TapRegionSurface class

A widget that provides notification of a tap inside or outside of a set of registered regions, without participating in the gesture disambiguation system.

The regions are defined by adding TapRegion widgets to the widget tree around the regions of interest, and they will register with this TapRegionSurface. Each of the tap regions can optionally belong to a group by assigning a TapRegion.groupId, where all the regions with the same groupId act as if they were all one region.

When a tap outside of a registered region or region group is detected, its TapRegion.onTapOutside callback is called. If the tap is outside one member of a group, but inside another, no notification is made.

When a tap inside of a registered region or region group is detected, its TapRegion.onTapInside callback is called. If the tap is inside one member of a group, all members are notified.

The TapRegionSurface should be defined at the highest level needed to encompass the entire area where taps should be monitored. This is typically around the entire app. If the entire app isn't covered, then taps outside of the TapRegionSurface will be ignored and no TapRegion.onTapOutside calls will be made for those events. The WidgetsApp, MaterialApp and CupertinoApp automatically include a TapRegionSurface around their entire app.

TapRegionSurface does not participate in the gesture disambiguation system, so if multiple TapRegionSurfaces are active at the same time, they will all fire, and so will any other gestures recognized by a GestureDetector or other pointer event handlers.

TapRegions register only with the nearest ancestor TapRegionSurface.

See also:

• RenderTapRegionSurface, the render object that is inserted into the render tree by this widget.
• flutter.dev/gestures/#gesture-disambiguation for more information about the gesture system and how it disambiguates inputs.