In Auto-parameter selection mode, mouse press over an item emits
        `componentSelected`

def mousePressEvent(self, event):
        """In Auto-parameter selection mode, mouse press over an item emits
        `componentSelected`"""
        if self.mode == BuildMode:
            super(StimulusView, self).mousePressEvent(event)
        else:
            # select and de-select components
            index = self.indexAt(event.pos())
            if index.isValid():
                self.selectionModel().select(index, QtGui.QItemSelectionModel.Toggle)
                comp = self.model().data(index, AbstractDragView.DragRole)
                self.componentSelected.emit(comp)
                self.hintRequested.emit('Click components to toggle more members of auto-parameter\n\n-or-\n\nEdit fields of auto-parameter (parameter type should be selected first)')