going to just use the ol update and click routine

src/button.rs

@@ -36,8 +36,8 @@ impl<'s> Button<'s> {
         self.text.set_position(position);
     }
 
-    pub fn set_callback(&mut self, callback: &'s FnMut(i32)){
-        self.callback = Some(callback);
+    pub fn is_within(point: Vector2f, button: &Button) -> bool {
+        button.body.local_bounds().contains(point)
     }
 }
 

src/slider.rs

@@ -9,6 +9,7 @@ pub struct Slider<'a> {
     right_button: Button<'a>,
     slider_button: Button<'a>,
     rail: RectangleShape<'a>,
+    root_position: Vector2f,
 }
 
 impl<'a> Slider<'a> {
@@ -30,10 +31,9 @@ impl<'a> Slider<'a> {
             right_button: Button::new(Vector2f::new(30.0, 50.0), right_button_position, font),
             slider_button: Button::new(Vector2f::new(30.0, 50.0), slider_position, font),
             rail: RectangleShape::with_size(Vector2f::new(150.0, 2.0)),
+            root_position: position,
         };
 
-        slider.left_button.set_callback(&|a| slider.set_value(a));
-
         slider.left_button.set_text("<");
         slider.right_button.set_text(">");
 
@@ -42,10 +42,18 @@ impl<'a> Slider<'a> {
         slider
     }
 
-    pub fn set_value(&mut self, inp: i32){
+    pub fn click(&mut self, click: Vector2f) {
+        if Button::is_within(click, &self.left_button) {
+            self.value -= 1.0;
+        }
+        if Button::is_within(click, &self.right_button) {
             self.value += 1.0;
         }
+    }
 
+    pub fn update(&mut self) {
+        self.slider_button.set_position(self.root_position + Vector2f::new(self.value,0.0));
+    }
 }
 
 impl<'s> Drawable for Slider<'s> {