Chart Modifier APIs
Within the SciChart SDK, ChartModifiers are the classes which can be added to a chart to give it a certain behaviour. For instance, all zooming, panning operations, tooltips, legends and even selection of points or lines are handled by
SCIChartModifierBase derived classes in the SciChart codebase.
There are many different ChartModifiers provided by SciChart and each one deserves an article by itself! This article is concerned with simply giving an overview of the modifiers and where you can find the examples in our SciChart iOS Examples Suite which demonstrate them.
There are also several individual articles on the ChartModifier’s and how to configure them in the SciChart iOS. Those could be grouped like the following:
Zoom and Pan Modifiers
The following modifiers can be used if you want to add scrolling or zooming behavior to a chart:
|SCIZoomExtentsModifier||Resets the zoom to the data extents via double-tapping. Available almost everywhere, e.g. see the Sync Multi Chart example.|
|SCIPinchZoomModifier||Zooms a chart in and out via the pinch and spread gestures correspondingly. Available almost everywhere, e.g. see the Multiple X-Axes example.|
|SCIZoomPanModifier||Pans the chart in X, Y or both directions with inertia via finger sliding. Available almost everywhere, e,g. see the Multiple X-Axes example.|
|SCIXAxisDragModifier||Scales or pans an X Axis via finger drag. See Drag Axis to Scale a Chart example.|
|SCIYAxisDragModifier||Scales or pans an Y Axis via finger drag. See Drag Axis to Scale a Chart example.|
These modifiers allow to interact with chart series or inspect them:
|SCISeriesSelectionModifier||Provides selection of a series via tapping on it. See the Series Selection example.|
|SCITooltipModifier||Provides a tooltip for the nearest point on a series under the finger. See the Using TooltipModifier example.|
|SCIRolloverModifier||Provides a vertical slice cursor with tooltips and markers rolling over a series. See the Using RolloverModifier example.|
|SCICursorModifier||Provides a crosshairs with a tooltip and axis labels. See Using CursorModifier example.|
Modifiers below are used as helpers and can be a useful addition to a chart:
|SCIModifierGroup||Can be used to group chart modifiers together. This can useful in multi-chart scenarios, to unite ModifierGroups into one EventGroup of modifiers. If an Event occurs on a chart, it will be propagated to modifiers from other charts that are in the same EventGroup. See the Multi-Panel Stock Chart example.|
|SCILegendModifier||Allows to creates and configure a Legend for a chart. See the Legend Chart example.|
|SCISeriesValueModifier||A custom ChartModifier which places an
NOTE: To learn more about ChartModifiers API, please read the Common ChartModifiers Features section. To find out more about a specific ChartModifier, please refer to a corresponding article about this Modifier type.
Adding a Chart Modifier
All 2D Chart Modifiers are inherited from
SCIChartModifierBase, conforms to the
ISCIChartModifier and are added to the
SCIChartModifierCollection which is stored in
Please see the code below, to see how to add SCIPinchZoomModifier to your
Common Chart Modifier Features
As mentioned above - all the ChartModifiers provided by SciChart conforms to the
ISCIChartModifier protocol and derive from the
These provide a powerful API which gives the full access to internals of a chart, axes, series, annotations.
It is a must that Custom Modifiers implement
ISCIChartModifier, and hence we recommend inheriting
SCIChartModifierBase in such cases as well to get some base implementation for free.
Please see the list of common features below:
||Returns the ModifierSurface from the parental
||Value which indicates whether a modifier is attached to a
||Allows to specify if a modifier should be available for interaction or not.|
||Allows to specify whether a modifier should receive events handled by another modifier.|
SCIModifierGroup allows grouping of modifiers. This can be useful if modifiers create a logical group within which they are handled together.
For example, all modifiers inside a
SCIModifierGroup can be enabled/disabled together via the
ISCIChartModifierCore.isEnabled property on the
Also, this is useful in multi-chart scenarios. Several
SCIModifierGroups can be united to share events between charts.
This can be done by setting
SCIModifierGroup.eventGroup to be the same for ModifierGroups which belong to different
||Allows to specify which EventGroup this modifier goes in. It is used to share events between modifiers that belong to different surfaces.|
||Returns the ModifierSurface which is the source of the events.|
||Assigns a collection of modifiers to a ModifierGroup. Also a collection can be passed into the class constructor during creation.|