Add UI for precisely picking an exact sequence time (#7673)

### What
* Part of #7653

I only implemented it for sequence timelines for now, since I didn't
want to parse timestamps in different formats this early in the morning.
Hopefully this can still help @teh-cmc.

It also shows how to do it for temporal timelines if someone wants to
follow my lead.


![precise-time-control](https://github.com/user-attachments/assets/2577a551-5ce2-4f18-a396-37c4488998a9)

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/7673?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/7673?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!
* [x] If have noted any breaking changes to the log API in
`CHANGELOG.md` and the migration guide

- [PR Build Summary](https://build.rerun.io/pr/7673)
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

To run all checks from `main`, comment on the PR with `@rerun-bot
full-check`.

crates/store/re_log_types/src/time_point/mod.rs

@@ -127,7 +127,22 @@ impl TimeType {
         }
     }
 
-    #[inline]
+    pub fn format_sequence(time_int: TimeInt) -> String {
+        Self::Sequence.format(time_int, TimeZone::Utc)
+    }
+
+    pub fn parse_sequence(s: &str) -> Option<TimeInt> {
+        match s {
+            "<static>" => Some(TimeInt::STATIC),
+            "−∞" => Some(TimeInt::MIN),
+            "+∞" => Some(TimeInt::MAX),
+            _ => {
+                let s = s.strip_prefix('#').unwrap_or(s);
+                re_format::parse_i64(s).map(TimeInt::new_temporal)
+            }
+        }
+    }
+
     pub fn format(
         &self,
         time_int: impl Into<TimeInt>,
@@ -136,7 +151,7 @@ impl TimeType {
         let time_int = time_int.into();
         match time_int {
             TimeInt::STATIC => "<static>".into(),
-            TimeInt::MIN => "-∞".into(),
+            TimeInt::MIN => "−∞".into(),
             TimeInt::MAX => "+∞".into(),
             _ => match self {
                 Self::Time => Time::from(time_int).format(time_zone_for_timestamps),
@@ -221,3 +236,26 @@ impl<T: TryInto<TimeInt>, const N: usize> From<[(Timeline, T); N]> for TimePoint
         )
     }
 }
+
+// ----------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::{TimeInt, TimeType};
+
+    #[test]
+    fn test_format_parse() {
+        let cases = [
+            (TimeInt::STATIC, "<static>"),
+            (TimeInt::MIN, "−∞"),
+            (TimeInt::MAX, "+∞"),
+            (TimeInt::new_temporal(-42), "#−42"),
+            (TimeInt::new_temporal(12345), "#12 345"),
+        ];
+
+        for (int, s) in cases {
+            assert_eq!(TimeType::format_sequence(int), s);
+            assert_eq!(TimeType::parse_sequence(s), Some(int));
+        }
+    }
+}

crates/store/re_log_types/src/time_point/time_int.rs

@@ -60,8 +60,8 @@ impl TimeInt {
     pub const ONE: Self = Self(Some(NonMinI64::ONE));
 
     #[inline]
-    pub fn is_static(&self) -> bool {
-        *self == Self::STATIC
+    pub fn is_static(self) -> bool {
+        self == Self::STATIC
     }
 
     /// Creates a new temporal [`TimeInt`].
@@ -100,7 +100,7 @@ impl TimeInt {
 
     /// Returns `i64::MIN` for [`Self::STATIC`].
     #[inline]
-    pub const fn as_i64(&self) -> i64 {
+    pub const fn as_i64(self) -> i64 {
         match self.0 {
             Some(t) => t.get(),
             None => i64::MIN,
@@ -109,7 +109,7 @@ impl TimeInt {
 
     /// Returns `f64::MIN` for [`Self::STATIC`].
     #[inline]
-    pub const fn as_f64(&self) -> f64 {
+    pub const fn as_f64(self) -> f64 {
         match self.0 {
             Some(t) => t.get() as _,
             None => f64::MIN,
@@ -119,20 +119,20 @@ impl TimeInt {
     /// Always returns [`Self::STATIC`] for [`Self::STATIC`].
     #[inline]
     #[must_use]
-    pub fn inc(&self) -> Self {
+    pub fn inc(self) -> Self {
         match self.0 {
             Some(t) => Self::new_temporal(t.get().saturating_add(1)),
-            None => *self,
+            None => self,
         }
     }
 
     /// Always returns [`Self::STATIC`] for [`Self::STATIC`].
     #[inline]
     #[must_use]
-    pub fn dec(&self) -> Self {
+    pub fn dec(self) -> Self {
         match self.0 {
             Some(t) => Self::new_temporal(t.get().saturating_sub(1)),
-            None => *self,
+            None => self,
         }
     }
 }

crates/utils/re_format/src/lib.rs

@@ -408,6 +408,20 @@ pub fn parse_f64(text: &str) -> Option<f64> {
     text.parse().ok()
 }
 
+/// Parses a number, ignoring whitespace (e.g. thousand separators),
+/// and treating the special minus character `MINUS` (−) as a minus sign.
+pub fn parse_i64(text: &str) -> Option<i64> {
+    let text: String = text
+        .chars()
+        // Ignore whitespace (trailing, leading, and thousands separators):
+        .filter(|c| !c.is_whitespace())
+        // Replace special minus character with normal minus (hyphen):
+        .map(|c| if c == '−' { '-' } else { c })
+        .collect();
+
+    text.parse().ok()
+}
+
 /// Pretty format a large number by using SI notation (base 10), e.g.
 ///
 /// ```

crates/viewer/re_time_panel/src/lib.rs

@@ -22,7 +22,7 @@ use re_data_ui::{item_ui::guess_instance_path_icon, sorted_component_list_for_ui
 use re_entity_db::{EntityTree, InstancePath};
 use re_log_types::{
     external::re_types_core::ComponentName, ComponentPath, EntityPath, EntityPathPart,
-    ResolvedTimeRange, TimeInt, TimeReal,
+    ResolvedTimeRange, TimeInt, TimeReal, TimeType,
 };
 use re_types::blueprint::components::PanelState;
 use re_ui::{list_item, ContextExt as _, DesignTokens, UiExt as _};
@@ -1088,10 +1088,33 @@ fn help_button(ui: &mut egui::Ui) {
     );
 }
 
-fn current_time_ui(ctx: &ViewerContext<'_>, ui: &mut egui::Ui, time_ctrl: &TimeControl) {
+fn current_time_ui(ctx: &ViewerContext<'_>, ui: &mut egui::Ui, time_ctrl: &mut TimeControl) {
     if let Some(time_int) = time_ctrl.time_int() {
         let time_type = time_ctrl.time_type();
-        ui.monospace(time_type.format(time_int, ctx.app_options.time_zone));
+        match time_type {
+            re_log_types::TimeType::Time => {
+                // TODO(#7653): parse time stamps
+                ui.monospace(time_type.format(time_int, ctx.app_options.time_zone));
+            }
+            re_log_types::TimeType::Sequence => {
+                // NOTE: egui uses `f64` for all numbers internally, so we get precision problems if the integer gets too big.
+                if time_int.as_f64() as i64 == time_int.as_i64() {
+                    let mut int = time_int.as_i64();
+                    let drag_value = egui::DragValue::new(&mut int)
+                        .custom_formatter(|x, _range| {
+                            TimeType::format_sequence(TimeInt::new_temporal(x as i64))
+                        })
+                        .custom_parser(|s| TimeType::parse_sequence(s).map(TimeInt::as_f64));
+                    let response = ui.add(drag_value);
+                    if response.changed() {
+                        time_ctrl.set_time(TimeInt::new_temporal(int));
+                    }
+                } else {
+                    // Avoid the precision problems by just displaying the number without the ability to change it (here).
+                    ui.monospace(time_type.format(time_int, ctx.app_options.time_zone));
+                }
+            }
+        }
     }
 }