{
  Copyright (C) 2010 Felipe Monteiro de Carvalho

  License: The same modifying LGPL with static linking exception as the LCL

  This unit should be a repository for various custom drawn components,
  such as a custom drawn version of TButton, of TEdit, of TPageControl, etc,
  eventually forming a full set of custom drawn components.
}
unit customdrawnextras;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Graphics, Controls, LCLType, LCLIntf, IntfGraphics,
  Math,
  // fpimage
  fpcanvas, fpimgcanv, fpimage;

type

  // commented items are not yet supported
  TBitmappedButtonOption = (bboUseImageForSelection
    {bboUseImageForMouseOver, bboDrawFocusRectangle,}
    (*bboCheckable,*));

  TBitmappedButtonOptions = set of TBitmappedButtonOption;

  // commented items are not yet supported
  TBitmappedButtonState = (bbsNormal, bbsDown, bbsMouseOver, bbsFocused
    (* bbsChecked, bbsCheckedSelected, bbsCheckedDown { is going to be unchecked }*));

  { TCustomBitmappedButton }

  TCustomBitmappedButton = class(TCustomControl)
  private
    FOnChange: TNotifyEvent;
    BmpBuffer: TBitmap;
    StrBuffer: TStringList;
  protected
    FImageBtn: TPicture;
    FImageBtnDown: TPicture;
    FImageBtnMouseOver: TPicture;
    FImageBtnFocused: TPicture;
    FImageBtnChecked: TPicture;
    FOptions: TBitmappedButtonOptions;
    FState: TBitmappedButtonState;
    // keyboard
    procedure DoEnter; override;
    procedure DoExit; override;
    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
    procedure KeyUp(var Key: Word; Shift: TShiftState); override;
    // mouse
    procedure MouseDown(Button: TMouseButton; Shift:TShiftState; X,Y:Integer); override;
    procedure MouseUp(Button: TMouseButton; Shift:TShiftState; X,Y:Integer); override;
    procedure MouseEnter; override;
    procedure MouseLeave; override;
    // button state change
    procedure DoButtonDown();
    procedure DoButtonUp();
    // inherited
    procedure RealSetText(const Value: TCaption); override;
  protected
    // Properties
    property ImageBtn: TPicture read FImageBtn;
    property ImageBtnDown: TPicture read FImageBtnDown;
    property ImageBtnFocused: TPicture read FImageBtnFocused;
    property Options: TBitmappedButtonOptions read FOptions write FOptions;
    // Events
    property OnChange: TNotifyEvent read FOnChange write FOnChange;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure EraseBackground(DC: HDC); override;
    procedure Paint; override;
    function GetStateBitmap(): TBitmap;
  end;

  {@@
    TBitmappedButton is a simple custom drawn button which bases it's drawing
    on provided raster images. Currently the following states are supported:
    normal, down and focused.

    The Caption of this button may have multiple lines of text, separated by any
    line separator. The text is drawn centralized in the button.

    Some work was done trying to achieve alpha blending for the button, but this
    wasn't successfull. It would work like this: The button may be drawn flat
    or alpha blended using a separate image for the Alpha channel. While pixels
    in the alpha channel will result in the button pixel being fully drawn,
    while black pixels represent pixels which aren't drawn. grey pixels are
    alpha blended.
  }

  TBitmappedButton = class(TCustomBitmappedButton)
  published
    // LCL properties and events
    property Action;
    property Anchors;
    property AnchorSide;
//    property BidiMode;
//    property BorderSpacing;
//    property Cancel;
    property Caption;
    property Constraints;
//    property Default;
//    property DragCursor;
//    property DragKind;
//    property DragMode;
    property Enabled;
    property Font;
//    property ParentBidiMode;
//    property ModalResult;
    property OnChangeBounds;
    property OnClick;
    property OnContextPopup;
    property OnDragDrop;
    property OnDragOver;
    property OnEndDrag;
    property OnEnter;
    property OnExit;
    property OnKeyDown;
    property OnKeyPress;
    property OnKeyUp;
    property OnMouseDown;
    property OnMouseEnter;
    property OnMouseLeave;
    property OnMouseMove;
    property OnMouseUp;
    property OnResize;
    property OnStartDrag;
    property OnUTF8KeyPress;
    property ParentFont;
    property ParentShowHint;
    property PopupMenu;
    property ShowHint;
    property TabOrder;
    property TabStop;
    property Visible;
    // Specific properties
    property ImageBtn;
    property ImageBtnDown;
    property ImageBtnFocused;
    property Options;
  end;

  TCDDrawStyle = (dsWinCE, dsCustom);

  {@@
    TCDGroupBox is a custom-drawn group box control
  }

  TCDGroupBoxDrawer = class;
  TCDGroupBoxDrawerWinCE = class;

  { TCDGroupBox }

  TCDGroupBox = class(TCustomControl)
  private
    FDrawStyle: TCDDrawStyle;
    FCurrentDrawer: TCDGroupBoxDrawer;
    FDrawerWinCE: TCDGroupBoxDrawerWinCE;
    procedure PrepareCurrentDrawer();
    procedure SetDrawStyle(const AValue: TCDDrawStyle);
  public
    CustomDrawer: TCDGroupBoxDrawer; // Fill the field to use the dsCustom draw mode
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure EraseBackground(DC: HDC); override;
    procedure Paint; override;
  published
    property DrawStyle: TCDDrawStyle read FDrawStyle write SetDrawStyle;
    property Caption;
    property TabStop default False;
  end;

  { TCDGroupBoxDrawer }

  TCDGroupBoxDrawer = class
  public
    procedure SetClientRectPos(CDGroupBox: TCDGroupBox); virtual; abstract;
    procedure DrawToIntfImage(ADest: TFPImageCanvas; CDGroupBox: TCDGroupBox); virtual; abstract;
  end;

  { TCDGroupBoxDrawerWinCE }

  TCDGroupBoxDrawerWinCE = class(TCDGroupBoxDrawer)
  public
    procedure SetClientRectPos(CDGroupBox: TCDGroupBox); override;
    procedure DrawToIntfImage(ADest: TFPImageCanvas; CDGroupBox: TCDGroupBox); override;
  end;

  {@@
    TCDTrackBar is a custom-drawn trackbar control
  }

//  TCDTrackBarDrawer = class;

  { TCDTrackBar }

{  TCDTrackBar = class(TCustomControl)
  private
    FMin: Integer;
    FMax: Integer;
    FPosition: Integer;
    FOnChange: TNotifyEvent;
    procedure SetMax(Value: Integer);
    procedure SetMin(Value: Integer);
    procedure SetPosition(Value: Integer);
  protected
    procedure Changed; virtual;
    // keyboard
    procedure DoEnter; override;
    procedure DoExit; override;
    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
    procedure KeyUp(var Key: Word; Shift: TShiftState); override;
    // mouse
    procedure MouseDown(Button: TMouseButton; Shift:TShiftState; X,Y:Integer); override;
    procedure MouseUp(Button: TMouseButton; Shift:TShiftState; X,Y:Integer); override;
    procedure MouseEnter; override;
    procedure MouseLeave; override;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure EraseBackground(DC: HDC); override;
    procedure Paint; override;
  published
    property Max: Integer read FMax write SetMax default 10;
    property Min: Integer read FMin write SetMin default 0;
    property OnChange: TNotifyEvent read FOnChange write FOnChange;
    property Position: Integer read FPosition write SetPosition;
    property TabStop default True;
  end;}

  { TCDTrackBarDrawer }

{  TCDTrackBarDrawer = class
  public
    procedure DrawToIntfImage(ADest: TLazIntfImage; CDTrackBar: TCDTrackBar); virtual; abstract;
  end;}

procedure Register;

implementation

const
  INT_BitmappedButton_LineSpacing = 2;

procedure Register;
begin
  RegisterComponents('Common Controls', [TBitmappedButton]);
end;

{ TCustomBitmappedButton }

procedure TCustomBitmappedButton.DoEnter;
begin
  DoButtonUp();

  inherited DoEnter;
end;

procedure TCustomBitmappedButton.DoExit;
begin
  DoButtonUp();

  inherited DoExit;
end;

procedure TCustomBitmappedButton.KeyDown(var Key: Word; Shift: TShiftState);
begin
  inherited KeyDown(Key, Shift);

  if Key = VK_SPACE then DoButtonDown();
end;

procedure TCustomBitmappedButton.KeyUp(var Key: Word; Shift: TShiftState);
begin
  DoButtonUp();

  inherited KeyUp(Key, Shift);
end;

procedure TCustomBitmappedButton.MouseDown(Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  DoButtonDown();

  inherited MouseDown(Button, Shift, X, Y);
end;

procedure TCustomBitmappedButton.MouseUp(Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  DoButtonUp();

  inherited MouseUp(Button, Shift, X, Y);
end;

procedure TCustomBitmappedButton.MouseEnter;
begin
  inherited MouseEnter;
end;

procedure TCustomBitmappedButton.MouseLeave;
begin
  inherited MouseLeave;
end;

procedure TCustomBitmappedButton.DoButtonDown();
var
  NewState: TBitmappedButtonState;
begin
  NewState := bbsDown;

  case FState of
  bbsNormal, bbsFocused: NewState := bbsDown;
  //  bbsChecked, bbsCheckedSelected: NewState := bbsCheckedDown;
  end;

  if NewState <> FState then
  begin
    FState := NewState;
    Invalidate;
  end;
end;

procedure TCustomBitmappedButton.DoButtonUp();
var
  NewState: TBitmappedButtonState;
begin
  if Focused then NewState := bbsFocused
  else NewState := bbsNormal;

{  case FState of
  bbsCheckedDown:
  begin
    if Focused then NewState := bbsCheckedSelected
    else NewState := bbsChecked;
  end;
  end;}

  if NewState <> FState then
  begin
    FState := NewState;
    Invalidate;
  end;
end;

procedure TCustomBitmappedButton.RealSetText(const Value: TCaption);
begin
  inherited RealSetText(Value);

  // Makes sure that caption changes are drawn
  Invalidate;
end;

constructor TCustomBitmappedButton.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);

  BmpBuffer := TBitmap.Create;
  StrBuffer := TStringList.Create;

  FImageBtn := TPicture.Create;
  FImageBtnDown := TPicture.Create;
  FImageBtnMouseOver := TPicture.Create;
  FImageBtnFocused := TPicture.Create;
  FImageBtnChecked := TPicture.Create;

  FOptions := [{bboDrawSelectionRectangle}];

  TabStop := True;
end;

destructor TCustomBitmappedButton.Destroy;
begin
  if Assigned(FImageBtn) then FImageBtn.Free;
  if Assigned(FImageBtnDown) then FImageBtnDown.Free;
  if Assigned(FImageBtnMouseOver) then FImageBtnMouseOver.Free;
  if Assigned(FImageBtnFocused) then FImageBtnFocused.Free;
  if Assigned(FImageBtnChecked) then FImageBtnChecked.Free;

  BmpBuffer.Free;
  StrBuffer.Free;

  inherited Destroy;
end;

procedure TCustomBitmappedButton.EraseBackground(DC: HDC);
begin
  // The correct implementation is doing nothing
end;

procedure TCustomBitmappedButton.Paint;
var
  lTextX, lTextY, lTextCX, lTextCY, lTmp, lTextHeightPlusLineSpacing: integer;
  i: Integer;
begin
  // First draw the button image
  BmpBuffer.Width := Width;
  BmpBuffer.Height := Height;
  BmpBuffer.Canvas.Draw(0, 0, GetStateBitmap());

  // Now measure the text position

  BmpBuffer.Canvas.Font.Assign(Self.Font);
  BmpBuffer.Canvas.Brush.Style := bsClear;

  StrBuffer.Text := Caption;

  lTextCX := 0;
  for i := 0 to StrBuffer.Count - 1 do
  begin
    lTmp := BmpBuffer.Canvas.TextWidth(StrBuffer.Strings[i]);
    lTextCX := Max(lTextCX, lTmp);
  end;

  lTextHeightPlusLineSpacing := BmpBuffer.Canvas.TextHeight(Caption) + INT_BitmappedButton_LineSpacing;
  lTextCY := BmpBuffer.Canvas.TextHeight(Caption) * StrBuffer.Count
    + INT_BitmappedButton_LineSpacing * (StrBuffer.Count - 1);

  lTextX := Width div 2 - lTextCX div 2;
  lTextY := Height div 2 - lTextCY div 2;

  // Draw the text

  for i := 0 to StrBuffer.Count - 1 do
  begin
    BmpBuffer.Canvas.TextOut(lTextX, lTextY + lTextHeightPlusLineSpacing * i, StrBuffer.Strings[i]);
  end;

  // And flush the buffer to the screen
  Canvas.Draw(0, 0, BmpBuffer);
end;

function TCustomBitmappedButton.GetStateBitmap(): TBitmap;
begin
  case FState of
  bbsDown:      Result := FImageBtnDown.Bitmap;
//  bbsMouseOver: Result := FImageBtnMouseOver;
  bbsFocused:
  begin
    if bboUseImageForSelection in Options then
      Result := FImageBtnFocused.Bitmap
    else Result := FImageBtn.Bitmap;
  end;
//  bbsChecked:   Result := FImageBtnChecked;
  else
    Result := FImageBtn.Bitmap;
  end;
end;

{ TCDGroupBox }

procedure TCDGroupBox.PrepareCurrentDrawer();
begin
  case DrawStyle of
   dsWince:  FCurrentDrawer := FDrawerWinCE;
   dsCustom: FCurrentDrawer := CustomDrawer;
  end;
end;

procedure TCDGroupBox.SetDrawStyle(const AValue: TCDDrawStyle);
begin
  if FDrawStyle=AValue then exit;
  FDrawStyle:=AValue;

  Invalidate;

  PrepareCurrentDrawer();
  FCurrentDrawer.SetClientRectPos(Self);
end;

constructor TCDGroupBox.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);

  TabStop := False;

  FDrawerWinCE := TCDGroupBoxDrawerWinCE.Create;
end;

destructor TCDGroupBox.Destroy;
begin
  inherited Destroy;
end;

procedure TCDGroupBox.EraseBackground(DC: HDC);
begin

end;

procedure TCDGroupBox.Paint;
var
  AImage: TLazIntfImage = nil;
  ABmp: TBitmap = nil;
  lCanvas: TFPImageCanvas = nil;
begin
  inherited Paint;

  PrepareCurrentDrawer();

  ABmp := TBitmap.Create;
  try
    ABmp.Width := Width;
    ABmp.Height := Height;
    AImage := ABmp.CreateIntfImage;
    lCanvas := TFPImageCanvas.create(AImage);
    FCurrentDrawer.DrawToIntfImage(lCanvas, Self);
    ABmp.LoadFromIntfImage(AImage);
    Canvas.Draw(0, 0, ABmp);
  finally
    if lCanvas <> nil then lCanvas.Free;
    if AImage <> nil then AImage.Free;
    ABmp.Free;
  end;
end;

{ TCDGroupBoxDrawerWinCE }

procedure TCDGroupBoxDrawerWinCE.SetClientRectPos(CDGroupBox: TCDGroupBox);
var
  lRect: TRect;
  lCaptionHeight: Integer;
begin
  lCaptionHeight := 10;
  lRect := Rect(1, lCaptionHeight, CDGroupBox.Width - 1, CDGroupBox.Height - 1);
  CDGroupBox.AdjustClientRect(lRect);
end;

procedure TCDGroupBoxDrawerWinCE.DrawToIntfImage(ADest: TFPImageCanvas;
  CDGroupBox: TCDGroupBox);
begin
  ADest.Brush.FPColor := colRed;
  ADest.Rectangle(0, 0, CDGroupBox.Width, CDGroupBox.height);
end;

{ TCDTrackBar }

{procedure TCDTrackBar.SetMax(Value: Integer);
begin
  if Value = FMax then Exit;
  FMax := Value;
  Invalidate;
end;

procedure TCDTrackBar.SetMin(Value: Integer);
begin
  if Value = FMin then Exit;
  FMin := Value;
  Invalidate;
end;

procedure TCDTrackBar.SetPosition(Value: Integer);
begin
  if Value = FPosition then Exit;
  FPosition := Value;
  Invalidate;
end;

procedure TCDTrackBar.Changed;
begin

end;

procedure TCDTrackBar.DoEnter;
begin
  inherited DoEnter;
end;

procedure TCDTrackBar.DoExit;
begin
  inherited DoExit;
end;

procedure TCDTrackBar.KeyDown(var Key: Word; Shift: TShiftState);
begin
  inherited KeyDown(Key, Shift);
end;

procedure TCDTrackBar.KeyUp(var Key: Word; Shift: TShiftState);
begin
  inherited KeyUp(Key, Shift);
end;

procedure TCDTrackBar.MouseDown(Button: TMouseButton; Shift: TShiftState; X,
  Y: Integer);
begin
  inherited MouseDown(Button, Shift, X, Y);
end;

procedure TCDTrackBar.MouseUp(Button: TMouseButton; Shift: TShiftState; X,
  Y: Integer);
begin
  inherited MouseUp(Button, Shift, X, Y);
end;

procedure TCDTrackBar.MouseEnter;
begin
  inherited MouseEnter;
end;

procedure TCDTrackBar.MouseLeave;
begin
  inherited MouseLeave;
end;

constructor TCDTrackBar.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
end;

destructor TCDTrackBar.Destroy;
begin
  inherited Destroy;
end;

procedure TCDTrackBar.EraseBackground(DC: HDC);
begin
  inherited EraseBackground(DC);
end;

procedure TCDTrackBar.Paint;
begin
  inherited Paint;
end;}

{ TCDTrackBarDrawer }

//procedure TCDTrackBarDrawer.DrawToIntfImage(ADest: TLazIntfImage; CDTrackBar: TCDTrackBar);
//begin
//  inherited DrawToIntfImage(ADest);
//end;

end.