Редактирование: PyGTK FAQ Dialogs

In this part of the PyGTK programming tutorial, we will introduce dialogs. 

Dialog windows or dialogs are an indispensable part of most modern GUI applications. A dialog is defined as a conversation between two or more persons. In a computer application a dialog is a window which is used to "talk" to the application. And vice versa. A dialog is used to input data, modify data, change the application settings etc. Dialogs are important means of communication between a user and a computer program.

== Message dialogs ==
Message dialogs are convenient dialogs that provide messages to the user of the application. The message consists of  textual and image data. 
<source lang="python">
#!/usr/bin/python
# ZetCode PyGTK tutorial 
#
# This example shows message
# dialogs
#
# author: jan bodnar
# website: zetcode.com 
# last edited: February 2009

import gtk

class PyApp(gtk.Window): 
    def __init__(self):
        super(PyApp, self).__init__()
        
        self.set_size_request(250, 100)
        self.set_position(gtk.WIN_POS_CENTER)
        self.connect("destroy", gtk.main_quit)
        self.set_title("Message dialogs")
        
        
        table = gtk.Table(2, 2, True);
        
        info = gtk.Button("Information")
        warn = gtk.Button("Warning")
        ques = gtk.Button("Question")
        erro = gtk.Button("Error")

        
        info.connect("clicked", self.on_info)
        warn.connect("clicked", self.on_warn)
        ques.connect("clicked", self.on_ques)
        erro.connect("clicked", self.on_erro)
        
        table.attach(info, 0, 1, 0, 1)
        table.attach(warn, 1, 2, 0, 1)
        table.attach(ques, 0, 1, 1, 2)
        table.attach(erro, 1, 2, 1, 2)
        
        
        self.add(table)
        self.show_all()

    def on_info(self, widget):
        md = gtk.MessageDialog(self, 
            gtk.DIALOG_DESTROY_WITH_PARENT, gtk.MESSAGE_INFO, 
            gtk.BUTTONS_CLOSE, "Download completed")
        md.run()
        md.destroy()
        
    
    def on_erro(self, widget):
        md = gtk.MessageDialog(self, 
            gtk.DIALOG_DESTROY_WITH_PARENT, gtk.MESSAGE_ERROR, 
            gtk.BUTTONS_CLOSE, "Error loading file")
        md.run()
        md.destroy()
    
    
    
    def on_ques(self, widget):
        md = gtk.MessageDialog(self, 
            gtk.DIALOG_DESTROY_WITH_PARENT, gtk.MESSAGE_QUESTION, 
            gtk.BUTTONS_CLOSE, "Are you sure to quit?")
        md.run()
        md.destroy()
    
    
    def on_warn(self, widget):
        md = gtk.MessageDialog(self, 
            gtk.DIALOG_DESTROY_WITH_PARENT, gtk.MESSAGE_WARNING, 
            gtk.BUTTONS_CLOSE, "Unallowed operation")
        md.run()
        md.destroy()
    

PyApp()
gtk.main()
</source>

In our example, we will show four kinds of message dialogs.  Information, Warning, Question and Error message dialogs.

<source lang="python">
 info = gtk.Button("Information")
 warn = gtk.Button("Warning")
 ques = gtk.Button("Question")
 erro = gtk.Button("Error")
</source>

We have four buttons. Each of these buttons will show a different kind of message dialog. 

<source lang="python">
 md = gtk.MessageDialog(self, 
     gtk.DIALOG_DESTROY_WITH_PARENT, gtk.MESSAGE_INFO, 
         gtk.BUTTONS_CLOSE, "Download completed")
 md.run()
 md.destroy()
</source>

If we click on the info button, the Information dialog is displayed. The <b>MESSAGE_INFO</b> specifies the type of the dialog. The <b>BUTTONS_CLOSE</b> specifies the button to be displayed in the dialog. The last parameter is the message dislayed. The dialog is displayed with the <b>run()</b> method. The programmer must also call either the <b>destroy()</b> or the <b>hide()</b> method.

<center>
{|
|-
| [[image: pygtk_faq_information.png | center]]
| [[image: pygtk_faq_warning.png | center]]
|-
| [[image: pygtk_faq_question.png | center]]
| [[image: pygtk_faq_error.png | center]]
|}
</center>

== AboutDialog ==
The <b>AboutDialog</b> displays information about the application. 

<b>AboutDialog</b> can display a logo, the name of the application, version, copyright, website or licence information. It is also possible to give credits to the authors, documenters, translators and artists.

<source lang="python">
#!/usr/bin/python
# ZetCode PyGTK tutorial 
#
# This example demonstrates the
# AboutDialog dialog
#
# author: jan bodnar
# website: zetcode.com 
# last edited: February 2009

import gtk

class PyApp(gtk.Window): 
    def __init__(self):
        super(PyApp, self).__init__()
        self.set_size_request(300, 150)
        self.set_position(gtk.WIN_POS_CENTER)
        self.connect("destroy", gtk.main_quit)
        self.set_title("About battery")
        
        
        button = gtk.Button("About")
        button.set_size_request(80, 30)
        button.connect("clicked", self.on_clicked)
        
        fix = gtk.Fixed()
        fix.put(button, 20, 20)
   
        self.add(fix)
        self.show_all()

    def on_clicked(self, widget):
        about = gtk.AboutDialog()
        about.set_program_name("Battery")
        about.set_version("0.1")
        about.set_copyright("(c) Jan Bodnar")
        about.set_comments("Battery is a simple tool for battery checking")
        about.set_website("http://www.zetcode.com")
        about.set_logo(gtk.gdk.pixbuf_new_from_file("battery.png"))
        about.run()
        about.destroy()

PyApp()
gtk.main()
</source>

The code example uses a <b>AboutDialog</b> with some of it's features. 

<source lang="python">
 about = gtk.AboutDialog()
</source>

We create an <b>AboutDialog</b>. 

<source lang="python">
 about = gtk.AboutDialog()
 about.set_program_name("Battery")
 about.set_version("0.1")
 about.set_copyright("(c) Jan Bodnar")
</source>

We specify the name, version and the copyright.

<source lang="python">
 about.set_logo(gtk.gdk.pixbuf_new_from_file("battery.png"))
</source>

This line creates a logo. 

[[image: pygtk_faq_about.png | center]]

== FontSelectionDialog ==
The <b>FontSelectionDialog</b> is a dialog for selecting fonts.  It is typically used in applications, that do some text editing or formatting. 
<source lang="python">
#!/usr/bin/python
# ZetCode PyGTK tutorial 
#
# This example works with the
# FontSelection dialog
#
# author: jan bodnar
# website: zetcode.com 
# last edited: February 2009

import gtk
import pango

class PyApp(gtk.Window): 
    def __init__(self):
        gtk.Window.__init__(self)
        self.set_size_request(300, 150)
        self.set_position(gtk.WIN_POS_CENTER)
        self.connect("destroy", gtk.main_quit)
        self.set_title("Font Selection Dialog")
        
        
        self.label = gtk.Label("The only victory over love is flight.")
        button = gtk.Button("Select font")
        button.connect("clicked", self.on_clicked)

        fix = gtk.Fixed()
        fix.put(button, 100, 30)
        fix.put(self.label, 30, 90)
        self.add(fix)

        self.show_all()

    def on_clicked(self, widget):
        fdia = gtk.FontSelectionDialog("Select font name")
        response = fdia.run()
              
        if response == gtk.RESPONSE_OK:
            font_desc = pango.FontDescription(fdia.get_font_name())
            if font_desc:
                self.label.modify_font(font_desc)
        
        fdia.destroy()


PyApp()
gtk.main()
</source>

In the code example, we have a button and a label. We show the  <b>FontSelectionDialog</b> by clicking on the button.

<source lang="python">
 fdia = gtk.FontSelectionDialog("Select font name")
</source>

We create the <b>FontSelectionDialog.</b>

<source lang="python">
 if response == gtk.RESPONSE_OK:
     font_desc = pango.FontDescription(fdia.get_font_name())
     if font_desc:
         self.label.modify_font(font_desc)
</source>

If we click on the OK button, the font of the label widget changes to the one, that we selected in the dialog. 

[[image: pygtk_faq_fontdialog.png | center]]

== ColorSelectionDialog ==
<b>ColorSelectionDialog</b> is a dialog for selecting a color. 
<source lang="python">
#!/usr/bin/python
# ZetCode PyGTK tutorial 
#
# This example works with the
# ColorSelection dialog
#
# author: jan bodnar
# website: zetcode.com 
# last edited: February 2009

import gtk

class PyApp(gtk.Window): 
    def __init__(self):
        super(PyApp, self).__init__()
        
        self.set_size_request(300, 150)
        self.set_position(gtk.WIN_POS_CENTER)
        self.connect("destroy", gtk.main_quit)
        self.set_title("Color Selection Dialog")
        
        
        self.label = gtk.Label("The only victory over love is flight.")
        button = gtk.Button("Select color")
        button.connect("clicked", self.on_clicked)

        fix = gtk.Fixed()
        fix.put(button, 100, 30)
        fix.put(self.label, 30, 90)
        self.add(fix)

        self.show_all()

    def on_clicked(self, widget):
        cdia = gtk.ColorSelectionDialog("Select color")
        response = cdia.run()
              
        if response == gtk.RESPONSE_OK:
            colorsel = cdia.colorsel
            color = colorsel.get_current_color()
            self.label.modify_fg(gtk.STATE_NORMAL, color)
        
        cdia.destroy()


PyApp()
gtk.main()
</source>

The example is very similar to the previous one. This time we change the color of the label. 

<source lang="python">
 cdia = gtk.ColorSelectionDialog("Select color")
</source>

We create the <b>ColorSelectionDialog</b>.

<source lang="python">
 if response == gtk.RESPONSE_OK:
     colorsel = cdia.colorsel
     color = colorsel.get_current_color()
     self.label.modify_fg(gtk.STATE_NORMAL, color)
</source>

If the user pressed OK, we get the color and modify the label's color. 

[[image: pygtk_faq_colordialog.png | center]]

In this part of the PyGTK programming tutorial, we worked with PyGTK built-in dialogs. 

[[Категория:Python]]
[[Категория:GTK]]