def _init_extent_layer_dialog(self, filters=QgsMapLayerProxyModel.All):
dialog = QDialog()
layout = QVBoxLayout()
buttons = QDialogButtonBox(
QDialogButtonBox.Ok | QDialogButtonBox.Cancel, dialog)
layer_combobox = QgsMapLayerComboBox()
layout.addWidget(layer_combobox)
layout.addWidget(buttons)
layer_combobox.setFilters(filters)
layer_combobox.setAccessibleName('')
dialog.setModal(True)
dialog.setLayout(layout)
buttons.accepted.connect(dialog.accept)
buttons.rejected.connect(dialog.reject)
# ugly, but better to keep the function as pure as possible pure.
# I guess it begs for it's own class
dialog.layer_combobox = layer_combobox
return dialog
