PyObjC - API Notes for the CoreGraphics bindings

Introduction

This document describes special considerations for the PyObjC based CoreGraphics bindings.

Callbacks

The userinfo for CGDataConsumerCreate, CGDataProviderCreate, CGDataProviderCreateDirect, CGDataProviderCreateDirectAccess, CGDataProviderCreateSequential, CGDataProviderCreateWithData, CGDisplayRegisterReconfigurationCallback, CGDisplayRemoveReconfigurationCallback, CGFunctionCreate, CGRegisterScreenRefreshCallback, CGReleaseScreenRefreshRects, CGScreenRegisterMoveCallback, CGScreenUnregisterMoveCallback, CGUnregisterScreenRefreshCallback, CGPDFDictionaryApplyFunction, CGPathApply, CGPatternCreate, CGEventTapCreate, CGEventTapCreateForPSN, CGPDFOperatorTableSetCallback and CGPSConverterCreate can be any Python object.

The function arguments for these functions can be any Python callable, including bound methods. Functions mentioned earlier that have a struct with callback functions take in tuple with those callbacks in Python.

CGEventTapCreate and CGEventTapCreateForPSN leak some memory when they are called. This is needed to avoid memory management problems. It is therefore advisable not to call these functions, are at least call them a small number of times.

CGPDFOperatorTableSetCallback is not supported at the moment.