模拟Nokia手机输入的编辑框

{
功能：模拟Nokia手机的输入法控件，继承自TCustomEdit
作者：CoolSlob
支持：CoolSlob # 163.com 
最后更新：2004/12/11
}
unit NokiaEdit;

interface

uses
  SysUtils, Classes, Controls, StdCtrls, ExtCtrls, Dialogs;

type
  KeysetInt = -1..9; //-1表示发生错误

  TNokiaEdit = class(TCustomEdit)
  PRivate
    FInterval: Integer;
    FKeyset: TStrings;
    procedure SetKeyset(const Value: TStrings);
    function GetTimerEnabled: Boolean;
    procedure SetTimerEnabled(const Value: Boolean);
    function GetTextLength: Integer;
    { Private declarations }
  protected
    { Protected declarations }
    FTimer: TTimer;
    procedure OnTimer(Sender: TObject);virtual;
    property TimerEnabled: Boolean read GetTimerEnabled write SetTimerEnabled;
    procedure KeyPress(var Key: Char); override;
    function IndexByChar(const Key: Char): KeysetInt;
    function SearchNextChar(const Index: KeysetInt; Key: Char): Char;
    function SearchFirstChar(const Index: KeysetInt): Char;
    function EndOfChar(const Value: string): Char;
  public
    { Public declarations }
    constructor Create(AOwner: TComponent);override;
    destructor Destroy;override;

    property TextLength: Integer read GetTextLength;
  published
    { Published declarations }
    property MaxLength default 1;
    property Interval: Integer read FInterval write FInterval;
    property Keyset: TStrings read FKeyset write SetKeyset;
    property Font;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('CoolSlob', [TNokiaEdit]);
end;

{ TNokiaEdit }

constructor TNokiaEdit.Create(AOwner: TComponent);
begin
  inherited;
  FKeySet := TStringList.Create;
  FTimer := TTimer.Create(Self);
  FTimer.OnTimer := OnTimer;
end;

destructor TNokiaEdit.Destroy;
begin
  FKeySet.Free;
  FKeySet := nil;
  inherited;
end;

function TNokiaEdit.EndOfChar(const Value: string): Char;
begin
  if Value = '' then Result := #0
  else Result := Value[Length(Value)];
end;

function TNokiaEdit.GetTextLength: Integer;
begin
  Result := Length(Trim(Text));
end;

function TNokiaEdit.GetTimerEnabled: Boolean;
begin
  Result := FTimer.Enabled;
end;

function TNokiaEdit.IndexByChar(const Key: Char): KeysetInt;
//
var
  I: Integer;
begin
  Result := -1;
  if not Assigned(FKeyset) then Exit;
  for I := 0 to FKeyset.Count - 1 do
  begin
    if Pos(Key, FKeyset.Strings[I]) > 0 then
    begin
      Result := I;
      Break;
    end;
  end;
end;

procedure TNokiaEdit.KeyPress(var Key: Char);
var
  CurIndex, NewIndex: KeysetInt;
  S: string;
  CurChar: Char;
  Selected: Boolean;
begin
  inherited;
  if Key in ['0'..'9'] then
  begin
    FTimer.Enabled := False; 
    if TextLength = 0 then CurIndex := -1
    else CurIndex := IndexByChar(Text[Length(Text)]);
    NewIndex := Ord(Key) - 48;
    if CurIndex = NewIndex then
    begin
      CurChar := EndOfChar(Text);
      S := Text;
      Selected := WordBool(SelLength);
      Delete(S, SelStart + 1, SelLength);
      Text := S;
      if (not Selected)or(CurChar='') then Text := Text + SearchFirstChar(CurIndex)
      else Text := Text + SearchNextChar(CurIndex, CurChar);
    end
    else
      Text := Text + SearchFirstChar(NewIndex);

    SelStart := Length(Text) - 1;
    SelLength := 1;
    FTimer.Enabled := True;
    Key := #0;
  end;
end;

procedure TNokiaEdit.OnTimer(Sender: TObject);
begin
  SelLength := 0;
  SelStart := Length(Text);
  FTimer.Enabled := False;
end;

function TNokiaEdit.SearchFirstChar(const Index: KeysetInt): Char;
var
  S: string;
begin
  Result := #0;
  S := FKeyset.Strings[Index];
  if S <> '' then Result := S[1];
end;

function TNokiaEdit.SearchNextChar(const Index: KeysetInt;
  Key: Char): Char;
var
  I: Integer;
  S: string;
begin
  S := FKeyset.Strings[Index];
  I := Pos(Key, S);
  if I = Length(S) then I := 1
  else I := I + 1;
  Result := S[I];
end;

procedure TNokiaEdit.SetKeyset(const Value: TStrings);
begin
  if Assigned(FKeyset) then FKeySet.Assign(Value)
  else FKeyset := Value;
end;

procedure TNokiaEdit.SetTimerEnabled(const Value: Boolean);
begin
  if FTimer.Enabled <> Value then
    FTimer.Enabled := Value;        
end;

end.