()));
+            }
+            let held = ctx.data(|d| d.get_temp::<u64>(egui::Id::new("layer-drag")).is_some() || d.get_temp::<FxDrag>(fx_drag_key()).is_some());
+            let dragging = held && ctx.input(|i| i.pointer.primary_down());
             let pointer = ctx.input(|i| i.pointer.interact_pos());
             let delta = layer_drag_edge_scroll(pointer, ui.clip_rect(), dragging, ctx.input(|i| i.stable_dt));
             if delta != 0.0 {
@@ -1645,9 +1650,11 @@ fn layers(app: &mut PhotocraftApp, ui: &mut egui::Ui) {
         let in_selection = selection.iter().any(|s| s.0 == id);
         (id, in_selection)
     });
+    fx_drag_feedback(&ctx, &doc);
     // End any layer drag after every row has had a chance to accept the drop.
     if ctx.input(|i| i.pointer.any_released()) {
         ctx.data_mut(|d| d.remove::<u64>(egui::Id::new("layer-drag")));
+        ctx.data_mut(|d| d.remove::<FxDrag>(fx_drag_key()));
     }
     widgets::panel_footer(ui, |ui| {
         let trash = icons::button(ui, "trash", 26.0, false, tl!("Delete layer"));
@@ -1887,6 +1894,7 @@ fn layer_row(
     let row_h = if t.pro { 32.0 } else { 46.0 };
     let (rect, resp) = ui.allocate_exact_size(vec2(ui.available_width(), row_h), Sense::click_and_drag());
     layer_drag_and_drop(app, ctx, ui, l, rect, &resp, actions);
+    fx_drop(ctx, ui, l, rect, actions);
     if resp.drag_started() {
         crate::layer_transfer::begin_from_panel(app, ctx, l.id);
     }
@@ -1978,6 +1986,13 @@ fn layer_row(
     // Right-hand indicators first; the name gets what is left and ends in "…" (#144).
     let fx_open = app.session.active().is_none_or(|d| !d.fx_collapsed.contains(&l.id));
     let (name_right, indicators, fx_toggled) = crate::layer_row_ui::indicators(ui, &painter, rect, x, l, fx_open, actions);
+    // Dragging the fx badge drags all the layer's effects, not the layer (Photoshop). Like the eye,
+    // it takes the drag from the row; clicks still reach the row.
+    if let Some(&(_, badge)) = indicators.iter().find(|(k, _)| *k == crate::layer_row_ui::Indicator::Fx)
+        && ui.interact(badge, ui.id().with(("fx-badge", l.id.0)), Sense::drag()).drag_started()
+    {
+        start_fx_drag(ctx, l.id, None);
+    }
     let name_color = if l.visible { t.text } else { t.text_faint };
     let font = if selected && !t.pro { theme::medium(13.0) } else { egui::FontId::proportional(if t.pro { 12.0 } else { 13.0 }) };
     // Photoshop before 2026 set the Background layer's name in italics; 2026 sets it upright.
@@ -2826,6 +2841,60 @@ fn layer_drag_and_drop(
     }
 }
 
+/// An fx row being dragged: the layer it belongs to and the effect index (`None` = the "Effects"
+/// row, all of them).
+type FxDrag = (u64, Option<usize>);
+
+fn fx_drag_key() -> egui::Id {
+    egui::Id::new("fx-drag")
+}
+
+/// Start dragging the effects of `layer`: one (`effect`) or all of them.
+fn start_fx_drag(ctx: &egui::Context, layer: LayerId, effect: Option<usize>) {
+    ctx.data_mut(|d| d.insert_temp::<FxDrag>(fx_drag_key(), (layer.0, effect)));
+}
+
+/// While effects are dragged: their name by the pointer, and the copy cursor while ⌥ is held.
+fn fx_drag_feedback(ctx: &egui::Context, doc: &photocraft_doc::Document) {
+    let Some((from, effect)) = ctx.data(|d| d.get_temp::<FxDrag>(fx_drag_key())) else { return };
+    let Some(p) = ctx.input(|i| i.pointer.interact_pos()) else { return };
+    let label = match effect {
+        Some(i) => doc.layer(LayerId(from)).and_then(|l| l.effects.items.get(i)).map_or("", |e| e.label()),
+        None => "Effects",
+    };
+    crate::layer_transfer::ghost(ctx, p, label);
+    if ctx.input(|i| i.modifiers.alt) {
+        ctx.set_cursor_icon(egui::CursorIcon::Copy);
+    }
+}
+
+/// The command for dropping effects of layer `from` on `target`: they move there, or with ⌥ held
+/// on release are copied (Photoshop). `effect` is one effect row, or all effects when `None`.
+fn fx_drop_action(from: u64, effect: Option<usize>, target: LayerId, copy: bool) -> (String, Value) {
+    let mut payload = json!({"from": from, "to": target.0, "copy": copy});
+    if let Some(o) = payload.as_object_mut()
+        && let Some(i) = effect
+    {
+        o.insert("effect".into(), json!(i));
+    }
+    ("layer.layerStyle.transferEffects".into(), payload)
+}
+
+/// A layer row accepts the fx row being dragged: outlined while the pointer is over it, dropped
+/// on release.
+fn fx_drop(ctx: &egui::Context, ui: &egui::Ui, l: &Layer, rect: Rect, actions: &mut Vec<(String, Value)>) {
+    let Some((from, effect)) = ctx.data(|d| d.get_temp::<FxDrag>(fx_drag_key())) else { return };
+    let Some(p) = ctx.input(|i| i.pointer.interact_pos()) else { return };
+    if from == l.id.0 || !rect.contains(p) {
+        return;
+    }
+    let t = Tokens::get(ctx);
+    ui.painter().rect_stroke(rect.shrink(1.0), t.radius_sm, Stroke::new(2.0, t.accent), StrokeKind::Inside);
+    if ctx.input(|i| i.pointer.any_released()) {
+        actions.push(fx_drop_action(from, effect, l.id, ctx.input(|i| i.modifiers.alt)));
+    }
+}
+
 /// Photoshop shows a layer's effects as indented sub-rows ("Effects", then each effect). The eye
 /// on "Effects" shows or hides them all, the eye on an effect's row just that one (#1622).
 fn effect_rows(app: &mut PhotocraftApp, ui: &mut egui::Ui, l: &Layer, depth: usize, actions: &mut Vec<(String, Value)>) {
@@ -2837,7 +2906,11 @@ fn effect_rows(app: &mut PhotocraftApp, ui: &mut egui::Ui, l: &Layer, depth: usi
         rows.push((e.label().to_string(), e.enabled(), kind));
     }
     for (i, (name, on, kind)) in rows.into_iter().enumerate() {
-        let (rect, resp) = ui.allocate_exact_size(vec2(ui.available_width(), 22.0), Sense::click());
+        let (rect, resp) = ui.allocate_exact_size(vec2(ui.available_width(), 22.0), Sense::click_and_drag());
+        // Drag the row onto another layer to move its effects there, ⌥-drag to copy them.
+        if resp.drag_started() {
+            start_fx_drag(ui.ctx(), l.id, i.checked_sub(1));
+        }
         if !ui.is_rect_visible(rect) {
             continue;
         }
@@ -3173,6 +3246,10 @@ mod history_transform_tests {
 #[path = "layer_pct_slider_tests.rs"]
 mod layer_pct_slider_tests;
 
+#[cfg(test)]
+#[path = "fx_drag_tests.rs"]
+mod fx_drag_tests;
+
 #[cfg(test)]
 mod lock_tests {
     use super::*;