Delphi Magazine Collection 2001/Delphi Magazine Collection 20001 (2001).iso/DISKS/ISSUE02/TPACK/TPACK.ZIP/WORKING.PAS

Pascal/Delphi Source File | 1995-06-01 | 8.8 KB | 282 lines

{------------------------------------------------------------------------------}
{UNREGISTERED VERSION (6/1/95) PLEASE REDISTRIBUTE IN tPACK.ZIP!
 This revision does not contain everything, nor are the exciting
 DataSetReporter and ExtendedMenu[Item] components included.
 Use SWREG#5906 to receive these, icons and a help file for $130.
 You must register when using this code in a business application!
 You'll receive a license to use this code in up to 50 copies of
 any app you write. In turn you will get responsive e-mail
 tech support and enhancements till I run out of registrations
 or suggestions. Meanwhile.. enjoy the code. Bye! I'll make more.
 {(C)'1995 Michael/Ax-Systems, 71560,[e-mail]}
{------------------------------------------------------------------------------}

unit Working;

interface

uses
  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, StdCtrls, Buttons,
  OkCore, PasUtils, MiscComp, ExtCtrls;

type
{------------------------------------------------------------------------------}
{TOkBoxForm defines the look the generic OkBox. Change this form or modify the
look at runtime via TOk.OnActivate; Take care to keep the default events!
attached to FormClose and ButtonClick; The Defaults are implemented at the end.}

  TWorkingMsgFormStop   = procedure(Sender: TObject;Var CanStop:Boolean) of object;

  TWorkingForm = class(TDemoForm)
    StopLabel: TLabel;
    StopButton: TBitBtn;
    procedure StopButtonClick(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanStop: Boolean);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  protected
    { Protected declarations }
    fOkClose: Boolean;
    fOnOkStop: TWorkingMsgFormStop;
  public
    { Public declarations }
    property OkClose:Boolean read fOkClose write fOkClose;
    property OnOkStop: TWorkingMsgFormStop read fOnOkStop write fOnOkStop;
  published
    { Published declarations }
  end;

{------------------------------------------------------------------------------}

  TOkFormActivate = procedure(StopForm:TForm;StopLabel:TLabel;StopButton:TButton) of object;

  TWorkingMsg = class(TOk)
    Form:  TWorkingForm;
  private
    { Private declarations }
    fVisible:        Boolean;
    fOnFormActivate: TOkFormActivate;  {used to setup form.}
  protected
    { Protected declarations }
    function BusyCount(Add:ShortInt):Integer;
    procedure   SetActive(Flag:Boolean);             override;
    procedure   SetVisible(Flag:Boolean);            Virtual;
    procedure   DoOkStart(Var CanStart:Boolean);     override;
    function    FreezeFormHandle:HWND;               override;
    procedure   SetCritical(Flag:Boolean);           override;
  public
    { Public declarations }
    constructor Create(AOwner:TComponent);           override;
    procedure   Reset;                               virtual;
    procedure   OkStopHandler(Sender:TObject;Var CanStop:Boolean);

    function IsNotBusy:Boolean;
    procedure BusyReset;
    procedure BusyOn;
    procedure BusyMsg(const Text:String);
    procedure BusyOff;

  published
    { Published declarations }
    property Visible:     Boolean      read fVisible    write SetVisible default true;
    property OnFormActivate: TOkFormActivate read fOnFormActivate write fOnFormActivate;
  end;

{------------------------------------------------------------------------------}

implementation

{$R *.DFM}

{------------------------------------------------------------------------------}
{TOkBoxUForm.  *Here* is the OkBox Form code which defines ESSENTIAL events.
You can completely redefine the Form via Ok.OnActivate; Below are the
things that have to happen on the Form and CancelButton}

procedure TWorkingForm.StopButtonClick(Sender: TObject);
begin
  If Assigned(fOnOkStop) then   {if a OnOkStop proc is defined, allow closing.}
    fOnOkStop(Sender,fOkClose);
end;

procedure TWorkingForm.FormCloseQuery(Sender: TObject; var CanStop: Boolean);
begin
  StopButtonClick(Sender);
  CanStop:=fOkClose;      {Form Property can be reset via fOnOkStop proc}
end;

procedure TWorkingForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
 { Action:=caFree;}   {can't free all the time; keep one instance up to reset.}
end;

{------------------------------------------------------------------------------}

constructor TWorkingMsg.Create(AOwner:TComponent);
begin
  inherited create(AOwner);
  fVisible:=true;
end;

procedure TWorkingMsg.SetVisible(Flag:Boolean);
{must be much stronger on memory issues?
  just not call activate if not visible!}
begin
  if flag<>fVisible then begin
    fVisible:=Flag;
    if assigned(Form) then
      Form.Visible:=Flag;
    end;
end;

procedure TWorkingMsg.SetActive(Flag:Boolean);
begin
  if Enabled and Flag<>Active then begin
    inherited SetActive(Flag);
    if not Active and assigned(Form) then  {do we have one?}
      Form.hide{Close};
    end;
end;

procedure TWorkingMsg.SetCritical(Flag:Boolean);
{OkTry can not be stopped when in a critical section}
var
  l:boolean;
begin
  if flag<>Critical then begin
    inherited SetCritical(Flag);
    if assigned(Form) then
      Form.StopButton.Enabled:=not Critical;
    end;
end;

procedure TWorkingMsg.DoOkStart(Var CanStart:Boolean);
begin
  Inherited DoOkStart(CanStart);
  if CanStart then begin
    Application.CreateForm(TWorkingForm,Form);
    Form.OnOkStop:=OkStopHandler;
    Form.OkClose:=True;
    if assigned(fOnFormActivate) then
      fOnFormActivate(tForm(Form),Form.StopLabel,Form.StopButton);
    if fVisible then begin
      Form.Show;
      Form.Update;
      end;
    end;
end;

function TWorkingMsg.FreezeFormHandle:HWND;
begin
  result:=Form.Handle;
end;

procedure TWorkingMsg.OkStopHandler(Sender:TObject;Var CanStop:Boolean);
begin
  if Critical then                {can not exit in a critical section!}
    CanStop:=False               {let the user beware!}
  else begin
    Active:=False;  {try to turn off.. ancestor will now call user's CanCanel proc}
    CanStop:=Stop; {if that proc concurs, we allow the OkBoxform to close}
     {That's all. The Active Flag has already been set to false when we return}
    end;
end;

procedure TWorkingMsg.Reset;
var                            {not done}
  OrgOnOkStop: TOkOnOkStop;
  OrgOkClose:  Boolean;
{unconditional deactivate. very useful while setting up OkTryes. put a call
on a button somewhere to allow you to break out of things regardless of what you
coded! very helpful during development (to me anyway) it is not used inside here}
begin
  inherited Reset;
  if assigned(Form) then  {do we have one?}
    with Form do begin     {begin manual override <g>}
      OnOkStop:=nil;            {no denying the exit this time}
      OkClose:=True;          {manually allow Close-- that'll set the vars.}
      end;
  Active:=False;
  if assigned(Form) then begin
    Form.Free;
    Form:=nil;
    end;
end;



{------------------------------------------------------------------------------}
{ BUSY..                                                                       }
{------------------------------------------------------------------------------}
{the following is a set of procs to manage telling the user that we're busy.}
{in order to implement this well, we're tracking how often the box has been turned
on and off, placing it and removing it as needed.}


{this is a little out of context and would/could cause trouble when exceptions occour}


function TWorkingMsg.BusyCount(Add:ShortInt):Integer;
{keep track of how often we've been turned on.}
{parameters used to combine get/set}
const
  Count:Integer=0;
  c:TCursor=crDefault;
begin
  Count:=Count+Add;
  if Count<=0 then begin
    Count:=0;
    Screen.Cursor:=c;
    end
  else
    if Count=Add then begin {just turned on}
      c:=Screen.Cursor;
      Screen.Cursor:=crHourGlass;
      end;
  Result:=Count;
end;

function TWorkingMsg.IsNotBusy:Boolean;
{inquire about the box status and syncronize the counter if it's off}
begin
  Result:=Stop;
  if Result then
    if BusyCount(0)>0 then
      BusyCount(-BusyCount(0));
end;

procedure TWorkingMsg.BusyOn;
{Turn it on anyway!! (resetting the box) and up the counter}
begin
  OkOn;
  BusyCount(1);
end;

procedure TWorkingMsg.BusyMsg(const Text:String);
{could stall! this is why this functionality belongs into StopBox! and TOK!}
begin
  Form.StopLabel.Caption:=Text;
end;

procedure TWorkingMsg.BusyOff;
{turn off only when we're counting back to 0 and it's on in the second place}
begin
  if BusyCount(0)=1 then
    if not IsNotBusy then
      OkOff;
  BusyCount(-1);
end;

procedure TWorkingMsg.BusyReset;
begin
  if BusyCount(0)>0 then
    BusyCount(-BusyCount(0));
  BusyOff;
end;



end.