continue external axes development

Author: DanielGoldfarb

examples/external_axes.ipynb

@@ -2,3 +2,4 @@
 from   mplfinance.plotting  import plot, make_addplot
 from   mplfinance._styles   import make_mpf_style, make_marketcolors, available_styles
 from   mplfinance._version  import __version__
+from   mplfinance._mplwraps import figure

examples/scratch_pad/dev_external_axes.ipynb

@@ -303,18 +303,18 @@ def _check_for_external_axes(config):
 
     # At this point, if we have not raised an exception, then plot(ax=) and make_addplot(ax=)
     # are in sync: either they are all None, or they are all of type `matplotlib.axes.Axes`.
-    # Therefore we only need plot(ax=), i.e. config['ax'], as we check `volume` and `fig`:
+    # Therefore we only need plot(ax=), i.e. config['ax'], as we check `volume`: ### and `fig`:
 
     if config['ax'] is None:
         if isinstance(config['volume'],mpl.axes.Axes):
             raise ValueError('`volume` set to external Axes requires all other Axes be external.')
-        if config['fig'] is not None:
-            raise ValueError('`fig` kwarg must be None if `ax` kwarg is None.')
+        #if config['fig'] is not None:
+        #    raise ValueError('`fig` kwarg must be None if `ax` kwarg is None.')
     else:
         if not isinstance(config['volume'],mpl.axes.Axes) and config['volume'] != False:
             raise ValueError('`volume` must be of type `matplotlib.axis.Axes`')
-        if not isinstance(config['fig'],mpl.figure.Figure):
-            raise ValueError('`fig` kwarg must be of type `matplotlib.figure.Figure`')
+        #if not isinstance(config['fig'],mpl.figure.Figure):
+        #    raise ValueError('`fig` kwarg must be of type `matplotlib.figure.Figure`')
 
     external_axes_mode = True if isinstance(config['ax'],mpl.axes.Axes) else False
     return external_axes_mode

src/mplfinance/__init__.py

@@ -0,0 +1,109 @@
+import matplotlib.pyplot as plt
+import matplotlib.figure as mplfigure
+from   mplfinance import _styles
+
+"""
+    This file contains:
+
+    (1) A wrapper of method `matplotlib.pyplot.figure()` that creates a 
+        `mplfinance.Mpf_Figure` which is derived from `matplotlib.figure.Figure`
+        The wrapper function is the same as `matplotlib.pyplot.figure()` except
+        that it additionally accepts kwarg `style=` to set the mplfinance style.
+
+    (2) Class `mplfinance.Mpf_Figure` derived from `matplotlib.figure.Figure`
+        which has the following overrides:
+        - Attribute `mpfstyle` indicating the mplfinance style used at Figure creation.
+        - Methods (listed below) which are identical to the same method in class
+          `matplotlib.figure.Figure` except that the `mplfinance.Mpf_Figure` versions:
+            - accept kwarg `style=` to set the mplfinance style of Subplot Axes, or
+            - if `style=` is not specified, then the attribute
+              `mplfinance.Mpf_Figure.mpfstyle` is used for the Subplot Axes style.
+          - Figure.add_subplot() 
+          - Figure.add_axes() 
+          - Figure.subplot()  (this is analogous to pyplot.subplot() which calls Figure.add_subplot())
+          - Figure.subplots() 
+"""
+
+
+def _check_for_and_apply_style(kwargs):
+
+    if 'style' in kwargs:
+        style = kwargs['style']
+        del kwargs['style']
+    else:
+        style = 'default'
+
+    if not _styles._valid_mpf_style(style):
+        raise TypeError('Invalid mplfinance style')
+
+    if isinstance(style,str):
+        style = _styles._get_mpfstyle(style)
+
+    if isinstance(style,dict):
+        _styles._apply_mpfstyle(style)
+    else:
+        raise TypeError('style should be a `dict`; why is it not?')
+
+    return style
+
+
+def figure(*args,**kwargs):
+
+    style = _check_for_and_apply_style(kwargs)
+
+    f = plt.figure(FigureClass=Mpf_Figure,*args,**kwargs)
+    f.mpfstyle = style
+    return f
+
+
+class Mpf_Figure(mplfigure.Figure):
+
+    def add_subplot(self,*args,**kwargs):
+
+        if 'style' in kwargs or not hasattr(self,'mpfstyle'):
+            style = _check_for_and_apply_style(kwargs)
+        else:
+            style = _check_for_and_apply_style(dict(style=self.mpfstyle))
+
+        ax = mplfigure.Figure.add_subplot(self,*args,**kwargs)
+        ax.mpfstyle = style
+        return ax
+
+    def add_axes(self,*args,**kwargs):
+    
+        if 'style' in kwargs or not hasattr(self,'mpfstyle'):
+            style = _check_for_and_apply_style(kwargs)
+        else:
+            style = _check_for_and_apply_style(dict(style=self.mpfstyle))
+
+        ax = mplfigure.Figure.add_axes(self,*args,**kwargs)
+        ax.mpfstyle = style
+        return ax
+
+    def subplot(self,*args,**kwargs):
+    
+        plt.figure(self.number)  # make it the current Figure
+
+        if 'style' in kwargs or not hasattr(self,'mpfstyle'):
+            style = _check_for_and_apply_style(kwargs)
+        else:
+            style = _check_for_and_apply_style(dict(style=self.mpfstyle))
+
+        ax = plt.subplot(*args,**kwargs)
+        ax.mpfstyle = style
+        return ax
+
+
+    def subplots(self,*args,**kwargs):
+    
+        if 'style' in kwargs or not hasattr(self,'mpfstyle'):
+            style = _check_for_and_apply_style(kwargs)
+        else:
+            style = _check_for_and_apply_style(dict(style=self.mpfstyle))
+    
+        axlist = mplfigure.Figure.subplots(self,*args,**kwargs)
+    
+        self.mpfstyle = style
+        if ax in axlist:
+            ax.mpfstyle = style
+        return fig, axlist

src/mplfinance/_arg_validators.py

@@ -125,6 +125,33 @@ def _valid_mpf_color_spec(value):
              )
            )
 
+def _valid_mpf_style(value):
+    if value in available_styles():
+        return True
+    if not isinstance(value,dict):
+        return False
+    if 'marketcolors' not in value:
+        return False
+    if not isinstance(value['marketcolors'],dict):
+        return False
+    # {'candle': {'up': 'b', 'down': 'g'},
+    #  'edge': {'up': 'k', 'down': 'k'},
+    #  'wick': {'up': 'k', 'down': 'k'},
+    #  'ohlc': {'up': 'k', 'down': 'k'},
+    #  'volume': {'up': '#1f77b4', 'down': '#1f77b4'},
+    #  'vcedge': {'up': '#1f77b4', 'down': '#1f77b4'},
+    #  'vcdopcod': False,
+    #  'alpha': 0.9}
+    for item in ('candle','edge','wick','ohlc','volume'):
+        if item not in value['marketcolors']:
+            return False
+        itemcolors = value['marketcolors'][item]
+        if not isinstance(itemcolors,dict):
+            return False
+        if 'up' not in itemcolors or 'down' not in itemcolors:
+            return False
+    return True
+
 def _valid_make_marketcolors_kwargs():
     vkwargs = {
         'up'         : { 'Default'     : None,