fmpower.pas

Delphi的另一款钢琴软件

(*====================================================================*
 | Unit fmPower - fmPower.pas                                       |
 |                                                                    |
 | Abstract base class for Power Sequencer Plus v3.0 active track     |
 | forms.                                                             |
 |                                                                    |
 | The main form maintains a list of active forms and sends them      |
 | notification messages.                                             |
 |                                                                    |
 | Active forms have an 'Animate' button, which turns on/off their    |
 | 'Active' property.                                                 |
 |                                                                    |
 | The Notify method is abstract and must be overriden.               |
 |                                                                    |
 | Copyright (c) Colin Wilson 1996.  All rights reserved              |
 |                                                                    |
 | Version  Date      By    Description                               |
 | -------  --------  ----  ------------------------------------------|
 | 1.0       02/11/96 CPWW  Original                                  |
 | 1.1       04/07/97 CPWW
 *--------------------------------------------------------------------*)
unit fmPower;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  Buttons, ExtCtrls;

type
  TActiveFormNotify = (        // Notification message types received from parent.
    ntFullUpdate,              // Redraw entire form.
    ntPositionUpdate           // Update form based on new position.
  );

  TPowerForm = class(TForm)
    bvlTopMargin: TBevel;      // 'Top Margin' bevel.
    btnAnimate: TSpeedButton;  // 'Animate' button

    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormShow(Sender: TObject);
    procedure btnAnimateClick(Sender: TObject);
    procedure FormResize(Sender: TObject);
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
  private
    fActive : boolean;
    procedure SetActive (value : boolean); virtual;
    procedure AdjustHeader;
    { Private declarations }
  protected
  public
    constructor Create (Owner : TComponent); override;
    procedure CopyToClipboard; virtual;
    procedure CutToClipboard; virtual;
    procedure DeleteToClipboard; virtual;
    procedure PasteFromClipboard; virtual;
    procedure Notify (tp : TActiveFormNotify); virtual; abstract;
    property Active : boolean read fActive write SetActive;
    procedure SetCaption (formName : string; trackNo : Integer);
    { Public declarations }
  end;

var
  PowerForm: TPowerForm;

implementation

uses Globals, ClipBrd, fmMainForm;

{$R *.DFM}

(*--------------------------------------------------------------------*
 | constructor TActiveForm.Create                                     |
 |                                                                    |
 | Create the form. Set the initial 'Active' value.                   |
 |                                                                    |
 | Parameters                                                         |
 |   Owner : TComponent           The form's owner - the main form    |
 *--------------------------------------------------------------------*)
constructor TPowerForm.Create (Owner : TComponent);
begin
  inherited Create (Owner);
  Active := AutoSynchronize;
end;

(*--------------------------------------------------------------------*
 | procedure TActiveForm.SetCaption                                   |
 |                                                                    |
 | Sets the form's caption, displaying the current track info.        |
 |                                                                    |
 | Parameters                                                         |
 |   formName : string         The form type name - eg. Note Editor   |
 |   trackNo : Integer         The track number to display.           |
 *--------------------------------------------------------------------*)
procedure TPowerForm.SetCaption (formName : string; trackNo : Integer);
var st : string;
begin
  if trackNo = 0 then
    st := 'Control - '
  else
    if trackNo < MainForm.MidiData.NoTracks then
      st := MainForm.MidiData.Tracks [trackNo].TrackName + ' - ';

  st := st + Format ('Track %d - %s', [trackNo, formName]);
  Caption := st
end;

(*--------------------------------------------------------------------*
 | procedure TActiveForm.AdjustHeader                                 |
 |                                                                    |
 | Adjust the form's heade to reposition the 'animate' button at the  |
 | far right of the screen.                                           |
 *--------------------------------------------------------------------*)
procedure TPowerForm.AdjustHeader;
begin
  btnAnimate.Left := ClientWidth - btnAnimate.Width - 2;
end;

(*--------------------------------------------------------------------*
 | procedure TActiveForm.FormClose                                    |
 |                                                                    |
 | OnClose method for active forms.  Remove the form from the Main    |
 | Form's active form list, and set the (modeless) form to auto-free. |
 *--------------------------------------------------------------------*)
procedure TPowerForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  MainForm.DeleteActiveForm (self);
  Action := caFree
end;

(*--------------------------------------------------------------------*
 | procedure TActiveForm.FormShow                                     |
 |                                                                    |
 | OnShow method for active form.  Add the form to the Main Form's    |
 | active form list.                                                  |
 |                                                                    |
 | Parameters                                                         |
 |   Sender : TObject         The main form.                          |
 *--------------------------------------------------------------------*)
procedure TPowerForm.FormShow(Sender: TObject);
begin
                                       // Set 'animate' button state
  btnAnimate.Down := AutoSynchronize;
  AdjustHeader;                        // Position the 'animate' button
  MainForm.AddActiveForm (self)        // Add to main form's active list
end;

(*--------------------------------------------------------------------*
 | TActiveForm.SetActive                                              |
 |                                                                    |
 | Helper function for 'Active' property.                             |
 |                                                                    |
 | Parameters                                                         |
 |   value : boolean            The new value to set                  |
 *--------------------------------------------------------------------*)
procedure TPowerForm.SetActive (value : boolean);
begin
  if value <> fActive then
  begin
    fActive := value;
    if fActive then              // Redraw the screen to relect the current
      Notify (ntPositionUpdate); // position
  end
end;

(*--------------------------------------------------------------------*
 | procedure TActiveForm.btnAnimateClick                              |
 |                                                                    |
 | Update the 'active' property to relect the (new) state of the      |
 | 'animate' button.                                                  |
 *--------------------------------------------------------------------*)
procedure TPowerForm.btnAnimateClick(Sender: TObject);
begin
  Active := btnAnimate.Down
end;

(*--------------------------------------------------------------------*
 | procedure TActiveForm.FormResize                                   |
 |                                                                    |
 | Adjust the header to update the position of the 'animate' button   |
 | when the form resizes                                              |
 *--------------------------------------------------------------------*)
procedure TPowerForm.FormResize(Sender: TObject);
begin
 AdjustHeader;
end;

procedure TPowerForm.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  MainForm.FormKeyDown (sender, key, shift);
end;

procedure TPowerForm.CopyToClipboard;
begin
  with MainForm, MidiData.Tracks [CurrentTrackNo] do
    CopyToClipboard (selStartPos, selEndPos);
end;

procedure TPowerForm.CutToClipboard;
begin
  with MainForm, MidiData.Tracks [CurrentTrackNo] do
    CutToClipboard (selStartPos, selEndPos);
end;

procedure TPowerForm.PasteFromClipboard;
begin
  with MainForm, MidiData.Tracks [CurrentTrackNo] do
    PasteFromClipboard (CurrentPosition);
end;

procedure TPowerForm.DeleteToClipboard;
begin
  with MainForm, MidiData.Tracks [CurrentTrackNo] do
    DeleteToClipboard (selStartPos, selEndPos);
end;

end.