PdfScrollIndicatorBuilder typedef

PdfScrollIndicatorBuilder = Widget Function(BuildContext context, PdfViewerController controller, PdfScrollMetrics metrics)

Signature for PdfViewer.scrollIndicatorBuilder: builds a custom main-axis scroll indicator (a compact page number, a draggable page scrubber, a platform-styled bar) in place of the viewer's built-in scrollbar. It fills the viewer, rebuilt whenever the scroll position, zoom, or current page changes; use PdfScrollMetrics.scrollAxis to orient it - the viewer's right edge for a vertical PdfPageLayout.verticalContinuous layout, the bottom edge for a horizontal PdfPageLayout.horizontalContinuous one.

Use metrics for the page count, the layout axis, and the normalized position/extent, and drive the view through controller - PdfViewerController.jumpToNormalized for a scrubber-thumb drag, PdfViewerController.jumpToPage or PdfViewerController.animateToPage for page taps. Return an empty widget (e.g. SizedBox.shrink()) to show nothing; the indicator is not built at all before the viewer has laid out or when the document does not overflow (PdfScrollMetrics.hasOverflow is false), so a builder never has to guard those cases.

Implementation

typedef PdfScrollIndicatorBuilder = Widget Function(BuildContext context,
    PdfViewerController controller, PdfScrollMetrics metrics);