{*******************************************************}
{                                                       }
{         Delphi VCL Extensions (RX)                    }
{                                                       }
{         Copyright (c) 2001,2002 SGB Software          }
{         Copyright (c) 1997, 1998 Fedor Koshevnikov,   }
{                        Igor Pavluk and Serge Korolev  }
{                                                       }
{*******************************************************}
unit GIFCtrl;

interface

{$I RX.INC}

uses Messages, {$IFDEF WIN32} Windows, {$ELSE} WinTypes, WinProcs, {$ENDIF}
  SysUtils, Classes, Graphics, Controls, Forms, StdCtrls, Menus, ExtCtrls,
  Animate, RxGIF, RxTimer;

type

{ TRxGIFAnimator }

  TRxGIFAnimator = class(TRxImageControl)
  private
    FAnimate: Boolean;
    FImage: TGIFImage;
    FTimer: TRxTimer;
    FFrameIndex: Integer;
    FStretch: Boolean;
    FLoop: Boolean;
    FCenter: Boolean;
    FTransparent: Boolean;
    FTimerRepaint: Boolean;
    FCache: TBitmap;
    FCacheIndex: Integer;
    FTransColor: TColor;
{$IFDEF RX_D3}
    FAsyncDrawing: Boolean;
{$ENDIF}
{$IFNDEF RX_D4}
    FAutoSize: Boolean;
{$ENDIF}
    FOnStart: TNotifyEvent;
    FOnStop: TNotifyEvent;
    FOnChange: TNotifyEvent;
    FOnFrameChanged: TNotifyEvent;
    procedure TimerDeactivate;
    function GetFrameBitmap(Index: Integer; var TransColor: TColor): TBitmap;
    function GetDelayTime(Index: Integer): Cardinal;
{$IFNDEF RX_D4}
    procedure SetAutoSize(Value: Boolean);
{$ENDIF}
{$IFDEF RX_D3}
    procedure SetAsyncDrawing(Value: Boolean);
{$ENDIF}
    procedure SetAnimate(Value: Boolean);
    procedure SetCenter(Value: Boolean);
    procedure SetImage(Value: TGIFImage);
    procedure SetFrameIndex(Value: Integer);
    procedure SetStretch(Value: Boolean);
    procedure SetTransparent(Value: Boolean);
    procedure ImageChanged(Sender: TObject);
    procedure TimerExpired(Sender: TObject);
    procedure WMSize(var Message: TWMSize); message WM_SIZE;
  protected
{$IFDEF RX_D4}
    function CanAutoSize(var NewWidth, NewHeight: Integer): Boolean; override;
{$ENDIF}
    function GetPalette: HPALETTE; override;
    procedure AdjustSize; override;
    procedure Paint; override;
    procedure DoPaintImage; override;
    procedure Change; dynamic;
    procedure FrameChanged; dynamic;
    procedure Start; dynamic;
    procedure Stop; dynamic;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  published
{$IFDEF RX_D3}
    property AsyncDrawing: Boolean read FAsyncDrawing write SetAsyncDrawing default False;
{$ENDIF}
    property Animate: Boolean read FAnimate write SetAnimate default False;
{$IFDEF RX_D4}
    property AutoSize default True;
{$ELSE}
    property AutoSize: Boolean read FAutoSize write SetAutoSize default True;
{$ENDIF}
    property Center: Boolean read FCenter write SetCenter default False;
    property FrameIndex: Integer read FFrameIndex write SetFrameIndex default 0;
    property Image: TGIFImage read FImage write SetImage;
    property Loop: Boolean read FLoop write FLoop default True;
    property Stretch: Boolean read FStretch write SetStretch default False;
    property Transparent: Boolean read FTransparent write SetTransparent default True;
{$IFDEF RX_D4}
    property Anchors;
    property Constraints;
    property DragKind;
{$ENDIF}
    property Align;
    property Cursor;
    property DragCursor;
    property DragMode;
    property Enabled;
    property ParentShowHint;
    property PopupMenu;
    property ShowHint;
    property Visible;
    property OnChange: TNotifyEvent read FOnChange write FOnChange;
    property OnFrameChanged: TNotifyEvent read FOnFrameChanged write FOnFrameChanged;
    property OnStart: TNotifyEvent read FOnStart write FOnStart;
    property OnStop: TNotifyEvent read FOnStop write FOnStop;
    property OnClick;
    property OnDblClick;
    property OnDragOver;
    property OnDragDrop;
    property OnEndDrag;
    property OnMouseMove;
    property OnMouseDown;
    property OnMouseUp;
{$IFDEF RX_D5}
    property OnContextPopup;
{$ENDIF}
{$IFDEF WIN32}
    property OnStartDrag;
{$ENDIF}
{$IFDEF RX_D4}
    property OnEndDock;
    property OnStartDock;
{$ENDIF}
  end;

implementation

uses VCLUtils, MaxMin, RxGraph;

{ Maximum delay (10 sec) guarantees that a very long and slow
  GIF does not hang the system }
const
  MaxDelayTime = 10000;
{$IFDEF WIN32}
  MinDelayTime = 50;
{$ELSE}
  MinDelayTime = 1;
{$ENDIF}

{ TRxGIFAnimator }

constructor TRxGIFAnimator.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  FTimer := TRxTimer.Create(Self);
  AutoSize := True;
  FImage := TGIFImage.Create;
  FGraphic := FImage;
  FImage.OnChange := ImageChanged;
  FCacheIndex := -1;
  FTransColor := clNone;
  FLoop := True;
  FTransparent := True;
end;

destructor TRxGIFAnimator.Destroy;
begin
  Destroying;
  FOnStart := nil;
  FOnStop := nil;
  FOnChange := nil;
  FOnFrameChanged := nil;
  Animate := False;
  FCache.Free;
  FImage.OnChange := nil;
  FImage.Free;
  inherited Destroy;
end;

procedure TRxGIFAnimator.AdjustSize;
begin
  if not (csReading in ComponentState) then begin
    if AutoSize and Assigned(FImage) and not FImage.Empty then
      SetBounds(Left, Top, FImage.ScreenWidth, FImage.ScreenHeight);
  end;
end;

{$IFDEF RX_D4}
function TRxGIFAnimator.CanAutoSize(var NewWidth, NewHeight: Integer): Boolean;
begin
  Result := True;
  if not (csDesigning in ComponentState) and Assigned(FImage) and
    not FImage.Empty then
  begin
    if Align in [alNone, alLeft, alRight] then
      NewWidth := FImage.ScreenWidth;
    if Align in [alNone, alTop, alBottom] then
      NewHeight := FImage.ScreenHeight;
  end;
end;
{$ENDIF}

function TRxGIFAnimator.GetDelayTime(Index: Integer): Cardinal;
begin
  if (FFrameIndex >= 0) and (FFrameIndex < FImage.Count) and
    (FImage.Count > 1) then
  begin
    Result := FImage.Frames[FFrameIndex].AnimateInterval;
    if Result < MinDelayTime then Result := MinDelayTime
    else if Result > MaxDelayTime then Result := MaxDelayTime;
  end
  else Result := 0;
end;

function TRxGIFAnimator.GetFrameBitmap(Index: Integer;
  var TransColor: TColor): TBitmap;
var
  I, Last, First: Integer;
  SavePal: HPalette;
  UseCache: Boolean;
begin
  Index := Min(Index, FImage.Count - 1);
  UseCache := (FCache <> nil) and (FCacheIndex = Index - 1) and (FCacheIndex >= 0) and
    (FImage.Frames[FCacheIndex].DisposalMethod <> dmRestorePrevious);
  if UseCache then begin
    Result := FCache;
    TransColor := FTransColor;
  end
  else begin
    FCache.Free;
    FCache := nil;
    Result := TBitmap.Create;
  end;
{$IFDEF RX_D3}
  Result.Canvas.Lock;
{$ENDIF}
  try
    with Result do begin
      if not UseCache then begin
        Width := FImage.ScreenWidth;
        Height := FImage.ScreenHeight;
      end;
      Last := Index;
      First := Max(0, Last);
      SavePal := 0;
      if FImage.Palette <> 0 then begin
        SavePal := SelectPalette(Canvas.Handle, FImage.Palette, False);
        RealizePalette(Canvas.Handle);
      end;
      if not UseCache then begin
        if (FImage.Frames[FImage.FrameIndex].TransparentColor <> clNone) then
        begin
          TransColor := GetNearestColor(Canvas.Handle,
            ColorToRGB(FImage.Frames[FImage.FrameIndex].TransparentColor));
          Canvas.Brush.Color := PaletteColor(TransColor);
        end
        else if (FImage.BackgroundColor <> clNone) and FImage.Transparent then
          Canvas.Brush.Color := PaletteColor(FImage.BackgroundColor)
        else Canvas.Brush.Color := PaletteColor(clWindow);
        Canvas.FillRect(Bounds(0, 0, Width, Height));
        while First > 0 do begin
          if (FImage.ScreenWidth = FImage.Frames[First].Width) and
            (FImage.ScreenHeight = FImage.Frames[First].Height) then
          begin
            if (FImage.Frames[First].TransparentColor = clNone) or
              ((FImage.Frames[First].DisposalMethod = dmRestoreBackground) and
              (First < Last)) then Break;
          end;
          Dec(First);
        end;
        for I := First to Last - 1 do begin
          with FImage.Frames[I] do
            case DisposalMethod of
              dmUndefined, dmLeave:
                Draw(Canvas, Bounds(Origin.X, Origin.Y, Width, Height), True);
              dmRestoreBackground:
                if I > First then
                  Canvas.FillRect(Bounds(Origin.X, Origin.Y, Width, Height));
              dmRestorePrevious:
                begin { do nothing } end;
            end;
        end;
      end
      else begin
        with FImage.Frames[FCacheIndex] do
          if DisposalMethod = dmRestoreBackground then
            Canvas.FillRect(Bounds(Origin.X, Origin.Y, Width, Height));
      end; { UseCache }
      with FImage.Frames[Last] do
        Draw(Canvas, Bounds(Origin.X, Origin.Y, Width, Height), True);
{$IFDEF RX_D3}
      if (not UseCache) and (TransColor <> clNone) and FTransparent then
      begin
        TransparentColor := PaletteColor(TransColor);
        Transparent := True;
      end;
{$ENDIF}
      if FImage.Palette <> 0 then
        SelectPalette(Canvas.Handle, SavePal, False);
    end;
    FCache := Result;
    FCacheIndex := Index;
    FTransColor := TransColor;
{$IFDEF RX_D3}
    Result.Canvas.Unlock;
{$ENDIF}
  except
{$IFDEF RX_D3}
    Result.Canvas.Unlock;
{$ENDIF}
    if not UseCache then Result.Free;
    raise;
  end;
end;

function TRxGIFAnimator.GetPalette: HPALETTE;
begin
  Result := 0;
  if not FImage.Empty then Result := FImage.Palette;
end;

procedure TRxGIFAnimator.ImageChanged(Sender: TObject);
begin
  Lock;
  try
    FCacheIndex := -1;
    FCache.Free;
    FCache := nil;
    FTransColor := clNone;
    FFrameIndex := FImage.FrameIndex;
    if (FFrameIndex >= 0) and (FImage.Count > 0) then
      FTimer.Interval := GetDelayTime(FFrameIndex);
  finally
    Unlock;
  end;
  PictureChanged;
  Change;
end;

procedure TRxGIFAnimator.SetImage(Value: TGIFImage);
begin
  Lock;
  try
    FImage.Assign(Value);
  finally
    Unlock;
  end;
end;

procedure TRxGIFAnimator.SetCenter(Value: Boolean);
begin
  if Value <> FCenter then begin
    Lock;
    try
      FCenter := Value;
    finally
      Unlock;
    end;
    PictureChanged;
    if Animate then Repaint;
  end;
end;

procedure TRxGIFAnimator.SetStretch(Value: Boolean);
begin
  if Value <> FStretch then begin
    Lock;
    try
      FStretch := Value;
    finally
      Unlock;
    end;
    PictureChanged;
    if Animate then Repaint;
  end;
end;

procedure TRxGIFAnimator.SetTransparent(Value: Boolean);
begin
  if Value <> FTransparent then begin
    Lock;
    try
      FTransparent := Value;
    finally
      Unlock;
    end;
    PictureChanged;
    if Animate then Repaint;
  end;
end;

procedure TRxGIFAnimator.SetFrameIndex(Value: Integer);
begin
  if Value <> FFrameIndex then begin
    if (Value < FImage.Count) and (Value >= 0) then begin
      Lock;
      try
        FFrameIndex := Value;
        if (FFrameIndex >= 0) and (FImage.Count > 0) then
          FTimer.Interval := GetDelayTime(FFrameIndex);
      finally
        Unlock;
      end;
      FrameChanged;
      PictureChanged;
    end;
  end;
end;

procedure TRxGIFAnimator.DoPaintImage;
var
  Frame: TBitmap;
  Dest: TRect;
  TransColor: TColor;
begin
  { copy image from parent and back-level controls }
  if FImage.Transparent or FImage.Empty then
    CopyParentImage(Self, Canvas);
  if (not FImage.Empty) and (FImage.ScreenWidth > 0) and
    (FImage.ScreenHeight> 0) then
  begin
    TransColor := clNone;
    Frame := GetFrameBitmap(FrameIndex, TransColor);
{$IFDEF RX_D3}
    Frame.Canvas.Lock;
    try
{$ENDIF}
      if Stretch then Dest := ClientRect
      else if Center then
        Dest := Bounds((ClientWidth - Frame.Width) div 2,
          (ClientHeight - Frame.Height) div 2, Frame.Width, Frame.Height)
      else
        Dest := Rect(0, 0, Frame.Width, Frame.Height);
      if (TransColor = clNone) or not FTransparent then
        Canvas.StretchDraw(Dest, Frame)
      else begin
        StretchBitmapRectTransparent(Canvas, Dest.Left, Dest.Top,
          WidthOf(Dest), HeightOf(Dest), Bounds(0, 0, Frame.Width,
          Frame.Height), Frame, TransColor);
      end;
{$IFDEF RX_D3}
    finally
      Frame.Canvas.Unlock;
    end;
{$ENDIF}
  end;
end;

procedure TRxGIFAnimator.Paint;
begin
  PaintImage;
  if FImage.Transparent or FImage.Empty then
    PaintDesignRect;
end;

procedure TRxGIFAnimator.TimerDeactivate;
var
  F: TCustomForm;
begin
  SetAnimate(False);
  if (csDesigning in ComponentState) then begin
    F := GetParentForm(Self);
    if (F <> nil) and (F.Designer <> nil) then
      F.Designer.Modified;
  end;
end;

procedure TRxGIFAnimator.TimerExpired(Sender: TObject);
begin
{$IFDEF RX_D3}
  if csPaintCopy in ControlState then Exit;
{$ENDIF}
  if Visible and (FImage.Count > 1) and (Parent <> nil) and
    Parent.HandleAllocated then
  begin
    Lock;
    try
      if FFrameIndex < FImage.Count - 1 then Inc(FFrameIndex)
      else FFrameIndex := 0;
{$IFDEF RX_D3}
      Canvas.Lock;
      try
        FTimerRepaint := True;
        if AsyncDrawing and Assigned(FOnFrameChanged) then
          FTimer.Synchronize(FrameChanged)
        else FrameChanged;
        DoPaintControl;
      finally
        FTimerRepaint := False;
        Canvas.Unlock;
        if (FFrameIndex >= 0) and (FFrameIndex < FImage.Count) then
          FTimer.Interval := GetDelayTime(FFrameIndex);
      end;
      if not FLoop and (FFrameIndex = 0) then
        if AsyncDrawing then FTimer.Synchronize(TimerDeactivate)
        else TimerDeactivate;
{$ELSE}
      FTimerRepaint := True;
      try
        FrameChanged;
        Repaint;
      finally
        FTimerRepaint := False;
        if (FFrameIndex >= 0) and (FFrameIndex < FImage.Count) then
          FTimer.Interval := GetDelayTime(FFrameIndex);
      end;
      if not FLoop and (FFrameIndex = 0) then TimerDeactivate;
{$ENDIF}
    finally
      Unlock;
    end;
  end;
end;

procedure TRxGIFAnimator.Change;
begin
  if Assigned(FOnChange) then FOnChange(Self);
end;

procedure TRxGIFAnimator.FrameChanged;
begin
  if Assigned(FOnFrameChanged) then FOnFrameChanged(Self);
end;

procedure TRxGIFAnimator.Stop;
begin
  if Assigned(FOnStop) then FOnStop(Self);
end;

procedure TRxGIFAnimator.Start;
begin
  if Assigned(FOnStart) then FOnStart(Self);
end;

{$IFNDEF RX_D4}
procedure TRxGIFAnimator.SetAutoSize(Value: Boolean);
begin
  if Value <> FAutoSize then begin
    FAutoSize := Value;
    PictureChanged;
  end;
end;
{$ENDIF}

{$IFDEF RX_D3}
procedure TRxGIFAnimator.SetAsyncDrawing(Value: Boolean);
begin
  if FAsyncDrawing <> Value then begin
    Lock;
    try
      if Value then HookBitmap;
      if Assigned(FTimer) then FTimer.SyncEvent := not Value;
      FAsyncDrawing := Value;
    finally
      Unlock;
    end;
  end;
end;
{$ENDIF}

procedure TRxGIFAnimator.SetAnimate(Value: Boolean);
begin
  if FAnimate <> Value then begin
    if Value then begin
      FTimer.OnTimer := TimerExpired;
      FTimer.Enabled := True;
      FAnimate := FTimer.Enabled;
      Start;
    end
    else begin
      FTimer.Enabled := False;
      FTimer.OnTimer := nil;
      FAnimate := False;
      Stop;
      PictureChanged;
    end;
  end;
end;

procedure TRxGIFAnimator.WMSize(var Message: TWMSize);
begin
  inherited;
{$IFNDEF RX_D4}
  AdjustSize;
{$ENDIF}
end;

end.