PrintOperation.PaginateCallback (java-gi API)

All Superinterfaces:: FunctionPointer

Enclosing class:: PrintOperation

Functional Interface:: This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface public static interface PrintOperation.PaginateCallback extends FunctionPointer

Functional interface declaration of the PaginateCallback callback.

See Also:

Method Summary

Modifier and Type

Method

Description

boolean

run(@Nullable PrintContext context)

Emitted after the ::begin-print signal, but before the actual rendering starts.

default MemorySegment

toCallback(Arena arena)

Creates a native function pointer to the upcall(java.lang.foreign.MemorySegment, java.lang.foreign.MemorySegment) method.

default int

upcall(MemorySegment sourcePrintOperation, MemorySegment context)

The upcall method is called from native code.

Method Details
- run
  
  boolean run(@Nullable PrintContext context)
  
  Emitted after the ::begin-print signal, but before the actual rendering starts.
  It keeps getting emitted until a connected signal handler returns true.
  The ::paginate signal is intended to be used for paginating a document in small chunks, to avoid blocking the user interface for a long time. The signal handler should update the number of pages using PrintOperation.setNPages(int), and return true if the document has been completely paginated.
  If you don't need to do pagination in chunks, you can simply do it all in the ::begin-print handler, and set the number of pages from there.
- upcall
  
  default int upcall(MemorySegment sourcePrintOperation, MemorySegment context)
  
  The upcall method is called from native code. The parameters are marshaled and run(org.gnome.gtk.PrintContext) is executed.
- toCallback
  
  default MemorySegment toCallback(Arena arena)
  
  Creates a native function pointer to the upcall(java.lang.foreign.MemorySegment, java.lang.foreign.MemorySegment) method.
  
  Specified by:
  
  toCallback in interface FunctionPointer
  
  Parameters:
  
  arena - the arena in which the function pointer is allocated
  
  Returns:
  
  the native function pointer