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📜  PyGTK-滚动条类

📅  最后修改于: 2020-11-08 07:54:12             🧑  作者: Mango

此类是gtk.Hscrollbar和gtk.Vscrollbar小部件的抽象基类。两者都与调整对象关联。滚动条的拇指位置由滚动调整控制。调整对象的属性如下使用-

lower The minimum value of the scroll region
upper The maximum value of the scroll region
value Represents the position of the scrollbar, which must be between lower and upper
page_size Represents the size of the visible scrollable area
step_increment Distance to scroll when the small stepper arrows are clicked
page_increment Distance to scroll when the Page Up or Page Down keys pressed

以下程序显示了放置在添加到顶层窗口的VBox中的HScale和HScrollbar小部件。它们每个都与一个调整对象相关联。

adj1 = gtk.Adjustment(0, 0, 101, 0.1, 1, 1)
self.adj2 = gtk.Adjustment(10,0,101,5,1,1)

gtk.HScale窗口小部件是附带adj1的滑块控件。其更新策略，编号和图纸值位置设置如下-

scale1 = gtk.HScale(adj1)
scale1.set_update_policy(gtk.UPDATE_CONTINUOUS)
scale1.set_digits(1)
scale1.set_value_pos(gtk.POS_TOP)
scale1.set_draw_value(True)

gtk.HScrollbar提供水平滚动条。它与adj2对象关联。其更新策略也设置为CONTINUOUS。

self.bar1 = gtk.HScrollbar(self.adj2)
self.bar1.set_update_policy(gtk.UPDATE_CONTINUOUS)

为了显示滚动条的瞬时值，将调整对象adj2的“ value-changed”信号连接到回调函数on_scrolled() 。该函数检索调整对象的value属性，并将其显示在滚动条下方的标签上。

self.adj2.connect("value_changed", self.on_scrolled)
   def on_scrolled(self, widget, data = None):
   self.lbl2.set_text("HScrollbar value: "+str(int(self.adj2.value)))

例

观察以下代码-

import gtk

class PyApp(gtk.Window):
   
   def __init__(self):
      super(PyApp, self).__init__()
      self.set_title("Range widgets Demo")
      self.set_default_size(250, 200)
      self.set_position(gtk.WIN_POS_CENTER)
      
      adj1 = gtk.Adjustment(0.0, 0.0, 101.0, 0.1, 1.0, 1.0)
      self.adj2 = gtk.Adjustment(10,0,101,5,1,1)
      
      scale1 = gtk.HScale(adj1)
      scale1.set_update_policy(gtk.UPDATE_CONTINUOUS)
      scale1.set_digits(1)
      scale1.set_value_pos(gtk.POS_TOP)
      scale1.set_draw_value(True)
      
      vb = gtk.VBox()
      vb.add(scale1)
      lbl1 = gtk.Label("HScale")
      
      vb.add(lbl1)
      self.bar1 = gtk.HScrollbar(self.adj2)
      self.bar1.set_update_policy(gtk.UPDATE_CONTINUOUS)
      vb.add(self.bar1)
      self.lbl2 = gtk.Label("HScrollbar value: ")
      
      vb.add(self.lbl2)
      self.adj2.connect("value_changed", self.on_scrolled)
      self.add(vb)
      self.connect("destroy", gtk.main_quit)
      self.show_all()
   
   def on_scrolled(self, widget, data=None):
      self.lbl2.set_text("HScrollbar value: "+str(int(self.adj2.value)))
if __name__ == '__main__':
   PyApp()
   gtk.main()

上面的代码将生成以下输出-

范围小部件演示