Adds range field to wx.lib.agw.pygauge.PyGauge format string. (#2583)

* Adds range to wx.lib.awg.pygauge.PyGauge format string.

The format string can now have fields for `value` and `range`.

* Updates the desciption.

* Uses field names in default format string (as described).

* Removes dependency on the `copy` module.

wx/lib/agw/pygauge.py

@@ -113,7 +113,6 @@ def __init__(self, parent):
 """
 
 import wx
-import copy
 
 
 class PyGauge(wx.Window):
@@ -343,15 +342,15 @@ def OnPaint(self, event):
             for i, gradient in enumerate(self._barGradientSorted):
                 c1,c2 = gradient
                 w = rect.width * (float(self._valueSorted[i]) / self._range)
-                r = copy.copy(rect)
+                r = wx.Rect(rect)
                 r.width = int(w)
                 dc.GradientFillLinear(r, c1, c2, wx.EAST)
         else:
             for i, colour in enumerate(self._barColourSorted):
                 dc.SetBrush(wx.Brush(colour))
                 dc.SetPen(wx.Pen(colour))
                 w = rect.width * (float(self._valueSorted[i]) / self._range)
-                r = copy.copy(rect)
+                r = wx.Rect(rect)
                 r.width = int(w)
                 dc.DrawRectangle(r)
 
@@ -364,7 +363,8 @@ def OnPaint(self, event):
             if self._drawIndicatorText_drawPercent:
                 drawValue = (float(self._valueSorted[i]) * 100)  / self._range
 
-            drawString = self._drawIndicatorText_formatString.format(drawValue)
+            drawString = self._drawIndicatorText_formatString.format(
+                drawValue, value=drawValue, range=self._range)
             rect = self.GetClientRect()
             (textWidth, textHeight, descent, extraLeading) = dc.GetFullTextExtent(drawString)
             textYPos = (rect.height-textHeight)//2
@@ -392,9 +392,10 @@ def SetDrawValue(self, draw=True, drawPercent=True, font=None, colour=wx.BLACK,
          will be used. Usually text would be displayed centered in the control, but if the text font is too large
          to be displayed (either in width or height) the corresponding coordinate will be set to zero;
         :param wx.Colour `colour`: the colour with which indication should be drawn, if ``None`` then ``wx.BLACK`` will be used;
-        :param string `formatString`: a string specifying format of the indication (should have one and only one
-         number placeholder). If set to ``None``, will use ``{:.0f}`` format string for values and ``{:.0f}%``
-         format string for percentages. As described in http://docs.python.org/library/string.html#format-specification-mini-language.
+        :param string `formatString`: a string specifying format of the indication (could have one and only one unnamed
+         number placeholder and a `value` and `range` number placeholder). If set to ``None``, will use ``{value:.0f}``
+         format string for values and ``{value:.0f}%` format string for percentages. As described in
+         http://docs.python.org/library/string.html#format-specification-mini-language.
 
         .. note:: `formatString` will override addition of percent sign (after value) even if `drawPercent` is ``True``.
 
@@ -423,7 +424,7 @@ def SetDrawValue(self, draw=True, drawPercent=True, font=None, colour=wx.BLACK,
             error_occurred = True
             try:
                 # This is to test if format string is valid. If not, it will be replaced with default one.
-                formatString.format(12.345)
+                formatString.format(12.345, value=12.345, range=54.321)
                 error_occurred = False
             except Exception as e:
                 print(("We have exception: %s"%e))
@@ -434,8 +435,8 @@ def SetDrawValue(self, draw=True, drawPercent=True, font=None, colour=wx.BLACK,
         # Here formatString is either valid formatting string, or None in case of error or None passed
         if formatString is None:
             if self._drawIndicatorText_drawPercent:
-                self._drawIndicatorText_formatString = "{:.0f}%"
-            else: self._drawIndicatorText_formatString = "{:.0f}"
+                self._drawIndicatorText_formatString = "{value:.0f}%"
+            else: self._drawIndicatorText_formatString = "{value:.0f}"
         else:
             self._drawIndicatorText_formatString = formatString