The Entry widget allows text to be typed and displayed in a single line text box. The text may be set with method calls that allow new text to replace, prepend or append the current contents of the Entry widget.
Create a new Entry widget with the following method.
Gtk::Entry.new
The next two methods alter the text which is currently within the Entry widget.
Gtk::Entry#set_text( text ) Gtk::Entry#text=( text )
The methods above set the contents of the Entry widget, replacing the current contents. Note that the class Entry implements the Editable interface which contains some more methods for manipulating the contents.
The contents of the Entry can be retrieved by using a call to the following method. This is useful in the callback methods described below.
Gtk::Entry#text
If we don't want the contents of the Entry widget to be changed by someone typing into it, we can change its editable state.
Gtk::Entry#set_editable( editable ) Gtk::Entry#editable=( editable )
The methods above allows us to toggle the editable state of the Entry widget by passing in a true or false value for the editable argument. You can retrieve the editable state of the widget by using:
Gtk::Entry#editable? #Returns boolean
If we are using the Entry where we don't want the text entered to be visible, for example when a password is being entered, we can use the following methods, which also takes a boolean flag. The last method shows you how to retrieve the visible state of the Entry widget.
Gtk::Entry#set_visibility( visible ) Gtk::Entry#visibility=( visible ) Gtk::Entry#visibility? #Returns boolean
A region of the text may be set as selected by using the following method. This would most be used after setting some default text in an Entry, making it easy for the user to remove it.
Gtk::Editable#select_region( start_position, end_position )
If we want to catch when the user has entered text, we can connect to the activate or changed signal. Acivate is raised when the user hits the enter key within the Entry widget. Changed is raised when the text changes at all, e.g. for every character entered or removed.
The following code is an example of using an Entry widget.
require 'gtk2'
def enter_callback( entry )
# Print the contents of the entry
puts entry.text
# Deletes the contents of the entry
entry.delete_text( 0, -1 )
end
def entry_toggle_editable( checkbutton, entry )
# Toggle whether or not the entry is editable
# We get the value by grabbing the boolean response
# from the checkbutton.
entry.set_editable( checkbutton.active? )
end
def entry_toggle_visibility( checkbutton, entry )
# Toggle whether or not the contents of the
# entry are readable, or whether the characthers
# are replaced by asteriks.
entry.visibility=( checkbutton.active? )
end
Gtk.init
# Create a new window
window = Gtk::Window.new( Gtk::Window::TOPLEVEL )
# Set the default minium size of the window.
window.set_default_size( 200, 100 )
# Set the title and setup a signal handler
window.title=( "Ruby-GNOME2 Entry" )
window.signal_connect( "destroy" ) { Gtk.main_quit }
# Create a new vbox
vbox = Gtk::VBox.new( false, 0 )
window.add( vbox )
vbox.show
entry = Gtk::Entry.new
entry.set_max_length( 50 )
entry.signal_connect( "activate" ) { |w| enter_callback( w ) }
entry.set_text( "hello" )
entry.insert_text( " world", entry.text.length)
# Selects all of the text. The first argument is the starting position
# and the second, is the end position (but not including). If the number
# is negative like it is here, it will highlight from the start position
# all the way to the end of the text
entry.select_region( 0, -1 )
# Pack our Entry widget
vbox.pack_start( entry, true, true, 0 )
entry.show
hbox = Gtk::HBox.new( false, 0 )
vbox.add( hbox )
hbox.show
check = Gtk::CheckButton.new( "Editable" )
hbox.pack_start( check, true, true, 0 )
check.signal_connect( "toggled" ) { |w| entry_toggle_editable( w, entry ) }
check.set_active( true )
check.show
check = Gtk::CheckButton.new( "Visible" )
hbox.pack_start( check, true, true, 0 )
check.signal_connect( "toggled" ) { |w| entry_toggle_visibility( w, entry ) }
check.set_active( true )
check.show
button = Gtk::Button.new( Gtk::Stock::QUIT )
vbox.pack_start( button, true, true, 0 )
button.signal_connect( "clicked" ) { Gtk.main_quit }
button.set_flags( Gtk::Widget::CAN_DEFAULT )
button.show
button.grab_default
window.show
Gtk.main
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