unit Shell.MainForm;

// Main form of the Atlas VCL application shell: a workspace with a navigation
// pane, a command bar and a content pane, themed by TAtlasThemer.

interface

uses
  System.Classes, Vcl.Forms, Vcl.Controls, Vcl.ComCtrls, Vcl.ActnList,
  Atlas.Layout, Atlas.Charts, Atlas.Gauges, Atlas.Themes;

type
  TShellForm = class(TForm)
  private
    FWorkspace: TAtlasWorkspace;
    FCommands: TAtlasCommandBar;
    FNavigation: TAtlasNavigation;
    FTiles: TAtlasTileBoard;
    FPages: TPageControl;
    FChart: TAtlasChart;
    FEast, FWest: TAtlasChartSeries;
    FQueue: TAtlasGauge;
    FThemer: TAtlasThemer;
    FAddMonth: TAction;
    FMonths: Integer;
    function NewAction(const Caption: string; Handler: TNotifyEvent; Tag: Integer = 0): TAction;
    function NewPage(const Caption: string): TTabSheet;
    function AddGauge(Parent: TWinControl; const Caption: string; Top: Integer; Value: Double): TAtlasGauge;
    procedure ShowPage(Sender: TObject);
    procedure AddMonth(Sender: TObject);
    procedure ToggleBars(Sender: TObject);
    procedure NextTheme(Sender: TObject);
    procedure FloatNavigation(Sender: TObject);
    procedure QueueChanged(Sender: TObject);
    procedure FirstActivate(Sender: TObject);
    procedure SaveLayout(Sender: TObject; var Action: TCloseAction);
  public
    constructor Create(AOwner: TComponent); override;
    procedure SelectPage(Index: Integer);
  end;

implementation

uses
  System.SysUtils, System.Types, System.IOUtils, Vcl.Graphics, Vcl.StdCtrls;

const
  MonthNames: array[0..11] of string = ('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
    'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec');
  EastSales: array[0..11] of Double = (18, 22, 21, 29, 35, 38, 41, 39, 44, 47, 52, 58);
  WestSales: array[0..11] of Double = (24, 29, 27, 32, 38, 42, 40, 45, 49, 51, 55, 61);

function LayoutFile: string;
begin
  Result := TPath.Combine(ExtractFilePath(ParamStr(0)), 'shell-layout.json');
end;

constructor TShellForm.Create(AOwner: TComponent);
var
  Page: TTabSheet;
  Slider: TTrackBar;
  Action: TAction;
  I: Integer;
begin
  inherited CreateNew(AOwner);
  Caption := 'Atlas VCL application shell';
  Position := poScreenCenter;
  Width := 1000;
  Height := 680;
  Font.Name := 'Segoe UI';
  Font.Size := 10;
  OnActivate := FirstActivate;
  OnClose := SaveLayout;
  // 1. A workspace with three panes. The pane caption becomes the title of its floating window.
  FWorkspace := TAtlasWorkspace.Create(Self);
  FWorkspace.Parent := Self;
  FWorkspace.Align := alClient;
  FWorkspace.AddPane('navigation', 'Navigation', alLeft, 200);
  FWorkspace.AddPane('commands', '', alTop, 150);
  FWorkspace.AddPane('content', '', alClient, 400);
  // AddPane leaves the splitter of a left or top pane on the outer edge, where it
  // cannot be dragged; MovePane to the same edge puts it between pane and content.
  FWorkspace.MovePane('navigation', alLeft, 200);
  FWorkspace.MovePane('commands', alTop, 150);
  // 2. The command bar, the navigation list and a page control inside the panes.
  FCommands := TAtlasCommandBar.Create(Self);
  FCommands.Parent := FWorkspace.Pane('commands');
  FCommands.Align := alClient;
  FNavigation := TAtlasNavigation.Create(Self);
  FNavigation.Parent := FWorkspace.Pane('navigation');
  FNavigation.Align := alClient;
  FPages := TPageControl.Create(Self);
  FPages.Parent := FWorkspace.Pane('content');
  FPages.Align := alClient;
  // 3. Content pages: a tile board, a chart and three gauges.
  Page := NewPage('Home');
  FTiles := TAtlasTileBoard.Create(Self);
  FTiles.Parent := Page;
  FTiles.Align := alClient;
  FTiles.BevelOuter := bvNone;
  Page := NewPage('Sales');
  FChart := TAtlasChart.Create(Self);
  FChart.Parent := Page;
  FChart.Align := alClient;
  FChart.Title := 'Regional sales (thousands)';
  FEast := FChart.AddSeries('East', $00876524);
  FWest := FChart.AddSeries('West', $005986B4);
  for I := 1 to 6 do AddMonth(nil);
  Page := NewPage('Gauges');
  FQueue := AddGauge(Page, 'Queue depth (0-500, warning 300, critical 450)', 16, 0);
  FQueue.SetRange(0, 500);
  FQueue.SetThresholds(300, 450);
  FQueue.Value := 120;
  AddGauge(Page, 'CPU % (warning 70, critical 90)', 132, 62);
  AddGauge(Page, 'Disk % (warning 70, critical 90)', 248, 91);
  Slider := TTrackBar.Create(Self);
  Slider.Parent := Page;
  Slider.SetBounds(16, 364, 560, 40);
  Slider.Anchors := [akLeft, akTop, akRight];
  Slider.Max := 500;
  Slider.Frequency := 50;
  Slider.Position := 120;
  Slider.OnChange := QueueChanged;
  FPages.ActivePageIndex := 0;
  // 4. Actions shared by the navigation list, the tile board and the command bar.
  for I := 0 to FPages.PageCount - 1 do
  begin
    Action := NewAction(FPages.Pages[I].Caption, ShowPage, I);
    FNavigation.AddAction(Action);
    FTiles.AddTile(Action);
    FCommands.AddCommand('Home', 'Pages', Action);
  end;
  FAddMonth := NewAction('Add month', AddMonth);
  FCommands.AddCommand('Home', 'Sales', FAddMonth);
  FCommands.AddCommand('Home', 'Sales', NewAction('Bars / lines', ToggleBars));
  FCommands.AddCommand('View', 'Appearance', NewAction('Next theme', NextTheme));
  FCommands.AddCommand('View', 'Layout', NewAction('Float navigation', FloatNavigation));
  // 5. The themer colours every control below its root; assign it after the controls exist.
  FThemer := TAtlasThemer.Create(Self);
  FThemer.Root := FWorkspace;
end;

function TShellForm.NewAction(const Caption: string; Handler: TNotifyEvent; Tag: Integer): TAction;
begin
  Result := TAction.Create(Self);
  Result.Caption := Caption;
  Result.Tag := Tag;
  Result.OnExecute := Handler;
end;

function TShellForm.NewPage(const Caption: string): TTabSheet;
begin
  Result := TTabSheet.Create(Self);
  Result.PageControl := FPages;
  Result.Caption := Caption;
  Result.TabVisible := False;
end;

function TShellForm.AddGauge(Parent: TWinControl; const Caption: string; Top: Integer; Value: Double): TAtlasGauge;
begin
  Result := TAtlasGauge.Create(Self);
  Result.Parent := Parent;
  Result.SetBounds(16, Top, 560, 100);
  Result.Anchors := [akLeft, akTop, akRight];
  Result.Caption := Caption;
  Result.Value := Value;
end;

procedure TShellForm.SelectPage(Index: Integer);
begin
  FPages.ActivePageIndex := Index;
  FNavigation.ItemIndex := Index;
end;

procedure TShellForm.ShowPage(Sender: TObject);
begin
  SelectPage(TAction(Sender).Tag);
end;

procedure TShellForm.AddMonth(Sender: TObject);
begin
  if FMonths >= Length(MonthNames) then Exit;
  // X is the month number. Captions label the bars; line charts use the numeric axis.
  FEast.Add(FMonths + 1, EastSales[FMonths], MonthNames[FMonths]);
  if FMonths = 3 then
    FWest.AddMissing(FMonths + 1) // a gap: the line breaks and no bar is drawn
  else
    FWest.Add(FMonths + 1, WestSales[FMonths], MonthNames[FMonths]);
  Inc(FMonths);
  if Assigned(FAddMonth) then FAddMonth.Enabled := FMonths < Length(MonthNames);
end;

procedure TShellForm.ToggleBars(Sender: TObject);
begin
  if FChart.Kind = acLine then FChart.Kind := acBar else FChart.Kind := acLine;
end;

procedure TShellForm.NextTheme(Sender: TObject);
begin
  FThemer.ThemeIndex := (FThemer.ThemeIndex + 1) mod AtlasThemeCount;
  Caption := 'Atlas VCL application shell - ' + AtlasTheme(FThemer.ThemeIndex).Name;
end;

procedure TShellForm.FloatNavigation(Sender: TObject);
var
  Origin: TPoint;
begin
  if FWorkspace.IsFloating('navigation') then
    FWorkspace.DockPane('navigation')
  else
  begin
    Origin := ClientToScreen(Point(40, 120));
    FWorkspace.FloatPane('navigation', Rect(Origin.X, Origin.Y, Origin.X + 240, Origin.Y + 400));
  end;
end;

procedure TShellForm.QueueChanged(Sender: TObject);
begin
  FQueue.Value := TTrackBar(Sender).Position;
end;

procedure TShellForm.FirstActivate(Sender: TObject);
begin
  // Restore the saved layout once the workspace is showing, so a floating pane can open its window.
  OnActivate := nil;
  if not FileExists(LayoutFile) then Exit;
  try
    FWorkspace.LoadLayout(TFile.ReadAllText(LayoutFile, TEncoding.UTF8));
  except
    on EAtlasLayoutError do ; // a stale or edited file: keep the default layout
  end;
end;

procedure TShellForm.SaveLayout(Sender: TObject; var Action: TCloseAction);
begin
  TFile.WriteAllText(LayoutFile, FWorkspace.SaveLayout, TEncoding.UTF8);
end;

end.