Fix missing repaint after consume_key (#7134)

Usually input events automatically trigger a repaint. But since
consume_key would remove the event egui would think there were no events
and not trigger a repaint. This fixes it by setting a flag on InputState
on consume_key.

* related: rerun-io/rerun#10165

Author: lucasmerlin

crates/egui/src/context.rs

@@ -492,6 +492,7 @@ impl ContextImpl {
             pixels_per_point,
             self.memory.options.input_options,
         );
+        let repaint_after = viewport.input.wants_repaint_after();
 
         let screen_rect = viewport.input.screen_rect;
 
@@ -553,6 +554,10 @@ impl ContextImpl {
         }
 
         self.update_fonts_mut();
+
+        if let Some(delay) = repaint_after {
+            self.request_repaint_after(delay, viewport_id, RepaintCause::new());
+        }
     }
 
     /// Load fonts unless already loaded.
@@ -2398,10 +2403,7 @@ impl ContextImpl {
 
         if repaint_needed {
             self.request_repaint(ended_viewport_id, RepaintCause::new());
-        } else if let Some(delay) = viewport.input.wants_repaint_after() {
-            self.request_repaint_after(delay, ended_viewport_id, RepaintCause::new());
         }
-
         //  -------------------
 
         let all_viewport_ids = self.all_viewport_ids();

crates/egui/src/input_state/mod.rs

@@ -597,10 +597,14 @@ impl InputState {
         (self.time - self.last_scroll_time) as f32
     }
 
-    /// The [`crate::Context`] will call this at the end of each frame to see if we need a repaint.
+    /// The [`crate::Context`] will call this at the beginning of each frame to see if we need a repaint.
     ///
     /// Returns how long to wait for a repaint.
-    pub fn wants_repaint_after(&self) -> Option<Duration> {
+    ///
+    /// NOTE: It's important to call this immediately after [`Self::begin_pass`] since calls to
+    /// [`Self::consume_key`] will remove events from the vec, meaning those key presses wouldn't
+    /// cause a repaint.
+    pub(crate) fn wants_repaint_after(&self) -> Option<Duration> {
         if self.pointer.wants_repaint()
             || self.unprocessed_scroll_delta.abs().max_elem() > 0.2
             || self.unprocessed_scroll_delta_for_zoom.abs() > 0.2