Gantt Charts

uses
  TeEngine, Series, GanttCh, TeeProcs, Chart;

procedure CreateBasicGanttChart(GanttSeries: TGanttSeries);
begin
  GanttSeries.FillSampleValues(20);
  
  // Recommended for Gantt charts
  Chart1.View3D := False;
end;

procedure CreateProjectSchedule(GanttSeries: TGanttSeries; Chart: TChart);
begin
  // Set 2D view for clarity
  Chart.View3D := False;
  
  // Disable automatic sorting by date
  GanttSeries.XValues.Order := loNone;
  
  // Add tasks with date-time values
  // AddGantt parameters: (StartDate, EndDate, YPosition, Label)
  with GanttSeries do
  begin
    AddGantt(EncodeDate(2003, 4, 1),  EncodeDate(2003, 4, 10), 0, 'Task A');
    AddGantt(EncodeDate(2003, 4, 5),  EncodeDate(2003, 4, 15), 1, 'Task B');
    AddGantt(EncodeDate(2003, 4, 2),  EncodeDate(2003, 4, 8),  2, 'Task C');
    AddGantt(EncodeDate(2003, 4, 9),  EncodeDate(2003, 4, 21), 3, 'Task D');
    
    // Multiple bars on the same row (Y position)
    AddGantt(EncodeDate(2003, 4, 12), EncodeDate(2003, 4, 18), 2, 'Task C2');
    
    // Make marks visible
    Marks.Visible := True;
    Marks.Shadow.Size := 0;
    Marks.Gradient.Visible := True;
  end;
  
  // Configure horizontal axis for dates
  Chart.BottomAxis.SetMinMax(EncodeDate(2003, 4, 1), EncodeDate(2003, 5, 1));
  Chart.BottomAxis.Increment := DateTimeStep[dtOneDay];
  Chart.BottomAxis.LabelsAngle := 90;
  Chart.BottomAxis.DateTimeFormat := 'dd-mmm';
  
  // Configure vertical axis for tasks
  Chart.LeftAxis.SetMinMax(-2, 5);
  Chart.LeftAxis.Grid.Centered := False;
end;

uses
  TeeGanttTool;

var
  GanttTool: TGanttTool;

procedure SetupInteractiveGantt(GanttSeries: TGanttSeries; Chart: TChart);
begin
  // Disable zoom to allow dragging
  Chart.Zoom.Allow := False;
  
  // Initialize Gantt Tool for drag functionality
  GanttTool := TGanttTool.Create(Self);
  GanttTool.Series := GanttSeries;
  GanttTool.ParentChart := Chart;
  GanttTool.OnDragBar := GanttToolDragBar;
end;

// Handle drag events
procedure GanttToolDragBar(Sender: TGanttTool; GanttBar: Integer);
var
  StatusText: String;
begin
  StatusText := Format('Task %d: %s to %s', [
    GanttBar,
    DateTimeToStr(Sender.Gantt.StartValues[GanttBar]),
    DateTimeToStr(Sender.Gantt.EndValues[GanttBar])
  ]);
  
  StatusBar1.SimpleText := StatusText;
end;

procedure CustomizeGanttMarks(GanttSeries: TGanttSeries);
begin
  GanttSeries.OnGetMarkText := GetGanttMarkText;
end;

procedure GetGanttMarkText(Sender: TChartSeries; ValueIndex: Integer; 
  var MarkText: String);
begin
  // Customize mark text for each task
  case ValueIndex of
    0: MarkText := 'John';
    1: MarkText := 'Ann';
    2: MarkText := 'David';
    3: MarkText := 'Carol';
    4: MarkText := 'David 2';
  else
    MarkText := 'Task ' + IntToStr(ValueIndex);
  end;
end;

procedure SetGanttBarHeight(GanttSeries: TGanttSeries; Height: Integer);
begin
  GanttSeries.Pointer.VertSize := Height;
end;

with GanttSeries.Pointer do
begin
  // Bar height
  VertSize := 20;
  
  // Bar style
  Style := psRectangle;
  
  // Bar border
  Pen.Visible := True;
  Pen.Color := clBlack;
  Pen.Width := 1;
  
  // Bar fill
  Brush.Style := bsSolid;
end;

procedure ColorCodeTasks(GanttSeries: TGanttSeries);
begin
  // Use different color for each task
  GanttSeries.ColorEachPoint := True;
  
  // Or set specific colors
  GanttSeries.Colors[0] := clRed;    // High priority
  GanttSeries.Colors[1] := clYellow; // Medium priority
  GanttSeries.Colors[2] := clGreen;  // Low priority
end;

procedure SetTaskDependencies(GanttSeries: TGanttSeries);
begin
  // Connect tasks to show dependencies
  // Task 1 depends on Task 0 (must finish before Task 1 starts)
  GanttSeries.NextTask[0] := 1;
  GanttSeries.NextTask[1] := 2;
  
  // Customize connecting lines
  GanttSeries.ConnectingPen.Color := clBlue;
  GanttSeries.ConnectingPen.Width := 2;
  GanttSeries.ConnectingPen.Style := psDash;
end;

procedure SetTimeScale(Chart: TChart; ScaleType: Integer);
begin
  case ScaleType of
    0: Chart.BottomAxis.Increment := DateTimeStep[dtOneDay];
    1: Chart.BottomAxis.Increment := DateTimeStep[dtOneWeek];
    2: Chart.BottomAxis.Increment := DateTimeStep[dtHalfMonth];
    3: Chart.BottomAxis.Increment := DateTimeStep[dtOneMonth];
  end;
  
  // Adjust label format based on scale
  case ScaleType of
    0: Chart.BottomAxis.DateTimeFormat := 'dd-mmm';
    1: Chart.BottomAxis.DateTimeFormat := 'dd-mmm';
    2: Chart.BottomAxis.DateTimeFormat := 'mmm-yy';
    3: Chart.BottomAxis.DateTimeFormat := 'mmm-yy';
  end;
end;

// Scroll left (earlier dates)
procedure ScrollLeft(Chart: TChart);
begin
  with Chart.BottomAxis do
    SetMinMax(Minimum - 1, Maximum - 1);
end;

// Scroll right (later dates)
procedure ScrollRight(Chart: TChart);
begin
  with Chart.BottomAxis do
    SetMinMax(Minimum + 1, Maximum + 1);
end;

// Zoom in
procedure ZoomIn(Chart: TChart);
begin
  with Chart.BottomAxis do
    SetMinMax(Minimum + 1, Maximum - 1);
end;

// Zoom out
procedure ZoomOut(Chart: TChart);
begin
  with Chart.BottomAxis do
    SetMinMax(Minimum - 1, Maximum + 1);
end;

procedure AddMilestone(GanttSeries: TGanttSeries; Date: TDateTime; 
  YPos: Integer; Caption: String);
begin
  // Add milestone as zero-duration task
  GanttSeries.AddGantt(Date, Date, YPos, Caption);
  
  // Use different pointer style for milestones
  GanttSeries.Pointer.Style := psDiamond;
  GanttSeries.Colors[GanttSeries.Count - 1] := clRed;
end;

uses
  TeeTools;

procedure AddTodayLine(Chart: TChart);
var
  TodayLine: TColorLineTool;
begin
  TodayLine := TColorLineTool.Create(Chart);
  Chart.Tools.Add(TodayLine);
  
  TodayLine.Axis := Chart.BottomAxis;
  TodayLine.Value := Now;
  TodayLine.Pen.Color := clRed;
  TodayLine.Pen.Width := 2;
  TodayLine.Pen.Style := psDash;
end;

procedure HighlightCriticalPath(GanttSeries: TGanttSeries; 
  CriticalTasks: array of Integer);
var
  i: Integer;
begin
  for i := Low(CriticalTasks) to High(CriticalTasks) do
  begin
    GanttSeries.Colors[CriticalTasks[i]] := clRed;
  end;
end;

procedure ShowResourceAllocation;
var
  Resource1, Resource2, Resource3: TGanttSeries;
begin
  // Create separate series for each resource
  Resource1 := TGanttSeries.Create(Chart1);
  Resource2 := TGanttSeries.Create(Chart1);
  Resource3 := TGanttSeries.Create(Chart1);
  
  Chart1.AddSeries(Resource1);
  Chart1.AddSeries(Resource2);
  Chart1.AddSeries(Resource3);
  
  Resource1.Title := 'Team A';
  Resource2.Title := 'Team B';
  Resource3.Title := 'Team C';
  
  // Add tasks for each resource
  Resource1.AddGantt(EncodeDate(2024, 1, 1), EncodeDate(2024, 1, 10), 0, 'Task 1');
  Resource2.AddGantt(EncodeDate(2024, 1, 5), EncodeDate(2024, 1, 15), 1, 'Task 2');
  Resource3.AddGantt(EncodeDate(2024, 1, 8), EncodeDate(2024, 1, 20), 2, 'Task 3');
end;

procedure ExportGanttData(GanttSeries: TGanttSeries);
var
  i: Integer;
  Data: TStringList;
begin
  Data := TStringList.Create;
  try
    Data.Add('Task,Start,End,Duration');
    
    for i := 0 to GanttSeries.Count - 1 do
    begin
      Data.Add(Format('%s,%s,%s,%.0f days', [
        GanttSeries.Labels[i],
        DateToStr(GanttSeries.StartValues[i]),
        DateToStr(GanttSeries.EndValues[i]),
        GanttSeries.EndValues[i] - GanttSeries.StartValues[i]
      ]));
    end;
    
    Data.SaveToFile('gantt_export.csv');
  finally
    Data.Free;
  end;
end;