Add Restart command and keyboard shortcut for moving time to start of…

… timeline (#1802)

* Add Restart button to timeline UI. This sets the timeline back to zero.

* Adds Restart Command & Timeline Command

* Adds Ctrl-Shift-Space keyboard modifier

* Remove restart button from timeline UI.

* Use cmd(Key::LeftArrow) as key combo for restart timeline.

* Add TimeControl::restart to restart the current timeline.

* Use this from the kb_shortcut function

* fix some code nits

---------

Co-authored-by: Emil Ernerfeldt <[email protected]>

crates/re_ui/src/command.rs

@@ -45,6 +45,7 @@ pub enum Command {
     PlaybackTogglePlayPause,
     PlaybackStepBack,
     PlaybackStepForward,
+    PlaybackRestart,
 }
 
 impl Command {
@@ -124,6 +125,7 @@ impl Command {
                 "Step time forward",
                 "Move the time marker to the next point in time with any data",
             ),
+            Command::PlaybackRestart => ("Restart", "Restart from beginning of timeline"),
         }
     }
 
@@ -183,6 +185,7 @@ impl Command {
             Command::PlaybackTogglePlayPause => Some(key(Key::Space)),
             Command::PlaybackStepBack => Some(key(Key::ArrowLeft)),
             Command::PlaybackStepForward => Some(key(Key::ArrowRight)),
+            Command::PlaybackRestart => Some(cmd(Key::ArrowLeft)),
         }
     }
 

crates/re_viewer/src/app.rs

@@ -36,6 +36,7 @@ enum TimeControlCommand {
     TogglePlayPause,
     StepBack,
     StepForward,
+    Restart,
 }
 
 // ----------------------------------------------------------------------------
@@ -341,6 +342,9 @@ impl App {
             Command::PlaybackStepForward => {
                 self.run_time_control_command(TimeControlCommand::StepForward);
             }
+            Command::PlaybackRestart => {
+                self.run_time_control_command(TimeControlCommand::Restart);
+            }
         }
     }
 
@@ -362,6 +366,9 @@ impl App {
             TimeControlCommand::StepForward => {
                 time_ctrl.step_time_fwd(times_per_timeline);
             }
+            TimeControlCommand::Restart => {
+                time_ctrl.restart(times_per_timeline);
+            }
         }
     }
 

crates/re_viewer/src/misc/time_control.rs

@@ -293,6 +293,14 @@ impl TimeControl {
         }
     }
 
+    pub fn restart(&mut self, times_per_timeline: &TimesPerTimeline) {
+        if let Some(time_points) = times_per_timeline.get(&self.timeline) {
+            if let Some(state) = self.states.get_mut(&self.timeline) {
+                state.time = min(time_points).into();
+            }
+        }
+    }
+
     pub fn toggle_play_pause(&mut self, times_per_timeline: &TimesPerTimeline) {
         #[allow(clippy::collapsible_else_if)]
         if self.playing {