From 272503873ca9faed678476410cba612612cef4a4 Mon Sep 17 00:00:00 2001
From: Dustin Carlino <dabreegster@gmail.com>
Date: Sun, 5 May 2019 18:19:19 -0700
Subject: [PATCH] avoid menu flickering and incorrect entries by sending a NoOp
 after used events

---
 docs/TODO_refactoring.md |  5 +++++
 docs/TODO_ux.md          |  8 +++++---
 ezgui/src/event.rs       |  4 +++-
 ezgui/src/runner.rs      | 12 +++++++-----
 4 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/docs/TODO_refactoring.md b/docs/TODO_refactoring.md
index 9e3bc7466f..6338226a7b 100644
--- a/docs/TODO_refactoring.md
+++ b/docs/TODO_refactoring.md
@@ -33,3 +33,8 @@
 	- canvas owning text-drawing is maybe a bit weird, at least API-wise
 	- hide stuff inside the ctx's? canvas and prerender shouldnt even be known outside of crate
 - generic World with quadtree should have actions on objects
+- loading screen
+	- cleanup hack: dont put glyphbrush in canvas at all
+	- FileWithProgress should go directly into Timer
+		- need to understand lifetimes
+	- cleanup abstutil Timer stuff generally
diff --git a/docs/TODO_ux.md b/docs/TODO_ux.md
index e333295849..a2d636a86f 100644
--- a/docs/TODO_ux.md
+++ b/docs/TODO_ux.md
@@ -26,11 +26,14 @@
 ## General ezgui stuff
 
 - optionally limit canvas scrolling/zooming to some map bounds
-- X on all menus
 - when dragging, dont give mouse movement to UI elements
 - start context menu when left click releases and we're not dragging
 - can we change labels in modal or top menu? show/hide
-- bold hotkey letters
+- label sections of modal menus
+- distinguish hints from status of modal menus, for hiding purposes
+- move context menus out of ezgui
+	- simplify/remove UserInput.
+	- maybe separate impls for context, wizard, modal menu make sense.
 
 ## New features
 
@@ -110,4 +113,3 @@
 		- highlight a region, draw counts to/from it in some meaningful way
 		- timer slider (except timeslices arent neatly in hour blocks, though they maybe should be)
 		- a table (with color-coded entries) is actually perfect
-
diff --git a/ezgui/src/event.rs b/ezgui/src/event.rs
index b3facbb7f3..7fed1b419b 100644
--- a/ezgui/src/event.rs
+++ b/ezgui/src/event.rs
@@ -3,7 +3,9 @@ use glium::glutin;
 
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum Event {
-    InitializeApplication,
+    // Used to initialize the application and also to recalculate menu state when some other event
+    // is used.
+    NoOp,
     LeftMouseButtonDown,
     LeftMouseButtonUp,
     RightMouseButtonDown,
diff --git a/ezgui/src/runner.rs b/ezgui/src/runner.rs
index e9ec77cdf1..925aac0ff2 100644
--- a/ezgui/src/runner.rs
+++ b/ezgui/src/runner.rs
@@ -191,11 +191,7 @@ pub fn run<G: GUI, F: FnOnce(&mut EventCtx) -> G>(
     };
 
     let gui = make_gui(&mut EventCtx {
-        input: &mut UserInput::new(
-            Event::InitializeApplication,
-            ContextMenu::new(),
-            &mut canvas,
-        ),
+        input: &mut UserInput::new(Event::NoOp, ContextMenu::new(), &mut canvas),
         canvas: &mut canvas,
         prerender: &prerender,
         program: &program,
@@ -296,6 +292,12 @@ fn loop_forever<G: GUI>(
         // Don't draw if an event was ignored. Every keypress also fires a release event, most of
         // which are ignored.
         if any_input_used {
+            // But if the event caused a state-change, the drawing state might be different too.
+            // Need to recalculate what menu entries and such are valid. So send through a no-op
+            // event.
+            let (new_state, _, _) = state.event(Event::NoOp, &prerender, &program);
+            state = new_state;
+
             state.draw(&prerender.display, &program, &prerender, false);
             prerender.num_uploads.set(0);
         }