Merge pull request #306 from mikrosimage/ui_custom_widgets

loadUi: load custom widgets with PySide(2)

Qt.py

@@ -41,9 +41,10 @@
 import sys
 import types
 import shutil
+import importlib
 
 
-__version__ = "1.2.0.b2"
+__version__ = "1.2.0.b3"
 
 # Enable support for `from Qt import *`
 __all__ = []
@@ -851,6 +852,41 @@ class _UiLoader(Qt._QtUiTools.QUiLoader):
             def __init__(self, baseinstance):
                 super(_UiLoader, self).__init__(baseinstance)
                 self.baseinstance = baseinstance
+                self.custom_widgets = {}
+
+            def _loadCustomWidgets(self, etree):
+                """
+                Workaround to pyside-77 bug.
+
+                From QUiLoader doc we should use registerCustomWidget method.
+                But this causes a segfault on some platforms.
+
+                Instead we fetch from customwidgets DOM node the python class
+                objects. Then we can directly use them in createWidget method.
+                """
+
+                def headerToModule(header):
+                    """
+                    Translate a header file to python module path
+                    foo/bar.h => foo.bar
+                    """
+                    # Remove header extension
+                    module = os.path.splitext(header)[0]
+
+                    # Replace os separator by python module separator
+                    return module.replace("/", ".").replace("\\", ".")
+
+                custom_widgets = etree.find("customwidgets")
+
+                if custom_widgets is None:
+                    return
+
+                for custom_widget in custom_widgets:
+                    class_name = custom_widget.find("class").text
+                    header = custom_widget.find("header").text
+                    module = importlib.import_module(headerToModule(header))
+                    self.custom_widgets[class_name] = getattr(module,
+                                                              class_name)
 
             def load(self, uifile, *args, **kwargs):
                 from xml.etree.ElementTree import ElementTree
@@ -860,6 +896,7 @@ def load(self, uifile, *args, **kwargs):
                 # a RuntimeError.
                 etree = ElementTree()
                 etree.parse(uifile)
+                self._loadCustomWidgets(etree)
 
                 widget = Qt._QtUiTools.QUiLoader.load(
                     self, uifile, *args, **kwargs)
@@ -889,7 +926,8 @@ def createWidget(self, class_name, parent=None, name=""):
                                                                   class_name,
                                                                   parent,
                                                                   name)
-
+                elif class_name in self.custom_widgets:
+                    widget = self.custom_widgets[class_name](parent)
                 else:
                     raise Exception("Custom widget '%s' not supported"
                                     % class_name)

tests.py

@@ -51,6 +51,18 @@ def captured_output():
         sys.stdout, sys.stderr = old_out, old_err
 
 
+def CustomWidget(parent=None):
+    """
+    Wrap CustomWidget class into a function to avoid global Qt import
+    """
+    from Qt import QtWidgets
+
+    class Widget(QtWidgets.QWidget):
+        pass
+
+    return Widget(parent)
+
+
 self = sys.modules[__name__]
 
 
@@ -197,6 +209,38 @@ def captured_output():
 """
 
 
+qcustomwidget_ui = u"""\
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>238</width>
+    <height>44</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>MainWindow</string>
+  </property>
+  <widget class="CustomWidget" name="customwidget">
+  </widget>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>CustomWidget</class>
+   <extends>QWidget</extends>
+   <header>tests.h</header>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>
+"""
+
+
 def setup():
     """Module-wide initialisation
 
@@ -216,6 +260,8 @@ def saveUiFile(filename, ui_template):
     self.ui_qmainwindow = saveUiFile("qmainwindow.ui", qmainwindow_ui)
     self.ui_qdialog = saveUiFile("qdialog.ui", qdialog_ui)
     self.ui_qdockwidget = saveUiFile("qdockwidget.ui", qdockwidget_ui)
+    self.ui_qcustomwidget = saveUiFile("qcustomwidget.ui", qcustomwidget_ui)
+
 
 def teardown():
     shutil.rmtree(self.tempdir)
@@ -350,6 +396,26 @@ def test_load_ui_dockwidget():
     app.exit()
 
 
+def test_load_ui_customwidget():
+    """Tests to see if loadUi loads a custom widget properly"""
+    import sys
+    from Qt import QtWidgets, QtCompat
+
+    app = QtWidgets.QApplication(sys.argv)
+    win = QtWidgets.QMainWindow()
+
+    QtCompat.loadUi(self.ui_qcustomwidget, win)
+
+    # Ensure that the derived class was properly created
+    # and not the base class (in case of failure)
+    custom_class_name = getattr(win, "customwidget", None).__class__.__name__
+    excepted_class_name = CustomWidget(win).__class__.__name__
+    assert custom_class_name == excepted_class_name, \
+        "loadUi could not load custom widget to main window"
+
+    app.exit()
+
+
 def test_load_ui_invalidpath():
     """Tests to see if loadUi successfully fails on invalid paths"""
     import sys