content: from qtpy.QtWidgets import QWidget, QPushButton, QHBoxLayout
  
  
  class FlowViewZoomWidget(QWidget):
      def __init__(self, flow_view):
          super(FlowViewZoomWidget, self).__init__()
  
          self.flow_view = flow_view
  
          self.setObjectName('FlowViewZoomWidget')
  
          self.zoom_in_button = QPushButton('+')
          self.zoom_in_button.clicked.connect(self.on_zoom_in_button_clicked)
          self.zoom_out_button = QPushButton('-')
          self.zoom_out_button.clicked.connect(self.on_zoom_out_button_clicked)
  
          main_horizontal_layout = QHBoxLayout()
  
          main_horizontal_layout.addWidget(self.zoom_out_button)
          main_horizontal_layout.addWidget(self.zoom_in_button)
          self.setLayout(main_horizontal_layout)
  
          self.setStyleSheet('''
  QWidget#FlowViewZoomWidget {
      background: transparent; 
  }
          ''')
  
  
      def on_zoom_in_button_clicked(self):
          self.flow_view.zoom_in(250)
  
      def on_zoom_out_button_clicked(self):
          self.flow_view.zoom_out(250)