Python Listeners : Creating Event Listeners

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# Creating Event Listeners

Events raised by dialogs, documents, forms or graphical controls can be linked to macros, which is referred to as event-driven programming. The most common method to relate events to macros are the Events tab in Tools – Customize menu and the Dialog Editor Control properties pane from Tools - Macros – Organise Dialogs... menu.

Graphical artifacts, keyboard inputs, mouse moves and other man/machine interactions can be controlled using UNO listeners that watch for the user’s behavior. Listeners are dynamic program code alternatives to macro assignments. One may create as many UNO listeners as events to watch for. A single listener can also handle multiple user interface controls.

## Creating an event listener

Listeners get attached to controls held in dialogs, as well as to document or form events. Listeners are also used when creating runtime dialogs or when adding controls to a dialog on the fly.

This example creates a listener for Button1 control of Dialog1 dialog in Standard library.

### With Python

             # -*- coding: utf-8 -*-
             from __future__ import unicode_literals

             import uno, unohelper
             from com.sun.star.awt import XActionListener
             from com.sun.star.awt import ActionEvent
             from com.sun.star.lang import EventObject
             from com.sun.star.ui.dialogs.ExecutableDialogResults \
                 import OK, CANCEL
             import msgbox as util

             _MY_BUTTON =  "Button1"
             _MY_LABEL = 'Python listens..'
             _DLG_PROVIDER = "com.sun.star.awt.DialogProvider"

             def Main(*args):
                 ui = createUnoDialog("Standard.Dialog1", embedded=True)
                 ui.Title = "Python X[any]Listener"
                 ctl = ui.getControl(_MY_BUTTON)
                 ctl.Model.Label = _MY_LABEL
                 act = ActionListener()
                 ctl.addActionListener(act)
                 rc = ui.execute()
                 if rc == OK:
                     MsgBox("The user acknowledged the dialog.")
                 elif rc == CANCEL:
                     MsgBox("The user canceled the dialog.")
                 ui.dispose()  # ui.endExecute
                 ctl.removeActionListener(act)

             def createUnoDialog(libr_dlg: str, embedded=False):
                 """ Create a Dialog from its location """
                 smgr = XSCRIPTCONTEXT.getComponentContext().ServiceManager
                 if embedded:
                     model = XSCRIPTCONTEXT.getDocument()
                     dp = smgr.createInstanceWithArguments(_DLG_PROVIDER, (model,))
                     location = "?location=document"
                 else:
                     dp = smgr.createInstanceWithContext(_DLG_PROVIDER, ctx)
                     location = "?location=application"
                 dlg = dp.createDialog("vnd.sun.star.script:"+libr_dlg+location)
                 return dlg

             class ActionListener(unohelper.Base, XActionListener):
                 """ Listen to & count button clicks """
                 def __init__(self):
                     self.count = 0

                 def actionPerformed(self, evt: ActionEvent):
                     self.count = self.count + 1
                     #mri(evt)
                     if evt.Source.Model.Name == _MY_BUTTON:
                         evt.Source.Model.Label = _MY_LABEL+ str( self.count )
                 return

                 def disposing(self, evt: EventObject):  # mandatory routine
                     pass

             def MsgBox(txt: str):
                 mb = util.MsgBox(uno.getComponentContext())
                 mb.addButton("Ok")
                 mb.show(txt, 0, "Python")

             g_exportedScripts = (Main,)

msgbox.py in {installation}/program/ directory has some examples of button listeners.

### With LibreOffice Basic

             Option Explicit

             Const MY_LIBRARY = "Standard", MY_DIALOG = "Dialog1", MY_BUTTON = "Button1"
             Const MY_LABEL = "Basic listens.."
             Dim count As Integer

             Sub Main
                 Dim libr As Object ' com.sun.star.script.XLibraryContainer
                 Dim dlg As Object
                 Dim ui As Object  ' stardiv.Toolkit.UnoDialogControl
                 Dim ctl As Object ' stardiv.Toolkit.UnoButtonControl
                 Dim act As Object ' com.sun.star.awt.XActionListener
                 Dim rc As Object : rc = com.sun.star.ui.dialogs.ExecutableDialogResults

                 BasicLibraries.LoadLibrary(MY_LIBRARY)
                 libr = DialogLibraries.GetByName(MY_LIBRARY)
                 dlg = libr.GetByName(MY_DIALOG)
                 ui = CreateUnoDialog(dlg)
                 ui.Title = "Basic X[any]Listener example"
                 count = 0
                 ctl = ui.GetControl(MY_BUTTON)
                 ctl.Model.Label = MY_LABEL
                 act = CreateUnoListener("awt_", "com.sun.star.awt.XActionListener")
                 ctl.addActionListener(act)
                 Select Case ui.Execute
                     Case rc.OK : MsgBox "The user acknowledged the dialog.",, "Basic"
                     Case rc.CANCEL : MsgBox "The user canceled the dialog.",, "Basic"
                 End Select
                 ui.dispose ' ui.endExecute()
                 ctl.removeActionListener(act)
             End Sub

             Private Sub awt_actionPerformed(evt As com.sun.star.awt.ActionEvent)
                 ''' Listen to & count button clicks '''
                 With evt.Source.Model
                     If .Name = MY_BUTTON Then
                         count = count + 1
                         .Label = MY_LABEL+Cstr(count)
                     End If
                 End With
             End Sub ' awt_actionPerformed

             Private Sub awt_disposing(evt As com.sun.star.lang.EventObject) ' mandatory Sub
                 ' your code goes here
             End Sub ' awt_disposing

## Other Event Listeners

Listeners are usually coded along with dialog opening. Numerous listener approaches are possible such as event handlers for dialogs or event monitors for documents or forms.

Chủ đề Liên quan

Programming Examples for Controls in the Dialog Editor

CreateUnoListener Function

D'oh! You found a bug (text/swriter/01/05060700.xhp# not found).

Events mapping to objects

See also Document events, Form events.

Creating a Dialog Handler

Listening to Document Events

Python programming examples