From 1d099bd464c1564c45ae0644b2633b41fb2f88f4 Mon Sep 17 00:00:00 2001
From: sjoshid <ILGitHub2>
Date: Sun, 12 Apr 2020 13:40:27 -0400
Subject: [PATCH 01/10] 1) More aggressive Timer event traversal. 2) Aggressive
 traversal is achieved by storing a map of TimerToken -> WidgetId in each
 window. 3) On Timer event, we check the map from step 2 and recurse only if
 child MIGHT contain the WidgetId.

---
 druid/src/contexts.rs | 11 ++++++++++-
 druid/src/core.rs     | 27 ++++++++++++++++++++++++---
 druid/src/window.rs   | 15 ++++++++++++---
 3 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/druid/src/contexts.rs b/druid/src/contexts.rs
index bbdebfd161..bc77550690 100644
--- a/druid/src/contexts.rs
+++ b/druid/src/contexts.rs
@@ -26,6 +26,7 @@ use crate::{
     Affine, Command, Cursor, Insets, Rect, Size, Target, Text, TimerToken, WidgetId, WindowHandle,
     WindowId,
 };
+use std::collections::HashMap;
 
 /// A mutable context provided to event handling methods of widgets.
 ///
@@ -46,6 +47,8 @@ pub struct EventCtx<'a> {
     pub(crate) had_active: bool,
     pub(crate) is_handled: bool,
     pub(crate) is_root: bool,
+    /// Map of TimerTokens and WidgetIds that requested them.
+    pub(crate) timers: &'a HashMap<TimerToken, WidgetId>,
 }
 
 /// A mutable context provided to the [`lifecycle`] method on widgets.
@@ -349,7 +352,13 @@ impl<'a> EventCtx<'a> {
     /// request with the event.
     pub fn request_timer(&mut self, deadline: Instant) -> TimerToken {
         self.base_state.request_timer = true;
-        self.window.request_timer(deadline)
+        let timer_token = self.window.request_timer(deadline);
+        self.base_state.add_timer(timer_token);
+        timer_token
+    }
+
+    pub fn remove_timer(&mut self, timer_token: &TimerToken) {
+        self.base_state.remove_timer(timer_token);
     }
 
     /// The layout size.
diff --git a/druid/src/core.rs b/druid/src/core.rs
index c23402dec6..645731acfe 100644
--- a/druid/src/core.rs
+++ b/druid/src/core.rs
@@ -14,7 +14,7 @@
 
 //! The fundamental druid types.
 
-use std::collections::VecDeque;
+use std::collections::{HashMap, VecDeque};
 
 use log;
 
@@ -23,7 +23,7 @@ use crate::kurbo::{Affine, Insets, Rect, Shape, Size};
 use crate::piet::RenderContext;
 use crate::{
     BoxConstraints, Command, Data, Env, Event, EventCtx, LayoutCtx, LifeCycle, LifeCycleCtx,
-    PaintCtx, Target, UpdateCtx, Widget, WidgetId,
+    PaintCtx, Target, TimerToken, UpdateCtx, Widget, WidgetId,
 };
 
 /// Our queue type
@@ -99,6 +99,7 @@ pub(crate) struct BaseState {
     pub(crate) request_focus: Option<FocusChange>,
     pub(crate) children: Bloom<WidgetId>,
     pub(crate) children_changed: bool,
+    pub(crate) timers: HashMap<TimerToken, WidgetId>,
 }
 
 /// Methods by which a widget can attempt to change focus state.
@@ -376,6 +377,7 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
             is_handled: false,
             is_root: false,
             focus_widget: ctx.focus_widget,
+            timers: &ctx.timers,
         };
         let rect = child_ctx.base_state.layout_rect;
         // Note: could also represent this as `Option<Event>`.
@@ -438,7 +440,14 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
                 Event::Zoom(*zoom)
             }
             Event::Timer(id) => {
-                recurse = child_ctx.base_state.request_timer;
+                if let Some(widget_id) = child_ctx.timers.get(id) {
+                    if *widget_id != child_ctx.base_state.id {
+                        recurse = child_ctx.base_state.children.may_contain(widget_id);
+                    }
+                } else {
+                    log::error!("Timer Token must be in timers map.");
+                    recurse = false;
+                }
                 Event::Timer(*id)
             }
             Event::Command(cmd) => Event::Command(cmd.clone()),
@@ -467,6 +476,8 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
         };
 
         ctx.base_state.merge_up(&child_ctx.base_state);
+        // Clear current widget's timers after merging with parent.
+        child_ctx.base_state.timers.clear();
         ctx.is_handled |= child_ctx.is_handled;
     }
 
@@ -630,9 +641,18 @@ impl BaseState {
             focus_chain: Vec::new(),
             children: Bloom::new(),
             children_changed: false,
+            timers: HashMap::new(),
         }
     }
 
+    pub(crate) fn add_timer(&mut self, timer_token: TimerToken) {
+        self.timers.insert(timer_token, self.id);
+    }
+
+    pub(crate) fn remove_timer(&mut self, timer_token: &TimerToken) {
+        self.timers.remove(timer_token);
+    }
+
     /// Update to incorporate state changes from a child.
     fn merge_up(&mut self, child_state: &BaseState) {
         self.needs_inval |= child_state.needs_inval;
@@ -642,6 +662,7 @@ impl BaseState {
         self.has_active |= child_state.has_active;
         self.children_changed |= child_state.children_changed;
         self.request_focus = self.request_focus.or(child_state.request_focus);
+        self.timers.extend(&child_state.timers);
     }
 
     #[inline]
diff --git a/druid/src/window.rs b/druid/src/window.rs
index 8be999066b..6cc63bf46d 100644
--- a/druid/src/window.rs
+++ b/druid/src/window.rs
@@ -14,18 +14,19 @@
 
 //! Management of multiple windows.
 
+use std::collections::HashMap;
 use std::mem;
 use std::time::Instant;
 
+use crate::core::{BaseState, CommandQueue, FocusChange};
 use crate::kurbo::{Insets, Point, Rect, Size};
 use crate::piet::{Piet, RenderContext};
 use crate::shell::{Counter, Cursor, WindowHandle};
-
-use crate::core::{BaseState, CommandQueue, FocusChange};
 use crate::win_handler::RUN_COMMANDS_TOKEN;
 use crate::{
     BoxConstraints, Command, Data, Env, Event, EventCtx, LayoutCtx, LifeCycle, LifeCycleCtx,
-    LocalizedString, MenuDesc, PaintCtx, UpdateCtx, Widget, WidgetId, WidgetPod, WindowDesc,
+    LocalizedString, MenuDesc, PaintCtx, TimerToken, UpdateCtx, Widget, WidgetId, WidgetPod,
+    WindowDesc,
 };
 
 /// A unique identifier for a window.
@@ -43,6 +44,7 @@ pub struct Window<T> {
     pub(crate) last_anim: Option<Instant>,
     pub(crate) focus: Option<WidgetId>,
     pub(crate) handle: WindowHandle,
+    pub(crate) timers: HashMap<TimerToken, WidgetId>,
     // delegate?
 }
 
@@ -58,6 +60,7 @@ impl<T> Window<T> {
             last_anim: None,
             focus: None,
             handle,
+            timers: HashMap::new(),
         }
     }
 }
@@ -145,6 +148,7 @@ impl<T: Data> Window<T> {
                 window: &self.handle,
                 window_id: self.id,
                 focus_widget: self.focus,
+                timers: &self.timers,
             };
 
             self.root.event(&mut ctx, &event, data, env);
@@ -169,6 +173,11 @@ impl<T: Data> Window<T> {
             self.lifecycle(queue, &LifeCycle::RouteWidgetAdded, data, env);
         }
 
+        //If at least one widget requested timer, collect those timers from widgets and add to window's timers map.
+        if base_state.request_timer {
+            self.timers.extend(base_state.timers);
+        }
+
         is_handled
     }
 

From 3f47c3fbed4ee586c8a19a0b1f30193789c6d8d5 Mon Sep 17 00:00:00 2001
From: sjoshid <ILGitHub2>
Date: Sun, 12 Apr 2020 14:08:06 -0400
Subject: [PATCH 02/10] 1) Comment

---
 druid/src/core.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/druid/src/core.rs b/druid/src/core.rs
index 645731acfe..f73274586e 100644
--- a/druid/src/core.rs
+++ b/druid/src/core.rs
@@ -99,6 +99,7 @@ pub(crate) struct BaseState {
     pub(crate) request_focus: Option<FocusChange>,
     pub(crate) children: Bloom<WidgetId>,
     pub(crate) children_changed: bool,
+    /// Associate timers with widgets that requested them.
     pub(crate) timers: HashMap<TimerToken, WidgetId>,
 }
 

From 1bdc803944e5e66d62c7552566547e566b575cd6 Mon Sep 17 00:00:00 2001
From: sjoshid <ILGitHub2>
Date: Sun, 12 Apr 2020 14:30:55 -0400
Subject: [PATCH 03/10] Fix clippy warnings.

---
 druid/src/contexts.rs | 2 +-
 druid/src/core.rs     | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/druid/src/contexts.rs b/druid/src/contexts.rs
index bc77550690..74f947f921 100644
--- a/druid/src/contexts.rs
+++ b/druid/src/contexts.rs
@@ -357,7 +357,7 @@ impl<'a> EventCtx<'a> {
         timer_token
     }
 
-    pub fn remove_timer(&mut self, timer_token: &TimerToken) {
+    pub fn remove_timer(&mut self, timer_token: TimerToken) {
         self.base_state.remove_timer(timer_token);
     }
 
diff --git a/druid/src/core.rs b/druid/src/core.rs
index f73274586e..d478ec7c45 100644
--- a/druid/src/core.rs
+++ b/druid/src/core.rs
@@ -650,8 +650,8 @@ impl BaseState {
         self.timers.insert(timer_token, self.id);
     }
 
-    pub(crate) fn remove_timer(&mut self, timer_token: &TimerToken) {
-        self.timers.remove(timer_token);
+    pub(crate) fn remove_timer(&mut self, timer_token: TimerToken) {
+        self.timers.remove(&timer_token);
     }
 
     /// Update to incorporate state changes from a child.

From dd7892e426d2d1954f921b0a122e7e742d7a1742 Mon Sep 17 00:00:00 2001
From: Sujit Joshi <joshi.sujit020386@gmail.com>
Date: Mon, 13 Apr 2020 08:56:33 -0400
Subject: [PATCH 04/10] 1) After merging up, Im clearing the map of BaseState.
 So remove is not needed when event is handled.

---
 druid/src/contexts.rs | 4 ----
 druid/src/core.rs     | 4 ----
 2 files changed, 8 deletions(-)

diff --git a/druid/src/contexts.rs b/druid/src/contexts.rs
index 74f947f921..a2641614f3 100644
--- a/druid/src/contexts.rs
+++ b/druid/src/contexts.rs
@@ -357,10 +357,6 @@ impl<'a> EventCtx<'a> {
         timer_token
     }
 
-    pub fn remove_timer(&mut self, timer_token: TimerToken) {
-        self.base_state.remove_timer(timer_token);
-    }
-
     /// The layout size.
     ///
     /// This is the layout size as ultimately determined by the parent
diff --git a/druid/src/core.rs b/druid/src/core.rs
index d478ec7c45..0cc49bab8f 100644
--- a/druid/src/core.rs
+++ b/druid/src/core.rs
@@ -650,10 +650,6 @@ impl BaseState {
         self.timers.insert(timer_token, self.id);
     }
 
-    pub(crate) fn remove_timer(&mut self, timer_token: TimerToken) {
-        self.timers.remove(&timer_token);
-    }
-
     /// Update to incorporate state changes from a child.
     fn merge_up(&mut self, child_state: &BaseState) {
         self.needs_inval |= child_state.needs_inval;

From 6349aa4480496d56327ce2eda8954eb75b3058c4 Mon Sep 17 00:00:00 2001
From: sjoshid <ILGitHub2>
Date: Sun, 19 Apr 2020 11:18:43 -0400
Subject: [PATCH 05/10] 1) Removing window's timer token before adding base
 state's token to it.

---
 druid/src/window.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/druid/src/window.rs b/druid/src/window.rs
index dbab091959..9c3f5f6029 100644
--- a/druid/src/window.rs
+++ b/druid/src/window.rs
@@ -218,6 +218,12 @@ impl<T: Data> Window<T> {
 
         self.post_event_processing(queue, data, env, false);
 
+        //In some platforms, timer tokens are reused. So it is necessary to remove token from
+        //window's timer before adding base state's timers to it.
+        if let Event::Timer(token) = event {
+            self.timers.remove(&token);
+        }
+
         //If at least one widget requested timer, collect those timers from widgets and add to window's timers map.
         if base_state.request_timer {
             self.timers.extend(base_state.timers);

From 3d4870a29ce13e97ae703b4e94c0d29502bc46de Mon Sep 17 00:00:00 2001
From: Sujit Joshi <joshi.sujit020386@gmail.com>
Date: Sun, 26 Apr 2020 14:49:53 -0400
Subject: [PATCH 06/10] Changes as per
 https://github.com/xi-editor/druid/pull/831#issuecomment-616188133

---
 druid/src/contexts.rs |  2 --
 druid/src/core.rs     | 20 ++++++++++----------
 druid/src/event.rs    |  1 +
 druid/src/window.rs   |  9 ++++++++-
 4 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/druid/src/contexts.rs b/druid/src/contexts.rs
index 3490ff5917..f904851d2f 100644
--- a/druid/src/contexts.rs
+++ b/druid/src/contexts.rs
@@ -44,8 +44,6 @@ pub struct EventCtx<'a> {
     pub(crate) focus_widget: Option<WidgetId>,
     pub(crate) is_handled: bool,
     pub(crate) is_root: bool,
-    /// Map of TimerTokens and WidgetIds that requested them.
-    pub(crate) timers: &'a HashMap<TimerToken, WidgetId>,
 }
 
 /// A mutable context provided to the [`lifecycle`] method on widgets.
diff --git a/druid/src/core.rs b/druid/src/core.rs
index fe5230dcf3..a5945e3ae0 100644
--- a/druid/src/core.rs
+++ b/druid/src/core.rs
@@ -479,7 +479,6 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
             is_handled: false,
             is_root: false,
             focus_widget: ctx.focus_widget,
-            timers: &ctx.timers,
         };
 
         let rect = child_ctx.base_state.layout_rect.unwrap_or_default();
@@ -519,6 +518,15 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
                         }
                     }
                 }
+                InternalEvent::RouteTimer(token, widget_id) => {
+                    let widget_id = *widget_id;
+                    if widget_id != child_ctx.base_state.id {
+                        recurse = child_ctx.base_state.children.may_contain(&widget_id);
+                        Event::Internal(InternalEvent::RouteTimer(*token, widget_id))
+                    } else {
+                        Event::Timer(*token)
+                    }
+                }
             },
             Event::WindowConnected => Event::WindowConnected,
             Event::WindowSize(size) => {
@@ -595,15 +603,7 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
                 Event::Zoom(*zoom)
             }
             Event::Timer(id) => {
-                if let Some(widget_id) = child_ctx.timers.get(id) {
-                    if *widget_id != child_ctx.base_state.id {
-                        recurse = child_ctx.base_state.children.may_contain(widget_id);
-                    }
-                } else {
-                    log::error!("Timer Token must be in timers map.");
-                    recurse = false;
-                }
-                Event::Timer(*id)
+                panic!("We cannot be here");
             }
             Event::Command(cmd) => Event::Command(cmd.clone()),
         };
diff --git a/druid/src/event.rs b/druid/src/event.rs
index 6bb306f9c8..7c4c8d80ac 100644
--- a/druid/src/event.rs
+++ b/druid/src/event.rs
@@ -147,6 +147,7 @@ pub enum InternalEvent {
     MouseLeave,
     /// A command still in the process of being dispatched.
     TargetedCommand(Target, Command),
+    RouteTimer(TimerToken, WidgetId),
 }
 
 /// Application life cycle events.
diff --git a/druid/src/window.rs b/druid/src/window.rs
index 8c867e9246..3cd9edcdb8 100644
--- a/druid/src/window.rs
+++ b/druid/src/window.rs
@@ -173,6 +173,14 @@ impl<T: Data> Window<T> {
                 let scale = 96.0 / dpi;
                 self.size = Size::new(size.width * scale, size.height * scale);
                 Event::WindowSize(self.size)
+            },
+            Event::Timer(token) => {
+                if let Some(widget_id) = self.timers.get(&token) {
+                    Event::Internal(InternalEvent::RouteTimer(token, *widget_id))
+                } else {
+                    log::error!("No widget found for timer {:?}", token);
+                    return false;
+                }
             }
             other => other,
         };
@@ -198,7 +206,6 @@ impl<T: Data> Window<T> {
                 window: &self.handle,
                 window_id: self.id,
                 focus_widget: self.focus,
-                timers: &self.timers,
             };
 
             self.root.event(&mut ctx, &event, data, env);

From 2e6b4935f87a693ce13b610474b8ebd40ea56327 Mon Sep 17 00:00:00 2001
From: Sujit Joshi <joshi.sujit020386@gmail.com>
Date: Sun, 26 Apr 2020 15:14:07 -0400
Subject: [PATCH 07/10] Changes as per
 https://github.com/xi-editor/druid/pull/831#issuecomment-616188133

---
 druid/src/core.rs   | 4 ++--
 druid/src/window.rs | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/druid/src/core.rs b/druid/src/core.rs
index a5945e3ae0..7f86cb21e6 100644
--- a/druid/src/core.rs
+++ b/druid/src/core.rs
@@ -602,8 +602,8 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
                 recurse = had_active || child_ctx.base_state.is_hot;
                 Event::Zoom(*zoom)
             }
-            Event::Timer(id) => {
-                panic!("We cannot be here");
+            Event::Timer(token) => {
+                Event::Timer(*token)
             }
             Event::Command(cmd) => Event::Command(cmd.clone()),
         };
diff --git a/druid/src/window.rs b/druid/src/window.rs
index 3cd9edcdb8..8041287ef4 100644
--- a/druid/src/window.rs
+++ b/druid/src/window.rs
@@ -228,7 +228,7 @@ impl<T: Data> Window<T> {
 
         //In some platforms, timer tokens are reused. So it is necessary to remove token from
         //window's timer before adding base state's timers to it.
-        if let Event::Timer(token) = event {
+        if let Event::Internal(InternalEvent::RouteTimer(token, _)) = event {
             self.timers.remove(&token);
         }
 

From 9a919132206a3b0c390bfd9b0ba98c545cfe1148 Mon Sep 17 00:00:00 2001
From: Sujit Joshi <joshi.sujit020386@gmail.com>
Date: Sun, 26 Apr 2020 15:42:25 -0400
Subject: [PATCH 08/10] Removing unused import.

---
 druid/src/contexts.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/druid/src/contexts.rs b/druid/src/contexts.rs
index f904851d2f..dc3f9df4dd 100644
--- a/druid/src/contexts.rs
+++ b/druid/src/contexts.rs
@@ -24,7 +24,6 @@ use crate::{
     Affine, Command, Cursor, Insets, Point, Rect, Size, Target, Text, TimerToken, Vec2, WidgetId,
     WindowHandle, WindowId,
 };
-use std::collections::HashMap;
 
 /// A mutable context provided to event handling methods of widgets.
 ///

From 0b777632940f4cd7e351d369c41fee6c85b15849 Mon Sep 17 00:00:00 2001
From: sjoshid <ILGitHub2>
Date: Sun, 26 Apr 2020 15:58:12 -0400
Subject: [PATCH 09/10] 1) Fmt changes

---
 druid/src/core.rs   | 8 +++-----
 druid/src/window.rs | 6 +++---
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/druid/src/core.rs b/druid/src/core.rs
index 7f86cb21e6..b6719cff7c 100644
--- a/druid/src/core.rs
+++ b/druid/src/core.rs
@@ -21,8 +21,8 @@ use crate::kurbo::{Affine, Insets, Point, Rect, Shape, Size, Vec2};
 use crate::piet::RenderContext;
 use crate::{
     BoxConstraints, Command, Data, Env, Event, EventCtx, InternalEvent, InternalLifeCycle,
-    LayoutCtx, LifeCycle, LifeCycleCtx, PaintCtx, Region, Target, TimerToken, UpdateCtx, Widget, WidgetId,
-    WindowId,
+    LayoutCtx, LifeCycle, LifeCycleCtx, PaintCtx, Region, Target, TimerToken, UpdateCtx, Widget,
+    WidgetId, WindowId,
 };
 
 /// Our queue type
@@ -602,9 +602,7 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
                 recurse = had_active || child_ctx.base_state.is_hot;
                 Event::Zoom(*zoom)
             }
-            Event::Timer(token) => {
-                Event::Timer(*token)
-            }
+            Event::Timer(token) => Event::Timer(*token),
             Event::Command(cmd) => Event::Command(cmd.clone()),
         };
         if recurse {
diff --git a/druid/src/window.rs b/druid/src/window.rs
index 8041287ef4..c863458bb3 100644
--- a/druid/src/window.rs
+++ b/druid/src/window.rs
@@ -29,8 +29,8 @@ use crate::widget::LabelText;
 use crate::win_handler::RUN_COMMANDS_TOKEN;
 use crate::{
     BoxConstraints, Command, Data, Env, Event, EventCtx, InternalEvent, InternalLifeCycle,
-    LayoutCtx, LifeCycle, LifeCycleCtx, MenuDesc, PaintCtx, TimerToken, UpdateCtx, Widget, WidgetId, WidgetPod,
-    WindowDesc,
+    LayoutCtx, LifeCycle, LifeCycleCtx, MenuDesc, PaintCtx, TimerToken, UpdateCtx, Widget,
+    WidgetId, WidgetPod, WindowDesc,
 };
 
 /// A unique identifier for a window.
@@ -173,7 +173,7 @@ impl<T: Data> Window<T> {
                 let scale = 96.0 / dpi;
                 self.size = Size::new(size.width * scale, size.height * scale);
                 Event::WindowSize(self.size)
-            },
+            }
             Event::Timer(token) => {
                 if let Some(widget_id) = self.timers.get(&token) {
                     Event::Internal(InternalEvent::RouteTimer(token, *widget_id))

From 38210fa63c925d56885b4d0941cda0b977b0caa1 Mon Sep 17 00:00:00 2001
From: sjoshid <ILGitHub2>
Date: Mon, 27 Apr 2020 09:33:24 -0400
Subject: [PATCH 10/10] 1) Code review changes.

---
 druid/src/core.rs   | 5 ++++-
 druid/src/event.rs  | 1 +
 druid/src/window.rs | 6 +++---
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/druid/src/core.rs b/druid/src/core.rs
index b6719cff7c..1c3cca22f1 100644
--- a/druid/src/core.rs
+++ b/druid/src/core.rs
@@ -602,7 +602,10 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
                 recurse = had_active || child_ctx.base_state.is_hot;
                 Event::Zoom(*zoom)
             }
-            Event::Timer(token) => Event::Timer(*token),
+            Event::Timer(token) => {
+                recurse = false;
+                Event::Timer(*token)
+            }
             Event::Command(cmd) => Event::Command(cmd.clone()),
         };
         if recurse {
diff --git a/druid/src/event.rs b/druid/src/event.rs
index 7c4c8d80ac..cb2ebd885d 100644
--- a/druid/src/event.rs
+++ b/druid/src/event.rs
@@ -147,6 +147,7 @@ pub enum InternalEvent {
     MouseLeave,
     /// A command still in the process of being dispatched.
     TargetedCommand(Target, Command),
+    /// Used for routing timer events.
     RouteTimer(TimerToken, WidgetId),
 }
 
diff --git a/druid/src/window.rs b/druid/src/window.rs
index c863458bb3..2437530a89 100644
--- a/druid/src/window.rs
+++ b/druid/src/window.rs
@@ -226,13 +226,13 @@ impl<T: Data> Window<T> {
 
         self.post_event_processing(queue, data, env, false);
 
-        //In some platforms, timer tokens are reused. So it is necessary to remove token from
-        //window's timer before adding base state's timers to it.
+        //In some platforms, timer tokens are reused. So it is necessary to remove the token from
+        //the window's timer map before adding new tokens to it.
         if let Event::Internal(InternalEvent::RouteTimer(token, _)) = event {
             self.timers.remove(&token);
         }
 
-        //If at least one widget requested timer, collect those timers from widgets and add to window's timers map.
+        //If at least one widget requested a timer, add all the requested timers to window's timers map.
         if base_state.request_timer {
             self.timers.extend(base_state.timers);
         }