Merge pull request #119 from fredrikaverpil/feature/examples

Add examples

Dockerfile-py2.7

@@ -27,13 +27,14 @@ WORKDIR /workspace/Qt.py
 ENTRYPOINT cp -r /Qt.py /workspace && \
     python build_caveats.py && \
     python build_membership.py && \
-	Xvfb :99 -screen 0 1024x768x16 2>/dev/null & \
-	sleep 3 && \
+    Xvfb :99 -screen 0 1024x768x16 2>/dev/null & \
+    while ! ps aux | grep -q '[0]:00 Xvfb :99 -screen 0 1024x768x16'; \
+        do echo "Waiting for Xvfb..."; sleep 1; done && \
+    ps aux | grep Xvfb && \
     nosetests \
         --verbose \
         --with-process-isolation \
         --with-doctest \
         --exe \
-            test_membership.py \
-            test_caveats.py \
-            tests.py
+            test*.py \
+            examples/*/*.py

Dockerfile-py3.5

@@ -26,12 +26,13 @@ ENV DISPLAY :99
 WORKDIR /workspace/Qt.py
 ENTRYPOINT cp -r /Qt.py /workspace && \
     python3 build_caveats.py && \
-	Xvfb :99 -screen 0 1024x768x16 2>/dev/null & \
-	sleep 3 && \
+    Xvfb :99 -screen 0 1024x768x16 2>/dev/null & \
+    while ! ps aux | grep -q '[0]:00 Xvfb :99 -screen 0 1024x768x16'; \
+        do echo "Waiting for Xvfb..."; sleep 1; done && \
     nosetests \
         --verbose \
         --with-process-isolation \
         --with-doctest \
         --exe \
-            test_caveats.py \
-            tests.py
+            test*.py \
+            examples/*/*.py

build_examples.py

@@ -0,0 +1,11 @@
+import os
+import glob
+import shutil
+
+# Copy example files into current working directory
+for filepath in glob.glob('examples/*/*'):
+    filename = os.path.basename(filepath)
+    if filepath.endswith('.py'):
+        shutil.copyfile(filepath, 'test_'+filename)  # Prepend 'test' to *.py
+    else:
+        shutil.copyfile(filepath, filename)

examples/README.md

@@ -0,0 +1,15 @@
+## Examples
+
+#### Purpose
+
+Sometimes a pull request or a feature request doesn't make it into Qt.py because it doesn't fit [the contribution guidelines](https://github.com/mottosso/Qt.py/blob/master/CONTRIBUTING.md). This is hopefully a good thing for the end product in the long term perspective, but we're always sad to see good code drift into oblivion and disappear when a pull request is turned down and closed.
+
+This part of the Qt.py project is a more loosely maintained (although tested) space, where we welcome example use of Qt.py to be shown off especially if it solves a problem Qt.py by itself doesn't solve out of the box.
+
+If you wish to contribute, make a pull request. Please put your example files in a sub-folder of `/examples`. If you also wish to have your example included in testing, make sure the function you wish to be executed during testing is named in such a way that it starts with `test`. For a working example of examples :wink:, see the `/examples/load_ui` folder.
+
+<br>
+
+#### List of examples   
+
+* [`load_ui`](https://github.com/mottosso/Qt.py/blob/master/examples/load_ui/README.md) - add base instance argument

examples/load_ui/README.md

@@ -0,0 +1,17 @@
+## `load_ui` examples
+
+#### Base instance as argument
+
+The `uic.loadUi` function of PyQt4 and PyQt5 as well as the `QtUiTools.QUiLoader().load` function of PySide/PySide2 are mapped to a convenience function in Qt.py called `load_ui`. This function only accepts the filename argument of the .ui file.
+
+A popular approach is to provide a base instance argument to PyQt's `uic.loadUi`, into which all widgets are loaded:
+
+```python
+# PyQt4, PyQt5
+class MainWindow(QtWidgets.QWidget):
+    def __init__(self, parent=None):
+        QtWidgets.QWidget.__init__(self, parent)
+        uic.loadUi('uifile.ui', self)  # Loads all widgets of uifile.ui into self
+```
+
+PySide does not support this out of the box, but it can be implemented in various ways. In the example in `baseinstance1.py`, a support function `setup_ui` is defined which wraps `load_ui` and provides this second base instance argument. In `baseinstance2.py`, another approach is used where `pysideuic` is required for PySide/PySide2 and `uic` is required for PyQt4/PyQt5.

examples/load_ui/baseinstance1.py

@@ -0,0 +1,56 @@
+import sys
+import os
+
+# Set preferred binding
+os.environ['QT_PREFERRED_BINDING'] = os.pathsep.join(['PySide', 'PyQt4'])
+
+from Qt import QtWidgets, load_ui
+
+
+def setup_ui(uifile, base_instance=None):
+    """Load a Qt Designer .ui file and returns an instance of the user interface
+
+    Args:
+        uifile (str): Absolute path to .ui file
+        base_instance (QWidget): The widget into which UI widgets are loaded
+
+    Returns:
+        QWidget: the base instance
+
+    """
+    ui = load_ui(uifile)  # Qt.py mapped function
+    if not base_instance:
+        return ui
+    else:
+        for member in dir(ui):
+            if not member.startswith('__') and \
+               member is not 'staticMetaObject':
+                setattr(base_instance, member, getattr(ui, member))
+        return ui
+
+
+class MainWindow(QtWidgets.QWidget):
+    """Load .ui file example, using setattr/getattr approach"""
+    def __init__(self, parent=None):
+        QtWidgets.QWidget.__init__(self, parent)
+        self.base_instance = setup_ui('qwidget.ui', self)
+
+
+def test():
+    """Example: load_ui with setup_ui wrapper"""
+    working_directory = os.path.dirname(__file__)
+    os.chdir(working_directory)
+
+    app = QtWidgets.QApplication(sys.argv)
+    window = MainWindow()
+
+    # Tests
+    assert isinstance(window, QtWidgets.QWidget)
+    assert isinstance(window.parent(), type(None))
+    assert isinstance(window.base_instance, QtWidgets.QWidget)
+    assert isinstance(window.lineEdit, QtWidgets.QWidget)
+    assert window.lineEdit.text() == ''
+    window.lineEdit.setText('Hello')
+    assert window.lineEdit.text() == 'Hello'
+
+    app.exit()

examples/load_ui/baseinstance2.py

@@ -0,0 +1,135 @@
+import sys
+import os
+
+# Set preferred binding, or Qt.py tests will fail which doesn't have pysideuic
+os.environ['QT_PREFERRED_BINDING'] = 'PyQt4'
+
+from Qt import QtWidgets
+from Qt import __binding__
+
+
+def load_ui_type(uifile):
+    """Pyside equivalent for the loadUiType function in PyQt.
+
+    From the PyQt4 documentation:
+        Load a Qt Designer .ui file and return a tuple of the generated form
+        class and the Qt base class. These can then be used to create any
+        number of instances of the user interface without having to parse the
+        .ui file more than once.
+
+    Note:
+        Pyside lacks the "loadUiType" command, so we have to convert the ui
+        file to py code in-memory first and then execute it in a special frame
+        to retrieve the form_class.
+
+    Args:
+        uifile (str): Absolute path to .ui file
+
+
+    Returns:
+        tuple: the generated form class, the Qt base class
+    """
+    import pysideuic
+    import xml.etree.ElementTree as ElementTree
+    from cStringIO import StringIO
+
+    parsed = ElementTree.parse(uifile)
+    widget_class = parsed.find('widget').get('class')
+    form_class = parsed.find('class').text
+
+    with open(uifile, 'r') as f:
+        o = StringIO()
+        frame = {}
+
+        pysideuic.compileUi(f, o, indent=0)
+        pyc = compile(o.getvalue(), '<string>', 'exec')
+        exec(pyc) in frame
+
+        # Fetch the base_class and form class based on their type in
+        # the xml from designer
+        form_class = frame['Ui_%s' % form_class]
+        base_class = eval('QtWidgets.%s' % widget_class)
+    return form_class, base_class
+
+
+def pyside_load_ui(uifile, base_instance=None):
+    """Provide PyQt4.uic.loadUi functionality to PySide
+
+    Args:
+        uifile (str): Absolute path to .ui file
+        base_instance (QWidget): The widget into which UI widgets are loaded
+
+
+    Note:
+        pysideuic is required for this to work with PySide.
+
+        This seems to work correctly in Maya as well as outside of it as
+        opposed to other implementations which involve overriding QUiLoader.
+
+    Returns:
+        QWidget: the base instance
+
+    """
+    form_class, base_class = load_ui_type(uifile)
+    if not base_instance:
+        typeName = form_class.__name__
+        finalType = type(typeName,
+                         (form_class, base_class),
+                         {})
+        base_instance = finalType()
+    else:
+        if not isinstance(base_instance, base_class):
+            raise RuntimeError(
+                'The base_instance passed to loadUi does not inherit from'
+                ' needed base type (%s)' % type(base_class))
+        typeName = type(base_instance).__name__
+        base_instance.__class__ = type(typeName,
+                                       (form_class, type(base_instance)),
+                                       {})
+    base_instance.setupUi(base_instance)
+    return base_instance
+
+
+def load_ui_wrapper(uifile, base_instance=None):
+    """Load a Qt Designer .ui file and returns an instance of the user interface
+
+    Args:
+        uifile (str): Absolute path to .ui file
+        base_instance (QWidget): The widget into which UI widgets are loaded
+
+    Returns:
+        function: pyside_load_ui or uic.loadUi
+
+    """
+    if 'PySide' in __binding__:
+        return pyside_load_ui(uifile, base_instance)
+    elif 'PyQt' in __binding__:
+        from Qt import uic
+        return uic.loadUi(uifile, base_instance)
+
+
+class MainWindow(QtWidgets.QWidget):
+    """Load .ui file example, utilizing pysideuic and/or PyQt4.uic.loadUi"""
+    def __init__(self, parent=None):
+        QtWidgets.QWidget.__init__(self, parent)
+        self.base_instance = load_ui_wrapper('qwidget.ui', self)
+
+
+def test():
+    """Example: load_ui with custom uic.loadUi-like wrapper"""
+    working_directory = os.path.dirname(__file__)
+    os.chdir(working_directory)
+
+    app = QtWidgets.QApplication(sys.argv)
+    window = MainWindow()
+
+    # Tests
+    assert isinstance(window, QtWidgets.QWidget)
+    assert isinstance(window.parent(), type(None))
+    assert isinstance(window.base_instance, QtWidgets.QWidget)
+    assert isinstance(window.lineEdit, QtWidgets.QWidget)
+    assert window.lineEdit.text() == ''
+    window.lineEdit.setText('Hello')
+    assert window.lineEdit.text() == 'Hello'
+
+    app.exit()

examples/load_ui/qwidget.ui

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>Form</class>
+ <widget class="QWidget" name="Form">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>235</width>
+    <height>149</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QGridLayout" name="gridLayout">
+   <item row="0" column="0">
+    <widget class="QLineEdit" name="lineEdit"/>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>