News download: Allow using show_browser() in recipes when using --test

src/calibre/gui2/__init__.py

@@ -1149,16 +1149,16 @@ def open_local_file(path):
 
 _ea_lock = Lock()
 
-def ensure_app():
+def ensure_app(headless=True):
     global _store_app
     with _ea_lock:
         if _store_app is None and QApplication.instance() is None:
             args = sys.argv[:1]
-            headless = islinux or isbsd
-            if headless:
+            if headless and (islinux or isbsd):
                 args += ['-platformpluginpath', sys.extensions_location, '-platform', 'headless']
             _store_app = QApplication(args)
-            _store_app.headless = headless
+            if headless and (islinux or isbsd):
+                _store_app.headless = True
             import traceback
             # This is needed because as of PyQt 5.4 if sys.execpthook ==
             # sys.__excepthook__ PyQt will abort the application on an
@@ -1175,14 +1175,17 @@ def ensure_app():
                     pass
             sys.excepthook = eh
 
-def must_use_qt():
+def app_is_headless():
+    return getattr(_store_app, 'headless', False)
+
+def must_use_qt(headless=True):
     ''' This function should be called if you want to use Qt for some non-GUI
     task like rendering HTML/SVG or using a headless browser. It will raise a
     RuntimeError if using Qt is not possible, which will happen if the current
     thread is not the main GUI thread. On linux, it uses a special QPA headless
     plugin, so that the X server does not need to be running. '''
     global gui_thread
-    ensure_app()
+    ensure_app(headless=headless)
     if gui_thread is None:
         gui_thread = QThread.currentThread()
     if gui_thread is not QThread.currentThread():

src/calibre/web/feeds/news.py

@@ -487,7 +487,7 @@ class BasicNewsRecipe(Recipe):
             if getattr(self, 'browser', None) is not None:
                 return self.clone_browser(self.browser)
             from calibre.web.jsbrowser.browser import Browser
-            br = Browser()
+            br = Browser(headless=not self.test)
             with br:
                 self.javascript_login(br, self.username, self.password)
                 kwargs['user_agent'] = br.user_agent

src/calibre/web/jsbrowser/browser.py

@@ -14,15 +14,15 @@ from threading import current_thread
 from PyQt5.QtWebKit import QWebSettings, QWebElement
 from PyQt5.QtWebKitWidgets import QWebPage, QWebView
 from PyQt5.Qt import (
-    QObject, QNetworkAccessManager, QNetworkDiskCache, QCoreApplication,
-    QNetworkProxy, QNetworkProxyFactory, QEventLoop, QUrl, pyqtSignal,
-    QDialog, QVBoxLayout, QSize, QNetworkCookieJar, Qt, pyqtSlot, QPixmap)
+    QObject, QNetworkAccessManager, QNetworkDiskCache, QNetworkProxy,
+    QNetworkProxyFactory, QEventLoop, QUrl, pyqtSignal, QDialog, QVBoxLayout,
+    QSize, QNetworkCookieJar, Qt, pyqtSlot, QPixmap)
 
 from calibre import USER_AGENT, prints, get_proxies, get_proxy_info, prepare_string_for_xml
 from calibre.constants import ispy3, cache_dir
 from calibre.ptempfile import PersistentTemporaryDirectory
 from calibre.utils.logging import ThreadSafeLog
-from calibre.gui2 import must_use_qt
+from calibre.gui2 import must_use_qt, app_is_headless
 from calibre.web.jsbrowser.forms import FormsMixin, default_timeout
 
 class Timeout(Exception):
@@ -364,9 +364,12 @@ class Browser(QObject, FormsMixin):
             verbosity=0,
 
             # The default timeout (in seconds)
-            default_timeout=30
+            default_timeout=30,
+
+            # If True, do not connect to the X server on linux
+            headless=True
         ):
-        must_use_qt()
+        must_use_qt(headless=headless)
         QObject.__init__(self)
         FormsMixin.__init__(self)
 
@@ -682,7 +685,7 @@ class Browser(QObject, FormsMixin):
         '''
         Show the currently loaded web page in a window. Useful for debugging.
         '''
-        if getattr(QCoreApplication.instance(), 'headless', False):
+        if app_is_headless():
             raise RuntimeError('Cannot show browser when running in a headless Qt application')
         view = BrowserView(self.page)
         view.exec_()