Adjusted matplotlib.widgets.Slider to have optional vertical orientatation (matplotlib#10746)

* Adjusted matplotlib.widgets.Slider to have optional vertical orientation.

The slider widget now takes an optional argument (orientation) with
values 'h' or 'v, which defaults to 'h'.

Argument checking is in keeping with the existing code, and the actual
changes to the source are minimal, replacing hspans, hlines and xdata with a
if switch to vspans and vlines and ydata.

* Changed 'h' and 'v' to 'horizontal' and 'vertical'

* Typo corrections so that code is PEP-8 compliant

I forgot that I had not yet installed pyflakes and pylint on my new
system, so my vim syntax checker didn't pick it up.

* Added test for horizontal and vertical orientations

* Corrected typo in my modifications, and made test_widgets.py pep compliant regarding line-continuing indentation

* Adjusted docstring to follow numpydoc

* Added whats new

* Moved what's new section to doc/users/whats_new.rst

* Changed is to ==, and sets to lists

Author: williamjameshandley

doc/users/whats_new.rst

@@ -192,6 +192,15 @@ and the title will not be moved via this algorithm.
 
 
 
+Adjusted ``matplotlib.widgets.Slider`` to have vertical orientation
+-------------------------------------------------------------------
+
+The :class:`matplotlib.widgets.Slider` widget now takes an optional argument
+``orientation`` which indicates the direction (``'horizontal'`` or
+``'vertical'``) that the slider should take.
+
+
+
 New convenience methods for GridSpec
 ------------------------------------
 

lib/matplotlib/tests/test_widgets.py

@@ -319,6 +319,20 @@ def test_slider_valmin_valmax():
     assert slider.val == slider.valmax
 
 
+def test_slider_horizontal_vertical():
+    fig, ax = plt.subplots()
+    slider = widgets.Slider(ax=ax, label='', valmin=0.0, valmax=24.0,
+                            valinit=12.0, orientation='horizontal')
+    slider.set_val(10.0)
+    assert slider.val == 10.0
+
+    fig, ax = plt.subplots()
+    slider = widgets.Slider(ax=ax, label='', valmin=0.0, valmax=24.0,
+                            valinit=12.0, orientation='vertical')
+    slider.set_val(10.0)
+    assert slider.val == 10.0
+
+
 def check_polygon_selector(event_sequence, expected_result, selections_count):
     """Helper function to test Polygon Selector
 

lib/matplotlib/widgets.py

@@ -268,7 +268,8 @@ class Slider(AxesWidget):
     """
     def __init__(self, ax, label, valmin, valmax, valinit=0.5, valfmt='%1.2f',
                  closedmin=True, closedmax=True, slidermin=None,
-                 slidermax=None, dragging=True, valstep=None, **kwargs):
+                 slidermax=None, dragging=True, valstep=None,
+                 orientation='horizontal', **kwargs):
         """
         Parameters
         ----------
@@ -310,6 +311,9 @@ def __init__(self, ax, label, valmin, valmax, valinit=0.5, valfmt='%1.2f',
         valstep : float, optional, default: None
             If given, the slider will snap to multiples of `valstep`.
 
+        orientation : str, 'horizontal' or 'vertical', default: 'horizontal'
+            The orientation of the slider.
+
         Notes
         -----
         Additional kwargs are passed on to ``self.poly`` which is the
@@ -325,6 +329,11 @@ def __init__(self, ax, label, valmin, valmax, valinit=0.5, valfmt='%1.2f',
         if slidermax is not None and not hasattr(slidermax, 'val'):
             raise ValueError("Argument slidermax ({}) has no 'val'"
                              .format(type(slidermax)))
+        if orientation not in ['horizontal', 'vertical']:
+            raise ValueError("Argument orientation ({}) must be either"
+                             "'horizontal' or 'vertical'".format(orientation))
+
+        self.orientation = orientation
         self.closedmin = closedmin
         self.closedmax = closedmax
         self.slidermin = slidermin
@@ -338,27 +347,44 @@ def __init__(self, ax, label, valmin, valmax, valinit=0.5, valfmt='%1.2f',
             valinit = valmin
         self.val = valinit
         self.valinit = valinit
-        self.poly = ax.axvspan(valmin, valinit, 0, 1, **kwargs)
-        self.vline = ax.axvline(valinit, 0, 1, color='r', lw=1)
+        if orientation == 'vertical':
+            self.poly = ax.axhspan(valmin, valinit, 0, 1, **kwargs)
+            self.hline = ax.axhline(valinit, 0, 1, color='r', lw=1)
+        else:
+            self.poly = ax.axvspan(valmin, valinit, 0, 1, **kwargs)
+            self.vline = ax.axvline(valinit, 0, 1, color='r', lw=1)
 
         self.valfmt = valfmt
         ax.set_yticks([])
-        ax.set_xlim((valmin, valmax))
+        if orientation == 'vertical':
+            ax.set_ylim((valmin, valmax))
+        else:
+            ax.set_xlim((valmin, valmax))
         ax.set_xticks([])
         ax.set_navigate(False)
 
         self.connect_event('button_press_event', self._update)
         self.connect_event('button_release_event', self._update)
         if dragging:
             self.connect_event('motion_notify_event', self._update)
-        self.label = ax.text(-0.02, 0.5, label, transform=ax.transAxes,
-                             verticalalignment='center',
-                             horizontalalignment='right')
+        if orientation == 'vertical':
+            self.label = ax.text(0.5, 1.02, label, transform=ax.transAxes,
+                                 verticalalignment='bottom',
+                                 horizontalalignment='center')
+
+            self.valtext = ax.text(0.5, -0.02, valfmt % valinit,
+                                   transform=ax.transAxes,
+                                   verticalalignment='top',
+                                   horizontalalignment='center')
+        else:
+            self.label = ax.text(-0.02, 0.5, label, transform=ax.transAxes,
+                                 verticalalignment='center',
+                                 horizontalalignment='right')
 
-        self.valtext = ax.text(1.02, 0.5, valfmt % valinit,
-                               transform=ax.transAxes,
-                               verticalalignment='center',
-                               horizontalalignment='left')
+            self.valtext = ax.text(1.02, 0.5, valfmt % valinit,
+                                   transform=ax.transAxes,
+                                   verticalalignment='center',
+                                   horizontalalignment='left')
 
         self.cnt = 0
         self.observers = {}
@@ -412,7 +438,10 @@ def _update(self, event):
             self.drag_active = False
             event.canvas.release_mouse(self.ax)
             return
-        val = self._value_in_bounds(event.xdata)
+        if self.orientation == 'vertical':
+            val = self._value_in_bounds(event.ydata)
+        else:
+            val = self._value_in_bounds(event.xdata)
         if val not in [None, self.val]:
             self.set_val(val)
 
@@ -425,8 +454,12 @@ def set_val(self, val):
         val : float
         """
         xy = self.poly.xy
-        xy[2] = val, 1
-        xy[3] = val, 0
+        if self.orientation == 'vertical':
+            xy[1] = 0, val
+            xy[2] = 1, val
+        else:
+            xy[2] = val, 1
+            xy[3] = val, 0
         self.poly.xy = xy
         self.valtext.set_text(self.valfmt % val)
         if self.drawon: