Add a dummy warm-up frame to the demo app to pre-cache emojis

egui/src/containers/collapsing_header.rs

@@ -35,7 +35,7 @@ impl State {
 
     // Helper
     pub fn is_open(ctx: &Context, id: Id) -> Option<bool> {
-        if ctx.memory().all_collpasing_are_open {
+        if ctx.memory().everything_is_visible() {
             Some(true)
         } else {
             ctx.memory()
@@ -52,7 +52,11 @@ impl State {
 
     /// 0 for closed, 1 for open, with tweening
     pub fn openness(&self, ctx: &Context, id: Id) -> f32 {
-        ctx.animate_bool(id, self.open || ctx.memory().all_collpasing_are_open)
+        if ctx.memory().everything_is_visible() {
+            1.0
+        } else {
+            ctx.animate_bool(id, self.open)
+        }
     }
 
     /// Show contents if we are open, with a nice animation between closed and open

egui/src/containers/popup.rs

@@ -25,6 +25,8 @@ pub fn show_tooltip(ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui)) {
         let position = position.min(ctx.input().screen_rect().right_bottom() - expected_size);
         let position = position.max(ctx.input().screen_rect().left_top());
         position
+    } else if ctx.memory().everything_is_visible() {
+        Pos2::default()
     } else {
         return; // No good place for a tooltip :(
     };

egui/src/containers/window.rs

@@ -209,7 +209,7 @@ impl<'open> Window<'open> {
             with_title_bar,
         } = self;
 
-        if matches!(open, Some(false)) && !ctx.memory().all_windows_are_open {
+        if matches!(open, Some(false)) && !ctx.memory().everything_is_visible() {
             return None;
         }
 

egui/src/context.rs

@@ -38,6 +38,7 @@ pub(crate) struct FrameState {
 
     /// How much space is used by panels.
     used_by_panels: Rect,
+
     pub(crate) scroll_delta: Vec2,
     pub(crate) scroll_target: Option<(f32, Align)>,
     // TODO: move some things from `Memory` to here
@@ -56,7 +57,7 @@ impl Default for FrameState {
 }
 
 impl FrameState {
-    pub fn begin_frame(&mut self, input: &InputState) {
+    fn begin_frame(&mut self, input: &InputState) {
         self.available_rect = input.screen_rect();
         self.unused_rect = input.screen_rect();
         self.used_by_panels = Rect::nothing();
@@ -717,6 +718,11 @@ impl Context {
         }
         animated_value
     }
+
+    /// Clear memory of any animations.
+    pub fn clear_animations(&self) {
+        *self.animation_manager.lock() = Default::default();
+    }
 }
 
 impl Context {

egui/src/memory.rs

@@ -60,12 +60,8 @@ pub struct Memory {
     #[cfg_attr(feature = "serde", serde(skip))]
     pub(crate) tooltip_rect: Option<Rect>,
 
-    /// Useful for debugging, benchmarking etc.
-    pub all_collpasing_are_open: bool,
-    /// Useful for debugging, benchmarking etc.
-    pub all_menus_are_open: bool,
-    /// Useful for debugging, benchmarking etc.
-    pub all_windows_are_open: bool,
+    #[cfg_attr(feature = "serde", serde(skip))]
+    everything_is_visible: bool,
 }
 
 /// Say there is a button in a scroll area.
@@ -258,7 +254,7 @@ impl Memory {
 /// Only one can be be open at a time.
 impl Memory {
     pub fn is_popup_open(&mut self, popup_id: Id) -> bool {
-        self.popup == Some(popup_id)
+        self.popup == Some(popup_id) || self.everything_is_visible()
     }
 
     pub fn open_popup(&mut self, popup_id: Id) {
@@ -276,6 +272,24 @@ impl Memory {
             self.open_popup(popup_id);
         }
     }
+
+    /// If true, all windows, menus, tooltips etc are to be visible at once.
+    ///
+    /// This is useful for testing, benchmarking, pre-caching, etc.
+    ///
+    /// Experimental feature!
+    pub fn everything_is_visible(&self) -> bool {
+        self.everything_is_visible
+    }
+
+    /// If true, all windows, menus, tooltips etc are to be visible at once.
+    ///
+    /// This is useful for testing, benchmarking, pre-caching, etc.
+    ///
+    /// Experimental feature!
+    pub fn set_everything_is_visible(&mut self, value: bool) {
+        self.everything_is_visible = value;
+    }
 }
 
 // ----------------------------------------------------------------------------

egui/src/menu.rs

@@ -94,7 +94,7 @@ fn menu_impl<'c>(
         bar_state.open_menu = Some(menu_id);
     }
 
-    if bar_state.open_menu == Some(menu_id) || ui.memory().all_menus_are_open {
+    if bar_state.open_menu == Some(menu_id) || ui.ctx().memory().everything_is_visible() {
         let area = Area::new(menu_id)
             .order(Order::Foreground)
             .fixed_pos(button_response.rect.left_bottom());

egui/src/types.rs

@@ -139,7 +139,7 @@ impl Response {
     /// Show this UI if the item was hovered (i.e. a tooltip).
     /// If you call this multiple times the tooltips will stack underneath the previous ones.
     pub fn on_hover_ui(self, add_contents: impl FnOnce(&mut Ui)) -> Self {
-        if self.hovered {
+        if self.hovered || self.ctx.memory().everything_is_visible() {
             crate::containers::show_tooltip(&self.ctx, add_contents);
         }
         self