Add AnimationHelper

Signed-off-by: kernelkind <kernelkind@gmail.com>

src/ui/anim.rs

@@ -1,3 +1,5 @@
+use egui::{Pos2, Rect, Response, Sense};
+
 pub fn hover_expand(
     ui: &mut egui::Ui,
     id: egui::Id,
@@ -25,3 +27,70 @@ pub fn hover_expand_small(ui: &mut egui::Ui, id: egui::Id) -> (egui::Rect, f32,
 
     hover_expand(ui, id, size, expand_size, anim_speed)
 }
+
+pub static ICON_EXPANSION_MULTIPLE: f32 = 1.2;
+pub static ANIM_SPEED: f32 = 0.05;
+pub struct AnimationHelper {
+    rect: Rect,
+    center: Pos2,
+    response: Response,
+    animation_progress: f32,
+    expansion_multiple: f32,
+}
+
+impl AnimationHelper {
+    pub fn new(
+        ui: &mut egui::Ui,
+        animation_name: impl std::hash::Hash,
+        max_size: egui::Vec2,
+    ) -> Self {
+        let id = ui.id().with(animation_name);
+        let (rect, response) = ui.allocate_exact_size(max_size, Sense::click());
+
+        let animation_progress =
+            ui.ctx()
+                .animate_bool_with_time(id, response.hovered(), ANIM_SPEED);
+
+        Self {
+            rect,
+            center: rect.center(),
+            response,
+            animation_progress,
+            expansion_multiple: ICON_EXPANSION_MULTIPLE,
+        }
+    }
+
+    pub fn scale_1d_pos(&self, min_object_size: f32) -> f32 {
+        let max_object_size = min_object_size * self.expansion_multiple;
+
+        if self.response.is_pointer_button_down_on() {
+            min_object_size
+        } else {
+            min_object_size + ((max_object_size - min_object_size) * self.animation_progress)
+        }
+    }
+
+    pub fn scale_radius(&self, min_diameter: f32) -> f32 {
+        self.scale_1d_pos((min_diameter - 1.0) / 2.0)
+    }
+
+    pub fn get_animation_rect(&self) -> egui::Rect {
+        self.rect
+    }
+
+    pub fn center(&self) -> Pos2 {
+        self.rect.center()
+    }
+
+    pub fn take_animation_response(self) -> egui::Response {
+        self.response
+    }
+
+    // Scale a minimum position from center to the current animation position
+    pub fn scale_from_center(&self, x_min: f32, y_min: f32) -> Pos2 {
+        Pos2::new(
+            self.center.x + self.scale_1d_pos(x_min),
+            self.center.y + self.scale_1d_pos(y_min),
+        )
+    }
+}