Refactored labeled.py file

manim/mobject/geometry/labeled.py

@@ -4,7 +4,7 @@
 
 __all__ = ["Label", "LabeledLine", "LabeledArrow", "LabeledPolygram"]
 
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Self
 
 import numpy as np
 
@@ -20,6 +20,7 @@
 from manim.mobject.types.vectorized_mobject import VGroup
 from manim.utils.color import WHITE
 from manim.utils.polylabel import polylabel
+from manim.utils.space_ops import rotate_vector
 
 if TYPE_CHECKING:
     from manim.typing import Point3DLike_Array
@@ -102,13 +103,8 @@ def __init__(
         else:
             raise TypeError("Unsupported label type. Must be MathTex, Tex, or Text.")
 
-        # Add a background box
         self.background_rect = BackgroundRectangle(self.rendered_label, **box_config)
-
-        # Add a frame around the label
         self.frame = SurroundingRectangle(self.rendered_label, **frame_config)
-
-        # Add components to the VGroup
         self.add(self.background_rect, self.rendered_label, self.frame)
 
 
@@ -128,8 +124,20 @@ class LabeledLine(Line):
         A dictionary containing the configuration for the background box.
     frame_config
          A dictionary containing the configuration for the frame.
-
-        .. seealso::
+    align_label_with_line
+        If set to `True`, the label is aligned with the line.
+    label_above_line
+        If set to `True`, the label is above the line. For this to work,
+        the parameter `align_label_with_line` must also be set to True.
+    label_below_line
+        If set to `True`, the label is below the line. For this to work,
+        the parameter `align_label_with_line` must also be set to True.
+        The parameters `label_above_line` and `label_below_line` cannot both be
+        `True` at the same time.
+    buff
+        Buffer space between label and line.
+
+         .. seealso::
             :class:`LabeledArrow`
 
     Examples
@@ -141,15 +149,21 @@ class LabeledLine(Line):
         class LabeledLineExample(Scene):
             def construct(self):
                 line = LabeledLine(
+                    color= BLUE,
                     label          = '0.5',
-                    label_position = 0.8,
+                    label_position = 0.5,
                     label_config = {
-                        "font_size" : 20
+                        "font_size" : 45,
+                        "stroke_color" : RED
                     },
                     start=LEFT+DOWN,
-                    end=RIGHT+UP)
+                    end=RIGHT+UP,
+                    align_label_with_line=True,
+                    label_above_line=False,
+                    label_below_line=True,
+                    )
 
-                line.set_length(line.get_length() * 2)
+                line.set_length(line.get_length()*2)
                 self.add(line)
     """
 
@@ -160,26 +174,63 @@ def __init__(
         label_config: dict[str, Any] | None = None,
         box_config: dict[str, Any] | None = None,
         frame_config: dict[str, Any] | None = None,
+        align_label_with_line: bool = False,
+        label_above_line: bool = False,
+        label_below_line: bool = False,
+        buff: float = MED_SMALL_BUFF,
         *args: Any,
         **kwargs: Any,
     ) -> None:
+        if label_above_line and label_below_line:
+            raise ValueError(
+                "label_above_line and label_below_line cannot both be True."
+            )
+
         super().__init__(*args, **kwargs)
+        self.label_position = label_position
+        self.align_label_with_line = align_label_with_line
+        self.label_above_line = label_above_line
+        self.label_below_line = label_below_line
+        self.buff = buff
+        self.label_angle: float = 0
 
-        # Create Label
         self.label = Label(
             label=label,
             label_config=label_config,
             box_config=box_config,
             frame_config=frame_config,
         )
+        self.position_label()
+        self.add(self.label)
 
-        # Compute Label Position
-        line_start, line_end = self.get_start_and_end()
-        new_vec = (line_end - line_start) * label_position
-        label_coords = line_start + new_vec
+    def position_label(self) -> None:
+        normal_unit_vector = rotate_vector(self.get_unit_vector(), TAU / 4)
+        label_position = np.clip(self.label_position, 0, 1)
+        label_position_on_line = self.point_from_proportion(label_position)
 
-        self.label.move_to(label_coords)
-        self.add(self.label)
+        if self.align_label_with_line:
+            current_angle = self.get_angle()
+            delta = current_angle - self.label_angle
+            self.label.rotate(delta, about_point=ORIGIN)
+            self.label_angle = current_angle
+
+            if self.label_above_line:
+                label_position_on_line += normal_unit_vector * self.buff
+            elif self.label_below_line:
+                label_position_on_line -= normal_unit_vector * self.buff
+        self.label.move_to(label_position_on_line)
+
+    def scale(
+        self,
+        scale_factor: float = 1,
+        *args: Any,
+        **kwargs: Any,
+    ) -> Self:
+        super().scale(scale_factor, *args, **kwargs)
+        if hasattr(self, "label"):
+            self.label.scale(1 / scale_factor)
+            self.position_label()
+        return self
 
 
 class LabeledArrow(LabeledLine, Arrow):
@@ -211,8 +262,21 @@ class LabeledArrow(LabeledLine, Arrow):
 
         class LabeledArrowExample(Scene):
             def construct(self):
-                l_arrow = LabeledArrow("0.5", start=LEFT*3, end=RIGHT*3 + UP*2, label_position=0.5)
-
+                l_arrow = LabeledArrow(
+                    "0.5",
+                    color = YELLOW,
+                    start=LEFT*1.5+ 1.5*DOWN,
+                    end=RIGHT*1.5 + UP*1.5,
+                    label_config = {
+                        #"font_size" : 20,
+                        "stroke_color" : RED
+                    },
+                    label_position=0.5,
+                    align_label_with_line=True,
+                    label_above_line=False,
+                    label_below_line = True,
+                )
+                l_arrow.set_length(l_arrow.get_length() * 1.2)
                 self.add(l_arrow)
     """
 
@@ -223,6 +287,14 @@ def __init__(
     ) -> None:
         super().__init__(*args, **kwargs)
 
+    def scale(  # type: ignore[override]
+        self,
+        scale_factor: float = 1,
+        *args: Any,
+        **kwargs: Any,
+    ) -> Self:
+        return super().scale(scale_factor, *args, **kwargs)
+
 
 class LabeledPolygram(Polygram):
     """Constructs a polygram containing a label box at its pole of inaccessibility.