Mega Code Archive
CheckEdit a special Editfield
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Title: CheckEdit - a special Editfield
Question: A few month ago, I need a TEdit, that corresponds with a Checkbox. If the Checkbox is checked the Editfield allowes input, otherwise it must be disabled.
Answer:
In fact I need a lot of those edits, so I made this little component. 8-)
While writing and using it, I added some more features: It can interact also with two radiobuttons, and it can chance the background color to show the user the enabled/disabled state.
Save the code to a file named CheckEdit.pas and compile it to a package of your choice. For more details about installing components refer to the online help.
Usage: Set the new editfield on a from and connect it with a checkbox or with up to two Radiobuttons in the object inspector. If you click the checkbox, the editfield enables and disables with the state of the checkbox.
unit CheckEdit;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls,
Forms, Dialogs, StdCtrls, ComCtrls, Buttons;
type TCheckEdit = Class (TEdit)
protected
f_check: TCheckBox;
f_radio1: TRadiobutton;
f_radio2: TRadiobutton;
f_color: TColor;
private
procedure Clicked (Sender: TObject);
procedure SetRadio1 (rb: TRadioButton);
procedure SetRadio2 (rb: TRadioButton);
procedure SetCheck (cb: TCheckBox);
published
constructor Create(AOwner: TComponent); OVERRIDE;
destructor Destroy; OVERRIDE;
property Checkbox: TCheckbox read f_check write SetCheck;
property RadioEnabled: TRadiobutton read f_radio1
write SetRadio1;
property RadioDisabled: TRadiobutton read f_radio2
write SetRadio2;
property BackColor: TColor read f_color write f_color;
procedure SetStatus;
end;
// property CheckBox = The Checkbox that is connected to the edit
// property RadioEnabled = Radiobutton that enable the edit
// property RadioDisabled = Radiobutton that disenable the edit
// property BackColor = Set the background color for disalbed
// state
// methode Setstatus = Set the status along with the
// checkbox/radios.
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Samples', [TCheckEdit]);
end;
constructor TCheckEdit.Create(AOwner: TComponent);
// Create the component
begin
f_color:= clBtnFace; // default color for disabled edit
inherited;
end;
destructor TCheckEdit.Destroy;
begin
inherited;
end;
procedure TCheckEdit.Clicked (Sender: TObject);
// Handles the OnClick event of the Checkbox or the Radiobuttons
var check: Boolean;
begin
if (Sender is TCheckBox) then
check:= (Sender as TCheckBox).Checked
else
check:= (Sender as TRadioButton).Checked;
if check then begin
Enabled:= TRUE; Color:= clWindow;
SetFocus; // Set Focus to the editfield
end else begin
Enabled:= FALSE; Color:= f_color;
end;
end;
procedure TCheckEdit.SetCheck (cb: TCheckbox);
// Set the Checkbox
begin
f_check:= cb;
if Assigned (cb) then cb.OnClick:= Clicked;
end;
procedure TCheckEdit.SetRadio1 (rb: TRadioButton);
// Set Radiobutton #1
begin
f_radio1:= rb;
if Assigned (rb) then rb.OnClick:= Clicked;
end;
procedure TCheckEdit.SetRadio2 (rb: TRadioButton);
// Set Radiobutton #2
begin
f_radio2:= rb;
if Assigned (rb) then rb.OnClick:= Clicked;
end;
procedure TCheckEdit.SetStatus;
// Set the whole status along the connected components
begin
if Assigned (f_check) then Clicked (f_check);
if Assigned (f_radio1) then Clicked (f_radio1);
if Assigned (f_radio2) then Clicked (f_radio2);
end;
end.
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