python - 通过 Esky 任务获取进度

Question

我将 Esky 与我卡住的应用程序一起使用。它具有以下属性和方法在 Esky 类上可用:

app.version:                the current best available version.

app.active_version:         the currently-executing version, or None
                            if the esky isn't for the current app.

app.find_update():          find the best available update, or None
                            if no updates are available.

app.fetch_version(v):       fetch the specified version into local storage.

app.install_version(v):     install and activate the specified version.

现在，这很好，但我想在我的 Gui 中显示下载任务的进度。

我怎样才能做到这一点？

Answer 1

wxPython 在他们自己的 SoftwareUpdate 方法中包装了 Esky:

https://github.com/wxWidgets/wxPython/blob/master/wx/lib/softwareupdate.py

在他们的实现中，应用程序检查新版本，并询问用户是否愿意更新(使用 wx GUI 进行交互)。如果用户选择更新，代码会简单地调用 esky 的 auto_update() 方法来处理剩下的事情，但是他们为它提供了一个 _updateProgress 方法来更新进度条并提供指示 Esky 进度的消息:

self._esky.auto_update(self._updateProgress)

...

def _updateProgress(self, status):
    # Show progress of the download and install. This function is passed to Esky
    # functions to use as a callback.
    if self._pd is None and status.get('status') != 'done':
        self._pd = wx.ProgressDialog('Software Update', ' '*40, 
                                      style=wx.PD_CAN_ABORT|wx.PD_APP_MODAL,
                                      parent=self._parentWindow)
        self._pd.Update(0, '')

        if self._parentWindow:
            self._pd.CenterOnParent()

    simpleMsgMap = { 'searching'   : 'Searching...',
                     'retrying'    : 'Retrying...',
                     'ready'       : 'Download complete...',
                     'installing'  : 'Installing...',
                     'cleaning up' : 'Cleaning up...',}

    if status.get('status') in simpleMsgMap:
        self._doUpdateProgress(True, simpleMsgMap[status.get('status')])

    elif status.get('status') == 'found':
        self._doUpdateProgress(True, 'Found version %s...' % status.get('new_version'))

    elif status.get('status') == 'downloading':
        received = status.get('received')
        size = status.get('size')
        currentPercentage = 1.0 * received / size * 100
        if currentPercentage > 99.5:
            self._doUpdateProgress(False, "Unzipping...", int(currentPercentage))
        else:
            self._doUpdateProgress(False, "Downloading...", int(currentPercentage))

    elif status.get('status') == 'done': 
        if self._pd:
            self._pd.Destroy()
        self._pd = None

    wx.Yield()


def _doUpdateProgress(self, pulse, message, value=0):
    if pulse:
        keepGoing, skip = self._pd.Pulse(message)
    else:
        keepGoing, skip = self._pd.Update(value, message)
    if not keepGoing: # user pressed the cancel button
        self._pd.Destroy()
        self._pd = None
        raise UpdateAbortedError()

上面的代码直接取自https://github.com/wxWidgets/wxPython/blob/master/wx/lib/softwareupdate.py .

此功能记录在 Esky 源中，file: init.py , line: 689 .

代码本身显示了您的回调在整个更新过程中期望看到的内容。以下是调用回调的一些摘录:

callback({"status":"searching"})
callback({"status":"found", "new_version":version})
callback({"status":"installing", "new_version":version})
for status in self.sudo_proxy.fetch_version_iter(version):
    if callback is not None:
        callback(status)
callback({"status":"cleaning up"})
callback({"status":"cleaning up"})
callback({"status":"error","exception":e})
callback({"status":"done"})