Review

Review

1. It is worth starting by reviewing the aspects of Grace program structure you have been exposed to in class.
   • Each program is constructed by completing an object definition.
   • An object definition consists of an object keyword followed by a collection of
     • An (optional) inherits statement
     • definition and variable declarations
     • Initialization code
     • method definitions

     all grouped within curly braces.

   • A method definition consists of a method header followed by a list of statements grouped by curly braces.
   • A method's name determines when the statements in the method are performed. In particular, the following names associate instructions with user actions:
     • onMousePress
     • onMouseRelease
     • onMouseClick
     • onMouseEnter
     • onMouseExit
     • onMouseMove
     • onMouseDrag
   • There are (at least) three kinds of statements:
     • constructions, e.g., filledRect.at()size()on() ,
     • method invocations, e.g. canvas.clear,
     • assignments, e.g., upText := ... )

Review