Chartlistbox and Hover Effect?

[moelski]

Hi !

Is it possible to detect if the mouse is over an item/series in the chartlistbox (without clicking the mouse)?

Let´s think about the following situation:
You have 10 or more active curves in your chart. Now the users hovers over the chartlistbox and the series items.
If there is any chance to detect the series where the mouse is over this series could be painted with a line pen width +1 as long as the mouse is over the series.

Greetz
Dominik

[Yeray]

Hi Dominik,

Taking this example as reference, it is easy to obtain the following solution:

Code: Select all

uses series;

var selectedSeries: Integer;

procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
begin
  chart1.View3D:=false;
  for i := 0 to 5 do
  begin
    Chart1.AddSeries(TFastLineSeries.Create(self));
    Chart1[i].FillSampleValues();
  end;

  Chart1.Legend.CheckBoxes:=true;
  selectedSeries:=-1;
end;

procedure TForm1.Chart1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
var i: Integer;
    tmpPnt: TPoint;
    tmpRect: TRect;
begin
  tmpPnt.X:=X;
  tmpPnt.Y:=Y;

  for i:=0 to Chart1.SeriesCount-1 do
  begin
    tmpRect.Left:=Chart1.Legend.Left;
    tmpRect.Right:=Chart1.Legend.Left + Chart1.Legend.Width - 1;
    tmpRect.Bottom:=Chart1.Legend.Item[i].Top + Chart1.Legend.Item[i].SymbolRect.Bottom - Chart1.Legend.Item[i].SymbolRect.Top + 3;

    if (i = 0) then tmpRect.Top:=Chart1.Legend.Item[i].Top-3
    else tmpRect.Top:=Chart1.Legend.Item[i].Top-2;

    if PtInRect(tmpRect,tmpPnt) then
    begin
      if selectedSeries>-1 then Chart1[selectedSeries].Pen.Width:=1;
      selectedSeries:=i;
      Chart1[selectedSeries].Pen.Width:=3;
      break;
    end;
  end;
end;

[moelski]

Hi Yeray,

that´s not what I need.

I want to hover over the ChartListBox - not over the Chart.

In easy words I need this:
Hover over a series in the ChartListBox and repaint the corresponding series with a line width +1 (as long as the hover takes).

[Yeray]

Hi Dominik,

Excuse me, I missed that. But the solution for a ChartListBox isn't very different:

Code: Select all

uses series;

var selectedSeries: Integer;

procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
begin
  ChartListBox1.Chart:=Chart1;
  chart1.View3D:=false;
  for i := 0 to 5 do
  begin
    Chart1.AddSeries(TFastLineSeries.Create(self));
    Chart1[i].FillSampleValues();
  end;

  Chart1.Legend.Visible:=false;
  selectedSeries:=-1;
end;

procedure TForm1.ChartListBox1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
var i: Integer;
    tmpPnt: TPoint;
    tmpRect: TRect;
begin
  tmpPnt.X:=X;
  tmpPnt.Y:=Y;

  for i:=0 to Chart1.SeriesCount-1 do
  begin
    if PtInRect(ChartListBox1.ItemRect(i),tmpPnt) then
    begin
      if selectedSeries>-1 then Chart1[selectedSeries].Pen.Width:=1;
      selectedSeries:=i;
      Chart1[selectedSeries].Pen.Width:=2;
      break;
    end;
  end;
end;