MacApp 2.0 Object And Method Reference

MacApp 2.0 Object and Method Reference ( This chapter describes the object classes that existed in MacApp 1.1. If you need infonnation on classes and methods not described here, refer to other release notes and to the source code. . Each object description in this chapter contains the following elements: • • • • • whether you customize the object type. instantiate it, or call its methods notes about the Object type the chain of ancestors leading to the object type field declarations and explanations descriptions of the methods for each object type Important Complete Information about the Implementation of each method Is not given In this chapter. It you _ need further details ab6ut any method, refer to the MocApp source code. TObject Customize: usually Instantiate: never Call methods: usually TObject is the ultimate ancestor for all objects in MacApp. TObject is documented here primarily for background information. It is an abstract object type that exists so that other object types can inherit characteristics from it, and thus share them. The only TObject methods you might override are Free and Clone. Ancestors: none Fields none MocApp 2.0 Globels 10/3/88 Page 1 Clone FUNCTION TOb ject. Clone: TOb ject; The return value An exact copy of the calling object Purpose To clone dependent objects referred to by the fields of an object as well as cloning the object itself. An object is dependent on another object when the second object has the only (or the only important) reference to the fU'St object Dependency is a relatively vague condition; when you override this method. you need to determine what objects are dependent on SELF. The default version Calls ShallowClone. and thus clones only the object itself Override Sometimes Call Sometimes Free PROCEDURE TObject.Free; Purpose To free the calling object and any dependent objects referred to by its fields. An' object is dependent on another object when the second object has the only (or the only important) reference to the fU'St object Dependency is a relatively vague condition; when you override this method. you need to determine what objects are dependent on SELF. The default version Calls ShallowFree Override Often. Your version should free any dependent objects you have added for your customization and then call INHERITED Free so that any ancestor methods can free other dependent objects. The chain of INHERlTED calls leads to TObjectFree. which calls TObject.ShallowFree. which frees SELF. Call Often ShallowClone FUNCTION TObject.ShallowClone: TObject; The return value Purpose This is the lowest-level method for copying an object Called by TObjectOone The default version Calls HandToHand. an Inside Macintosh routine, to copy the object data Override Never Call Rarely MacApp 2.0 Globals 10/3/88 Page 2 Shallow Free PROCEDURE ( TObject.ShallowFree; Purpose This is lhe lowest-level method for freeing an object Called by TObjecLFree The default v…