# MathText WX#

Demonstrates how to convert (math)text to a wx.Bitmap for display in various controls on wxPython.

from io import BytesIO

from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
from matplotlib.backends.backend_wx import NavigationToolbar2Wx
from matplotlib.figure import Figure
import numpy as np
import wx

IS_GTK = 'wxGTK' in wx.PlatformInfo
IS_WIN = 'wxMSW' in wx.PlatformInfo

def mathtext_to_wxbitmap(s):
# We draw the text at position (0, 0) but then rely on
# facecolor="none" and bbox_inches="tight", pad_inches=0 to get an
# transparent mask that is then loaded into a wx.Bitmap.
fig = Figure(facecolor="none")
text_color = (
np.array(wx.SystemSettings.GetColour(wx.SYS_COLOUR_WINDOWTEXT)) / 255)
fig.text(0, 0, s, fontsize=10, color=text_color)
buf = BytesIO()
fig.savefig(buf, format="png", dpi=150, bbox_inches="tight", pad_inches=0)
s = buf.getvalue()
return wx.Bitmap.NewFromPNGData(s, len(s))

functions = [
(r'$\sin(2 \pi x)$', lambda x: np.sin(2*np.pi*x)),
(r'$\frac{4}{3}\pi x^3$', lambda x: (4/3)*np.pi*x**3),
(r'$\cos(2 \pi x)$', lambda x: np.cos(2*np.pi*x)),
(r'$\log(x)$', lambda x: np.log(x))
]

class CanvasFrame(wx.Frame):
def __init__(self, parent, title):
super().__init__(parent, -1, title, size=(550, 350))

self.figure = Figure()

self.canvas = FigureCanvas(self, -1, self.figure)

self.change_plot(0)

self.sizer = wx.BoxSizer(wx.VERTICAL)
self.sizer.Add(self.canvas, 1, wx.LEFT | wx.TOP | wx.GROW)
self.add_toolbar()  # comment this out for no toolbar

wx.ID_EXIT, "E&xit\tAlt-X", "Exit this simple sample")

if IS_GTK or IS_WIN:
for i, (mt, func) in enumerate(functions):
bm = mathtext_to_wxbitmap(mt)
item = wx.MenuItem(menu, 1000 + i, " ")
item.SetBitmap(bm)

self.SetSizer(self.sizer)
self.Fit()

self.button_bar = wx.Panel(self)
self.button_bar_sizer = wx.BoxSizer(wx.HORIZONTAL)
self.sizer.Add(self.button_bar, 0, wx.LEFT | wx.TOP | wx.GROW)

for i, (mt, func) in enumerate(functions):
bm = mathtext_to_wxbitmap(mt)
button = wx.BitmapButton(self.button_bar, 1000 + i, bm)
self.Bind(wx.EVT_BUTTON, self.OnChangePlot, button)

self.button_bar.SetSizer(self.button_bar_sizer)

"""Copied verbatim from embedding_wx2.py"""
self.toolbar.Realize()
# By adding toolbar in sizer, we are able to put it at the bottom
# of the frame - so appearance is closer to GTK version.
self.sizer.Add(self.toolbar, 0, wx.LEFT | wx.EXPAND)
# update the axes menu on the toolbar
self.toolbar.update()

def OnChangePlot(self, event):
self.change_plot(event.GetId() - 1000)

def change_plot(self, plot_number):
t = np.arange(1.0, 3.0, 0.01)
s = functions[plot_number][1](t)
self.axes.clear()
self.axes.plot(t, s)
self.canvas.draw()

def OnClose(self, event):
self.Destroy()

class MyApp(wx.App):
def OnInit(self):
frame = CanvasFrame(None, "wxPython mathtext demo app")
self.SetTopWindow(frame)
frame.Show(True)
return True

if __name__ == "__main__":
app = MyApp()
app.MainLoop()


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