Design Patterns Explained

18O Part III • Design Patterns
Supplement: C++ Code Examples
Example 1O-4 C++ Code Fragments: A Switch
to Control Which Driver to Use
// C++ CODE FRAGMENT
// class ApControl
void ApControl::doDraw (} {
. . .
switch (RESOLUTION)
{ case LOW:
// use Irdd
case HIGH: //
use hrdd
}
}
void ApControl::doPrint () {
. . .
switch (RESOLUTION)
{ case LOW:
// use lrpd
case HIGH:
// use hrpd } }
Example 1O-5 C++ Code Fragments: Using
Polymorphism to Solve the Problem
// C++ CODE FRAGMENT
// class ApControl
void ApControl::doDraw () {
myDisplayDriver->draw();
}
void ApControl::doPrint () {
myPrintDriver->print();
}