unit StatusBar;

{$IFDEF FPC}
  {$MODE Delphi}
{$ENDIF}

interface

uses
  Classes, SysUtils, Forms, Controls, Graphics, StdCtrls, ExtCtrls, Math,
  AppTheme;

type
  TMainStatusBar = class(TPanel)
  private
    FCells:  array[0..7] of TPanel;
    FLabels: array[0..7] of TLabel;
    procedure CreateStatusCell(Index: Integer; const Cap: string);
    procedure LayoutCells;
  protected
    procedure Resize; override;
  public
    constructor Create(AOwner: TComponent); override;
    procedure SetStatusText(Index: Integer; const Text: string);
    procedure ApplyTheme(const T: TAppTheme);
  end;

implementation

const
  STATUS_H = 26;
  GAP      = 1;
  PAD_X    = 8;
  SEQ_MIN_W = 90;
  STATUS_ORDER: array[0..7] of Integer = (2, 0, 1, 3, 7, 4, 5, 6);
  BASE_W: array[0..7] of Integer = (280, 160, 170, 150, 190, 180, 130, 90);
  INITIAL_TEXT: array[0..7] of string = (
    'Board --',
    'IP --',
    'Disconnected',
    'Supply --',
    'RX idle',
    'TX idle',
    'SEQ --',
    'PLL --'
  );

constructor TMainStatusBar.Create(AOwner: TComponent);
var
  I: Integer;
begin
  inherited Create(AOwner);
  Align      := alBottom;
  Height     := STATUS_H;
  BevelOuter := bvNone;

  for I := Low(STATUS_ORDER) to High(STATUS_ORDER) do
    CreateStatusCell(STATUS_ORDER[I], INITIAL_TEXT[STATUS_ORDER[I]]);
  LayoutCells;
end;

procedure TMainStatusBar.CreateStatusCell(Index: Integer; const Cap: string);
begin
  FCells[Index] := TPanel.Create(Self);
  FCells[Index].Parent     := Self;
  FCells[Index].BevelOuter := bvNone;
  FCells[Index].Align      := alNone;
  FCells[Index].Width      := BASE_W[Index];
  FCells[Index].Top        := 1;
  FCells[Index].Height     := Height - 2;

  FLabels[Index] := TLabel.Create(Self);
  FLabels[Index].Parent     := FCells[Index];
  FLabels[Index].AutoSize   := False;
  FLabels[Index].Align      := alClient;
  FLabels[Index].BorderSpacing.Left  := PAD_X;
  FLabels[Index].BorderSpacing.Right := PAD_X;
  FLabels[Index].Alignment  := taLeftJustify;
  FLabels[Index].Layout     := tlCenter;
  FLabels[Index].Caption    := Cap;
  FLabels[Index].Font.Name  := 'Courier New';
  FLabels[Index].Font.Size  := 8;
end;

procedure TMainStatusBar.LayoutCells;
var
  PPI, X, I, Idx, W, H, G, Pad, FixedNatural, FixedAvail: Integer;

  function S(Value: Integer): Integer;
  begin
    Result := (Int64(Value) * PPI + 48) div 96;
    if (Value > 0) and (Result < 1) then
      Result := 1;
  end;

  function FixedCellWidth(Index: Integer): Integer;
  begin
    Result := S(BASE_W[Index]);
    if FixedAvail <= 0 then
      Result := 0
    else if FixedAvail < FixedNatural then
    begin
      Result := (Int64(Result) * FixedAvail + FixedNatural div 2) div FixedNatural;
      if FixedAvail >= S(48) * 7 then
        Result := Max(S(48), Result);
    end;
  end;

begin
  PPI := Screen.PixelsPerInch;
  if PPI <= 0 then PPI := 96;

  G   := S(GAP);
  Pad := S(PAD_X);
  if Height <> S(STATUS_H) then
    Height := S(STATUS_H);
  H := Max(1, ClientHeight - G * 2);

  FixedNatural := 0;
  for I := Low(STATUS_ORDER) to High(STATUS_ORDER) - 1 do
    Inc(FixedNatural, S(BASE_W[STATUS_ORDER[I]]));
  FixedAvail := ClientWidth - S(SEQ_MIN_W) - G * 8;

  X := 0;
  for I := Low(STATUS_ORDER) to High(STATUS_ORDER) do
  begin
    Idx := STATUS_ORDER[I];
    if FCells[Idx] = nil then Continue;

    Inc(X, G);
    if Idx = 6 then
      W := Max(0, ClientWidth - X)
    else
      W := FixedCellWidth(Idx);

    FCells[Idx].SetBounds(X, G, W, H);
    if FLabels[Idx] <> nil then
    begin
      FLabels[Idx].BorderSpacing.Left  := Pad;
      FLabels[Idx].BorderSpacing.Right := Pad;
    end;
    Inc(X, W);
  end;
end;

procedure TMainStatusBar.Resize;
begin
  inherited Resize;
  LayoutCells;
end;

procedure TMainStatusBar.SetStatusText(Index: Integer; const Text: string);
begin
  if (Index < Low(FLabels)) or (Index > High(FLabels)) then Exit;
  if FLabels[Index] = nil then Exit;
  if FLabels[Index].Caption <> Text then
    FLabels[Index].Caption := Text;
end;

procedure TMainStatusBar.ApplyTheme(const T: TAppTheme);
var
  I: Integer;
begin
  Color := T.Border;
  for I := Low(FCells) to High(FCells) do
  begin
    if FCells[I] <> nil then
    begin
      FCells[I].Color := T.Panel;
      FCells[I].Font.Color := T.Text;
    end;
    if FLabels[I] <> nil then
    begin
      if I in [4, 5] then
        FLabels[I].Font.Color := T.TextDim
      else if I = 6 then
        FLabels[I].Font.Color := T.Amber
      else if I = 2 then
        FLabels[I].Font.Color := T.TbStartText
      else
        FLabels[I].Font.Color := T.Text;
      FLabels[I].Color := T.Panel;
    end;
  end;
end;

end.