feat: make level preview more user-friendly

The simulation speeds are now clamped and it no longer restarts the
preview immediately after finishing.

Author: danielzting

levels/bogo_sort.gd

@@ -17,5 +17,5 @@ func next(action):
     if array.is_sorted():
         emit_signal("done")
 
-func get_effect(i):
+func _get_effect(i):
     return EFFECTS.NONE

levels/bubble_sort.gd

@@ -42,7 +42,7 @@ func next(action):
         _end -= 1
         _swapped = false
 
-func get_effect(i):
+func _get_effect(i):
     if i == _index or i == _index + 1:
         return EFFECTS.HIGHLIGHTED
     if i >= _end:

levels/comparison_sort.gd

@@ -27,7 +27,7 @@ func _init(array):
 
 func _input(event):
     """Pass input events for checking and take appropriate action."""
-    if not active:
+    if not active or array.is_sorted():
         return
     if event.is_pressed():
         return next(event.as_text())
@@ -36,6 +36,14 @@ func next(action):
     """Check the action and advance state or emit signal as needed."""
     push_error("NotImplementedError")
 
+func get_effect(i):
+    if array.is_sorted():
+        return EFFECTS.NONE
+    return _get_effect(i)
+
+func _get_effect(i):
+    push_error("NotImplementedError")
+
 func _on_ComparisonSort_mistake():
     """Disable the controls for one second."""
     active = false

levels/insertion_sort.gd

@@ -38,7 +38,7 @@ func next(action):
             return emit_signal("mistake")
         _grow()
 
-func get_effect(i):
+func _get_effect(i):
     if i == _index or i == _index - 1:
         return EFFECTS.HIGHLIGHTED
     if i < _end:

levels/merge_sort.gd

@@ -62,7 +62,7 @@ func next(action):
         _left = _get_begin()
         _right = _get_middle()
 
-func get_effect(i):
+func _get_effect(i):
     var is_left = _left != _get_middle() and i == _left
     var is_right = _right != _get_end() and i == _right
     if is_left or is_right:

levels/selection_sort.gd

@@ -42,7 +42,7 @@ func next(action):
     if _base == array.size - 1:
         emit_signal("done")
 
-func get_effect(i):
+func _get_effect(i):
     if i == _min or i == _index:
         return EFFECTS.HIGHLIGHTED
     if i < _base:

models/array_model.gd

@@ -21,7 +21,7 @@ func at(i):
 
 func is_sorted():
     """Check if the array is in monotonically increasing order."""
-    for i in range(size - 1):
+    for i in range(get_size() - 1):
         if _array[i] > _array[i + 1]:
             return false
     return true

scripts/levels.gd

@@ -6,6 +6,8 @@ const LEVELS = [
     SelectionSort,
     MergeSort,
 ]
+const MIN_WAIT = 1.0 / 32 # Should be greater than maximum frame time
+const MAX_WAIT = 4
 const MIN_SIZE = 8
 const MAX_SIZE = 128
 
@@ -32,6 +34,14 @@ func _ready():
         top_button.grab_focus()
 
 func _on_Button_focus_entered(size=_level.array.size):
+    # Pause a bit to show completely sorted array
+    if _level.array.is_sorted():
+        $Timer.stop()
+        yield(get_tree().create_timer(1), "timeout")
+        $Timer.start()
+        # Prevent race condition caused by switching levels during pause
+        if not _level.array.is_sorted():
+            return
     _level = _get_level(get_focus_owner().text).new(ArrayModel.new(size))
     _level.active = false
     $Preview/InfoBorder/Info/About.text = _cleanup(_level.ABOUT)
@@ -45,9 +55,9 @@ func _on_Button_focus_entered(size=_level.array.size):
 
 func _input(event):
     if event.is_action_pressed("faster"):
-        $Timer.wait_time /= 2
+        $Timer.wait_time = max(MIN_WAIT, $Timer.wait_time / 2)
     elif event.is_action_pressed("slower"):
-        $Timer.wait_time *= 2
+        $Timer.wait_time = min(MAX_WAIT, $Timer.wait_time * 2)
     elif event.is_action_pressed("bigger"):
         _on_Button_focus_entered(min(MAX_SIZE, _level.array.size * 2))
     elif event.is_action_pressed("smaller"):