wxpython run when textctrl changes - text

Question

I am making a simple text editor in wxpython. I would like it to be able to edit code such as python, and as such I would like to have it highlight the text in a similar manner to IDLE or Notepad++. I know how I would highlight it, but I would like the best way of running it. I don't know if it is possible but what I would really like is to run whenever a key is pressed, and not on a loop checking if it is pressed, so as to save on processing.
import wx
class MainWindow(wx.Frame):
def __init__(self, parent, title):
wx.Frame.__init__(self, parent, title=title, size=(500,600))
style = wx.TE_MULTILINE|wx.BORDER_SUNKEN|wx.TE_RICH2
self.status_area = wx.TextCtrl(self, -1,
pos=(10, 270),style=style,
size=(380,150))
self.status_area.AppendText("Type in your wonderfull code here.")
fg = wx.Colour(200,80,100)
at = wx.TextAttr(fg)
self.status_area.SetStyle(3, 5, at)
self.CreateStatusBar() # A Statusbar in the bottom of the window
# Setting up the menu.
filemenu= wx.Menu()
filemenu.Append(wx.ID_ABOUT, "&About","Use to edit python code")
filemenu.AppendSeparator()
filemenu.Append(wx.ID_EXIT,"&Exit"," Terminate the program")
# Creating the menubar.
menuBar = wx.MenuBar()
menuBar.Append(filemenu,"&File") # Adding the "filemenu" to the MenuBar
self.SetMenuBar(menuBar) # Adding the MenuBar to the Frame content.
self.Show(True)
app = wx.App(False)
frame = MainWindow(None, "Python Coder")
app.MainLoop()
If a loop is needed what would be the best way to make it loop, with a while loop, or a
def Loop():
<code>
Loop()
My new code with the added bind:
import wx
class MainWindow(wx.Frame):
def __init__(self, parent, title):
wx.Frame.__init__(self, parent, title=title, size=(500,600))
style = wx.TE_MULTILINE|wx.BORDER_SUNKEN|wx.TE_RICH2
self.status_area = wx.TextCtrl(self, -1,
pos=(10, 270),style=style,
size=(380,150))
#settup the syntax highlighting to run on a key press
self.Bind(wx.EVT_CHAR, self.onKeyPress, self.status_area)
self.status_area.AppendText("Type in your wonderfull code here.")
fg = wx.Colour(200,80,100)
at = wx.TextAttr(fg)
self.status_area.SetStyle(3, 5, at)
self.CreateStatusBar() # A Statusbar in the bottom of the window
# Setting up the menu.
filemenu= wx.Menu()
filemenu.Append(wx.ID_ABOUT, "&About","Use to edit python code")
filemenu.AppendSeparator()
filemenu.Append(wx.ID_EXIT,"&Exit"," Terminate the program")
# Creating the menubar.
menuBar = wx.MenuBar()
menuBar.Append(filemenu,"&File") # Adding the "filemenu" to the MenuBar
self.SetMenuBar(menuBar) # Adding the MenuBar to the Frame content.
self.Show(True)
def onKeyPress (self, event):
print "KEY PRESSED"
kc = event.GetKeyCode()
if kc == WXK_SPACE or kc == WXK_RETURN:
Line = self.status_area.GetValue()
print Line
app = wx.App(False)
frame = MainWindow(None, "Python Coder")
app.MainLoop()

Answer 1

In your MainWindow __init__ function add this
self.Bind(wx.EVT_CHAR, self.onKeyPress, self.status_area)
then define onKeyPress in MainWindow
def onKeyPress (self, event):
kc = event.GetKeyCode()
if kc == WXK_SPACE or kc == WXK_RETURN:
#Run your highlighting code here
Come to think of it, this might not be the most efficient way of doing code highlighting. Let me look this up. But in the meantime you can try this.
Edit:
Take a look at this - StyledTextCtrl . I think its more along the lines of what you need.

Answer 2

I solved this when I faced the same issue by creating a custom event.
First, I created a subclass of the TextCtrl, so I had a place in code to raise/post the custom event from:
import wx.lib.newevent
(OnChangeEvent, EVT_VALUE_CHANGED) = wx.lib.newevent.NewEvent()
class TextBox(wx.TextCtrl):
old_value = u''
def __init__(self,*args,**kwargs):
wx.TextCtrl.__init__(self,*args,**kwargs)
self.Bind(wx.EVT_SET_FOCUS, self.gotFocus) # used to set old value
self.Bind(wx.EVT_KILL_FOCUS, self.lostFocus) # used to get new value
def gotFocus(self, evt):
evt.Skip()
self.old_value = self.GetValue()
def lostFocus(self, evt):
evt.Skip()
if self.GetValue() != self.old_value:
evt = OnChangeEvent(oldValue=self.old_value, newValue=self.GetValue())
wx.PostEvent(self, evt)
Now, in my frame's code, here is a snippet of me Binding the event, and using it.
summ_text_ctrl = TextBox(self, -1, size=(400, -1))
summ_text_ctrl.Bind(EVT_VALUE_CHANGED, self.onTextChanged)
def OnTextChanged(self, evt):
evt.Skip()
print('old Value: %s' % evt.oldValue )
print('new Value: %s' % evt.newValue )