#3087: a placeholder's float slider keeps its range

It arrived as a plain number, so Effect Controls neither dragged it over its
slider range nor clamped an edit to its valid range, as After Effects does.

crates/aep/src/import/placeholder.rs

@@ -111,7 +111,7 @@ pub(crate) fn placeholder(
 /// parameter), its control and its value until one is read. `None` for a type that is not kept.
 fn shape(p: &EffectParam<'_, '_>, size: (u32, u32)) -> Option<(Option<Kind>, ParamUi, Value)> {
     let (kind, ui, default) = match p.kind {
-        ParamKind::IntSlider | ParamKind::FixedSlider | ParamKind::FloatSlider => (Kind::EffectNumber(1.0), ParamUi::Number, Value::Scalar(0.0)),
+        ParamKind::IntSlider | ParamKind::FixedSlider | ParamKind::FloatSlider => (Kind::EffectNumber(1.0), slider_ui(p), Value::Scalar(0.0)),
         ParamKind::Angle => (Kind::EffectNumber(1.0), ParamUi::Angle, Value::Scalar(0.0)),
         ParamKind::Checkbox => (Kind::EffectBool, ParamUi::Checkbox, Value::Bool(false)),
         ParamKind::Color => (Kind::EffectColor, ParamUi::Color, Value::Color([0.0, 0.0, 0.0, 1.0])),
@@ -131,6 +131,17 @@ fn shape(p: &EffectParam<'_, '_>, size: (u32, u32)) -> Option<(Option<Kind>, Par
     Some((Some(kind), ui, default))
 }
 
+/// A slider's control: a float slider's valid range and drag range when they are ranges (only a
+/// float slider's are decoded), else a plain number.
+fn slider_ui(p: &EffectParam<'_, '_>) -> ParamUi {
+    match (p.valid_min(), p.valid_max(), p.slider_range()) {
+        (Some(min), Some(max), Some((smin, smax))) if [min, max, smin, smax].iter().all(|v| v.is_finite()) && min <= max && smin <= smax => {
+            ParamUi::Slider { min, max, slider_min: smin.clamp(min, max), slider_max: smax.clamp(min, max), decimals: 2 }
+        }
+        _ => ParamUi::Number,
+    }
+}
+
 /// How many items a popup has: the file's names, else the count in its definition.
 fn popup_len(p: &EffectParam<'_, '_>) -> Option<usize> {
     p.items.as_ref().map(Vec::len).or_else(|| p.popup_item_count().map(usize::from))

crates/aep/tests/it/import/placeholders.rs

@@ -109,6 +109,24 @@ fn a_pseudo_effect_is_kept_with_its_parameter_names() {
     assert_eq!(path.as_deref().and_then(|p| layer.prop(p)).map(|p| p.name.as_str()), Some("Speed"), "{path:?}");
 }
 
+/// A float slider keeps its valid range and slider range, so Effect Controls drags and clamps it
+/// as After Effects does; a range that is not a range stays a plain number.
+#[test]
+fn a_float_slider_keeps_its_range() {
+    let fx = Fx {
+        match_name: "Pseudo/r",
+        name: "Rig",
+        defs: vec![slider(K::FloatSlider, "Speed", 1.0, (-10.0, 100.0)), slider(K::FloatSlider, "Odd", 1.0, (5.0, 1.0))],
+        values: vec![],
+        data: vec![],
+        keys: vec![],
+    };
+    let (g, _) = placeholder_of(&fx);
+    let ui = |id: &str| g.prop(id).map(|p| p.ui.clone());
+    assert_eq!(ui("param1"), Some(ParamUi::Slider { min: -10.0, max: 100.0, slider_min: -10.0, slider_max: 100.0, decimals: 2 }));
+    assert_eq!(ui("param2"), Some(ParamUi::Number));
+}
+
 /// A popup whose definition is borrowed (the project copy) and has no value record: its default
 /// slot holds another copy's selection, so the first item is used and that is reported.
 #[test]

docs/aep-import.md

@@ -324,7 +324,7 @@ parameter gets the file's value:
   is that name as one path segment, `Pseudo_0_25`). Like a missing plug-in it renders nothing and is listed by Find Missing
   Effects. It holds the effect's parameters flat (without the twirl-down group markers), named as
   in After Effects, each with its value, keys and expression, in the units After Effects'
-  expressions read (sliders and angles as stored, points in layer pixels, colours, checkboxes,
+  expressions read (sliders and angles as stored, a float slider with its range, points in layer pixels, colours, checkboxes,
   popups over the file's items with separators, read 1-based; layer parameters name their layer,
   without a record the layer itself as for Layer Control, and their keys and expression are
   reported),