用createWindow覆盖PyQt函数

Question

我正在尝试处理createWindow webkit中的PyQt方法。当您这样做时，PyQt给方法一个QWebPage.WebWindowType (或c++中的QWebPage::WebWindowType )。我所需要的只是一个URL来创建一个新窗口，所以我不知道如何处理这个类。文档也不能很好地解释它：http://doc.qt.digia.com/qt/qwebpage.html#WebWindowType-enum

我试着把它和我的"Tab“类整合起来：

class Tab(QtGui.QWidget):
    """
    Contains the variables and methods needed to open the Qt
    based user interface and the event bus to allow interaction.
    """
    def __init__(self, url, window):
        """
        Set the up the following:
          1) Initialise the Qt user interface.
          2) Set margins.
          3) Initialise the cookie jar.
          4) Set the default URL.
          5) Set the history buttons to disabled (there is not history yet).
          5) Hide the tools menu.
          6) Create the GUI event bus.
          7) Set keyboard bindings.
        """
        self.window = window
        QtGui.QWidget.__init__(self)
        self.ui = Ui_Browser()
        self.ui.setupUi(self)

        l = self.layout()
        l.setMargin(0)
        self.ui.horizontalLayout.setMargin(0)

        try:
            self.ui.webView.page().networkAccessManager().setCookieJar(self.window.cookies)
        except:
            pass

        self.ui.webView.setUrl(url)
        self.ui.url.setText(url.toString())

        self.ui.back.setEnabled(False)
        self.ui.forward.setEnabled(False)

        self.ui.toolsBox.hide()
        self.ui.tools.setChecked(False)

        QtCore.QObject.connect(self.ui.back, QtCore.SIGNAL("clicked()"), self.back)
        QtCore.QObject.connect(self.ui.forward, QtCore.SIGNAL("clicked()"), self.forward)
        QtCore.QObject.connect(self.ui.refresh, QtCore.SIGNAL("clicked()"), self.refresh)
        QtCore.QObject.connect(self.ui.url, QtCore.SIGNAL("returnPressed()"), self.url)
        QtCore.QObject.connect(self.ui.webView, QtCore.SIGNAL("linkClicked (const QUrl&)"), self.navigate)
        QtCore.QObject.connect(self.ui.webView, QtCore.SIGNAL("urlChanged (const QUrl&)"), self.navigate)
        QtCore.QObject.connect(self.ui.webView, QtCore.SIGNAL("titleChanged(const QString&)"), self.title)
        QtCore.QObject.connect(self.ui.webView, QtCore.SIGNAL("loadStarted()"), self.showProgressBar)
        QtCore.QObject.connect(self.ui.webView, QtCore.SIGNAL("loadProgress(int)"), self.setProgressBar)
        QtCore.QObject.connect(self.ui.webView, QtCore.SIGNAL("loadFinished(bool)"), self.hideProgressBar)
        QtCore.QObject.connect(self.ui.toolPrint, QtCore.SIGNAL("clicked()"), self.printPage)
        self.ui.webView.createWindow = self.createWindow

        QtGui.QShortcut(QtGui.QKeySequence("Backspace"), self, self.back)
        QtGui.QShortcut(QtGui.QKeySequence("F5"), self, self.refresh)
        QtGui.QShortcut(QtGui.QKeySequence("Ctrl+p"), self, self.printPage)

    def url(self):
        """
        Go to URL entered.
        """
        self.setHistory()
        url = self.ui.url.text()
        if not str(url).startswith("http://"):
            url = "http://" + url
        self.ui.webView.setUrl(QtCore.QUrl(url))

    def navigate(self, url):
        """
        Navigate to page requested.
        """
        self.setHistory()
        self.ui.url.setText(url.toString())

    def refresh(self):
        """
        Refresh the page.
        """
        self.ui.webView.setUrl(QtCore.QUrl(self.ui.webView.url()))

    def back(self):
        """
        Enable the back button.
        """
        page = self.ui.webView.page()
        history = page.history()
        history.back()
        if history.canGoBack():
            self.ui.back.setEnabled(True)
        else:
            self.ui.back.setEnabled(False)

    def forward(self):
        """
        Enable the forward button.
        """
        page = self.ui.webView.page()
        history = page.history()
        history.forward()
        if history.canGoForward():
            self.ui.forward.setEnabled(True)
        else:
            self.ui.forward.setEnabled(False)

    def title(self, title):
        """
        Change the title of the window.
        """
        self.window.tabs.setTabText(self.window.tabs.indexOf(self), title) or (self.window.setWindowTitle(title) if self.isThisFocused() else "New Tab")

    def createWindow(self, WebWindowType):
        """
        Overide the default behaviour.
        """
        tab = Tab(QtCore.QUrl("about:blank"), self.window)
        print(mode)
        if mode == QtWebKit.QWebPage.WebModalDialog:
            tab.ui.webView.setWindowModality(QtCore.Qt.ApplicationModal)
        self.window.tabs.setCurrentIndex(self.window.tabs.addTab(tab, ""))

    def isThisFocused(self):
        """
        Return whether this tab is focused or not.
        """
        if self.window.tabs.currentWidget() == self:
            return True
        return False

    def setHistory(self):
        """
        Check history and update buttons.
        """
        page = self.ui.webView.page()
        history = page.history()
        if history.canGoBack():
            self.ui.back.setEnabled(True)
        else:
            self.ui.back.setEnabled(False)
        if history.canGoForward():
            self.ui.forward.setEnabled(True)
        else:
            self.ui.forward.setEnabled(False)

    def showProgressBar(self):
        """
        We're loading a page, show the load progress bar.
        """
        self.ui.progress.show()

    def setProgressBar(self, percent):
        """
        Set the percentage of the progress bar.
        """
        self.ui.progress.setValue(percent)

    def hideProgressBar(self, bool):
        """
        We've finished loading the page, there is no need for the progress bar.
        """
        self.ui.progress.hide()

    def printPage(self):
        """
        Use Qt's goodness to print the page.
        """
        previewer = QtGui.QPrintPreviewDialog(paintRequested=self.ui.webView.print_)
        previewer.exec_()

Answer 1

createWindow函数用于处理打开新窗口的请求(例如javascript window.open()调用)。

默认情况下，createWindow什么也不做，因此必须在子类中重新实现它。

此外，要使用javascript，网页设置必须指定javascript程序为允许打开新窗口。

下面是一个演示脚本，演示如何使用createWindow

from PyQt4 import QtGui, QtCore, QtWebKit

class Browser(QtWebKit.QWebView):
    _windows = set()

    @classmethod
    def _removeWindow(cls, window):
        if window in cls._windows:
            cls._windows.remove(window)

    @classmethod
    def newWindow(cls):
        window = cls()
        cls._windows.add(window)
        return window

    def __init__(self, parent=None):
        QtWebKit.QWebView.__init__(self, parent)
        self.setAttribute(QtCore.Qt.WA_DeleteOnClose, True)
        self.settings().setAttribute(
            QtWebKit.QWebSettings.JavascriptEnabled, True)
        self.settings().setAttribute(
            QtWebKit.QWebSettings.JavascriptCanOpenWindows, True)

    def closeEvent(self, event):
        self._removeWindow(self)
        event.accept()

    def createWindow(self, mode):
        window = self.newWindow()
        if mode == QtWebKit.QWebPage.WebModalDialog:
            window.setWindowModality(QtCore.Qt.ApplicationModal)
        window.show()
        return window

html = """
<html>
<head>
<title>Test Page</title>
<script type="text/javascript"><!--
var url = 'https://www.google.com'
var count = 0
function newWindow() {
    count += 1;
    window.open(url, 'testwindow' + count, 'width=640,height=480');
}
--></script>
</head>
<body>
<input type="button" value="New Window" onclick="newWindow()" />
<p><a href="https://www.google.com">Test Link</a></p>
</body>
</html>"""

if __name__ == '__main__':

    import sys
    app = QtGui.QApplication(sys.argv)
    browser = Browser()
    browser.setHtml(html)
    browser.show()
    sys.exit(app.exec_())

(NB：必须保留对任何新创建的窗口的引用；如果不这样做，几乎肯定会导致分段错误)。

编辑

我只想澄清：

createWindow函数用于处理打开新浏览器窗口的外部请求(例如，javascript window.open()调用，如上面的示例所示)。请注意，createWindow是一个虚拟函数。这意味着，如果它在QWebView或QWebPage的子类中被重写，那么Qt可以在内部调用重新实现的函数。如果您需要从javascript代码调用您自己的creatWindow函数，这显然是至关重要的。

因此，如果您希望网页上的javascript程序能够创建和打开浏览器窗口类的实例，那么子类QWebView并重新实现它的createWindow函数(如上面的示例所示)。

简单地创建和显示一个createWindow (例如，添加一个新的选项卡)，根本不需要QWebView函数。QWebView只是一个用于显示网页的容器，它和其他小部件一样被创建和显示。