GUI enabling/disabling of controls
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.
- 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")
- a button ("increment")
- a button ("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.
Ada
disabling.adb: <lang Ada>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;</lang>
AutoHotkey
<lang AutoHotkey>GUI, Add, Edit, w150 number vValue gEnableDisable, 0 ; Number specifies a numbers-only edit field. g<Subroutine> specifies a subroutine to run when the value of control changes. 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
- No timer is needed
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.</lang>
BBC BASIC
<lang bbcbasic> 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</lang>
- Output:
C
file main.c
<lang c>#include <windows.h>
- include "resource.h"
- define MIN_VALUE 0
- define MAX_VALUE 10
BOOL CALLBACK DlgProc( HWND hwnd, UINT msg, WPARAM wPar, LPARAM lPar ); void Increment( HWND hwnd ); void Decrement( HWND hwnd ); void SetControlsState( HWND hwnd );
int WINAPI WinMain( HINSTANCE hInst, HINSTANCE hPInst, LPSTR cmdLn, int show ) {
return DialogBox( hInst, MAKEINTRESOURCE(IDD_DLG), NULL, DlgProc );
}
BOOL CALLBACK DlgProc( HWND hwnd, UINT msg, WPARAM wPar, LPARAM lPar ) {
switch( msg ) {
case WM_INITDIALOG:
srand( GetTickCount() );
SetDlgItemInt( hwnd, IDC_INPUT, 0, FALSE );
break;
case WM_COMMAND:
switch( LOWORD(wPar) ) {
case IDC_INCREMENT:
Increment( hwnd );
break;
case IDC_DECREMENT:
Decrement( hwnd );
break;
case IDC_INPUT:
// update controls' state according
// to the contents of the input field
if( HIWORD(wPar) == EN_CHANGE ) SetControlsState( hwnd );
break;
case IDC_QUIT:
SendMessage( hwnd, WM_CLOSE, 0, 0 );
break;
default: ;
}
break;
case WM_CLOSE: {
int reply = MessageBox( hwnd,
"Do you really want to quit?",
"Quit confirmation", MB_ICONQUESTION|MB_YESNO );
if( reply == IDYES )
EndDialog( hwnd, 0 );
} break;
default: ; }
return 0;
}
void Increment( HWND hwnd ) {
UINT n = GetDlgItemInt( hwnd, IDC_INPUT, NULL, FALSE );
if( n < MAX_VALUE ) {
SetDlgItemInt( hwnd, IDC_INPUT, ++n, FALSE );
SetControlsState( hwnd );
}
}
void Decrement( HWND hwnd ) {
UINT n = GetDlgItemInt( hwnd, IDC_INPUT, NULL, FALSE );
if( n > MIN_VALUE ) {
SetDlgItemInt( hwnd, IDC_INPUT, --n, FALSE );
SetControlsState( hwnd );
}
}
void SetControlsState( HWND hwnd ) {
UINT n = GetDlgItemInt( hwnd, IDC_INPUT, NULL, FALSE ); EnableWindow( GetDlgItem(hwnd,IDC_INCREMENT), n<MAX_VALUE ); EnableWindow( GetDlgItem(hwnd,IDC_DECREMENT), n>MIN_VALUE );
}</lang>
file resource.h
<lang c>#define IDD_DLG 101
- define IDC_INPUT 1001
- define IDC_INCREMENT 1002
- define IDC_DECREMENT 1003
- define IDC_QUIT 1004</lang>
file resource.rc
<lang c>#include <windows.h>
- include "resource.h"
LANGUAGE LANG_NEUTRAL, SUBLANG_NEUTRAL IDD_DLG DIALOG 0, 0, 154, 46 STYLE DS_3DLOOK | DS_CENTER | DS_MODALFRAME | DS_SHELLFONT | WS_CAPTION | WS_VISIBLE | WS_POPUP | WS_SYSMENU CAPTION "GUI Component Interaction" FONT 12, "Ms Shell Dlg" {
EDITTEXT IDC_INPUT, 33, 7, 114, 12, ES_AUTOHSCROLL | ES_NUMBER PUSHBUTTON "Increment", IDC_INCREMENT, 7, 25, 50, 14 PUSHBUTTON "Decrement", IDC_DECREMENT, 62, 25, 50, 14, WS_DISABLED PUSHBUTTON "Quit", IDC_QUIT, 117, 25, 30, 14 RTEXT "Value:", -1, 10, 8, 20, 8
}</lang>
C++
with Qt 4.4, creating project file with qmake -project, Makefile with qmake -o Makefile <projectfile> and finally make
file task.h
<lang cpp>#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</lang>
file task.cpp
<lang 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 )) ;
}</lang>
main.cpp
<lang cpp>#include <QApplication>
- include "task.h"
int main( int argc, char *argv[ ] ) {
QApplication app( argc , argv ) ; MyWidget theWidget ; theWidget.show( ) ; return app.exec( ) ;
}</lang>
C_sharp
Using Windows Forms; compile with csc -t:winexe Program.cs (on MS.NET) or gmcs -t:winexe Program.cs (on Mono) <lang c_sharp>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());
}
}</lang>
Delphi
<lang 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;</lang>
Fantom
<lang 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
}
}</lang>
FreeBASIC
<lang FreeBASIC>
- Include "windows.bi"
Dim As HWND Window_Main, Edit_Number, Button_Inc, Button_Dec Dim As MSG msg Dim As Integer n Dim As String text
'Create a window with an input field and two buttons: Window_Main = CreateWindow("#32770", "GUI Enabling/Disabling of Controls", WS_OVERLAPPEDWINDOW Or WS_VISIBLE, 100, 100, 250, 200, 0, 0, 0, 0) Var Static_Number = CreateWindow("STATIC", "Value:", WS_VISIBLE Or WS_CHILD, 10, 10, 100, 20, Window_Main, 0, 0, 0) Edit_Number = CreateWindow("EDIT", "0", WS_BORDER Or WS_VISIBLE Or WS_CHILD Or ES_AUTOHSCROLL Or ES_Number, 110, 10, 100, 20, Window_Main, 0, 0, 0) Button_Inc = CreateWindow("BUTTON", "Increment", WS_VISIBLE Or WS_CHILD, 110, 40, 100, 20, Window_Main, 0, 0, 0) Button_Dec = CreateWindow("BUTTON", "Decrement", WS_VISIBLE Or WS_CHILD, 110, 70, 100, 20, Window_Main, 0, 0, 0)
'Windows message loop: While GetMessage(@msg, Window_Main, 0, 0)
text = Space(GetWindowTextLength(Edit_Number) + 1) 'Buffer for the text
GetWindowText(Edit_Number, text, Len(text))
n = Val(text)
If n <> 0 Then EnableWindow(Edit_Number, False) Else EnableWindow(Edit_Number, True)
If n > 9 Then EnableWindow(Button_Inc, False) Else EnableWindow(Button_Inc, True)
If n > 0 Then EnableWindow(Button_Dec, True) Else EnableWindow(Button_Dec, False)
TranslateMessage(@msg)
DispatchMessage(@msg)
Select Case msg.hwnd
Case Button_Inc
'Increment value:
If msg.message = WM_LBUTTONDOWN Then SetWindowText(Edit_Number, Str(n + 1))
Case Button_Dec
'Decrement value:
If msg.message = WM_LBUTTONDOWN Then SetWindowText(Edit_Number, Str(n - 1))
Case Window_Main
If msg.message = WM_COMMAND Then End
End Select
Wend
End </lang>
Gambas
<lang gambas>hValueBox As ValueBox 'We need a ValueBox hButton0 As Button 'We need a button hButton1 As Button 'We need another button
Public Sub Form_Open()
With Me 'Set the Form's Properties..
.height = 95 'Set the Height .Width = 350 'Set the Width .Arrangement = Arrange.Vertical 'Arrange items vertically .Padding = 5 'Border area .Title = "GUI enable/disable" 'Title displayed on the Form
End With
hValueBox = New ValueBox(Me) As "ValBox" 'Add a ValueBox to the Form as Event 'ValBox'
With hValueBox 'Set the ValueBox's Properties..
.Expand = True 'Expand the ValueBox .Value = 0 'Set it's value to 0
End With
hButton0 = New Button(Me) As "ButtonInc" 'Add a Button to the form as Event "ButtonInc"
With hButton0 'Set the Button's Properties..
.Height = 28 'Set the Height .Text = "&Increment" 'Add Text (The '&' adds a keyboard shortcut)
End With
hButton1 = New Button(Me) As "ButtonDec" 'Add a Button to the form as Event "ButtonDec"
With hButton1 'Set the Button's Properties..
.Height = 28 'Set the Height .Text = "&Decrement" 'Add Text (The '&' adds a keyboard shortcut) .Enabled = False 'Disable the button
End With
End
Public Sub ButtonInc_Click() 'When the 'Increment' Button is clicked..
hValueBox.Value += 1 'Increase the Value in the ValueBox by 1 Checks
End
Public Sub ButtonDec_Click() 'When the 'Decrement' Button is clicked..
hValueBox.Value -= 1 'Increase the Value in the ValueBox by 1 Checks
End
Public Sub Checks() 'Checks the values to see which controls to en/disable
If hValueBox.Value = 0 Then 'If the ValueBox = 0 then..
hValueBox.enabled = True 'Enable the control
Else 'Else..
hValueBox.enabled = False 'Disable the control
End If
If hValueBox.Value > 9 Then 'If the ValueBox greater than 9 then..
hButton0.enabled = False 'Disable the control
Else 'Else..
hButton0.enabled = True 'Enable the control
End If
If hValueBox.Value < 1 Then 'If the ValueBox less than 1 then..
hButton1.enabled = False 'Disable the control
Else 'Else..
hButton1.enabled = True 'Enable the control
End If
End
Public Sub ValBox_Leave() 'When the mouse leaves the ValueBox..
Checks 'Rune the Checks routine
End</lang>
Icon and Unicon
This uses the Unicon specific graphics library.
<lang Unicon> 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 </lang>
J
J 8.x <lang j>task_run=: wd bind (noun define)
pc task nosize; cc decrement button;cn "Decrement"; cc increment button;cn "Increment"; cc Value edit center;set Value text 0; set decrement enable 0; pas 6 6;pcenter; pshow;
)
task_cancel=: task_close=: wd bind 'pclose'
task_Value_button=: update=: verb define
wd 'set Value text ', ": n=. {. 0 ". Value
wd 'set Value enable ', ": n=0
wd 'set increment enable ', ": n<10
wd 'set decrement enable ', ": n>0
)
task_increment_button=:verb define
update Value=: ": 1 + 0 ". Value
)
task_decrement_button=:verb define
update Value=: ": _1 + 0 ". Value
)</lang>
J 6.x <lang 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
)</lang>
Example use:
<lang> task_run</lang>
Java
<lang 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); } }</lang>
<lang java> import javafx.application.Application; import javafx.beans.property.LongProperty; import javafx.beans.property.SimpleLongProperty; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.TextField; import javafx.scene.layout.HBox; import javafx.scene.layout.VBox; import javafx.stage.Stage; import javafx.util.converter.NumberStringConverter;
public class InteractFX extends Application {
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage stage) throws Exception {
TextField input = new TextField("0"){
// only accept numbers as input
@Override public void replaceText(int start, int end, String text) {
if (text.matches("[0-9]*")) {
super.replaceText(start, end, text);
}
}
// only accept numbers on copy+paste
@Override public void replaceSelection(String text) {
if (text.matches("[0-9]*")) {
super.replaceSelection(text);
}
}
};
// when the textfield is empty, replace text with "0"
input.textProperty().addListener((observable, oldValue, newValue)->{
if(newValue == null || newValue.trim().isEmpty()){
input.setText("0");
}
});
// get a bi-directional bound long-property of the input value
LongProperty inputValue = new SimpleLongProperty();
input.textProperty().bindBidirectional(inputValue, new NumberStringConverter());
// textfield is disabled when the current value is other than "0"
input.disableProperty().bind(inputValue.isNotEqualTo(0));
Button increment = new Button("Increment");
increment.setOnAction(event-> inputValue.set(inputValue.get() + 1));
// incr-button is disabled when input is >= 10
increment.disableProperty().bind(inputValue.greaterThanOrEqualTo(10));
Button decrement = new Button("Decrement");
decrement.setOnAction(event-> inputValue.set(inputValue.get() - 1));
// decrement button is disabled when input is <=0
decrement.disableProperty().bind(inputValue.lessThanOrEqualTo(0));
// layout
VBox root = new VBox();
root.getChildren().add(input);
HBox buttons = new HBox();
buttons.getChildren().addAll(increment,decrement);
root.getChildren().add(buttons);
stage.setScene(new Scene(root));
stage.sizeToScene();
stage.show();
}
} </lang>
Julia
<lang 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 })
</lang>
Kotlin
<lang scala>// version 1.2.21
import javafx.application.Application import javafx.beans.property.SimpleLongProperty import javafx.scene.Scene import javafx.scene.control.Button import javafx.scene.control.TextField import javafx.scene.layout.HBox import javafx.scene.layout.VBox import javafx.stage.Stage import javafx.util.converter.NumberStringConverter import javafx.event.ActionEvent
val digits = Regex("[0-9]*")
class InteractFX : Application() {
override fun start(stage: Stage) {
val input = object : TextField("0") {
// only accept numbers as input
override fun replaceText(start: Int, end: Int, text: String) {
if (text.matches(digits)) super.replaceText(start, end, text)
}
// only accept numbers on copy + paste
override fun replaceSelection(text: String) {
if (text.matches(digits)) super.replaceSelection(text)
}
}
// when the textfield is empty, replace text with "0"
input.textProperty().addListener { _, _, newValue ->
if (newValue == null || newValue.trim().isEmpty()) input.text = "0"
}
// get a bi-directional bound long-property of the input value
val inputValue = SimpleLongProperty()
input.textProperty().bindBidirectional(inputValue, NumberStringConverter())
// textfield is disabled when the current value is other than "0"
input.disableProperty().bind(inputValue.isNotEqualTo(0))
val increment = Button("Increment")
increment.addEventHandler(ActionEvent.ACTION) { inputValue.set(inputValue.get() + 1) }
// increment button is disabled when input is >= 10
increment.disableProperty().bind(inputValue.greaterThanOrEqualTo(10))
val decrement = Button("Decrement")
decrement.addEventHandler(ActionEvent.ACTION) { inputValue.set(inputValue.get() - 1) }
// decrement button is disabled when input is <= 0
decrement.disableProperty().bind(inputValue.lessThanOrEqualTo(0))
// layout
val root = VBox()
root.children.add(input)
val buttons = HBox()
buttons.children.addAll(increment, decrement)
root.children.add(buttons)
stage.scene = Scene(root)
stage.sizeToScene()
stage.show()
}
}
fun main(args: Array<String>) {
Application.launch(InteractFX::class.java, *args)
}</lang>
Liberty BASIC
<lang lb>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</lang>
LiveCode
In LiveCode, GUIs are expected to be designed using the IDE, with the developer writing scripts to handle messages that are passed by the LC Engine. It is certainly possible to dynamically create windows (stacks) and all the various controls, however it is somewhat antithetical to the LC approach of rapid development.
1. Create a new mainstack
2. Draw on two buttons
2.1 The first button name is "Button1", with a label of "Increment"
2.2 The second button name is "Button2", with a label of "Decrement"
3. Draw a text field and name it "Field1", enter 0 as its content.
4. Select Object->Card Script and enter the following to handle enabling the buttons. <lang LiveCode>command enableButtons v
switch
case v <= 0
put 0 into fld "Field1"
set the enabled of btn "Button1" to true
set the enabled of btn "Button2" to false
break
case v >= 10
put 10 into fld "Field1"
set the enabled of btn "Button1" to false
set the enabled of btn "Button2" to true
break
default
set the enabled of btn "Button1" to true
set the enabled of btn "Button2" to true
put v into fld "Field1"
end switch
end enableButtons</lang>
For the increment button, click on Button 1 (in edit mode) and the select "code" from the toolbar and enter the following to handle clicks<lang LiveCode>on mouseUp
put field "Field1" into x add 1 to x enableButtons x
end mouseUp</lang>
Repeat for Button 2 (note we are subtracting here)<lang LiveCode>on mouseUp
put field "Field1" into x subtract 1 from x enableButtons x
end mouseUp</lang>
Finally add the code to handle keyboard entry in text field's code. Note this code prevents entering digits outside 0-9 and limits the value between 0 and 10.<lang LiveCode>on rawKeyDown k
if numToChar(k) is among the items of "1,2,3,4,5,6,7,8,9,0" then
if (numToChar(k) + the text of me) <= 10 then
enableButtons (numToChar(k) + the text of me)
end if
else if k = 65288 then
pass rawKeyDown
end if
end rawKeyDown</lang>
Switch back to the form, and enter run mode to execute.
n.b. Open stack handlers would be prudent to initialise the default value and button states if this were to be saved for standalone execution.
Maple
For this problem, you will need to open up Maple, go to the Components tab on the left, and insert a Text Area, and 2 Buttons. By right clicking each button, and clicking Component Properties, change one to Increase, and the other to Decrease. Then, click on 'Edit Content Changed Action". In the one labeled increase, type:
<lang Maple> Increase(); </lang>
In the one labeled Decrease, type:
<lang Maple> Decrease(); </lang>
Then, by clicking the 2 gears and opening up the start-up commands, enter this: <lang Maple> macro(SP=DocumentTools:-SetProperty, GP=DocumentTools:-GetProperty); with(Maplets[Elements]): SP("Text",value,0); Increase:=proc() SP("Text",value,parse(GP("Text",value))+1); if parse(GP("Text",value))>=10 then SP("Button0", enabled, false); else SP("Button0", enabled, true); end if; if parse(GP("Text",value))<=0 then SP("Button1", enabled, false); else SP("Button1", enabled, true); end if; end proc; Decrease:=proc() SP("Text",value,parse(GP("Text",value))-1); if parse(GP("Text",value))<=0 then SP("Button1", enabled, false); else SP("Button1", enabled, true); end if; if parse(GP("Text",value))>=10 then SP("Button0", enabled, false); else SP("Button0", enabled, true); end if; end proc; </lang>
Mathematica
<lang 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]]}]</lang>
NewLISP
<lang 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)</lang>
Screenshot:
Nim
<lang nim>import
gtk2, strutils, glib2
var valu: int = 0 var chngd_txt_hndler: gulong = 0
proc thisCheckBtns # forward declaration
proc thisDestroy(widget: pWidget, data: pgpointer){.cdecl.} =
main_quit()
nim_init() var window = window_new(gtk2.WINDOW_TOPLEVEL) var content = vbox_new(TRUE,10) var hbox1 = hbox_new(TRUE,10) var entry_fld = entry_new() entry_fld.set_text("0") var btn_quit = button_new("Quit") var btn_inc = button_new("Increment") var btn_dec = button_new("Decrement") add(hbox1,btn_inc) add(hbox1,btn_dec) pack_start(content, entry_fld, TRUE, TRUE, 0) pack_start(content, hbox1, TRUE, TRUE, 0) pack_start(content, btn_quit, TRUE, TRUE, 0) set_border_width(Window, 5) add(window, content)
proc thisInc(widget: pWidget, data: pgpointer){.cdecl.} =
inc(valu) entry_fld.set_text($valu) thisCheckBtns()
proc thisDec(widget: pWidget, data: pgpointer){.cdecl.} =
dec(valu) entry_fld.set_text($valu) thisCheckBtns()
proc thisTextChanged(widget: pWidget, data: pgpointer) {.cdecl.} =
#signal_handler_block(entry_fld, chngd_txt_hndler)
try:
valu = parseInt($entry_fld.get_text())
except EInvalidValue:
valu = 0
entry_fld.set_text($valu)
#signal_handler_unblock(entry_fld, chngd_txt_hndler)
#signal_emit_stop(entry_fld, signal_lookup("changed",TYPE_EDITABLE()),0)
thisCheckBtns()
proc thisCheckBtns =
set_sensitive(btn_inc, valu < 10) set_sensitive(btn_dec, valu > 0) set_sensitive(entry_fld, valu == 0)
discard signal_connect(window, "destroy",
SIGNAL_FUNC(thisDestroy), nil)
discard signal_connect(btn_quit, "clicked",
SIGNAL_FUNC(thisDestroy), nil)
discard signal_connect(btn_inc, "clicked",
SIGNAL_FUNC(thisInc), nil)
discard signal_connect(btn_dec, "clicked",
SIGNAL_FUNC(thisDec), nil)
chngd_txt_hndler = signal_connect(entry_fld, "changed",
SIGNAL_FUNC(thisTextChanged), nil)
show_all(window) thisCheckBtns() main()</lang>
<lang nim>import
iup, strutils, math
- assumes you have the iup .dll or .so installed
randomize() discard iup.open(nil,nil)
var lbl = Label("Value:")
setAttribute(lbl,"PADDING","2x2")
var valu = Text(nil) SetAtt(nil, valu, "PADDING", "2x2", "VALUE", "0", nil)
var txtBox = Hbox(lbl, valu, nil) SetAttribute(txtBox, "MARGIN", "10x10")
var incBtn = Button("+1", "") var decBtn = Button("-1", "") SetAttribute(incBtn,"RASTERSIZE","25x25") SetAttribute(decBtn,"RASTERSIZE","25x25") var btnBox = Vbox(incBtn, decBtn, nil) SetAttribute(btnBox, "MARGIN", "5x5")
proc toCB(fp: proc): ICallback =
return cast[ICallback](fp)
proc setValuState(value: int) =
if value == 0:
SetAttribute(valu, "ACTIVE", $(true))
else:
SetAttribute(valu, "ACTIVE", $(false))
proc setBtnsState(value: int) =
if value <= 0:
SetAttribute(decBtn,"ACTIVE", $(false))
SetAtt(nil, incBtn,"ACTIVE", $(true), "FOCUS", $(true), nil)
elif value >= 10:
SetAttribute(incBtn,"ACTIVE", $(false))
SetAtt(nil, decBtn,"ACTIVE", $(true), "FOCUS", $(true), nil)
else:
SetAttribute(decBtn,"ACTIVE", $(true))
SetAttribute(incBtn,"ACTIVE", $(true))
- Click handler for Click button
proc incClick(ih:PIhandle): cint {.cdecl.} =
var s: string = $(GetAttribute(valu,"VALUE"))
var x: int = 0
try:
x = 1 + parseInt(s)
except:
x = 1 # default to 1 if non-numeric entry
setAttribute(valu,"VALUE", $x)
setValuState(x)
setBtnsState(x)
return IUP_DEFAULT
- Click handler for Decrement button
proc decClick(ih:PIhandle): cint {.cdecl.} =
var s: string = $(GetAttribute(valu,"VALUE"))
var x: int = 0
try:
x = -1 + parseInt(s)
except:
x = 1 # default to 1 if non-numeric entry
setAttribute(valu,"VALUE", $x)
setValuState(x)
setBtnsState(x)
return IUP_DEFAULT
- Key handler to check for Esc pressed
proc key_cb(ih:PIhandle, c: cint):cint {.cdecl.} =
#echo c
if (c == Iup.K_esc) and (Iup.Alarm("Exit?", "Had enough?","Yes","Keep going",nil) == 1):
return IUP_CLOSE # Exit application
return IUP_CONTINUE
var contents = Hbox(txtBox, btnBox, nil) SetAttribute(contents, "MARGIN", "5x5")
discard setCallback(incBtn,"ACTION", toCB(incClick)) discard setCallback(decBtn,"ACTION", toCB(decClick)) discard setCallback(contents,"K_ANY", toCB(key_cb))
var dlg = Dialog(contents) SetAtt(nil, dlg, "TITLE","GUI Interaction", "SIZE","200x75", nil)
discard dlg.show() discard mainloop() iup.close()</lang>
Perl 6
Extremely basic implementation using the GTK library. <lang perl6>use GTK::Simple; use GTK::Simple::App;
my GTK::Simple::App $app .= new( title => 'Controls Enable / Disable' );
$app.set-content(
my $box = GTK::Simple::HBox.new(
my $inc = GTK::Simple::Button.new( label => ' + ' ),
my $value = GTK::Simple::Entry.new,
my $dec = GTK::Simple::Button.new( label => ' - ' )
)
);
$app.border-width = 10; $box.spacing = 10;
$value.changed.tap: {
$value.text.=subst(/\D/, ); $inc.sensitive = $value.text < 10; $dec.sensitive = $value.text > 0;
}
$value.text = '0';
$inc.clicked.tap: { my $val = $value.text; $val += 1; $value.text = $val.Str } $dec.clicked.tap: { my $val = $value.text; $val -= 1; $value.text = $val.Str }
$app.run;</lang>
Phix
Note: this validates each input char separately, and '-' is not "NUMBER": the only way to get numbers <0 or >9 into the input field is to paste them.
<lang Phix>include pGUI.e
Ihandle txt, inc, dec, hbx, vbx, dlg
function activate(integer v)
IupSetInt(txt,"VALUE",v) IupSetAttribute(inc,"ACTIVE",iff(v<10,"YES":"NO")) IupSetAttribute(dec,"ACTIVE",iff(v>0,"YES":"NO")) IupSetAttribute(txt,"ACTIVE",iff(v=0,"YES":"NO")) return IUP_CONTINUE
end function
function valuechanged_cb(Ihandle /*ih*/)
return activate(IupGetInt(txt,"VALUE"))
end function
function inc_cb(Ihandle /*ih*/)
return activate(IupGetInt(txt,"VALUE")+1)
end function
function dec_cb(Ihandle /*ih*/)
return activate(IupGetInt(txt,"VALUE")-1)
end function
function esc_close(Ihandle /*ih*/, atom c)
return iff(c=K_ESC?IUP_CLOSE:IUP_CONTINUE)
end function
IupOpen() txt = IupText("VALUECHANGED_CB",Icallback("valuechanged_cb"),"FILTER=NUMBER, EXPAND=YES") inc = IupButton("increment",Icallback("inc_cb")) dec = IupButton("decrement",Icallback("dec_cb"),"ACTIVE=NO") hbx = IupHbox({inc,dec},"MARGIN=0x10, GAP=20") vbx = IupVbox({txt,hbx},"MARGIN=40x20") dlg = IupDialog(vbx) IupSetCallback(dlg, "K_ANY", Icallback("esc_close")) IupShow(dlg) IupMainLoop() IupClose()</lang>
PicoLisp
The standard PicoLisp GUI is HTTP based. Connect your browser to http://localhost:8080 after starting the following script. <lang PicoLisp>#!/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)</lang>
Prolog
Works with SWI-Prolog and XPCE. <lang Prolog>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)).
</lang>
PureBasic
<lang 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</lang>
R
<lang 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) </lang>
Python
<lang Python>
- !/usr/bin/env python3
import tkinter as tk
class MyForm(tk.Frame):
def __init__(self, master=None):
tk.Frame.__init__(self, master)
self.pack(expand=True, fill="both", padx=10, pady=10)
self.master.title("Controls")
self.setupUI()
def setupUI(self):
self.value_entry = tk.Entry(self, justify=tk.CENTER)
self.value_entry.grid(row=0, column=0, columnspan=2,
padx=5, pady=5, sticky="nesw")
self.value_entry.insert('end', '0')
self.value_entry.bind("<KeyPress-Return>", self.eventHandler)
self.decre_btn = tk.Button(self, text="Decrement", state=tk.DISABLED)
self.decre_btn.grid(row=1, column=0, padx=5, pady=5)
self.decre_btn.bind("<Button-1>", self.eventHandler)
self.incre_btn = tk.Button(self, text="Increment")
self.incre_btn.grid(row=1, column=1, padx=5, pady=5)
self.incre_btn.bind("<Button-1>", self.eventHandler)
def eventHandler(self, event):
value = int(self.value_entry.get())
if event.widget == self.value_entry:
if value > 10:
self.value_entry.delete("0", "end")
self.value_entry.insert("end", "0")
elif value == 10:
self.value_entry.config(state=tk.DISABLED)
self.incre_btn.config(state=tk.DISABLED)
self.decre_btn.config(state=tk.NORMAL)
elif value == 0:
self.value_entry.config(state=tk.NORMAL)
self.incre_btn.config(state=tk.NORMAL)
self.decre_btn.config(state=tk.DISABLED)
elif (value > 0) and (value < 10):
self.value_entry.config(state=tk.DISABLED)
self.incre_btn.config(state=tk.NORMAL)
self.decre_btn.config(state=tk.NORMAL)
else:
if event.widget == self.incre_btn:
if (value >= 0) and (value < 10):
value += 1
self.value_entry.config(state=tk.NORMAL)
self.value_entry.delete("0", "end")
self.value_entry.insert("end", str(value))
if value > 0:
self.decre_btn.config(state=tk.NORMAL)
self.value_entry.config(state=tk.DISABLED)
if value == 10:
self.incre_btn.config(state=tk.DISABLED)
elif event.widget == self.decre_btn:
if (value > 0) and (value <= 10):
value -= 1
self.value_entry.config(state=tk.NORMAL)
self.value_entry.delete("0", "end")
self.value_entry.insert("end", str(value))
self.value_entry.config(state=tk.DISABLED)
if (value) < 10:
self.incre_btn.config(state=tk.NORMAL)
if (value) == 0:
self.decre_btn.config(state=tk.DISABLED)
self.value_entry.config(state=tk.NORMAL)
def main():
app = MyForm() app.mainloop()
if __name__ == "__main__":
main()
</lang>
Result: [1]
Racket
<lang 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) </lang>
Ring
<lang ring> Load "guilib.ring"
MyApp = New qApp {
num = 0
win1 = new qWidget() {
setwindowtitle("Hello World")
setGeometry(100,100,370,250)
btn1 = new qpushbutton(win1) {
setGeometry(50,200,100,30)
settext("Increment")
setclickevent("Increment()")}
btn2 = new qpushbutton(win1) {
setGeometry(200,200,100,30)
settext("Decrement")
setclickevent("Decrement()")}
lineedit1 = new qlineedit(win1) {
setGeometry(10,100,350,30)
settext("0")}
show()}
exec()}
func Increment
lineedit1{ num = text()}
num = string(number(num)+1)
lineedit1.settext(num)
if number(num)>9 btn1.setDisabled(True) ok
func Decrement
lineedit1{ num = text()}
num = string(number(num)-1)
lineedit1.settext(num)
if number(num)<0 btn2.setDisabled(True) ok
</lang>
Output:
Ruby
<lang 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</lang>
Scala
<lang Scala>import swing.{ BoxPanel, Button, GridPanel, Orientation, Swing, TextField } import swing.event.{ ButtonClicked, Key, KeyPressed, KeyTyped }
object Enabling extends swing.SimpleSwingApplication {
def top = new swing.MainFrame {
title = "Rosetta Code >>> Task: GUI enabling/disabling of controls | Language: Scala"
val numberField = new TextField {
text = "0" // start at 0
horizontalAlignment = swing.Alignment.Right
}
val (incButton, decButton) = (new Button("Increment"), // Two variables initialized
new Button("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 BoxPanel(Orientation.Vertical) { contents ++= List(numberField, buttonPanel) }
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 is a digit ...
Swing.onEDT(switching) // ensure GUI-updating
else kt.consume // ... eat the event (i.e. stop it from being processed)
case KeyPressed(_, kp, _, _) if (!specialKeys.contains(kp)) =>
Swing.onEDT(switching) // ensure GUI-updating
case ButtonClicked(`incButton`) =>
numberField.text = (numberField.text.toLong + 1).toString
switching
case ButtonClicked(`decButton`) =>
numberField.text = (numberField.text.toLong - 1).toString
switching
}
def switching = {
val n = (if (numberField.text.isEmpty()) "0" else numberField.text).toLong
numberField.text = n.toString
numberField.enabled = n == 0
incButton.enabled = n < 10
decButton.enabled = n > 0
}
centerOnScreen()
} // def top(
}</lang>
Smalltalk
<lang 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</lang>
Tcl
<lang 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</lang>
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.)
<lang vb>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</lang>
- Programming Tasks
- GUI
- ACL2/Omit
- Applesoft BASIC/Omit
- AWK/Omit
- Batch File/Omit
- Blast/Omit
- Brainf***/Omit
- Commodore BASIC/Omit
- GUISS/Omit
- Integer BASIC/Omit
- Lilypond/Omit
- Logtalk/Omit
- Lotus 123/Omit
- Maxima/Omit
- PARI/GP/Omit
- PostScript/Omit
- Retro/Omit
- SQL PL/Omit
- Ada
- GtkAda
- AutoHotkey
- BBC BASIC
- C
- C++
- C sharp
- Delphi
- Fantom
- FreeBASIC
- Gambas
- Unicon
- J
- Java
- JavaFX
- Julia
- Kotlin
- Liberty BASIC
- LiveCode
- Maple
- Mathematica
- NewLISP
- Nim
- Gtk2
- IUP
- Perl 6
- Phix
- PGUI
- PicoLisp
- Prolog
- PureBasic
- R
- Python
- Racket
- Ring
- Ruby
- Shoes
- Scala
- Smalltalk
- Tcl
- Tk
- Visual Basic