GUI enabling/disabling of controls
From Rosetta Code
You are encouraged to solve this task according to the task description, using any language you may know.
In addition to fundamental GUI component interaction, an application should dynamically enable and disable GUI components, to give some guidance to the user, and prohibit (inter)actions which are inappropriate in the current state of the application.
The task: Similar to the task GUI component interaction write a program that presents a form with three components to the user: A numeric input field ("Value") and two buttons ("increment" and "decrement").
The field is initialized to zero. The user may manually enter a new value into the field, increment its value with the "increment" button, or decrement the value with the "decrement" button.
The input field should be enabled only when its value is zero. The "increment" button only as long as the field's value is less then 10: When the value 10 is reached, the button should go into a disabled state. Analogously, the "decrement" button should be enabled only as long as the value is greater than zero.
Effectively, the user can now either increment up to 10, or down to zero. Manually entering values outside that range is still legal, but the buttons should reflect that and enable/disable accordingly.
Contents |
[edit] Ada
disabling.adb:
with Ada.Strings.Fixed;
with Gtk.Main;
with Gtk.Handlers;
with Gtk.Button;
with Gtk.Window;
with Gtk.GEntry;
with Gtk.Editable;
with Gtk.Box;
with Gtk.Widget;
with Glib.Values;
procedure Disabling is
type My_Natural is range 0 .. 10;
The_Value : My_Natural := 0;
Main_Window : Gtk.Window.Gtk_Window;
Content : Gtk.Box.Gtk_Vbox;
Increment_Button : Gtk.Button.Gtk_Button;
Decrement_Button : Gtk.Button.Gtk_Button;
Entry_Field : Gtk.GEntry.Gtk_Entry;
package Entry_Callbacks is new Gtk.Handlers.Callback
(Gtk.GEntry.Gtk_Entry_Record);
package Button_Callbacks is new Gtk.Handlers.Callback
(Gtk.Button.Gtk_Button_Record);
package Window_Callbacks is new Gtk.Handlers.Return_Callback
(Gtk.Window.Gtk_Window_Record, Boolean);
-- update displayed text
procedure Update_Entry is
begin
Gtk.GEntry.Set_Text
(The_Entry => Entry_Field,
Text =>
Ada.Strings.Fixed.Trim
(Source => My_Natural'Image (The_Value),
Side => Ada.Strings.Both));
end Update_Entry;
procedure Check_Value is
begin
Gtk.Widget.Set_Sensitive
(Gtk.Widget.Gtk_Widget (Decrement_Button),
The_Value > 0);
Gtk.Widget.Set_Sensitive
(Gtk.Widget.Gtk_Widget (Increment_Button),
The_Value < 10);
Gtk.Widget.Set_Sensitive
(Gtk.Widget.Gtk_Widget (Entry_Field),
The_Value = 0);
end Check_Value;
procedure On_Changed_Text
(Object : access Gtk.GEntry.Gtk_Entry_Record'Class;
Params : Glib.Values.GValues)
is
pragma Unreferenced (Params, Object);
begin
The_Value := My_Natural'Value (Gtk.GEntry.Get_Text (Entry_Field));
Check_Value;
Update_Entry;
exception
when Constraint_Error =>
The_Value := 0;
end On_Changed_Text;
-- make sure that only numbers are entered
procedure On_Insert_Text
(Object : access Gtk.GEntry.Gtk_Entry_Record'Class;
Params : Glib.Values.GValues)
is
Length : constant Glib.Gint :=
Glib.Values.Get_Int (Glib.Values.Nth (Params, 2));
Text : constant String :=
Glib.Values.Get_String (Glib.Values.Nth (Params, 1), Length);
begin
declare
Number : My_Natural;
pragma Unreferenced (Number);
begin
Number := My_Natural'Value (Text);
exception
when Constraint_Error =>
-- refuse values that are not parsable
Gtk.Handlers.Emit_Stop_By_Name
(Object => Object,
Name => Gtk.Editable.Signal_Insert_Text);
end;
end On_Insert_Text;
-- Callback for click event
procedure On_Increment_Click
(Object : access Gtk.Button.Gtk_Button_Record'Class)
is
pragma Unreferenced (Object);
begin
The_Value := The_Value + 1;
Check_Value;
Update_Entry;
end On_Increment_Click;
-- Callback for click event
procedure On_Decrement_Click
(Object : access Gtk.Button.Gtk_Button_Record'Class)
is
pragma Unreferenced (Object);
begin
The_Value := The_Value - 1;
Check_Value;
Update_Entry;
end On_Decrement_Click;
-- Callback for delete event
function On_Main_Window_Delete
(Object : access Gtk.Window.Gtk_Window_Record'Class)
return Boolean
is
pragma Unreferenced (Object);
begin
Gtk.Main.Main_Quit;
return True;
end On_Main_Window_Delete;
begin
Gtk.Main.Init;
Gtk.GEntry.Gtk_New (Widget => Entry_Field);
Entry_Callbacks.Connect
(Widget => Entry_Field,
Name => Gtk.Editable.Signal_Insert_Text,
Cb => On_Insert_Text'Access);
Entry_Callbacks.Connect
(Widget => Entry_Field,
Name => Gtk.Editable.Signal_Changed,
Cb => On_Changed_Text'Access);
Gtk.Button.Gtk_New (Button => Increment_Button, Label => "Increment");
Gtk.Button.Gtk_New (Button => Decrement_Button, Label => "Decrement");
Button_Callbacks.Connect
(Widget => Increment_Button,
Name => Gtk.Button.Signal_Clicked,
Marsh => Button_Callbacks.To_Marshaller (On_Increment_Click'Access));
Button_Callbacks.Connect
(Widget => Decrement_Button,
Name => Gtk.Button.Signal_Clicked,
Marsh => Button_Callbacks.To_Marshaller (On_Decrement_Click'Access));
Gtk.Box.Gtk_New_Vbox (Box => Content);
Gtk.Box.Add (Container => Content, Widget => Entry_Field);
Gtk.Box.Add (Container => Content, Widget => Increment_Button);
Gtk.Box.Add (Container => Content, Widget => Decrement_Button);
Gtk.Window.Gtk_New (Window => Main_Window);
Gtk.Window.Add (Container => Main_Window, Widget => Content);
Window_Callbacks.Connect
(Widget => Main_Window,
Name => Gtk.Widget.Signal_Delete_Event,
Cb => On_Main_Window_Delete'Access);
Gtk.Window.Show_All (Widget => Main_Window);
Update_Entry;
Gtk.Main.Main;
end Disabling;
[edit] AutoHotkey
GUI, Add, Edit, w150 number vValue, 0 ; Number specifies a numbers-only edit field.
GUI, Add, button,, Increment
GUI, Add, button, xp+70 yp, Decrement ; xp+70 and yp are merely positioning options
GUI, Show, w200 y200, Title ; Shows the GUI. Add your own title if you wish
SetTimer, EnableDisable, 100 ; Sets EnableDisable to run 10 times per second (100ms)
return ; ----------End Auto-Execute Section----------
ButtonIncrement:
GUI, Submit, NoHide ; "Set the contents of each variable to the contents of their corresponding controls without hiding the GUI"
If ( value < 10 ) ; Just in case EnableDisable didn't disable the button it in time.
Value++ ; Increment Value
GUIControl,, Value, %value% ; "Set the text of the control which alters the variable 'value' to the contents of 'value'"
return
ButtonDecrement:
GUI, Submit, Nohide
If value > 0
Value--
GuiControl,, Value, %value%
return
EnableDisable:
GUI, Submit, Nohide
If ( value < 10 )
GuiControl, enable, Increment
Else
GuiControl, disable, Increment
If ( value > 0)
GuiControl, enable, Decrement
Else
GuiControl, disable, Decrement
If ( value = 0 )
GuiControl, enable, Edit1
Else
GuiControl, disable, Edit1
return
GuiClose:
ExitApp
; Ensures the script ends when the GUI is closed.
[edit] BBC BASIC
INSTALL @lib$+"WINLIB2"
INSTALL @lib$+"WINLIB5"
ES_NUMBER = 8192
form% = FN_newdialog("Rosetta Code", 100, 100, 100, 52, 8, 1000)
idInc% = FN_setproc(PROCinc)
idDec% = FN_setproc(PROCdec)
PROC_static(form%, "Value:", 100, 10, 10, 24, 14, 0)
PROC_editbox(form%, "0", 101, 40, 8, 52, 14, ES_NUMBER)
PROC_pushbutton(form%, "Increment", idInc%, 7, 30, 40, 16, 0)
PROC_pushbutton(form%, "Decrement", idDec%, 52, 30, 40, 16, 0)
PROC_showdialog(form%)
REPEAT
WAIT 1
SYS "GetDlgItemInt", !form%, 101, 0, 1 TO number%
SYS "GetDlgItem", !form%, 101 TO hedit%
SYS "EnableWindow", hedit%, number% = 0
SYS "GetDlgItem", !form%, idInc% TO hinc%
SYS "EnableWindow", hinc%, number% < 10
SYS "GetDlgItem", !form%, idDec% TO hdec%
SYS "EnableWindow", hdec%, number% > 0
UNTIL !form% = 0
QUIT
DEF PROCinc
LOCAL number%
SYS "GetDlgItemInt", !form%, 101, 0, 1 TO number%
SYS "SetDlgItemInt", !form%, 101, number% + 1, 1
ENDPROC
DEF PROCdec
LOCAL number%
SYS "GetDlgItemInt", !form%, 101, 0, 1 TO number%
SYS "SetDlgItemInt", !form%, 101, number% - 1, 1
ENDPROC
Output:
[edit] C++
with Qt 4.4, creating project file with qmake -project, Makefile with qmake -o Makefile <projectfile> and finally make
file task.h
#ifndef TASK_H
#define TASK_H
#include <QWidget>
class QPushButton ;
class QString ;
class QLineEdit ;
class QLabel ;
class QVBoxLayout ;
class QHBoxLayout ;
class MyWidget : public QWidget {
Q_OBJECT
public:
MyWidget( QWidget *parent = 0 ) ;
private slots:
void buttonChange( const QString & ) ;
void addField( ) ;
void subtractField( ) ;
private :
QVBoxLayout *thisWidgetLayout ;
QLabel *instruction ;
QPushButton *increment ;
QPushButton *decrement ;
QLineEdit *entryField ;
QHBoxLayout *lowerPart ;
} ;
#endif
file task.cpp
#include <QtGui>
#include <QString>
#include "task.h"
MyWidget::MyWidget ( QWidget *parent )
: QWidget( parent ) {
thisWidgetLayout = new QVBoxLayout ( this ) ;
instruction = new QLabel ;
instruction->setText( "Enter a number between 1 and 10 ! Numbers above 10 are decremented, below 0 incremented!" ) ;
instruction->setWordWrap( true ) ;
lowerPart = new QHBoxLayout ;
entryField = new QLineEdit( "0" ) ;
increment = new QPushButton( "Increment" ) ;
decrement = new QPushButton( "Decrement" ) ;
increment->setDefault( true ) ;
connect( entryField , SIGNAL ( textChanged ( const QString & ) ) ,
this , SLOT ( buttonChange( const QString & )) ) ;
connect( entryField , SIGNAL ( textEdited ( const QString & ) ) ,
this , SLOT ( buttonChange( const QString & )) ) ;
connect( increment , SIGNAL ( clicked( ) ) , this ,
SLOT ( addField( ) )) ;
connect( decrement , SIGNAL ( clicked( ) ) , this ,
SLOT ( subtractField( ))) ;
lowerPart->addWidget( entryField ) ;
lowerPart->addWidget( increment ) ;
lowerPart->addWidget( decrement ) ;
thisWidgetLayout->addWidget( instruction ) ;
thisWidgetLayout->addLayout( lowerPart ) ;
setLayout( thisWidgetLayout ) ;
}
void MyWidget::buttonChange( const QString & text ) {
bool ok ;
increment->setEnabled( text.toInt( &ok, 10 ) < 10 ) ;
increment->setDisabled( text.toInt( &ok, 10 ) > 9 ) ;
decrement->setEnabled( text.toInt( &ok, 10 ) > 0 ) ;
decrement->setDisabled( text.toInt( &ok, 10 ) <= 0 ) ;
if ( ! ( text == "0" ) )
entryField->setReadOnly( true ) ;
}
void MyWidget::addField( ) {
bool ok ;
int number = entryField->text( ).toInt( &ok , 10 ) ;
number++ ;
entryField->setText( QString("%1").arg( number )) ;
}
void MyWidget::subtractField( ) {
bool ok ;
int number = entryField->text( ).toInt( &ok , 10 ) ;
number-- ;
entryField->setText( QString("%1").arg( number )) ;
}
main.cpp
#include <QApplication>
#include "task.h"
int main( int argc, char *argv[ ] ) {
QApplication app( argc , argv ) ;
MyWidget theWidget ;
theWidget.show( ) ;
return app.exec( ) ;
}
[edit] C#
Using Windows Forms; compile with csc -t:winexe Program.cs (on MS.NET) or gmcs -t:winexe Program.cs (on Mono)
using System;
using System.ComponentModel;
using System.Windows.Forms;
class RosettaInteractionForm : Form
{
// Model used for DataBinding.
// Notifies bound controls about Value changes.
class NumberModel: INotifyPropertyChanged
{
// initialize event with empty delegate to avoid checks on null
public event PropertyChangedEventHandler PropertyChanged = delegate {};
int _value;
public int Value
{
get { return _value; }
set
{
_value = value;
// Notify bound control about value change
PropertyChanged(this, new PropertyChangedEventArgs("Value"));
}
}
}
NumberModel model = new NumberModel{ Value = 0};
RosettaInteractionForm()
{
//MaskedTextBox is a TextBox variety with built-in input validation
var tbNumber = new MaskedTextBox
{
Mask="0000", // allow 4 decimal digits only
ResetOnSpace = false, // don't enter spaces
Dock = DockStyle.Top // place at the top of form
};
// bound TextBox.Text to NumberModel.Value;
tbNumber.DataBindings.Add("Text", model, "Value");
var enabledIfZero = new Binding("Enabled", model, "Value");
EnableControlWhen(tbNumber, value => value == 0);
var btIncrement = new Button{Text = "Increment", Dock = DockStyle.Bottom};
btIncrement.Click += delegate
{
model.Value++;
};
EnableControlWhen(btIncrement, value => value < 10);
var btDecrement = new Button{Text = "Decrement", Dock = DockStyle.Bottom};
btDecrement.Click += delegate
{
model.Value--;
};
EnableControlWhen(btDecrement, value => value > 0);
Controls.Add(tbNumber);
Controls.Add(btIncrement);
Controls.Add(btDecrement);
}
// common part of creating bindings for Enabled property
void EnableControlWhen(Control ctrl, Func<int, bool> predicate)
{
// bind Control.Enabled to NumberModel.Value
var enabledBinding = new Binding("Enabled", model, "Value");
// Format event is called when model value should be converted to Control value.
enabledBinding.Format += (sender, args) =>
{
// Enabled property is of bool type.
if (args.DesiredType != typeof(bool)) return;
// set resulting value by applying condition
args.Value = predicate((int)args.Value);
};
// as a result, control will be enabled if predicate returns true
ctrl.DataBindings.Add(enabledBinding);
}
static void Main()
{
Application.Run(new RosettaInteractionForm());
}
}
[edit] Delphi
type
TForm1 = class(TForm)
MaskEditValue: TMaskEdit; // Set Editmask on: "99;0; "
SpeedButtonIncrement: TSpeedButton;
SpeedButtonDecrement: TSpeedButton;
procedure MaskEditValueChange(Sender: TObject);
procedure SpeedButtonDecrementClick(Sender: TObject);
procedure SpeedButtonIncrementClick(Sender: TObject);
end;
var
Form1: TForm1;
implementation
procedure TForm1.MaskEditValueChange(Sender: TObject);
begin
TMaskEdit(Sender).Enabled := StrToIntDef(Trim(TMaskEdit(Sender).Text), 0) = 0;
SpeedButtonIncrement.Enabled := StrToIntDef(Trim(TMaskEdit(Sender).Text), 0) < 10;
SpeedButtonDecrement.Enabled := StrToIntDef(Trim(TMaskEdit(Sender).Text), 0) > 0;
end;
procedure TForm1.SpeedButtonDecrementClick(Sender: TObject);
begin
MaskEditValue.Text := IntToStr(Pred(StrToIntDef(Trim(MaskEditValue.Text), 0)));
end;
procedure TForm1.SpeedButtonIncrementClick(Sender: TObject);
begin
MaskEditValue.Text := IntToStr(Succ(StrToIntDef(Trim(MaskEditValue.Text), 0)));
end;
[edit] Fantom
using fwt
using gfx
class Main
{
public static Void main ()
{
Window
{
textField := Text
{
text = "0"
}
incButton := Button
{
text = "increment"
onAction.add |Event e|
{
if (textField.text != "")
{
try
{
Int value := textField.text.toInt
if (value < 10) value += 1
textField.text = value.toStr
}
catch {}
}
}
}
decButton := Button
{
text = "decrement"
onAction.add |Event e|
{
if (textField.text != "")
{
try
{
Int value := textField.text.toInt
if (value > 0) value -= 1
textField.text = value.toStr
}
catch {}
}
}
}
// add a listener for modifications to the text field
// which updates the button visibilities
textField.onModify.add |Event e|
{
try
{
Int value := textField.text.toInt
incButton.enabled = (value < 10) // update whether button can be used
decButton.enabled = (value > 0) // update whether button can be used
}
catch textField.text = "0" // reset if not an int
}
EdgePane
{
top = textField
left = incButton
right = decButton
},
}.open
}
}
[edit] Icon and Unicon
This uses the Unicon specific graphics library.
import gui
$include "guih.icn"
class MessageDialog : Dialog (message)
method component_setup ()
label := Label ("label="||message, "pos=20,20")
add (label)
button := TextButton("label=OK", "pos=100,60")
button.connect (self, "dispose", ACTION_EVENT)
add (button)
connect (self, "dispose", CLOSE_BUTTON_EVENT)
attrib ("size=200,100", "bg=light gray")
end
initially (message)
self.Dialog.initially()
self.message := message
end
class WindowApp : Dialog (button1, button2, field, value)
method set_enabled ()
if value = 0
then field.clear_is_shaded ()
else field.set_is_shaded ()
if value <= 0
then button2.set_is_shaded ()
else button2.clear_is_shaded ()
if value >= 10
then button1.set_is_shaded ()
else button1.clear_is_shaded ()
end
method increment ()
value +:= 1
field.set_contents (string(value))
set_enabled ()
end
method decrement ()
value -:= 1
field.set_contents (string(value))
set_enabled ()
end
method handle_text_field ()
if not(integer(field.get_contents ()))
then {
warning := MessageDialog ("Not a number")
warning.show_modal ()
field.set_contents (string(value))
}
else {
n := integer (field.get_contents ())
if not (0 <= n <= 10)
then {
warning := MessageDialog ("Not in range")
warning.show_modal ()
field.set_contents (string(value))
}
}
value := integer (field.get_contents ()) # must be ok
set_enabled ()
end
method component_setup ()
value := 0
field := TextField("contents="||value, "pos=20,20", "size=150")
field.connect (self, "handle_text_field", TEXTFIELD_CHANGED_EVENT)
add (field)
button1 := TextButton("label=Increment", "pos=20,60", "size=70")
button1.connect (self, "increment", ACTION_EVENT)
add (button1)
button2 := TextButton("label=Decrement", "pos=100,60", "size=70")
button2.connect (self, "decrement", ACTION_EVENT)
add (button2)
connect (self, "dispose", CLOSE_BUTTON_EVENT)
attrib ("size=200,100", "bg=light gray")
set_enabled ()
end
end
procedure main ()
w := WindowApp ()
w.show_modal ()
end
[edit] J
task_run=: wd bind (noun define)
pc task nosize;
xywh 6 30 48 12;cc decrement button;cn "-";
xywh 6 18 48 12;cc increment button;cn "+";
xywh 6 6 48 12;cc Value edit; set Value 0;
pas 6 6;pcenter;
pshow;
)
task_close=: wd bind 'pclose'
task_Value_button=: update=: verb define
wd 'set Value ',":n=.{.0".Value
wd 'setenable Value ',":n=0
wd 'setenable increment ',":n<10
wd 'setenable decrement ',":n>0
)
task_increment_button=:verb define
update Value=:":1+0".Value
)
task_decrement_button=:verb define
update Value=:":_1+0".Value
)
Example use:
task_run''
[edit] Java
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class Interact extends JFrame{
final JTextField numberField;
final JButton incButton, decButton;
public Interact(){
//stop the GUI threads when the user hits the X button
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
numberField = new JTextField();
incButton = new JButton("Increment");
decButton = new JButton("Decrement");
numberField.setText("0");//start at 0
decButton.setEnabled(false);//we're already at 0
//listen for button presses in the text field
numberField.addKeyListener(new KeyListener(){
@Override
public void keyTyped(KeyEvent e) {
//if the entered character is not a digit
if(!Character.isDigit(e.getKeyChar())){
//eat the event (i.e. stop it from being processed)
e.consume();
}else if(Character.isDigit(e.getKeyChar())){
//This method is executed from the event thread and updating the GUI
//from there doesn't always work. invokeLater will ensure that the
//GUI is updated
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
String text = numberField.getText();
if(text.isEmpty()){//default to 0 when all text is erased
numberField.setText("0");
decButton.setEnabled(false);
incButton.setEnabled(true);
return;
}
if(Long.valueOf(text) <= 0){
decButton.setEnabled(false);
incButton.setEnabled(true);
}else if(Long.valueOf(text) >= 10){
incButton.setEnabled(false);
decButton.setEnabled(true);
}else{
incButton.setEnabled(true);
decButton.setEnabled(true);
}
}
});
}
}
@Override
public void keyReleased(KeyEvent e){}
@Override
public void keyPressed(KeyEvent e){
//backspace and delete don't register in keyTyped because they don't
//display a Unicode character, so they must be handled here
if(e.getKeyCode() == KeyEvent.VK_BACK_SPACE ||
e.getKeyCode() == KeyEvent.VK_DELETE){
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
String text = numberField.getText();
if(text.isEmpty()){
numberField.setText("0");
decButton.setEnabled(false);
incButton.setEnabled(true);
return;
}
if(Long.valueOf(text) <= 0){
decButton.setEnabled(false);
incButton.setEnabled(true);
}else if(Long.valueOf(text) >= 10){
incButton.setEnabled(false);
decButton.setEnabled(true);
}else{
incButton.setEnabled(true);
decButton.setEnabled(true);
}
}
});
}
}
});
//listen for button clicks on the increment button
incButton.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
String text = numberField.getText();
numberField.setText((Long.valueOf(text) + 1) + "");
if(Long.valueOf(text) + 1 >= 10){
incButton.setEnabled(false);
}
if(Long.valueOf(text) + 1 > 0){
decButton.setEnabled(true);
}
}
});
//listen for button clicks on the random button
decButton.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
String text = numberField.getText();
numberField.setText((Long.valueOf(text) - 1) + "");
if(Long.valueOf(text) - 1 <= 0){
decButton.setEnabled(false);
}
if(Long.valueOf(text) - 1 < 10){
incButton.setEnabled(true);
}
}
});
//arrange the components in a grid with 2 rows and 1 column
setLayout(new GridLayout(2, 1));
//a secondary panel for arranging both buttons in one grid space in the window
JPanel buttonPanel = new JPanel();
//the buttons are in a grid with 1 row and 2 columns
buttonPanel.setLayout(new GridLayout(1, 2));
//add the buttons
buttonPanel.add(incButton);
buttonPanel.add(decButton);
//put the number field on top of the buttons
add(numberField);
add(buttonPanel);
//size the window appropriately
pack();
}
public static void main(String[] args){
new Interact().setVisible(true);
}
}
[edit] Julia
using Tk
w = Toplevel("GUI enabling/disabling")
fr = Frame(w)
pack(fr, {:expand=>true, :fill => "both"})
value = Entry(fr)
increment = Button(fr, "+")
decrement = Button(fr, "-")
formlayout(value, "Value:")
formlayout(increment, " ")
formlayout(decrement, " ")
## value stores a string
set_value(value, "0") ## The field is initialized to zero.
get(value::Tk_Entry) = try parseint(get_value(value)) catch e nothing end
function update()
cur_value = get(value)
set_enabled(value, isa(cur_value, Integer) && cur_value == 0)
set_enabled(increment, isa(cur_value, Integer) && cur_value < 10)
set_enabled(decrement, isa(cur_value, Integer) && cur_value > 0)
end
crement = function(step)
set_enabled(value, true)
set_value(value, string(get(value) + step))
update()
end
tk_bind(increment, "command", path -> crement(1))
tk_bind(decrement, "command", path -> crement(-1))
update()
function validate_command(path, P)
try
if length(P) > 0 parseint(P); update() end
tcl("expr", "TRUE")
catch e
tcl("expr", "FALSE")
end
end
function invalid_command(path, W)
println("Invalid value")
tcl(W, "delete", "@0", "end")
end
tk_configure(value, {:validate=>"focusout", :validatecommand=>validate_command, :invalidcommand=>invalid_command })
[edit] Liberty BASIC
nomainwin
textbox #demo.val, 20, 50, 90, 24
button #demo.dec, "Decrement", [btnDecrement], UL, 20, 90, 90, 24
button #demo.inc, "Increment", [btnIncrement], UL, 20, 120, 90, 24
statictext #demo.txt, "Positive or negative whole numbers only.", 20, 170, 240, 24
open "Rosetta Task: GUI enabling/disabling of controls" for window as #demo
#demo "trapclose [quit]"
#demo.val 0
#demo.dec "!disable"
wait
[quit]
close #demo
end
[btnDecrement]
validNum = validNum()
if validNum = 0 then
#demo.val "!contents? nVal$"
notice nVal$;" does not appear to be a valid whole number."
else
#demo.val "!contents? nVal"
if nVal > 0 then
nVal = nVal - 1
end if
end if
#demo.val nVal
call disEnableControls nVal
wait
[btnIncrement]
validNum = validNum()
if validNum = 0 then
#demo.val "!contents? nVal$"
notice nVal$;" does not appear to be a valid whole number."
else
#demo.val "!contents? nVal"
if nVal < 10 then
nVal = nVal + 1
end if
end if
#demo.val nVal
call disEnableControls nVal
wait
Function validNum()
validNum$ = "0123456789"
#demo.val "!contents? nVal$"
nVal$ = trim$(nVal$)
if left$(nVal$, 1) = "-" then
neg = 1
nVal$ = mid$(nVal$, 2)
else
neg = 0
end if
validNum = 1
for i = 1 to len(nVal$)
if instr(validNum$, mid$(nVal$, i, 1)) = 0 then
validNum = 0
end if
next i
End Function
Sub disEnableControls nVal
if nVal > 9 then
#demo.inc "!disable"
else
#demo.inc "!enable"
end if
if nVal < 1 then
#demo.dec "!disable"
else
#demo.dec "!enable"
end if
if nVal = 0 then
#demo.val "!enable"
else
#demo.val "!disable"
end if
End Sub
[edit] Mathematica
Manipulate[Null, {{value, 0},
InputField[Dynamic[value], Number,
Enabled -> Dynamic[value == 0]] &},
Row@{Button["increment", value++, Enabled -> Dynamic[value < 10]],
Button["decrement", value--, Enabled -> Dynamic[value > 0]]}]
[edit] NewLISP
; file: gui-enable.lsp
; url: http://rosettacode.org/wiki/GUI_enabling/disabling_of_controls
; author: oofoe 2012-02-02
; Load library and initialize GUI server:
(load (append (env "NEWLISPDIR") "/guiserver.lsp"))
(gs:init)
; The "interlock" function maintains GUI consistency by disabling all
; controls, then selectively re-enabling them depending on the value
; in the textbox.
(define (interlock)
(gs:disable 'value 'increment 'decrement)
(let ((v (int (gs:get-text 'value))))
(if (= 0 v) (gs:enable 'value))
(if (< v 10) (gs:enable 'increment))
(if (< 0 v) (gs:enable 'decrement))
))
; Callbacks.
(define (update f)
(gs:set-text 'value (string (f (int (gs:get-text 'value)) 1)))
(interlock))
(define (incrementing id) (update +))
(define (decrementing id) (update -))
(define (valuing id) (interlock))
; Create main window frame and set layout direction.
(gs:frame 'main 100 100 200 75 "GUI Enable")
(gs:set-flow-layout 'main "center" 4 4)
; Create and add widgets.
(gs:button 'decrement 'decrementing "-" 30)
(gs:text-field 'value 'valuing 8)
(gs:set-text 'value "0")
(gs:button 'increment 'incrementing "+" 30)
(gs:add-to 'main 'decrement 'value 'increment)
; Show main window.
(gs:set-visible 'main true)
; Start event loop.
(gs:listen)
(exit)
Screenshot:
[edit] PicoLisp
The standard PicoLisp GUI is HTTP based. Connect your browser to http://localhost:8080 after starting the following script.
#!/usr/bin/picolisp /usr/lib/picolisp/lib.l
(load "@ext.l" "@lib/http.l" "@lib/xhtml.l" "@lib/form.l")
(de start ()
(and (app) (zero *Number))
(action
(html 0 "Enable/Disable" "@lib.css" NIL
(form NIL
(gui '(+Var +Able +NumField) '*Number '(=0 *Number) 20 "Value")
(gui '(+Able +JS +Button) '(> 10 *Number) "increment"
'(inc '*Number) )
(gui '(+Able +JS +Button) '(gt0 *Number) "decrement"
'(dec '*Number) ) ) ) ) )
(server 8080 "!start")
(wait)
[edit] Prolog
Works with SWI-Prolog and XPCE.
dialog('GUI_Interaction',
[ object :=
GUI_Interaction,
parts :=
[ GUI_Interaction :=
dialog('Rosetta Code'),
Name := label(name, 'Value :'),
Input_field :=
text_item(input_field, '0'),
Increment :=
button(increment),
Decrement :=
button(decrement)
],
modifications :=
[ Input_field := [ label := 'Value :',
length := 28,
show_label := @off
],
Decrement := [active := @off]
],
layout :=
[ area(Name,
area(50, 26, 25, 24)),
area(Input_field,
area(95, 24, 200, 24)),
area(Increment,
area(50, 90, 80, 24)),
area(Decrement,
area(230, 90, 80, 24))
],
behaviour :=
[
Increment := [
message := message(@prolog,
increment,
Increment,
Decrement,
Input_field )
],
Decrement := [
message := message(@prolog,
decrement,
Increment,
Decrement,
Input_field)
],
Input_field := [
message := message(@prolog,
input,
Increment,
Decrement,
@receiver,
@arg1)
]
]
]).
gui_component :-
make_dialog(S, 'GUI_Interaction'),
send(S, open).
increment(Incr, Decr, Input) :-
get(Input, selection, V),
atom_number(V, Val),
Val1 is Val + 1,
send(Input, selection, Val1),
test(Val1, Incr, Decr, Input).
decrement(Incr, Decr, Input) :-
get(Input, selection, V),
atom_number(V, Val),
Val1 is Val - 1,
send(Input, selection, Val1),
test(Val1, Incr, Decr, Input).
input(Incr, Decr, Input, Selection) :-
catch( (term_to_atom(T, Selection), number(T)),
_,
( send(@display, inform, 'Please type a number !'),
T = 0,
send(Input,selection, T))),
test(T, Incr, Decr, Input).
test(V, Incr, Decr, Input) :-
( V = 0 -> send(Input, active, @on); send(Input, active, @off)),
send(Incr, active, @on),
send(Decr, active, @on),
( V < 1
-> send(Decr, active, @off)
; V > 9
-> send(Incr, active, @off)).
[edit] PureBasic
Enumeration
#TextGadget
#AddButton
#SubButton
EndEnumeration
Procedure UpdateGadgets(Value,UpdateValue=0)
Overmax=0: UnderMin=0
If Value>=10
Overmax=1
ElseIf Value<=0
UnderMin=1
EndIf
DisableGadget(#AddButton,Overmax)
DisableGadget(#SubButton,UnderMin)
If UpdateValue
SetGadgetText(#TextGadget,Str(Value))
EndIf
EndProcedure
If OpenWindow(0,#PB_Ignore,#PB_Ignore,110,70,"PB-GUI",#PB_Window_SystemMenu)
StringGadget(#TextGadget,10,10,90,20,"")
ButtonGadget(#AddButton,10,40,30,20,"+")
ButtonGadget(#SubButton,70,40,30,20,"-")
UpdateGadgets(Value,1)
Repeat
Event=WaitWindowEvent()
If Event=#PB_Event_Gadget
Gadget=EventGadget()
Select Gadget
Case #AddButton
Value+1
UpdateGadgets(Value,1)
Case #SubButton
Value-1
UpdateGadgets(Value,1)
Default
EType=EventType()
If EType=#PB_EventType_Change
Value=Val(GetGadgetText(#TextGadget))
UpdateGadgets(Value)
EndIf
EndSelect
EndIf
Until Event=#PB_Event_CloseWindow
EndIf
[edit] R
library(gWidgets)
options(guiToolkit="RGtk2") ## using gWidgtsRGtk2
w <- gwindow("Disable components")
g <- ggroup(cont=w, horizontal=FALSE)
e <- gedit("0", cont=g, coerce.with=as.numeric)
bg <- ggroup(cont=g)
down_btn <- gbutton("-", cont=bg)
up_btn <- gbutton("+", cont=bg)
update_ctrls <- function(h,...) {
val <- svalue(e)
enabled(down_btn) <- val >= 0
enabled(up_btn) <- val <= 10
}
rement <- function(h,...) {
svalue(e) <- svalue(e) + h$action
update_ctrls(h,...)
}
addHandlerChanged(e, handler=update_ctrls)
addHandlerChanged(down_btn, handler=rement, action=-1)
addHandlerChanged(up_btn, handler=rement, action=1)
[edit] Racket
#lang racket/gui
(define frame (new frame% [label "Interaction Demo"]))
(define (changed . _)
(define s (send inp get-value))
(define v (string->number s))
(unless v (set! v (or (string->number (regexp-replace* #rx"[^0-9]+" s "")) 0))
(send inp set-value (~a v)))
(send inc-b enable (< v 10))
(send dec-b enable (> v 0))
(send inp enable (zero? v)))
(define ((change-value f) . _)
(send inp set-value (number->string (f (string->number (send inp get-value)))))
(changed))
(define inp
(new text-field% [label "Value"] [parent frame] [init-value "0"] [callback changed]))
(define buttons (new horizontal-pane% [parent frame]))
(define inc-b
(new button% [parent buttons] [label "Increment"] [callback (change-value add1)]))
(define dec-b
(new button% [parent buttons] [label "Decrement"] [callback (change-value sub1)]))
(send frame show #t)
[edit] Ruby
Shoes.app do
@number = edit_line
@number.change {update_controls}
@incr = button('Increment') {update_controls(@number.text.to_i + 1)}
@decr = button('Decrement') {update_controls(@number.text.to_i - 1)}
def update_controls(value = @number.text.to_i)
@number.text = value
@incr.state = value.to_i >= 10 ? "disabled" : nil
@decr.state = value.to_i <= 0 ? "disabled" : nil
end
update_controls 0
end
[edit] Scala
import scala.swing._
import scala.swing.Swing._
import scala.swing.event._
object Enabling extends SimpleSwingApplication {
def top = new MainFrame {
title = "Rosetta Code >>> Task: GUI enabling/disabling of controls | Language: Scala"
val numberField = new TextField { text = "0" } // start at 0
val incButton = new Button("Increment")
val decButton = new Button {
text = "Decrement"
enabled = false
}
// arrange buttons in a grid with 1 row, 2 columns
val buttonPanel = new GridPanel(1, 2) {
contents ++= List(incButton, decButton)
}
// arrange text field and button panel in a grid with 2 row, 1 column
contents = new GridPanel(2, 1) {
contents ++= List(numberField, buttonPanel)
}
// backspace and delete don't cause a display of any Unicode char -
// therefore we need to catch them apart from the others
val specialKeys = List(Key.BackSpace, Key.Delete)
// listen for keys pressed in numberField and button clicks
listenTo(numberField.keys, incButton, decButton)
reactions += {
case kt: KeyTyped =>
if (!kt.char.isDigit) // if the entered char isn't a digit ...
kt.consume // ... eat the event (i.e. stop it from being processed)
else {
Swing.onEDT(switching) // ensure GUI-updating
}
case KeyPressed(_,kp,_,_) if (!specialKeys.filter(_==kp).isEmpty) =>
Swing.onEDT(switching) // ensure GUI-updating
case ButtonClicked(`incButton`) =>
numberField.text = "" + (java.lang.Long.valueOf(numberField.text)+1)
switching
case ButtonClicked(`decButton`) =>
numberField.text = "" + (java.lang.Long.valueOf(numberField.text)-1)
switching
}
def switching: Unit = {
val s = numberField.text match {
case "" => "0"
case _ => numberField.text
}
val n = java.lang.Long.valueOf(s)
numberField.text = "" + n
if (java.lang.Long.valueOf(numberField.text) <= 0) {
numberField.enabled = true
incButton.enabled = true
decButton.enabled = false
} else if (java.lang.Long.valueOf(numberField.text) >= 10) {
numberField.enabled = false
incButton.enabled = false
decButton.enabled = true
} else {
numberField.enabled = false
incButton.enabled = true
decButton.enabled = true
}
}
}
}
[edit] Smalltalk
|top input vh incButton decButton|
vh := ValueHolder with:0.
top := StandardSystemView label:'Rosetta GUI interaction'.
top extent:300@100.
top add:((Label label:'Value:') origin: 0 @ 10 corner: 100 @ 40).
top add:(input := EditField origin: 102 @ 10 corner: 1.0 @ 40).
input model:(TypeConverter onNumberValue:vh).
input enableChannel:(BlockValue with:[:v | v = 0] argument:vh).
top add:((incButton := Button label:'Inc') origin: 10 @ 50 corner: 100 @ 80).
top add:((decButton := Button label:'Dec') origin: 110 @ 50 corner: 210 @ 80).
incButton action:[ vh value: (vh value + 1) ].
incButton enableChannel:(BlockValue with:[:v | v < 10] argument:vh).
decButton action:[ vh value: (vh value - 1) ].
decButton enableChannel:(BlockValue with:[:v | v > 0] argument:vh).
top open
[edit] Tcl
package require Tk
# Model
set field 0
# View
place [ttk::frame .bg] -relwidth 1 -relheight 1; # Hack to make things look nice
pack [ttk::labelframe .val -text "Value"]
pack [ttk::entry .val.ue -textvariable field \
-validate key -invalidcommand bell \
-validatecommand {string is integer %P}]
pack [ttk::button .inc -text "increment" -command up]
pack [ttk::button .dec -text "decrement" -command down]
# Controller
proc up {} {
global field
incr field
}
proc down {} {
global field
incr field -1
}
# Attach this controller to the Model; easier than manual calling
trace add variable field write updateEnables
proc updateEnables {args} {
global field
.inc state [expr {$field < 10 ? "!disabled" : "disabled"}]
.dec state [expr {$field > 0 ? "!disabled" : "disabled"}]
}
updateEnables; # Force initial state of buttons
[edit] Visual Basic
In VB, windows are usually created in the IDE. The generated code is hidden from the user unless viewed outside of VB. For the sake of this task, I have included that code.
(Also, this sort of task would typically be performed by a "spinner" or "up-down" control, not by buttons.)
VERSION 5.00
Begin VB.Form Form1
Caption = "Form1"
ClientHeight = 2265
ClientLeft = 60
ClientTop = 600
ClientWidth = 2175
LinkTopic = "Form1"
ScaleHeight = 2265
ScaleWidth = 2175
StartUpPosition = 3 'Windows Default
Begin VB.CommandButton cmdDec
Caption = "Decrement"
Enabled = 0 'False
Height = 495
Left = 120
TabIndex = 2
Top = 1680
Width = 1215
End
Begin VB.CommandButton cmdInc
Caption = "Increment"
Height = 495
Left = 120
TabIndex = 1
Top = 1080
Width = 1215
End
Begin VB.TextBox txtValue
Height = 495
Left = 120
TabIndex = 0
Text = "0"
Top = 240
Width = 1215
End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
'-----user-written code begins here; everything above this line is hidden in the GUI-----
Private Sub cmdDec_Click()
If Val(txtValue.Text) > 0 Then txtValue.Text = Val(txtValue.Text) - 1
End Sub
Private Sub cmdInc_Click()
If Val(txtValue.Text) < 10 Then txtValue.Text = Val(txtValue.Text) + 1
End Sub
Private Sub txtValue_Change()
Select Case Val(txtValue.Text)
Case Is < 0
txtValue.Enabled = False
cmdInc.Enabled = True
cmdDec.Enabled = False
Case Is > 9
txtValue.Enabled = False
cmdInc.Enabled = False
cmdDec.Enabled = True
Case 0
txtValue.Enabled = True
cmdInc.Enabled = True
cmdDec.Enabled = False
Case Else
txtValue.Enabled = False
cmdInc.Enabled = True
cmdDec.Enabled = True
End Select
End Sub
Categories:
- Programming Tasks
- GUI
- Ada
- GtkAda
- AutoHotkey
- BBC BASIC
- C++
- C sharp
- Delphi
- Fantom
- Unicon
- J
- Java
- Julia
- Liberty BASIC
- Mathematica
- NewLISP
- PicoLisp
- Prolog
- PureBasic
- R
- Racket
- Ruby
- Shoes
- Scala
- Smalltalk
- Tcl
- Tk
- PARI/GP/Omit
- Retro/Omit
- Visual Basic
- ACL2/Omit
- Applesoft BASIC/Omit
- AWK/Omit
- Batch File/Omit
- Blast/Omit
- Brainf***/Omit
- GUISS/Omit
- Integer BASIC/Omit
- Lilypond/Omit
- Lotus 123/Omit
- Maxima/Omit
- PostScript/Omit
