UWP- double tap zoom out doesnt work

[Emil]

When i click double tap on andorid it zooms in and another double tap, zooms out.
I try the same action on UWP, zoom in works but zoom out wont work. below is my implementation of sfchart

                <chart:SfChart x:Name="Chart" SelectionChanged="Chart_SelectionChanged" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"  

                        >              

                    <chart:SfChart.PrimaryAxis>

                        <chart:DateTimeCategoryAxis AutoScrollingDelta="7"   AutoScrollingMode="End"  >

                            <chart:DateTimeCategoryAxis.Title>

                                <chart:ChartAxisTitle Text="{resx:Translate Date}"></chart:ChartAxisTitle>

                            </chart:DateTimeCategoryAxis.Title>

                        </chart:DateTimeCategoryAxis>

                    </chart:SfChart.PrimaryAxis>

                    <chart:SfChart.SecondaryAxis>

                        <chart:NumericalAxis  Minimum="0" Maximum="{Binding NumericalAxisMax}" Interval="{Binding NumericalAxisInterval}" >

                            <chart:NumericalAxis.Title>

                                <chart:ChartAxisTitle Text="{Binding NumericalAxisTitle}" ></chart:ChartAxisTitle>

                            </chart:NumericalAxis.Title>

                        </chart:NumericalAxis>

                    </chart:SfChart.SecondaryAxis>

                    <chart:SfChart.Series>

                        <chart:LineSeries EnableDataPointSelection="{Binding EnableDataPointSelection}"  XBindingPath="XValue" YBindingPath="YValue" 

                                  SelectedDataPointColor="Yellow"  ItemsSource="{Binding NumericMonthStats, Mode=OneWay}"  EnableAnimation = "true"

                                  AnimationDuration="0.8" >

                            <chart:LineSeries.DataMarker>

                                <chart:ChartDataMarker/>

                            </chart:LineSeries.DataMarker>

                        </chart:LineSeries>

                    </chart:SfChart.Series>

                    <chart:SfChart.ChartBehaviors>

                        <chart:ChartZoomPanBehavior x:Name="ZoomBehavior"  ZoomMode="X"/>

                    </chart:SfChart.ChartBehaviors>

                </chart:SfChart>

[Bharathiraja K]

Hi Emil, 

 

We have prepared the custom solution to achieve zoom in and zoom out by inheriting ChartZoomPanBehavior as a workaround for UWP. 

 

Please find the code snippet below. 

 

Note: Add below codes only for UWP. 

[C#] 

    public class CustomZoomPanBehavior: ChartZoomPanBehavior 

    { 

        protected override void DoubleTap(float pointX, float pointY) 

        { 

            if (Device.RuntimePlatform == Device.UWP) 

            { 

                if (EnableDoubleTap && !EnableSelectionZooming) 

                { 

                    var axis = Chart.PrimaryAxis; 

                    if (axis.ZoomFactor == 1 && axis.ZoomPosition == 0) 

                    { 

                        var seriesBound = Chart.SeriesBounds; 

                        var manipulationX = pointX - seriesBound.Left - Chart.ChartPadding.Left; 

                        var manipulationY = pointY - seriesBound.Top - Chart.ChartPadding.Top; 

 

                        var origin = GetOrigin(manipulationX, manipulationY, seriesBound.Width, seriesBound.Height, axis); 

 

                        Zoom(axis, 2.5f, origin); 

                    } 

                    else 

                    { 

                        Reset(); 

                    } 

                } 

            } 

            else 

            { 

                base.DoubleTap(pointX, pointY); 

            } 

        } 

 

        private static float GetOrigin(double manipulationX, double manipulationY, double width, double height, ChartAxis chartAxis) 

        { 

            float origin; 

            if (!chartAxis.IsVertical) 

            { 

                origin = (float)(chartAxis.IsInversed 

                    ? 1.0 - ((manipulationX - chartAxis.PlotOffset) / width) 

                    : (manipulationX - chartAxis.PlotOffset) / width); 

            } 

            else 

            { 

                origin = (float)(chartAxis.IsInversed 

                    ? (manipulationY - chartAxis.PlotOffset) / height 

                    : 1 - ((manipulationY - chartAxis.PlotOffset) / height)); 

            } 

 

            return origin; 

        } 

    } 

 

 

   <chart:SfChart.ChartBehaviors> 

            <local:CustomZoomPanBehavior ZoomMode="X"/> 

   </chart:SfChart.ChartBehaviors> 

 

And we have prepared the sample, that can be downloaded from below link. 

 

Sample: http://www.syncfusion.com/downloads/support/directtrac/general/ze/SimpleSample-784343048.zip  

 

Regards, 

Bharathi.