unit gui_progressbar;

{$mode objfpc}{$H+}

interface

uses
  Classes,
  SysUtils,
  gfxbase,
  fpgfx,
  gfx_widget;
  
type
  TfpgCustomProgressBar = class(TfpgWidget)
  private
    FBackgroundColor: TfpgColor;
    FMax: longint;
    FMin: longint;
    FPosition: longint;
    FShowCaption: boolean;
    FStep: longint;
    FFont: TfpgFont;
    procedure   SetBackgroundColor(const AValue: TfpgColor);
    procedure   SetMax(const AValue: longint);
    procedure   SetMin(const AValue: longint);
    procedure   SetPosition(const AValue: longint);
    procedure   SetShowCaption(const AValue: boolean);
    procedure   SetStep(const AValue: longint);
  protected
    procedure   HandlePaint; override;
    property    Max: longint read FMax write SetMax;
    property    Min: longint read FMin write SetMin;
    property    Position: longint read FPosition write SetPosition;
    property    Step: longint read FStep write SetStep;
//    property    FontName: string read GetFontName write SetFontName;
    property    BackgroundColor: TfpgColor read FBackgroundColor write SetBackgroundColor;
    property    ShowCaption: boolean read FShowCaption write SetShowCaption;
  public
    constructor Create(AOwner: TComponent); override;
    destructor  Destroy; override;
    procedure   StepIt;
    procedure   StepBy(AStep: integer);
    property    Font: TfpgFont read FFont;
  end;
  
  
  TfpgProgressBar = class(TfpgCustomProgressBar)
  published
    property    BackgroundColor;
    property    ShowCaption;
    property    Max;
    property    Min;
    property    Position;
    property    Step;
  end;

implementation

{ TfpgCustomProgressBar }

procedure TfpgCustomProgressBar.SetMax(const AValue: longint);
begin
  if FMax = AValue then
    Exit; //==>

  // correct wrong inputs
  if FMin > AValue then
    FMin := AValue - 1;
  if FPosition > AValue then
    FPosition := AValue;

  FMax := AValue;
	RePaint;
end;

procedure TfpgCustomProgressBar.SetBackgroundColor(const AValue: TfpgColor);
begin
  if FBackgroundColor = AValue then
    Exit; //==>
  FBackgroundColor := AValue;
  RePaint;
end;

procedure TfpgCustomProgressBar.SetMin(const AValue: longint);
begin
  if FMin = AValue then
    Exit; //==>

  // correct wrong inputs
  if AValue > FPosition then
    FPosition := AValue;
  if AValue > FMax then
    FMax := AValue+1;

  FMin := AValue;
	RePaint;
end;

procedure TfpgCustomProgressBar.SetPosition(const AValue: longint);
begin
  if FPosition = AValue then
    Exit; //==>

  // correct limits
  if AValue < Min then
    FPosition := Min
  else if AValue > Max then
    FPosition := Max
  else
    FPosition := AValue;

	RePaint;
end;

procedure TfpgCustomProgressBar.SetShowCaption(const AValue: boolean);
begin
  if FShowCaption = AValue then
    Exit; //==>
  FShowCaption := AValue;
  RePaint;
end;

procedure TfpgCustomProgressBar.SetStep(const AValue: longint);
begin
  if AValue < 1 then
    Exit; //==>
  if FStep = AValue then
    Exit; //==>
  FStep := AValue;
end;

procedure TfpgCustomProgressBar.HandlePaint;
var
  r: TfpgRect;
  diff: integer;
  aPos: integer;  // absolute position
  pos: integer;
  percent: integer;
  txt: string;
  x: TfpgCoord;
  y: TfpgCoord;
begin
  Canvas.BeginDraw;
//  inherited HandlePaint;
  Canvas.ClearClipRect;
  r.SetRect(0, 0, Width, Height);
  
  Canvas.Clear(BackgroundColor);
//  Canvas.SetColor(clInactiveWgFrame);

  // calculate position
  diff    := Max - Min; // diff..
  aPos    := Position - Min;	// absolute position
  percent := round(((100 / diff) * aPos));
  txt     := IntToStr(percent) + '%';
  pos     := round(percent * (Width-2) / 100);

  // Bluecurve theme  :)
  // outer dark border
  Canvas.SetColor(TfpgColor($999999));
  Canvas.SetLineStyle(1, lsSolid);
  Canvas.DrawRectangle(r);
  InflateRect(r, -1, -1);
  r.Width := pos;
  if FPosition > 0 then
  begin
    // left top
    Canvas.SetColor(TfpgColor($98b2ed));
    Canvas.DrawLine(r.Left, r.Bottom, r.Left, r.Top);  // left
    Canvas.DrawLine(r.Left, r.Top, r.Right, r.Top);    // top
    // right bottom
    Canvas.SetColor(TfpgColor($3b4c71));
    Canvas.DrawLine(r.Right, r.Top, r.Right, r.Bottom);   // right
    Canvas.DrawLine(r.Right, r.Bottom, r.Left-1, r.Bottom);   // bottom
    // inside gradient fill
    InflateRect(r, -1, -1);
    Canvas.GradientFill(r, TfpgColor($425d9b), TfpgColor($97b0e8), gdVertical);
  end;
  // paint percentage if required
  if FShowCaption then
  begin
  	x := (Width - FFont.TextWidth(txt)) div 2;
  	y := (Height - FFont.Height) div 2;
    Canvas.SetTextColor(clText1);
    Canvas.Font := FFont;
  	Canvas.DrawString(x, y, txt);
  end;
  Canvas.EndDraw;
end;

constructor TfpgCustomProgressBar.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  Focusable := False;
  Width := 150;
  Height := 22;
  FMin      := 0;
  FMax      := 100;
  FStep     := 1;
  FPosition := 0;
  FBackgroundColor := TfpgColor($c4c4c4); // clListBox;
  FShowCaption := False;
  FFont     := fpgStyle.DefaultFont;
end;

destructor TfpgCustomProgressBar.Destroy;
begin
  inherited Destroy;
end;

procedure TfpgCustomProgressBar.StepIt;
begin
  Position := Position + Step;
end;

procedure TfpgCustomProgressBar.StepBy(AStep: integer);
begin
  Position := Position + AStep;
end;

end.