在Python中,使用wxPython Phoenix 4.1.1 wx。html2模块的WebView,当页面加载时,我希望键盘焦点落在页面上的第一个元素上,这样我就可以使用JAWS或NVDA屏幕读取器使用向下箭头键从一开始就开始阅读页面。但我无法做到这一点,因为在页面加载时,屏幕阅读器键盘焦点总是跳转到页面中间的某个位置。我已经尝试使用JavaScript手动将焦点设置为第一个
<h1>
使用
RunScript
在中调用的函数
wx.html2.EVT_WEBVIEW_LOADED
事件处理程序,如下所示,但这根本没有效果。
请注意,在这段代码中,我使用的是
the trick described here
显示WebView组件后,将屏幕读取器焦点移到WebView组件中。
class HelpHTMLDialog(wx.Dialog):
def __init__(self, title, parent = None):
super(HelpHTMLDialog, self).__init__(parent = parent, title = title)
self.addBrowser()
self.SetSize((900, 700))
self.Centre()
self.ShowModal()
# Adds the web browser to this dialog and binds the page load event.
def addBrowser(self):
vbox = wx.BoxSizer(wx.VERTICAL)
self.browser = wx.html2.WebView.New(self)
self.Bind(wx.html2.EVT_WEBVIEW_LOADED, self.onPageLoad, self.browser)
html = self.getHTML()
self.browser.SetPage(html, '')
vbox.Add(self.browser, 1, wx.EXPAND, 10)
self.SetSizer(vbox)
# Handles the WebView page load.
def onPageLoad(self, event):
# Clicks on the left upper corner of the page to move screen reader focus to the page
self.browser.SetFocus()
position = self.browser.GetPosition()
position = self.browser.ClientToScreen(position)
robot = wx.UIActionSimulator()
robot.MouseMove(position)
robot.MouseClick()
# Move the keyboard focus to the first <h1> heading on the page
self.browser.RunScript('''
var first = document.getElementsByTagName('h1')[0];
first.tabIndex = -1;
first.focus();
// I know this code runs after page load without a problem, because I tried to put alert('test') here, and it worked.
''')
# Gets the HTML of the page.
def getHTML(self):
html = '''
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
</head>
<body>
<h1>Hello Python</h1>
<h2>First heading</h2>
<p>Here is some text just to demonstrate the use of wx.html2.WebView in Python.</p>
<ul>
<li>Firs item.</li>
<li>Second item.</li>
<li>Third item.</li>
<li>Fourth item.</li>
</ul>
<h2>Second heading</h2>
<p>Final paragraph is here just to make the page a bit longer.</p>
<script>
// I have also tried putting the JavaScript code for focusing the first <h1> element here instead, but with no success either.
</script>
</body>
</html>
'''
return html
那么,您对如何在页面加载后以我描述的方式有效控制屏幕阅读器键盘焦点有何想法?
谢谢
