[Stable] Finish deprecation for line_length and fold in style dict

qiskit/circuit/quantumcircuit.py

@@ -605,11 +605,13 @@ def draw(self, scale=0.7, filename=None, style=None, output=None,
             with_layout (bool): Include layout information, with labels on the physical
                 layout. Default is True.
             fold (int): Sets pagination. It can be disabled using -1.
-                In `text`, sets the length of the lines. This useful when the
+                In `text`, sets the length of the lines. This is useful when the
                 drawing does not fit in the console. If None (default), it will try to
                 guess the console width using `shutil.get_terminal_size()`. However, if
                 running in jupyter, the default line length is set to 80 characters.
                 In `mpl` is the amount of operations before folding. Default is 25.
+                This option will be ignored with the ``latex`` and
+                ``latex_source`` backends.
         Returns:
             PIL.Image or matplotlib.figure or str or TextDrawing:
                 * PIL.Image: (output `latex`) an in-memory representation of the

qiskit/visualization/circuit_visualization.py

@@ -103,6 +103,9 @@ def circuit_drawer(circuit,
             guess the console width using `shutil.get_terminal_size()`. However, if
             running in jupyter, the default line length is set to 80 characters.
             In `mpl` is the amount of operations before folding. Default is 25.
+            This option will be ignored with the ``latex`` and ``latex_source``
+            backends.
+
     Returns:
         PIL.Image: (output `latex`) an in-memory representation of the image
             of the circuit diagram.

releasenotes/notes/deprecate-line-length-circuit-draw-c32d7827c86186a7.yaml

@@ -0,0 +1,15 @@
+---
+deprecations:
+  - |
+    The ``line length`` kwarg for the ``qiskit.QuantumCircuit.draw()`` method
+    and the ``qiskit.visualization.circuit_drawer()`` function with the text
+    output mode is deprecated. It has been replaced by the ``fold`` kwarg which
+    will behave identically for the text output mode (but also now supports
+    the mpl output mode too). ``line_length`` will be removed in a future
+    release so calls should be updated to use ``fold`` instead.
+  - |
+    The ``fold`` field in the ``style`` dict kwarg for the
+    ``qiskit.QuantumCircuit.draw()`` method and the
+    ``qiskit.visualization.circuit_drawer()`` function has been deprecated. It
+    has been replaced by the ``fold`` kwarg on both functions. This kwarg
+    behaves identically to the field in the style dict.