Optimization of cursor animation

src/cursor.rs

@@ -31,46 +31,30 @@ impl Alpha {
 }
 
 enum AnimPhase {
-    Shown(i32),
+    Shown,
     Hide,
-    Hidden(i32),
+    Hidden,
     Show,
 }
 
-impl AnimPhase {
-    fn sub(&mut self, step: i32) -> bool {
-        match self {
-            &mut AnimPhase::Shown(ref mut val) |
-                &mut AnimPhase::Hidden(ref mut val) => {
-                    *val -= step;
-                    if *val <= 0 {
-                        false
-                    } else {
-                        true
-                    }
-                }
-            _ => false,
-        }
-    }
-}
-
 pub struct State {
     alpha: Alpha,
     anim_phase: AnimPhase,
+
+    timer: Option<glib::SourceId>,
 }
 
 impl State {
     pub fn new() -> State {
         State {
             alpha: Alpha(1.0),
-            anim_phase: AnimPhase::Shown(500),
+            anim_phase: AnimPhase::Shown,
+            timer: None,
         }
     }
 }
 
 pub struct Cursor {
-    timer: Option<glib::SourceId>,
-
     state: Arc<Mutex<State>>,
 }
 
@@ -78,49 +62,16 @@ impl Cursor {
     pub fn new() -> Cursor {
 
         Cursor {
-            timer: None,
             state: Arc::new(Mutex::new(State::new())),
         }
 
     }
 
     pub fn start(&mut self) {
-        if self.timer.is_none() {
-            let state = self.state.clone();
-            self.timer = Some(glib::timeout_add(100, move || {
-                let mut mut_state = state.lock().unwrap();
-
-                // wait
-                // [TODO]: Implement wait through new timeout - 2017-03-24 10:21
-                if mut_state.anim_phase.sub(100) {
-                    return glib::Continue(true);
-                }
-
-                match mut_state.anim_phase {
-                    AnimPhase::Shown(_) => {
-                        mut_state.anim_phase = AnimPhase::Hide;
-                    }
-                    AnimPhase::Hide => {
-                        if !mut_state.alpha.hide(0.3) {
-                            mut_state.anim_phase = AnimPhase::Hidden(300);
-                        }
-                    }
-                    AnimPhase::Hidden(_) => {
-                        mut_state.anim_phase = AnimPhase::Show;
-                    }
-                    AnimPhase::Show => {
-                        if !mut_state.alpha.show(0.3) {
-                            mut_state.anim_phase = AnimPhase::Shown(500);
-                        }
-                    }
-                }
-
-                SHELL!(&shell = {
-                    let point = shell.model.cur_point();
-                    shell.on_redraw(&RepaintMode::Area(point));
-                });
-                glib::Continue(true)
-            }));
+        let state = self.state.clone();
+        let mut mut_state = self.state.lock().unwrap();
+        if mut_state.timer.is_none() {
+            mut_state.timer = Some(glib::timeout_add(100, move || anim_step(&state)));
         }
     }
 
@@ -153,9 +104,60 @@ impl Cursor {
     }
 }
 
+// [TODO]: Reset animation phase on events - 2017-03-24 11:33
+fn anim_step(state: &Arc<Mutex<State>>) -> glib::Continue {
+    let moved_state = state.clone();
+    let mut mut_state = state.lock().unwrap();
+
+    let next_event = match mut_state.anim_phase {
+        AnimPhase::Shown => {
+            mut_state.anim_phase = AnimPhase::Hide;
+            Some(100)
+        }
+        AnimPhase::Hide => {
+            if !mut_state.alpha.hide(0.3) {
+                mut_state.anim_phase = AnimPhase::Hidden;
+
+                Some(300)
+            } else {
+                None
+            }
+        }
+        AnimPhase::Hidden => {
+            mut_state.anim_phase = AnimPhase::Show;
+
+            Some(100)
+        }
+        AnimPhase::Show => {
+            if !mut_state.alpha.show(0.3) {
+                mut_state.anim_phase = AnimPhase::Shown;
+
+                Some(500)
+            } else {
+                None
+            }
+        }
+    };
+
+    SHELL!(&shell = {
+        let point = shell.model.cur_point();
+        shell.on_redraw(&RepaintMode::Area(point));
+    });
+
+    
+    if let Some(timeout) = next_event {
+        mut_state.timer = Some(glib::timeout_add(timeout, move || anim_step(&moved_state) ));
+
+        glib::Continue(false)
+    } else {
+        glib::Continue(true)
+    }
+
+}
+
 impl Drop for Cursor {
     fn drop(&mut self) {
-        if let Some(timer_id) = self.timer {
+        if let Some(timer_id) = self.state.lock().unwrap().timer {
             glib::source_remove(timer_id);
         }
     }