How to display a message window in the right bottom corner of the active display using Delphi

Question

These days you see a lot of software displaying message windows in the right bottom corner of the active screen for a few seconds or until a close button is clicked (f.i. Norton does this after it has checked a download).

I would like to do this using Delphi 7 (and if possible Delphi 2010, since I am slowly migrating my code to the latest version).

I found some posts here on SO regarding forms not receiving focus, but that's only one part of the problem. I'm thinking also on how to determine the exact position of this message window (knowing that f.i. a user may have put his taskbar to the right of the screen.

Thx in advance.

UPDATE 26 Jan, 10: Starting from the code of drorhan I created the following form (in Delphi 7) which works whether the taskbar is displayed at the bottom, the right, the left or the top of the schreen.

fPopupMessage.dpr:

  object frmPopupMessage: TfrmPopupMessage
    Left = 537
    Top = 233
    AlphaBlend = True
    AlphaBlendValue = 200
    BorderStyle = bsToolWindow
    Caption = 'frmPopupMessage'
    ClientHeight = 48
    ClientWidth = 342
    Color = clBtnFace
    Font.Charset = DEFAULT_CHARSET
    Font.Color = clWindowText
    Font.Height = -11
    Font.Name = 'MS Sans Serif'
    Font.Style = []
    OldCreateOrder = False
    OnClose = FormClose
    OnCreate = FormCreate
    DesignSize = (
      342
      48)
    PixelsPerInch = 96
    TextHeight = 13
    object img: TImage
      Left = 0
      Top = 0
      Width = 64
      Height = 48
      Align = alLeft
      Center = True
      Transparent = True
    end
    object lblMessage: TLabel
      Left = 72
      Top = 8
      Width = 265
      Height = 34
      Alignment = taCenter
      Anchors = [akLeft, akTop, akRight, akBottom]
      AutoSize = False
      Caption = '...'
      Font.Charset = DEFAULT_CHARSET
      Font.Color = clNavy
      Font.Height = -11
      Font.Name = 'Verdana'
      Font.Style = [fsBold]
      ParentFont = False
      Transparent = True
      WordWrap = True
    end
    object tmr: TTimer
      Enabled = False
      Interval = 3000
      OnTimer = tmrTimer
      Left = 16
      Top = 16
    end
  end

and

fPopupMessage.pas

  unit fPopupMessage;

  interface

  uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls, ExtCtrls, ImgList;

  type
    TfrmPopupMessage = class(TForm)
      tmr: TTimer;
      img: TImage;
      lblMessage: TLabel;
      procedure FormCreate(Sender: TObject);
      procedure tmrTimer(Sender: TObject);
      procedure FormClose(Sender: TObject; var Action: TCloseAction);
    private
      { Private declarations }
      bBeingDisplayed : boolean;
      function GetPopupMessage: string;
      procedure SetPopupMessage(const Value: string);
      function GetPopupCaption: string;
      procedure SetPopupCaption(const Value: string);
      function TaskBarHeight: integer;
      function TaskBarWidth: integer;
      procedure ToHiddenPosition;
      procedure ToVisiblePosition;
    public
      { Public declarations }
      procedure StartAnimationToHide;
      procedure StartAnimationToShow;
      property PopupCaption: string read GetPopupCaption write SetPopupCaption;
      property PopupMessage: string read GetPopupMessage write SetPopupMessage;
    end;

  var
    frmPopupMessage: TfrmPopupMessage;

  procedure DisplayPopup( sMessage:string; sCaption:string = '');

  implementation

  {$R *.dfm}

  const
     DFT_TIME_SLEEP = 5;       // the speed you want to show/hide.Increase/descrease this to make it faster or slower
     DFT_TIME_VISIBLE = 3000;  // number of mili-seconds the form is visible before starting to disappear
     GAP = 2;                  // pixels between form and right and bottom edge of the screen

  procedure DisplayPopup( sMessage:string; sCaption:string = '');
  begin
     // we could create the form here if necessary ...
     if not Assigned(frmPopupMessage) then Exit;

     frmPopupMessage.PopupCaption := sCaption;
     frmPopupMessage.PopupMessage := sMessage;
     if not frmPopupMessage.bBeingDisplayed
     then begin
        ShowWindow( frmPopupMessage.Handle, SW_SHOWNOACTIVATE);
        frmPopupMessage.Visible := True;
     end;
     frmPopupMessage.StartAnimationToShow;
  end;

  procedure TfrmPopupMessage.FormCreate(Sender: TObject);
  begin
    img.Picture.Assign(Application.Icon);
    Caption := '';
    lblMessage.Caption := '';
    bBeingDisplayed := False;

    ToHiddenPosition();
  end;

  procedure TfrmPopupMessage.FormClose(Sender: TObject; var Action: TCloseAction);
  begin
     tmr.Enabled := False;
     Action := caHide;
     bBeingDisplayed := False;
  end;

  function TfrmPopupMessage.TaskBarHeight: integer; // this is just to get the taskbar height to put
  // my form in the correct position
  var
    hTB: HWND;
    TBRect: TRect;
  begin
    hTB := FindWindow('Shell_TrayWnd', '');
    if hTB = 0 then
      Result := 0
    else
    begin
      GetWindowRect(hTB, TBRect);
      if TBRect.Top = 0  // tray bar is positioned to the left or to the right
      then
         Result := 1
      else
         Result := TBRect.Bottom - TBRect.Top;
    end;
  end;

  function TfrmPopupMessage.TaskBarWidth: integer; // this is just to get the taskbar height to put
  // my form in the correct position
  var
    hTB: HWND;
    TBRect: TRect;
  begin
    hTB := FindWindow('Shell_TrayWnd', '');
    if hTB = 0 then
      Result := 0
    else
    begin
      GetWindowRect(hTB, TBRect);
      if TBRect.Left = 0  // tray bar is positioned to the left or to the right
      then
         Result := 1
      else
         Result := TBRect.Right - TBRect.Left
    end;
  end;

  procedure TfrmPopupMessage.ToHiddenPosition;
  begin
    Self.Left := Screen.Width - TaskbarWidth - Self.Width - GAP;
    Self.Top := Screen.Height - TaskBarHeight;
  end;

  procedure TfrmPopupMessage.ToVisiblePosition;
  begin
    Self.Left := Screen.Width - TaskBarWidth - Self.Width - GAP;
    Self.Top := Screen.Height - Self.Height - TaskBarHeight - GAP;
  end;

  procedure TfrmPopupMessage.StartAnimationToShow;
  var
    i: integer;
  begin
    if bBeingDisplayed
    then
       ToVisiblePosition()
    else begin
       ToHiddenPosition();

       for i := 1 to Self.Height+GAP do
       begin
         Self.Top := Self.Top-1;
         Application.ProcessMessages;
         Sleep(DFT_TIME_SLEEP);
       end;
    end;
    tmr.Interval := DFT_TIME_VISIBLE;
    tmr.Enabled := True;
    bBeingDisplayed := True;

  end;

  procedure TfrmPopupMessage.StartAnimationToHide;
  var
    i: integer;
  begin
    if not bBeingDisplayed then Exit;

    for i := 1 to Self.Height+GAP do
    begin
      Self.Top := Self.Top+1;
      Application.ProcessMessages;
      Sleep(DFT_TIME_SLEEP);
    end;
    bBeingDisplayed := False;
    Visible := False;
  end;

  procedure TfrmPopupMessage.tmrTimer(Sender: TObject);
  begin
     tmr.Enabled := False;
     StartAnimationToHide();
  end;

  function TfrmPopupMessage.GetPopupMessage: string;
  begin
     Result := lblMessage.Caption;
  end;

  procedure TfrmPopupMessage.SetPopupMessage(const Value: string);
  begin
     lblMessage.Caption := Value;
  end;

  function TfrmPopupMessage.GetPopupCaption: string;
  begin
     Result := frmPopupMessage.Caption;
  end;

  procedure TfrmPopupMessage.SetPopupCaption(const Value: string);
  begin
     frmPopupMessage.Caption := Value;
  end;

  end.

To be used as in my test form with two buttons:

procedure TfrmMain.button1Click(Sender: TObject);
begin
   DisplayPopup('Message displayed at ' + FormatDateTime('ddd mmm yy zzz', Now),'My Program');
   beep;
end;

procedure TfrmMain.button2Click(Sender: TObject);
begin
   DisplayPopup('Another message displayed at ' + FormatDateTime('hh:nn zzz', Now),'My Program');
end;

The message form will display the application icon, but I will probably add a TImageList and add a property to pass an image index so I can display different icons. I will also use the TcxLabel from the Dev.Express components as this will provide verticle positionting, but the above unit can be used as is.

I tested this with Delphi 7 and Windows XP. If anyone uses this unit with another version of Delphi and/or Windows Vista or Windows 7, please tell me if this unit will work there too.

Answer 1

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
  function TaskBarHeight: integer; // this is just to get the taskbar height to put
  // my form in the correct position
  var
    hTB: HWND;
    TBRect: TRect;
  begin
    hTB := FindWindow('Shell_TrayWnd', '');
    if hTB = 0 then
      Result := 0
    else
    begin
      GetWindowRect(hTB, TBRect);
      Result := TBRect.Bottom - TBRect.Top;
    end;
  end;

begin
  Self.Left := Screen.Width - Self.Width;
  Self.Top := Screen.Height-Self.Height-TaskBarHeight;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  i: integer;
  TimeSleep: integer;
begin
  TimeSleep := 5; // the speed you want to show/hide.Increase/descrease this to make it faster or slower
  for i := 1 to Self.Height do
  begin
    Self.Top := Self.Top+1;
    Sleep(TimeSleep);
  end;
  // now let's show it again(use this as code as the show code)
  for i := 1 to Self.Height do
  begin
    Self.Top := Self.Top-1;
    Sleep(TimeSleep);
  end;
end;

end.

via http://www.experts-exchange.com/Programming/Languages/Pascal/Delphi/Q_25043483.html

Answer 2

Try using the TJvDesktopAlert component wich is included in the JVCL, you can find an example in jvcl\examples\JvDesktopAlert\JvDesktopAlertDemo.dpr

_{(source: agnisoft.com)}