How to create hover effect on StaticBitmap in wxpython?

Question

Hi,

I want to create hover effect on StaticBitmap - If the cursor of mouse is over the the bitmap, shows one image, if not, shows second image. It's trivial program (works perfectly with a button). However, StaticBitmap doesn't emit EVT_WINDOW_ENTER, EVT_WINDOW_LEAVE events.

I can work with EVT_MOTION. If images are switched when the cursor is on the edge of image, switch sometimes doesn't work. (Mainly with fast moving over the edge).

Example code:

#!/usr/bin/python
# -*- coding: utf-8 -*-

import wx

def onWindow(event):
    print "window event:", event.m_x, event.m_y

def onMotion(event):
    print "motion event:", event.m_x, event.m_y

app = wx.App()

imageA = wx.Image("b.gif", wx.BITMAP_TYPE_ANY).ConvertToBitmap()
imageB = wx.Image("a.gif", wx.BITMAP_TYPE_ANY).ConvertToBitmap()

frame = wx.Frame(None, wx.ID_ANY, title="Hover effect", size=(100+imageA.GetWidth(), 100+imageA.GetHeight()))

w = wx.Window(frame)
bmp = wx.StaticBitmap(w, -1, imageA, (50, 50), (imageA.GetWidth(), imageA.GetHeight()))
bmp.Bind(wx.EVT_MOTION, onMotion) 
bmp.Bind(wx.EVT_ENTER_WINDOW, onWindow)
bmp.Bind(wx.EVT_LEAVE_WINDOW, onWindow)

frame.Show()
app.MainLoop()

Answer 1

It looks like this is a wxGTK bug, ENTER and LEAVE events work fine on windows. You should direct the attention of the core developers to the problem, a good place to do this is their bug tracker. This is an issue you should not have to work around IMHO.

I have found that GenericButtons do not have this problem on wxGTK, so maybe you can use that until StaticBitmap gets fixed.

#!/usr/bin/python
# -*- coding: utf-8 -*-

import wx
from wx.lib import buttons

def onWindow(event):
    print "window event:", event.m_x, event.m_y

def onMotion(event):
    print "motion event:", event.m_x, event.m_y

app = wx.App()

imageA = wx.Image("b.gif", wx.BITMAP_TYPE_ANY).ConvertToBitmap()
imageB = wx.Image("a.gif", wx.BITMAP_TYPE_ANY).ConvertToBitmap()

frame = wx.Frame(None, wx.ID_ANY, title="Hover effect", size=(100+imageA.GetWidth(), 100+imageA.GetHeight()))

w = wx.Window(frame)
#bmp = wx.StaticBitmap(w, -1, imageA, (50, 50), (imageA.GetWidth(), imageA.GetHeight()))
bmp = buttons.GenBitmapButton(w, -1, imageA, style=wx.BORDER_NONE)
#bmp.Bind(wx.EVT_MOTION, onMotion)
bmp.Bind(wx.EVT_ENTER_WINDOW, onWindow)
bmp.Bind(wx.EVT_LEAVE_WINDOW, onWindow)

frame.Show()
app.MainLoop()

Answer 2

There may be bug in wxStaticBitmap implementation, but if wxBitmapButton works you can use it for same effect, with less code

#!/usr/bin/python
# -*- coding: utf-8 -*-

import wx

app = wx.App()

frame = wx.Frame(None, wx.ID_ANY, title="Hover effect")
w = wx.Window(frame)
c = wx.BitmapButton(w, -1, wx.EmptyBitmap(25,25), style = wx.NO_BORDER)
c.SetBitmapHover(wx.EmptyBitmap(3,3))
frame.Show()

app.MainLoop()