Hints Over the Line

How can I display the X and Y point's values and text label moving mouse through the Line chart and chart Legend ?

Download ActiveX Visual Basic 6 example source code

Download Borland Delphi example source code

ActiveX Code :

Dim OnSeriesPoint As Boolean
Dim OnLegendPoint As Boolean

Private Sub Form_Load()
With TChart1
    .Aspect.View3D = False
    .AddSeries scLine
    .Series(0).FillSampleValues 10
    .Axis.Bottom.Labels.DateTimeFormat = "dd/mm/yy hh:mm:ss"
End With
End Sub

Private Sub TChart1_OnMouseMove(ByVal Shift As TeeChart.EShiftState, ByVal X As Long, ByVal Y As Long)
Dim tmpL, tmpL2, ClickedValue As Integer

ClickedValue = -1
tmpL = -1
tmpL2 = 1000

With TChart1
    If .Series(0).Clicked(X, Y) <> -1 And Not OnSeriesPoint Then
        .Canvas.Brush.Style = bsSolid
        .Canvas.Pen.Color = vbBlack
        .Canvas.Brush.Color = vbWhite
        .Canvas.TextOut X + 10, Y, TChart1.Axis.Bottom.Labels.FormattedValue(.Series(0).XScreenToValue(X)) _
        & ", " & Str$(TChart1.Axis.Left.Labels.FormattedValue(.Series(0).YScreenToValue(Y)))
        OnSeriesPoint = True
        ClickedValue = .Series(0).Clicked(X, Y)
    End If
    'Repaint Chart to clear Textoutputted Mark
    If ClickedValue = -1 And OnSeriesPoint Then
        OnSeriesPoint = False
        .Repaint
    End If

    tmpL = TChart1.Legend.Clicked(X, Y)
    If tmpL <> -1 And ((tmpL <> tmpL2) Or (Not OnLegendPoint)) Then
        .Repaint
        .Canvas.Brush.Color = .Series(0).LegendItemColor(tmpL)
        .Canvas.Rectangle X, Y, X + 20, Y + 20
        .Canvas.Brush.Color = vbWhite
        .Canvas.TextOut X + 20, Y + 7, Str$(.Series(0).YValues.Value(.Series(0).LegendToValueIndex(tmpL))) & " "
        tmpL2 = tmpL
        OnLegendPoint = True
    End If

    If tmpL = -1 And OnLegendPoint Then
        OnLegendPoint = False
        .Repaint
    End If
End With
End Sub

VCL  Code :

unit UHintsOverLine;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms,
Dialogs, TeEngine, Series, ExtCtrls, TeeProcs, Chart;

type
  TForm1 = class(TForm)
  Chart1: TChart;
  Series1: TLineSeries;
  procedure FormCreate(Sender: TObject);
  procedure Chart1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
  private
  { Private declarations }
    OnSeriesPoint : Boolean;
    OnLegendPoint : Boolean;
  public
  { Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
    Series1.FillSampleValues(10);
    Chart1.View3D := False;
end;

procedure TForm1.Chart1MouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
var tmpL,tmpL2,ClickedValue : Integer;
begin
    clickedvalue := -1;
    tmpL2:= -1;

    With Chart1 do
    begin
        If (Series1.Clicked(X, Y) <> -1) And (not OnSeriesPoint) Then
        begin
            Canvas.Brush.Style := bsSolid;
            Canvas.Pen.Color := clBlack;
            Canvas.Brush.Color := clWhite;
            Canvas.TextOut(x+10,y,FormatFloat('#.00',Series1.XScreenToValue(x))+','+FormatFloat('#.00',Series1.YScreenToValue(y)));
            OnSeriesPoint := True;
            ClickedValue:= Series1.Clicked(x,y);
        End;

        //Repaint Chart to clear Textoutputted Mark
        If (ClickedValue=-1) And (OnSeriesPoint) Then
        begin
            OnSeriesPoint := False;
            invalidate;
        End;

        tmpL := Chart1.Legend.Clicked(X, Y);

        If (tmpL <> -1) And ((tmpL <> tmpL2) Or (not OnLegendPoint)) Then
        begin
            repaint;
            Canvas.Brush.Color := Series1.LegendItemColor(tmpL);
            Canvas.Rectangle( X, Y, X + 20, Y + 20);
            Canvas.Brush.Color := clWhite;
            Canvas.TextOut(x+15,y+7,FormatFloat('#.00',Series1.XValues.Items[Series1.LegendToValueIndex(tmpl)]));
            tmpL2 := tmpL;
            OnLegendPoint := True;
        End;

        If (tmpL2 = -1) And (OnLegendPoint) Then
        begin
            OnLegendPoint := False;
            Invalidate;
        End;
    End;
End;

End.