Steema Central

Code: Select all

procedure TPlot2DuxF.ISO(Sender: TObject);
var
  MarginsSize, XYScreen: double;
  ChartSizeAdjustment: integer;
  newBottomAxisWidth, NewLeftAxisHeight: integer;
  ScreenAspectRatio, DataAspectRatio: double; { W/H }
begin
  // Does not work for a maximized window because it cannot change the shape of the screen!
  // code adjusts the length of the left and bottom axes and thus the size of the chart and
  // assumes that the window will change in size to accommodate.
  Chart.Axes.Left.Automatic := false;
  { needed to get Axis min and max not data }
  Chart.Axes.bottom.Automatic := false;
  XYScreen := 1.0 * (GetDeviceCaps(Canvas.Handle, HORZSIZE) / Screen.Width) /
    (GetDeviceCaps(Canvas.Handle, VERTSIZE) / Screen.Height);

  if ((Chart.BottomAxis.Maximum - Chart.BottomAxis.Minimum) > 0) and
    ((Chart.BottomAxis.Maximum - Chart.BottomAxis.Minimum) > 0) then
  begin { data exists in chart, safe to rescale }
    ScreenAspectRatio := (Chart.ChartWidth / Chart.ChartHeight) / XYScreen;
    DataAspectRatio := (Chart.BottomAxis.Maximum - Chart.BottomAxis.Minimum) /
      (Chart.LeftAxis.Maximum - Chart.LeftAxis.Minimum);

    if DataAspectRatio > ScreenAspectRatio then
    begin { form too high, expand Width }
      newBottomAxisWidth := round(Chart.ChartHeight * DataAspectRatio);
      ChartSizeAdjustment := newBottomAxisWidth - Chart.ChartWidth;
      if Chart.MarginUnits = muPercent then { allow for margins }
        MarginsSize := (Chart.MarginLeft + Chart.MarginRight) / 100
      else
        MarginsSize := 0;
      Plot2DuxF.ClientWidth := self.ClientWidth - Chart.ChartWidth +
        newBottomAxisWidth + round(MarginsSize * ChartSizeAdjustment);
    end
    else
    begin { form too wide, expand Height }
      NewLeftAxisHeight := round(Chart.ChartWidth / DataAspectRatio);
      ChartSizeAdjustment := NewLeftAxisHeight - Chart.ChartHeight;
      if Chart.MarginUnits = muPercent then // allow for margins
        MarginsSize := (Chart.MarginTop + Chart.MarginBottom) / 100
      else
        MarginsSize := 0;
      Plot2DuxF.ClientHeight := self.ClientHeight - Chart.ChartHeight +
        NewLeftAxisHeight + round(MarginsSize * ChartSizeAdjustment);
    end;
  end;
  Chart.Invalidate;
end { ISO };