AutoXFit without scaling when zooming or panning

[Salto]

Hello

I need a diagram with automatic scaling of the x-axis and the y-axis.

For the y-Axis, i can use AutoYFit:

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_lightningChart.ViewXY.ZoomPanOptions.AutoYFit.Enabled = true;

For the x-Axis (and also y-Axis), i can use:

Code: Select all

_xAxis.SetRange(0, xMax);

if i add one or more points.

My problem is, when i zoom into the chart and new points are added to the chart, the selected zoom range changed. Is there a solution(an event) to find out when you zoom into the chart and when the zoom is reset (revertToRange with the rectangle with the mouse). I also need to know if the diagram is panning or reset.
The code should look like this:

Code: Select all

if (!zooming && ! panning)
{
    _xAxis.SetRange(0, xMax); //or yAxis
}

I hope you can help me, thank you
Raphael

[ArctionPasi]

Hello Raphael,

_lightningChart.ViewXY.FitView() also makes auto-fit of both X and Y axes, to the whole data contents.

Axes have RangeChanged event. You can use that to store the range in your
private double _xMin, _xMax, _yMin, _yMax variables.

Then in the RangeChanged event, you can use a logic like the following
bool zoomed = false;
bool panned = false;

if( (newXMax-newXMIn) != (_xMax-_xMin))
{
zoomed = true;
}
else if(newXMin != _xMin)
{
panned = true;
}

something like this?

[Salto]

Hello Pasi

Thank you for your fast answer. Your idea is good, but I've a problem with the reset from the zoom. I've the following methods for each axis:

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        /// <summary>
        /// Update the min and the max value if they are larger than the current one.
        /// </summary>
        /// <param name="min">
        /// The min value from the new points.
        /// </param>
        /// <param name="max">
        /// The max value from the new points.
        /// </param>
        public void UpdateMinMax(double min, double max)
        {
            bool updateMax = false;
            bool updateMin = false;
            if (max > _max)
            {
                _max = max;
                _lightningChartAxisXYBase.RangeRevertMaximum = _max;
                updateMax = _autoScale && !_zoomed && !_panned;
            }

            if (min < _min || (!_includeZero && _min == 0))
            {
                _min = min;
                _lightningChartAxisXYBase.RangeRevertMinimum = _min;
                updateMin = _autoScale && !_zoomed && !_panned;
            }

            if (updateMin && updateMax)
            {
                _lightningChartAxisXYBase.SetRange(_min, _max);
            } 
            else if (updateMax)
            {
                _lightningChartAxisXYBase.Maximum = _max;
            }
            else if (updateMin)
            {
                _lightningChartAxisXYBase.Minimum = _min;
            }
        }

        private void LightningChartAxisBaseOnRangeChanged(double newMin, double newMax, Arction.WPF.LightningChartUltimate.Axes.AxisBase axis, ref bool cancelRendering)
        {
            _zoomed = false;
            _panned = false;

            if ((newMax - newMin) != (_max - _min))
            {
                _zoomed = true;
            }
            else if (newMin != _min)
            {
                _panned = true;
            }
        }

When I reset the zoom (rectangle with the mouse), I've the following values (y-axis):
(this._lightningChartAxisXYBase).RangeRevertMaximum 1.014568843
(this._lightningChartAxisXYBase).RangeRevertMinimum 0.900584273
_max 1.014568843
_min 0.900584273
newMax 1.0173329030115472
newMin 0.8980834567990762
newMax-_max 0.0027640600115472758
_min-newMin 0.0025008162009237944

There is a margin or something else. With a delta, it works, but that's not the correct solution.

Code: Select all

private void LightningChartAxisBaseOnRangeChanged(double newMin, double newMax, Arction.WPF.LightningChartUltimate.Axes.AxisBase axis, ref bool cancelRendering)
        {
            _zoomed = false;
            _panned = false;

            if (Math.Abs((newMax - newMin) - (_max - _min)) > 0.008)
            {
                _zoomed = true;
            }
            else if (Math.Abs(newMin - _min) > 0.008)
            {
                _panned = true;
            }
        }

I've disabled the AutoYFit and MarginPixels, but nothing works.

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            _lightningChart.ViewXY.ZoomPanOptions.AutoYFit.Enabled = false;
            _lightningChart.ViewXY.ZoomPanOptions.AutoYFit.MarginPercents = 0;
            _lightningChart.ViewXY.ZoomPanOptions.ViewFitYMarginPixels = 0;

Do you have an idea for my problem?

[Salto]

Hello again

I've found the problem. I've in a chartstyle set the ZoomPanViewFitYMarginPixels to 10 pixels
Thank you for your help!