unit combform;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, ComCtrls, Menus, ExtCtrls;
type
TComboForm = class(TForm)
CbDrop: TComboBox;
CbDropList: TComboBox;
CbSimple: TComboBox;
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
MainMenu1: TMainMenu;
ComboStyle: TMenuItem;
CmSimple: TMenuItem;
CmDrop: TMenuItem;
CmDropList: TMenuItem;
Add1: TMenuItem;
CmAddString: TMenuItem;
CmAddStringAt: TMenuItem;
Search1: TMenuItem;
CmFindString: TMenuItem;
CmFindIndex: TMenuItem;
CmDelete: TMenuItem;
CmList: TMenuItem;
CmDelString: TMenuItem;
CmDelIndex: TMenuItem;
CmShowList: TMenuItem;
CmClear: TMenuItem;
N1: TMenuItem;
Label5: TLabel;
EdCursel: TEdit;
EdCuridx: TEdit;
EdCurlen: TEdit;
EdEdit: TEdit;
EdEditlen: TEdit;
CmSortList: TMenuItem;
Bevel1: TBevel;
procedure ComboStyleClick(Sender: TObject);
procedure CmSimpleClick(Sender: TObject);
procedure CmDropClick(Sender: TObject);
procedure CmDropListClick(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure ComboChange(Sender: TObject);
procedure CmClearClick(Sender: TObject);
procedure CmDelStringClick(Sender: TObject);
procedure CmDelIndexClick(Sender: TObject);
procedure CmFindStringClick(Sender: TObject);
procedure CmFindIndexClick(Sender: TObject);
procedure CmAddStringClick(Sender: TObject);
procedure CmAddStringAtClick(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure CmSortListClick(Sender: TObject);
procedure CmListClick(Sender: TObject);
procedure CmShowListClick(Sender: TObject);
private
{ Private declarations }
FCbActive: TComboBox;
procedure SetCbActive(cb: TComboBox);
procedure NewSelection;
procedure DeleteAt(idx: Integer);
procedure AddAt(idx: Integer; s: string);
procedure SelectAt(idx: Integer);
function FindString(s: string): Integer;
property CbActive: TComboBox read FCbActive
write SetCbActive;
public
{ Public declarations }
end;
var
ComboForm: TComboForm;
implementation
uses inptform;
{$R *.DFM}
// -------------- //
// event handlers //
// -------------- //
procedure TComboForm.FormCreate(Sender: TObject);
begin
FCbActive := CbSimple;
CbSimple.Visible := True;
CbDrop.Visible := False;
CbDropList.Visible := False;
NewSelection;
end;
// Control notifications
// ---------------------
//
// close form
//
procedure TComboForm.Button1Click(Sender: TObject);
begin
Close;
end;
procedure TComboForm.ComboChange(Sender: TObject);
begin
NewSelection;
end;
// ComboBox menu
// -------------
procedure TComboForm.ComboStyleClick(Sender: TObject);
begin
CmSimple.Checked := CbActive = CbSimple;
CmDrop.Checked := CbActive = CbDrop;
CmDropList.Checked := CbActive = CbDropList;
end;
procedure TComboForm.CmSimpleClick(Sender: TObject);
begin
CbActive := CbSimple;
end;
procedure TComboForm.CmDropClick(Sender: TObject);
begin
CbActive := CbDrop;
end;
procedure TComboForm.CmDropListClick(Sender: TObject);
begin
CbActive := CbDropList;
end;
// Add menu
// --------
procedure TComboForm.CmAddStringClick(Sender: TObject);
var
s: string;
begin
if InputForm.GetString('String to add:', s) then
AddAt(0, s);
end;
procedure TComboForm.CmAddStringAtClick(Sender: TObject);
var
i: Integer;
s: string;
begin
if InputForm.GetString('String to add:', s)
and InputForm.GetInteger('Index to insert at:', i) then
AddAt(i, s);
end;
// Find menu
// ---------
procedure TComboForm.CmFindStringClick(Sender: TObject);
var
s: string;
begin
if InputForm.GetString('String to select:', s) then
SelectAt(FindString(s));
end;
procedure TComboForm.CmFindIndexClick(Sender: TObject);
var
i: Integer;
begin
if InputForm.GetInteger('Index to select:', i) then
SelectAt(i);
end;
// Delete menu
// -----------
procedure TComboForm.CmDelStringClick(Sender: TObject);
var
s: string;
begin
if InputForm.GetString('String to delete:', s) then
DeleteAt(FindString(s));
end;
procedure TComboForm.CmDelIndexClick(Sender: TObject);
var
i: Integer;
begin
if InputForm.GetInteger('Index to delete:', i) then
DeleteAt(i);
end;
procedure TComboForm.CmClearClick(Sender: TObject);
begin
CbActive.Clear;
end;
// List menu
// ---------
procedure TComboForm.CmShowListClick(Sender: TObject);
begin
CbActive.DroppedDown := not CbActive.DroppedDown;
end;
procedure TComboForm.CmSortListClick(Sender: TObject);
begin
CbActive.Sorted := not CbActive.Sorted;
end;
procedure TComboForm.CmListClick(Sender: TObject);
begin
CmShowList.Enabled := CbActive <> CbSimple;
CmSortList.Checked := CbActive.Sorted;
end;
// --------------- //
// private methods //
// --------------- //
procedure TComboForm.NewSelection;
begin
if CbActive.ItemIndex = -1 then
EdCursel.Text := ''
else
EdCursel.Text := CbActive.Items[CbActive.ItemIndex];
EdCuridx.Text := IntToStr(CbActive.ItemIndex);
EdCurlen.Text := IntToStr(length(EdCursel.Text));
EdEdit.Text := CbActive.Text;
EdEditlen.Text := IntToStr(length(EdEdit.Text));
end;
procedure TComboForm.SetCbActive(cb: TComboBox);
begin
if FCbActive <> cb then
begin
FCbActive.Visible := False;
FCbActive := cb;
FCbActive.Visible := True;
NewSelection;
end;
end;
//
// Delete an item from the active combobox given its index.
// Ignores bogus indices.
//
procedure TComboForm.DeleteAt(idx: Integer);
begin
if idx >= 0 then
CbActive.Items.Delete(idx);
end;
//
// Add a string into the active combobox at the given index.
// If the index is too big, append the item, if too small,
// insert it at the top.
//
procedure TComboForm.AddAt(idx: Integer; s: string);
begin
if idx > CbActive.Items.Count then
CbActive.Items.Append(s)
else
begin
if idx < 0 then
idx := 0;
CbActive.Items.Insert(idx, s);
end;
end;
//
// Select an item in the active combobox given it's index.
// A bogus index will result in an exception.
procedure TComboForm.SelectAt(idx: Integer);
begin
CbActive.ItemIndex := idx;
NewSelection;
end;
//
// Find the index of an item in the combobox given a string.
// If the string does not exist, return -1.
//
function TComboForm.FindString(s: string): Integer;
var
i: Integer;
begin
i := 0;
while (i < CbActive.Items.Count) and (CbActive.Items <> s) do
inc(i);
Result := i;
end;
end.
