Questions

Hi Peter,

You can customize legend item appearance this way:
1. define custom layout for legend item ( I’m using the same layout as default item and you can replace LegendPointMarker on custom View which draws anything you want )

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/legendItemMargin"
android:orientation="horizontal">

<CheckBox
    android:id="@+id/isVisible"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:textSize="@dimen/legendTextSize"
    android:layout_marginLeft="@dimen/legendItemCheckBoxNegativeMargin"
    android:layout_marginTop="@dimen/legendItemCheckBoxNegativeMargin"
    android:layout_marginRight="@dimen/legendItemCheckBoxNegativeMargin"
    android:layout_marginBottom="@dimen/legendItemCheckBoxNegativeMargin" />

<com.scichart.charting.visuals.legend.LegendPointMarker
    android:id="@+id/pointMarker"
    android:layout_width="@dimen/legendItemPointMarkerWidth"
    android:layout_height="match_parent"
    android:layout_gravity="center"
    android:layout_margin="@dimen/legendItemPointMarkerMargin"
    android:layout_marginTop="@dimen/legendItemPointMarkerMargin" />

<TextView
    android:id="@+id/name"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_vertical|start"
    android:layout_marginEnd="@dimen/legendItemSeriesNameRightMargin"
    android:layout_marginStart="@dimen/legendItemSeriesNameLeftMargin"
    android:textSize="@dimen/legendTextSize"
    android:textStyle="bold" />

</LinearLayout>

1. Then you need to create a custom class which implements ILegendItem ( wrapper for legend View ) and ILegendItemFactory ( factory which can create items ) interfaces:

   class CustomLegendItemFactory implements ILegendItemsFactory {
   
   @Override
   public ILegendItem createLegendItem(ViewGroup parent) {
       return new CustomLegendItem(LayoutInflater.from(parent.getContext()).inflate(R.layout.custom_legend_item, null));
   }
   }
   
   class CustomLegendItem extends LegendItemBase {
   protected final TextView name;
   protected final CheckBox checkBox;
   protected final LegendPointMarker pointMarker;
   
   public CustomLegendItem(@NonNull View itemView) {
       super(itemView);
   
       name = (TextView) itemView.findViewById(com.scichart.charting.R.id.name);
       checkBox = (CheckBox) itemView.findViewById(com.scichart.charting.R.id.isVisible);
       pointMarker = (LegendPointMarker) itemView.findViewById(com.scichart.charting.R.id.pointMarker);
   }
   
   @Override
   public void bindSeriesInfo(Object source, SciChartLegend legend) {
       final SeriesInfo seriesInfo = (SeriesInfo) source;
   
       name.setText(seriesInfo.seriesName);
       checkBox.setChecked(seriesInfo.isVisible());
       checkBox.setVisibility(legend.getShowCheckboxes() ? View.VISIBLE : View.GONE);
       checkBox.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View view) {
               IRenderableSeries renderableSeries = seriesInfo.renderableSeries;
               renderableSeries.setIsVisible(((CheckBox) view).isChecked());
               renderableSeries.invalidateElement();
           }
       });
       pointMarker.setColor(seriesInfo.seriesColor);
       pointMarker.setVisibility(legend.getShowSeriesMarkers() ? View.VISIBLE : View.GONE);
   
       ThemeManager.applyTheme(this, legend.getTheme(), legend.getContext());
   }
   
   @Override
   public void applyThemeProvider(IThemeProvider themeProvider) {
       final FontStyle legendLabelTextStyle = themeProvider.getDefaultLabelTextStyle();
       legendLabelTextStyle.initTextView(name);
   }
   }
   

   You’ll need to customize bindSeriesInfo() here and instead of pointMarker get your own View and set color to draw.

2. And finally use factory to create LegendModifier and add it into chart’s modifier collection:

               legendModifier = new LegendModifier(new SciChartLegend(getActivity()), new SeriesInfoLegendAdapter(new CustomLegendItemFactory()), true);
   
           ModifierGroup modifierGroup = sciChartBuilder.newModifierGroup()
                   .withModifier(legendModifier)
                   .build();
   

By default SciChart library has next dimension which is used by Legend items:

<dimen name="legendTextSize">10sp</dimen>
<dimen name="legendItemMargin">4dp</dimen>
<dimen name="legendItemPointMarkerMargin">4dp</dimen>
<dimen name="legendItemPointMarkerWidth">40dp</dimen>
<dimen name="legendItemSeriesNameLeftMargin">4dp</dimen>
<dimen name="legendItemSeriesNameRightMargin">1dp</dimen>

<!--use negative margin to reduces empty space around check box-->
<dimen name="legendItemCheckBoxNegativeMargin">-5dp</dimen>

Hope this will help you!

Best regards,
Yura