python - 如何在没有使用 python 的按键事件的情况下在内部更新/重绘 GTK 小部件 (GTKLabel)？

Question

下面有一些代码试图更新 GTK Label 元素。我包括两个文件:ui 文件和 py 文件。

界面文件:

<glade-interface>
  <widget class="GtkWindow" id="ApplicationFrame">
    <property name="width_request">320</property>
    <property name="height_request">240</property>
    <property name="visible">True</property>
    <property name="events">GDK_KEY_PRESS_MASK</property>
    <property name="title" translatable="yes">Simple</property>
    <property name="resizable">False</property>
    <property name="window_position">center-always</property>
    <property name="default_width">320</property>
    <property name="default_height">240</property>
    <property name="decorated">False</property>
    <property name="gravity">center</property>
    <child>
      <widget class="GtkFixed" id="layout">
        <property name="width_request">320</property>
        <property name="height_request">240</property>
        <property name="visible">True</property>
        <child>
          <widget class="GtkLabel" id="l1">
            <property name="width_request">320</property>
            <property name="height_request">40</property>
            <property name="visible">True</property>
            <property name="xalign">0</property>
            <property name="label" translatable="yes">l1</property>
          </widget>
          <packing>
            <property name="y">43</property>
          </packing>
        </child>
      </widget>
    </child>
  </widget>
</glade-interface>

Python文件

import os
from time import sleep as wait
import gtk as gtk
import gtk.glade as glade
import gobject

class Application(object):
    def __init__ (self):
        self.glade = glade.XML("simple.ui")
        self.setup_ui()

    def setup_ui (self):
        self.window = self.glade.get_widget("ApplicationFrame")
        self.l1 = self.glade.get_widget("l1")
        self.names = {'l1' : self.l1}
        self.all = [self.l1]
        gobject.timeout_add(1000,self.display_me)
        gobject.timeout_add(100,self.do_something_that_takes_a_while)
        self.window.add_events(gtk.gdk.KEY_PRESS_MASK)
        self.window.connect("key-press-event", self.handler)
        self.window.connect("delete_event", self.delete_event)
        self.window.connect("destroy", self.destroy)
        self.window.show()

    def get_signal (self,widget,event):
        keyname = gtk.gdk.keyval_name(event.keyval)
        ctrl = event.state & gtk.gdk.CONTROL_MASK
        alt = event.state & gtk.gdk.MOD1_MASK
        shift = event.state & gtk.gdk.SHIFT_MASK
        name = []
        if ctrl and keyname not in ["Control_L","Control_R"]: 
            name.append("CTRL")
        if alt and keyname not in ["Alt_L","Alt_R"]:
            name.append("ALT")
        if shift and keyname not in ["Shift_L","Shift_R"]:
            name.append("SHIFT")
        name.append(keyname)
        name = "+".join(name)
        return name

    def handler (self,widget,event):
        name = self.get_signal(widget,event)
        if name.lower() in ['ctrl+x','ctrl+c','alt+q']:
            self.destroy()

    def main(self):
        gtk.main()

    def delete_event (self,widget=None,event=None,data=None):
        return False

    def destroy (self,widget=None,data=None):
        gtk.main_quit()

    def get (self,item):
        if isinstance(item, str): 
            if item in self.names:
                item = self.names[item]
        retval = None
        if hasattr(item,"text"):
            retval = item.text()
        elif hasattr(item,"get_label"):
            retval = item.get_label()
        return retval

    def set (self,item,text='',font=None):
        print 'Setting...'
        if isinstance(item, str): 
            if item in self.names:
                item = self.names[item]
        retval = None
        if font == None and hasattr(self,"page") and hasattr(self.page,"NORMAL_FONT"): 
                font = self.page.NORMAL_FONT
        if hasattr(item,"setText"):
            retval = item.setText(text)
        elif font == None:
            if hasattr(item,'set_text'):
                retval = item.set_text(text)
        elif hasattr(item,"set_label"):
            retval = item.set_label(text)
            if hasattr(item,"modify_font") and font != None:
                item.modify_font(font)
        item.queue_draw()
        self.try_to_update(item)
        print 'done'
        return retval

    def try_to_update (self,item):
        """
        do something here to update the visual screen????
        """
        print str(self)

    def do_something_that_takes_a_while (self):
        timeout = 15
        while timeout != 0:
            self.set('l1','%s' % timeout)
            wait(1)
            timeout -= 1
            print timeout
        return 1

    def clean (self):
        if item != None:
            self.set(item,empty_text)
        else:
            if hasattr(self,'all'):
                for item in self.all:
                    self.set(item)

    def display_me (self):
        print str(self)
        return True

    def __str__ (self):
        space = 25
        value = '%'+str(space)+'s'
        lines = ['\n','-'*79]
        if hasattr(self,'all'):
            line = []
            for obj in self.all:
                obj_value = self.get(obj)
                line.append(value % obj_value if obj_value != None else '')
                #line.append(value % ' ')
            lines.append(''.join(line))
        lines.append('-'*79)
        return '\n'.join(lines)


if __name__ == "__main__":
    from time import sleep as wait
    SEC = 1
    app = Application()
    app.main()

这应该很简单，但我完全不知道我做错了什么。元素 l1 未正确更新。我认为 try_to_update 中的代码是我需要更新 UI 的地方，但我不知道我需要调用哪个函数。有人可以帮忙吗？

提前致谢!

Answer 1

您需要使用小部件的 queue_draw功能:

The queue_draw_area() method invalidates the rectangular area of the widget (...) by calling the gtk.gdk.Window.invalidate_rect() method on the widget's window and all its child windows.

但是，由于您已经在您的 set 方法中这样做了，我的猜测是

if hasattr(item,'show')

check 阻止项目更新。另一个检查是在整个窗口上调用 queue_draw 函数，看看是否有更新。

或者，强制按如下方式处理排队的事件:

while gtk.events_pending():
    gtk.main_iteration_do(True)