編集これを次の編集で更新していたときに、テスト中にPythonのトレースバック機能に一見問題があることに気付きました。新しい質問を投稿します
編集：質問をより簡単にするために更新されました
問題
問題は、なんらかの理由でパネルのサイズを変更する必要がある関数を EVT_SIZE イベント ハンドラで呼び出すと、無限ループになり、再帰エラーが発生することです。
これは、関数が EVT_SIZE ハンドラー内にあるかどうかのブール値の true/false 変数を使用して (2.8 で) 解決されていました。ただし、これは 2.9 では機能しません。これは、イベントが非同期になったように見えるためです (または、少なくとも何らかの方法で、SetSize 呼び出しが返され、フラグがリセットされ、イベント ハンドラーが呼び出されることを意味します)。
状況の例
デフォルト（いかなる方法でもそれを処理しない
import wx
class TestPanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent, -1)
self.Bind(wx.EVT_SIZE, self.OnSize, self)
wx.CallLater(10000, self.ResizeThing)
def ResizeThing(self):
print "Doing our resize thing...."
# calculate whatever we need to calculate
# seems we got to change it in some way
self.SetSize(self.GetSize() + (30, 30))
return "whatever we'd return"
def OnSize(self, event):
print "Size event got to resize"
self.ResizeThing()
if __name__ == '__main__':
app = wx.App(False)
f = wx.Frame(None, -1)
TestPanel(f)
f.Show()
app.MainLoop()
2.8 ブール値フラグを使用したソリューション
evt size イベントを発生させずにパネルのサイズを変更する方法はありますか? これは、そうすると無限ループが発生するためです (2.9 では、何らかの理由で 2.8 ではありません)。
注目すべきコード
def __init__(...):
..... other stuff....
self.Bind(wx.EVT_SIZE, self.OnSize, self)
def OnSize(self, event):
# if we didn't have it we would have a infinite recursion going evt_size -> update -> evt_size -> update -> evt_size -> update... forever
if not self.setting_size:
# update current size and set artwork
print self.GetSize()
print self.current_size
print "OnSize"
self.current_size = self.GetSize()
print self.current_size
self.UpdateArtwork(self.current_img)
else:
event.Skip()
def UpdateArtwork(self, img):
... get scaled image and set the bitmap
img = self.scale(img)
self.SetBitmap(img.ConvertToBitmap())
def scale(self, img):
print "Calling Scale"
# size the window to the correct dimensions
# get the size the sizer thinks is best
wW = self.GetBestVirtualSize()[0] # the width that the sizer reccomends
wH = self.GetBestVirtualSize()[1] # the height the sizer recommends
W = img.GetWidth()
H = img.GetHeight()
# modifiy the sizer recommendations to fit the image aspect ratio
# use bigger side as the base
if wW > wH:
# round to nearest integer value sense we are using future division
# get the new wH base on the image aspect ratio
wH = round(H/W * wW) # H/W how many H pixels per one W
else:
wW = round(W/H * wH) # W/H how many W pixels per one H
... this is SUPPOSE to prevent a loop by flagging it
self.setting_size = True
print time.time()
print "Setting size in scale..."
self.current_size = (wW, wH)
print self.current_size
self.SetSize((wW, wH))
print time.time()
self.setting_size = False
print time.time()
# then scale the image based on the panel size
return img.Scale(wW, wH)
ただし、これは EVT が非同期であるため機能しないため、false にリセットした後に起動し、無限ループが発生します。
完全なコード
# for proper scaling calculations (such things as .6451 going becoming 0)
from __future__ import division
import time
import wx
from twisted.web import client
from twisted.python import log
try:
import cStringIO as StringIO
except ImportError:
import StringIO
class URLImage(wx.StaticBitmap):
'''Allows a easy mechanism for setting url images'''
def __init__(self, parent, default_image):
wx.StaticBitmap.__init__(self, parent, -1)
self.current_img = None
self.current_url = None
self.current_size = self.GetSize()
self.di_d = default_image
self.default_image = wx.Image(default_image, wx.BITMAP_TYPE_ANY)
self.current_img = self.default_image
self.SetArtwork(self.default_image)
self.Bind(wx.EVT_SIZE, self.OnSize, self)
def OnSize(self, event):
# if we didn't have it we would have a infinite recursion going evt_size -> update -> evt_size -> update -> evt_size -> update... forever
if not self.current_size == self.GetSize():
# update current size and set artwork
print self.GetSize()
print self.current_size
print "OnSize"
self.current_size = self.GetSize()
print self.current_size
self.UpdateArtwork(self.current_img)
else:
event.Skip()
def SetArtwork(self, img):
# for bitmaps (use corresponding method for urls)
self.current_url = None # the current artwork isn't a url, it is a bitmap
print "SetArtwork Updating Artwork"
self.UpdateArtwork(img)
def SetDefaultImage(self):
# this is to change the image to the default
# NOT to change the default image to some other one
# ^(like Text SetLabel changes the Label)
# similiar to SetArtwork
self.current_url = None
print "SetDefault Updating Artwork"
self.UpdateArtwork(self.default_image)
def SetArtworkFromURL(self, url = None):
if url == self.current_url:
print "[URLImage] Duplicate URL"
return
else:
# set back the defualt art
print "Defaulting for URL loading"
self.UpdateArtwork(self.default_image)
# update current_url
self.current_url = url
if url == None:
return
d = client.getPage(url.encode("ascii"), method = "GET", agent = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; fr; rv:1.9.2b4) Gecko/20091124 Firefox/3.6b4 (.NET CLR 3.5.30729)')
d.addCallback(lambda data: self.UpdateArtwork(wx.ImageFromStream(StringIO.StringIO(data))))
d.addErrback(self.error)
def UpdateArtwork(self, img):
# ALBUM ART
# From: http://www.blog.pythonlibrary.org/2010/03/26/creating-a-simple-photo-viewer-with-wxpython/
# scale the image, preserving the aspect ratio
self.current_img = img
print "Update Artwork"
img = self.scale(img)
self.SetBitmap(img.ConvertToBitmap())
def scale(self, img):
print "Calling Scale"
# size the window to the correct dimensions
# get the size the sizer thinks is best
wW = self.GetBestVirtualSize()[0] # the width that the sizer reccomends
wH = self.GetBestVirtualSize()[1] # the height the sizer recommends
W = img.GetWidth()
H = img.GetHeight()
# modifiy the sizer recommendations to fit the image aspect ratio
# use bigger side as the base
if wW > wH:
# round to nearest integer value sense we are using future division
# get the new wH base on the image aspect ratio
wH = round(H/W * wW) # H/W how many H pixels per one W
else:
wW = round(W/H * wH) # W/H how many W pixels per one H
self.setting_size = True
print time.time()
print "Setting size in scale..."
self.current_size = (wW, wH)
print self.current_size
self.SetSize((wW, wH))
print time.time()
self.setting_size = False
print time.time()
# then scale the image based on the panel size
return img.Scale(wW, wH)
def error(self, err_):
''' Error callback for fetching the album art'''
self.current_url = None# no current (succesful) url artwork set
self.SetArtwork(self.default_image)
log.msg("Error getting Album Artwork")
log.err(err_)