Trying to clena the mess opened by plugins

plugins/nih-plug-egui/src/widgets/param_slider.rs

@@ -0,0 +1,357 @@
+use std::sync::{Arc, LazyLock};
+
+use egui_baseview::egui::emath::GuiRounding;
+use egui_baseview::egui::{
+    self, emath, vec2, Key, Response, Sense, Stroke, TextEdit, TextStyle, Ui, Vec2, Widget,
+    WidgetText,
+};
+use nih_plug::prelude::{Param, ParamSetter};
+use parking_lot::Mutex;
+
+use super::util;
+
+/// When shift+dragging a parameter, one pixel dragged corresponds to this much change in the
+/// noramlized parameter.
+const GRANULAR_DRAG_MULTIPLIER: f32 = 0.0015;
+
+static DRAG_NORMALIZED_START_VALUE_MEMORY_ID: LazyLock<egui::Id> =
+    LazyLock::new(|| egui::Id::new((file!(), 0)));
+static DRAG_AMOUNT_MEMORY_ID: LazyLock<egui::Id> = LazyLock::new(|| egui::Id::new((file!(), 1)));
+static VALUE_ENTRY_MEMORY_ID: LazyLock<egui::Id> = LazyLock::new(|| egui::Id::new((file!(), 2)));
+
+/// A slider widget similar to [`egui::widgets::Slider`] that knows about NIH-plug parameters ranges
+/// and can get values for it. The slider supports double click and control click to reset,
+/// shift+drag for granular dragging, text value entry by clicking on the value text.
+///
+/// TODO: Vertical orientation
+/// TODO: Check below for more input methods that should be added
+/// TODO: Decouple the logic from the drawing so we can also do things like nobs without having to
+///       repeat everything
+/// TODO: Add WidgetInfo annotations for accessibility
+#[must_use = "You should put this widget in an ui with `ui.add(widget);`"]
+pub struct ParamSlider<'a, P: Param> {
+    param: &'a P,
+    setter: &'a ParamSetter<'a>,
+
+    draw_value: bool,
+    slider_width: Option<f32>,
+
+    /// Will be set in the `ui()` function so we can request keyboard input focus on Alt+click.
+    keyboard_focus_id: Option<egui::Id>,
+}
+
+impl<'a, P: Param> ParamSlider<'a, P> {
+    /// Create a new slider for a parameter. Use the other methods to modify the slider before
+    /// passing it to [`Ui::add()`].
+    pub fn for_param(param: &'a P, setter: &'a ParamSetter<'a>) -> Self {
+        Self {
+            param,
+            setter,
+
+            draw_value: true,
+            slider_width: None,
+
+            keyboard_focus_id: None,
+        }
+    }
+
+    /// Don't draw the text slider's current value after the slider.
+    pub fn without_value(mut self) -> Self {
+        self.draw_value = false;
+        self
+    }
+
+    /// Set a custom width for the slider.
+    pub fn with_width(mut self, width: f32) -> Self {
+        self.slider_width = Some(width);
+        self
+    }
+
+    fn plain_value(&self) -> P::Plain {
+        self.param.modulated_plain_value()
+    }
+
+    fn normalized_value(&self) -> f32 {
+        self.param.modulated_normalized_value()
+    }
+
+    fn string_value(&self) -> String {
+        self.param.to_string()
+    }
+
+    /// Enable the keyboard entry part of the widget.
+    fn begin_keyboard_entry(&self, ui: &Ui) {
+        ui.memory_mut(|mem| mem.request_focus(self.keyboard_focus_id.unwrap()));
+
+        // Always initialize the field to the current value, that seems nicer than having to
+        // being typing from scratch
+        let value_entry_mutex = ui.memory_mut(|mem| {
+            mem.data
+                .get_temp_mut_or_default::<Arc<Mutex<String>>>(*VALUE_ENTRY_MEMORY_ID)
+                .clone()
+        });
+        *value_entry_mutex.lock() = self.string_value();
+    }
+
+    fn keyboard_entry_active(&self, ui: &Ui) -> bool {
+        ui.memory(|mem| mem.has_focus(self.keyboard_focus_id.unwrap()))
+    }
+
+    fn begin_drag(&self) {
+        self.setter.begin_set_parameter(self.param);
+    }
+
+    fn set_normalized_value(&self, normalized: f32) {
+        // This snaps to the nearest plain value if the parameter is stepped in some way.
+        // TODO: As an optimization, we could add a `const CONTINUOUS: bool` to the parameter to
+        //       avoid this normalized->plain->normalized conversion for parameters that don't need
+        //       it
+        let value = self.param.preview_plain(normalized);
+        if value != self.plain_value() {
+            self.setter.set_parameter(self.param, value);
+        }
+    }
+
+    /// Begin and end drag still need to be called when using this. Returns `false` if the string
+    /// could no tbe parsed.
+    fn set_from_string(&self, string: &str) -> bool {
+        match self.param.string_to_normalized_value(string) {
+            Some(normalized_value) => {
+                self.set_normalized_value(normalized_value);
+                true
+            }
+            None => false,
+        }
+    }
+
+    /// Begin and end drag still need to be called when using this..
+    fn reset_param(&self) {
+        self.setter
+            .set_parameter(self.param, self.param.default_plain_value());
+    }
+
+    fn granular_drag(&self, ui: &Ui, drag_delta: Vec2) {
+        // Remember the intial position when we started with the granular drag. This value gets
+        // reset whenever we have a normal itneraction with the slider.
+        let start_value = if Self::get_drag_amount_memory(ui) == 0.0 {
+            Self::set_drag_normalized_start_value_memory(ui, self.normalized_value());
+            self.normalized_value()
+        } else {
+            Self::get_drag_normalized_start_value_memory(ui)
+        };
+
+        let total_drag_distance = drag_delta.x + Self::get_drag_amount_memory(ui);
+        Self::set_drag_amount_memory(ui, total_drag_distance);
+
+        self.set_normalized_value(
+            (start_value + (total_drag_distance * GRANULAR_DRAG_MULTIPLIER)).clamp(0.0, 1.0),
+        );
+    }
+
+    fn end_drag(&self) {
+        self.setter.end_set_parameter(self.param);
+    }
+
+    fn get_drag_normalized_start_value_memory(ui: &Ui) -> f32 {
+        ui.memory(|mem| {
+            mem.data
+                .get_temp(*DRAG_NORMALIZED_START_VALUE_MEMORY_ID)
+                .unwrap_or(0.5)
+        })
+    }
+
+    fn set_drag_normalized_start_value_memory(ui: &Ui, amount: f32) {
+        ui.memory_mut(|mem| {
+            mem.data
+                .insert_temp(*DRAG_NORMALIZED_START_VALUE_MEMORY_ID, amount)
+        });
+    }
+
+    fn get_drag_amount_memory(ui: &Ui) -> f32 {
+        ui.memory(|mem| mem.data.get_temp(*DRAG_AMOUNT_MEMORY_ID).unwrap_or(0.0))
+    }
+
+    fn set_drag_amount_memory(ui: &Ui, amount: f32) {
+        ui.memory_mut(|mem| mem.data.insert_temp(*DRAG_AMOUNT_MEMORY_ID, amount));
+    }
+
+    fn slider_ui(&self, ui: &Ui, response: &mut Response) {
+        // Handle user input
+        // TODO: Optionally (since it can be annoying) add scrolling behind a builder option
+        if response.drag_started() {
+            // When beginning a drag or dragging normally, reset the memory used to keep track of
+            // our granular drag
+            self.begin_drag();
+            Self::set_drag_amount_memory(ui, 0.0);
+        }
+        if let Some(click_pos) = response.interact_pointer_pos() {
+            if ui.input(|i| i.modifiers.command) {
+                // Like double clicking, Ctrl+Click should reset the parameter
+                self.reset_param();
+                response.mark_changed();
+            // // FIXME: This releases the focus again when you release the mouse button without
+            // //        moving the mouse a bit for some reason
+            // } else if ui.input().modifiers.alt && self.draw_value {
+            //     // Allow typing in the value on an Alt+Click. Right now this is shown as part of the
+            //     // value field, so it only makes sense when we're drawing that.
+            //     self.begin_keyboard_entry(ui);
+            } else if ui.input(|i| i.modifiers.shift) {
+                // And shift dragging should switch to a more granulra input method
+                self.granular_drag(ui, response.drag_delta());
+                response.mark_changed();
+            } else {
+                let proportion =
+                    emath::remap_clamp(click_pos.x, response.rect.x_range(), 0.0..=1.0) as f64;
+                self.set_normalized_value(proportion as f32);
+                response.mark_changed();
+                Self::set_drag_amount_memory(ui, 0.0);
+            }
+        }
+        if response.double_clicked() {
+            self.reset_param();
+            response.mark_changed();
+        }
+        if response.drag_stopped() {
+            self.end_drag();
+        }
+
+        // And finally draw the thing
+        if ui.is_rect_visible(response.rect) {
+            // We'll do a flat widget with background -> filled foreground -> slight border
+            ui.painter()
+                .rect_filled(response.rect, 0.0, ui.visuals().widgets.inactive.bg_fill);
+
+            let filled_proportion = self.normalized_value();
+            if filled_proportion > 0.0 {
+                let mut filled_rect = response.rect;
+                filled_rect.set_width(response.rect.width() * filled_proportion);
+                let filled_bg = if response.dragged() {
+                    util::add_hsv(ui.visuals().selection.bg_fill, 0.0, -0.1, 0.1)
+                } else {
+                    ui.visuals().selection.bg_fill
+                };
+                ui.painter().rect_filled(filled_rect, 0.0, filled_bg);
+            }
+
+            ui.painter().rect_stroke(
+                response.rect,
+                0.0,
+                Stroke::new(1.0, ui.visuals().widgets.active.bg_fill),
+                egui::StrokeKind::Middle,
+            );
+        }
+    }
+
+    fn value_ui(&self, ui: &mut Ui) {
+        let visuals = ui.visuals().widgets.inactive;
+        let should_draw_frame = ui.visuals().button_frame;
+        let padding = ui.spacing().button_padding;
+
+        // Either show the parameter's label, or show a text entry field if the parameter's label
+        // has been clicked on
+        let keyboard_focus_id = self.keyboard_focus_id.unwrap();
+        if self.keyboard_entry_active(ui) {
+            let value_entry_mutex = ui.memory_mut(|mem| {
+                mem.data
+                    .get_temp_mut_or_default::<Arc<Mutex<String>>>(*VALUE_ENTRY_MEMORY_ID)
+                    .clone()
+            });
+            let mut value_entry = value_entry_mutex.lock();
+
+            ui.add(
+                TextEdit::singleline(&mut *value_entry)
+                    .id(keyboard_focus_id)
+                    .font(TextStyle::Monospace),
+            );
+            if ui.input(|i| i.key_pressed(Key::Escape)) {
+                // Cancel when pressing escape
+                ui.memory_mut(|mem| mem.surrender_focus(keyboard_focus_id));
+            } else if ui.input(|i| i.key_pressed(Key::Enter)) {
+                // And try to set the value by string when pressing enter
+                self.begin_drag();
+                self.set_from_string(&value_entry);
+                self.end_drag();
+
+                ui.memory_mut(|mem| mem.surrender_focus(keyboard_focus_id));
+            }
+        } else {
+            let text = WidgetText::from(self.string_value()).into_galley(
+                ui,
+                None,
+                ui.available_width() - (padding.x * 2.0),
+                TextStyle::Button,
+            );
+
+            let response = ui.allocate_response(text.size() + (padding * 2.0), Sense::click());
+            if response.clicked() {
+                self.begin_keyboard_entry(ui);
+            }
+
+            if ui.is_rect_visible(response.rect) {
+                if should_draw_frame {
+                    let fill = visuals.bg_fill;
+                    let stroke = visuals.bg_stroke;
+                    ui.painter().rect(
+                        response.rect.expand(visuals.expansion),
+                        visuals.corner_radius,
+                        fill,
+                        stroke,
+                        egui::StrokeKind::Middle,
+                    );
+                }
+
+                let text_pos = ui
+                    .layout()
+                    .align_size_within_rect(text.size(), response.rect.shrink2(padding))
+                    .min;
+
+                ui.painter().add(egui::epaint::TextShape::new(
+                    text_pos,
+                    text,
+                    visuals.fg_stroke.color,
+                ));
+            }
+        }
+    }
+}
+
+impl<P: Param> Widget for ParamSlider<'_, P> {
+    fn ui(mut self, ui: &mut Ui) -> Response {
+        let slider_width = self
+            .slider_width
+            .unwrap_or_else(|| ui.spacing().slider_width);
+
+        ui.horizontal(|ui| {
+            // Allocate space, but add some padding on the top and bottom to make it look a bit slimmer.
+            let height = ui
+                .text_style_height(&TextStyle::Body)
+                .max(ui.spacing().interact_size.y * 0.8);
+            let slider_height = (height * 0.8).round_to_pixels(ui.painter().pixels_per_point());
+            let mut response = ui
+                .vertical(|ui| {
+                    ui.allocate_space(vec2(slider_width, (height - slider_height) / 2.0));
+                    let response = ui.allocate_response(
+                        vec2(slider_width, slider_height),
+                        Sense::click_and_drag(),
+                    );
+                    let (kb_edit_id, _) =
+                        ui.allocate_space(vec2(slider_width, (height - slider_height) / 2.0));
+                    // Allocate an automatic ID for keeping track of keyboard focus state
+                    // FIXME: There doesn't seem to be a way to generate IDs in the public API, not sure how
+                    //        you're supposed to do this
+                    self.keyboard_focus_id = Some(kb_edit_id);
+
+                    response
+                })
+                .inner;
+
+            self.slider_ui(ui, &mut response);
+            if self.draw_value {
+                self.value_ui(ui);
+            }
+
+            response
+        })
+        .inner
+    }
+}