Steema Central

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    function  LabelsWidth(Chart: tCustomChart; Axis: tChartAxis): integer;
      (* compute the width (in pixels) of the labels of this vertical axis.
       This code ASSUMES that the longest label (in chars) will be the widest
       (in pixels) *)

      var
        MaxLength: integer;
        ThisLabelValue: real;
        strLabel, strLongest: string;
        SavedFont: tTeeFont;

      begin (* LabelsWidth *)
        SavedFont := tTeeFont.Create();
        try     (* must clean up SavedFont *)
          MaxLength := 0;
          with Axis do
            begin (* Axis *)
              if Minimum > 0 then
                ThisLabelValue := trunc(Minimum / Increment) * Increment
              else if Minimum > -Increment then
                ThisLabelValue := -Increment
              else
                ThisLabelValue := - (trunc(abs(Minimum) / Increment) + 1) * Increment;

              // here with LabelValue one Increment LESS THAN actual first label
              while ThisLabelValue <= Maximum - Increment do
                begin (* test next label *)
                  ThisLabelValue := ThisLabelValue + Increment;
                  strLabel := FloatToStrF(ThisLabelValue, ffGeneral, 15, 0);
                  if length(strLabel) > MaxLength then
                    begin (* found longest to date *)
                      strLongest := strLabel;
                      MaxLength := length(strLabel)
                    end   (* found longest to date *);
                end   (* test next label *);
              SavedFont.Assign(Chart.Canvas.Font);
              Chart.Canvas.Font.Assign(LabelsFont);
              Result := Chart.Canvas.TextWidth(strLongest);

              Chart.Canvas.Font.Assign(SavedFont)
            end   (* Axis *)
        finally (* must clean up SavedFont *)
          SavedFont.Destroy
        end     (* must clean up SavedFont *)
      end   (* LabelsWidth *);

Code: Select all

        DistanceCorrection := StrToIntDef(lbedDistanceCorrection.Text, 0);
        with chartTest do
          begin (* chartTest *)
            with LeftAxis do
              begin (* LeftAxis *)
                SetMinAndMax(LeftAxis, StrToFloat(lbedMinimum.Text), StrToFloat(lbedMaximum.Text));
                PositionPercent            := StrToIntDef(lbedFPositionPercent.Text, -1);
                SetIncrement(LeftAxis);
                Texts.MarginToAxis         := StrToIntDef(lbedFMarginToAxis.Text, 0);
                LeftFLabelsWidth           := LabelsWidth(chartTest, LeftAxis);
                lbLeftFLabelsWidth.Caption := Format('L °F labels width = %d', [LeftFLabelsWidth]);
                Title.Distance             := LeftFLabelsWidth - DistanceCorrection
              end   (* LeftAxis *);

            with LeftCelsiusScale do
              begin (* LeftCelsiusScale *)
                AdjustLimits;
                PositionPercent            := StrToIntDef(lbedCPositionPercent.Text, 0);
                Texts.MarginToAxis         := StrToIntDef(lbedCLabelsMargin.Text, 0);
                LeftCLabelsWidth           := LabelsWidth(chartTest, LeftCelsiusScale);
                lbLeftCLabelsWidth.Caption := Format('L °C labels width = %d', [LeftCLabelsWidth]);
                Title.Distance             := LeftCLabelsWidth - DistanceCorrection
              end   (* LeftCelsiusScale *);