How to use QT QGis custom widget in a plugin?

Question

I am writing a new plugin for QGIS 2.18. I can't find what are the libraries to import in my main code to access widgets such as QgsSpinBox or QgsFileWidget.

Answer 1

To properly use QT QGis custom widgets: Use imports such as: from PyQt4.QtGui import QDialog from qgis.gui import QgsFileWidget

You must also edit the xx_dialog_base.ui file, to ensure that the widgets are imported from the python module and not from the C libraries (it seems there is a bug in the generation of this .ui file, see Plugins crashing with "No module named qgsprojectionselectionwidget" in Windows?)

For example:

 <customwidget>
 <class>QgsProjectionSelectionWidget</class>
 <extends>QWidget</extends>
 <header>qgsprojectionselectionwidget.h</header>
 </customwidget>

must be edited as:

<customwidget>
 <class>QgsProjectionSelectionWidget</class>
 <extends>QWidget</extends>
 <header>qgis.gui</header>
 </customwidget>

It seems this edit as to be repeated every time the .ui file is saved by QT designer.