add Arranger::is_first_row/is_last_row for arrow focus

crates/tek_sequencer/src/arranger.rs

@@ -64,4 +64,22 @@ impl Arranger {
         //self.sequencer.show(phrase)
         Ok(())
     }
+    pub fn is_first_row (&self) -> bool {
+        let selected = self.selected;
+        selected.is_mix() || selected.is_track() || match selected {
+            ArrangerFocus::Clip(_, s) =>
+                s == 0,
+            _ => false
+        }
+    }
+    pub fn is_last_row (&self) -> bool {
+        let selected = self.selected;
+        match selected {
+            ArrangerFocus::Scene(s) =>
+                s == self.scenes.len() - 1,
+            ArrangerFocus::Clip(_, s) =>
+                s == self.scenes.len() - 1,
+            _ => false
+        }
+    }
 }