eric6/WebBrowser/WebInspector.py

# -*- coding: utf-8 -*-

# Copyright (c) 2015 - 2021 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a QWebEngineView to load the web inspector in.
"""

from PyQt5.QtCore import pyqtSignal, QSize
from PyQt5.QtWebEngineWidgets import (
    QWebEngineView, QWebEnginePage, QWebEngineSettings
)

import Preferences

_VIEWS = []


class WebInspector(QWebEngineView):
    """
    Class implementing a QWebEngineView to load the web inspector in.
    
    @signal inspectorClosed emitted to indicate the closing of the inspector
        window
    """
    inspectorClosed = pyqtSignal()
    
    def __init__(self, parent=None):
        """
        Constructor
        
        @param parent reference to the parent widget
        @type QWidget
        """
        super(WebInspector, self).__init__(parent)
        
        self.__view = None
        self.__inspectElement = False
        
        self.__reloadGeometry()
        
        registerView(self)
        
        self.page().windowCloseRequested.connect(self.close)
        self.page().loadFinished.connect(self.__loadFinished)
    
    def closeEvent(self, evt):
        """
        Protected method to save the geometry when closed.
        
        @param evt event object
        @type QCloseEvent
        """
        Preferences.setGeometry("WebInspectorGeometry", self.saveGeometry())
        super(WebInspector, self).closeEvent(evt)
        
        if evt.isAccepted():
            self.inspectorClosed.emit()

    def __reloadGeometry(self):
        """
        Private method to restore the geometry.
        """
        geom = Preferences.getGeometry("WebInspectorGeometry")
        if geom.isEmpty():
            s = QSize(600, 600)
            self.resize(s)
        else:
            self.restoreGeometry(geom)
    
    def setView(self, view, inspectElement=False):
        """
        Public method to connect a view to this inspector.
        
        @param view reference to the view object
        @type WebBrowserView
        @param inspectElement flag indicating to start a web inspection
        @type bool
        """
        self.__view = view
        if not self.isEnabled():
            return
        
        self.__inspectElement = inspectElement
        
        self.page().setInspectedPage(self.__view.page())
    
    def inspectElement(self):
        """
        Public method to inspect an element.
        """
        self.__inspectElement = True
    
    @classmethod
    def isEnabled(cls):
        """
        Class method to check, if the web inspector is enabled.
        
        @return flag indicating the enabled state
        @rtype bool
        """
        from WebBrowser.WebBrowserWindow import WebBrowserWindow
        if not WebBrowserWindow.webSettings().testAttribute(
                QWebEngineSettings.WebAttribute.JavascriptEnabled):
            return False
        
        return True
    
    def __loadFinished(self):
        """
        Private slot handling the finished signal.
        """
        if self.__inspectElement:
            self.__view.triggerPageAction(
                QWebEnginePage.WebAction.InspectElement)
            self.__inspectElement = False


def registerView(view):
    """
    Function to register a view.
    
    @param view reference to the view
    @type WebBrowserView
    """
    if _VIEWS is None:
        return
    
    _VIEWS.insert(0, view)


def unregisterView(view):
    """
    Function to unregister a view.
    
    @param view reference to the view
    @type WebBrowserView
    """
    if _VIEWS is None:
        return
    
    if view in _VIEWS:
        _VIEWS.remove(view)


def pushView(view):
    """
    Function to push a view to the front of the list.
    
    @param view reference to the view
    @type WebBrowserView
    """
    if _VIEWS is None:
        return
    
    if view in _VIEWS:
        _VIEWS.remove(view)
    _VIEWS.insert(0, view)