Here's an improved version of the example. (Disclaimer: I started digging into it half an hour ago, never before used wx/matplotlib scrollbars so there might be a much better solution.)
The path I took: first I checked the wx scroll events, then found out that the canvas is FigureCanvasWxAgg derived from wxPanel, inheriting wxWindow methods. There you may find the scroll position handling methods GetScrollPos
and SetScrollPos
.
from numpy import arange, sin, pi, float, size
import matplotlib
matplotlib.use('WXAgg')
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg
from matplotlib.figure import Figure
import wx
class MyFrame(wx.Frame):
def __init__(self, parent, id):
wx.Frame.__init__(self,parent, id, 'scrollable plot',
style=wx.DEFAULT_FRAME_STYLE ^ wx.RESIZE_BORDER,
size=(800, 400))
self.panel = wx.Panel(self, -1)
self.fig = Figure((5, 4), 75)
self.canvas = FigureCanvasWxAgg(self.panel, -1, self.fig)
self.scroll_range = 400
self.canvas.SetScrollbar(wx.HORIZONTAL, 0, 5,
self.scroll_range)
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add(self.canvas, -1, wx.EXPAND)
self.panel.SetSizer(sizer)
self.panel.Fit()
self.init_data()
self.init_plot()
self.canvas.Bind(wx.EVT_SCROLLWIN, self.OnScrollEvt)
def init_data(self):
# Generate some data to plot:
self.dt = 0.01
self.t = arange(0,5,self.dt)
self.x = sin(2*pi*self.t)
# Extents of data sequence:
self.i_min = 0
self.i_max = len(self.t)
# Size of plot window:
self.i_window = 100
# Indices of data interval to be plotted:
self.i_start = 0
self.i_end = self.i_start + self.i_window
def init_plot(self):
self.axes = self.fig.add_subplot(111)
self.plot_data =
self.axes.plot(self.t[self.i_start:self.i_end],
self.x[self.i_start:self.i_end])[0]
def draw_plot(self):
# Update data in plot:
self.plot_data.set_xdata(self.t[self.i_start:self.i_end])
self.plot_data.set_ydata(self.x[self.i_start:self.i_end])
# Adjust plot limits:
self.axes.set_xlim((min(self.t[self.i_start:self.i_end]),
max(self.t[self.i_start:self.i_end])))
self.axes.set_ylim((min(self.x[self.i_start:self.i_end]),
max(self.x[self.i_start:self.i_end])))
# Redraw:
self.canvas.draw()
def update_scrollpos(self, new_pos):
self.i_start = self.i_min + new_pos
self.i_end = self.i_min + self.i_window + new_pos
self.canvas.SetScrollPos(wx.HORIZONTAL, new_pos)
self.draw_plot()
def OnScrollEvt(self, event):
evtype = event.GetEventType()
if evtype == wx.EVT_SCROLLWIN_THUMBTRACK.typeId:
pos = event.GetPosition()
self.update_scrollpos(pos)
elif evtype == wx.EVT_SCROLLWIN_LINEDOWN.typeId:
pos = self.canvas.GetScrollPos(wx.HORIZONTAL)
self.update_scrollpos(pos + 1)
elif evtype == wx.EVT_SCROLLWIN_LINEUP.typeId:
pos = self.canvas.GetScrollPos(wx.HORIZONTAL)
self.update_scrollpos(pos - 1)
elif evtype == wx.EVT_SCROLLWIN_PAGEUP.typeId:
pos = self.canvas.GetScrollPos(wx.HORIZONTAL)
self.update_scrollpos(pos - 10)
elif evtype == wx.EVT_SCROLLWIN_PAGEDOWN.typeId:
pos = self.canvas.GetScrollPos(wx.HORIZONTAL)
self.update_scrollpos(pos + 10)
else:
print "unhandled scroll event, type id:", evtype
class MyApp(wx.App):
def OnInit(self):
self.frame = MyFrame(parent=None,id=-1)
self.frame.Show()
self.SetTopWindow(self.frame)
return True
if __name__ == '__main__':
app = MyApp()
app.MainLoop()
You may adjust e.g. the increments for PAGEUP/PAGEDOWN if you feel it too slow.
Also if you wish, the events can be handled separately setting up the specific event handlers instead of their collection EVT_SCROLLWIN
, then instead of if/elifs there will be OnScrollPageUpEvt etc.