Chapter 4: A Standard Object-Oriented Solution
Code Examples
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TOC
TOC
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Example 4-1: Instantiating the V1 Features
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// segment of code that instantiates the features
// no error checking provided--for illustration
// purposes only
public class V1Model extends Model {
static public Model buildV1Model (String modelName) {
V1Model myModel= new V1Model();
myModel.modelNumber= myModel.openModel( modelName);
if (myModel.modelNumber <= 0) return null;
myModel.buildModel();
return myModel;
}
private void buildModel () {
// each feature object needs to know the model number
// and feature ID it corresponds to in order to
// retrieve information when requested. Note how
// this information is passed to each object's
// constructor
nElements= getNumberOfElements();
features= new Feature[ nElements];
// do for each feature in the model
int i;
int ID;
for (i= 0; i < nElements; i++) {
// determine feature present and create
// appropriate feature object
ID= V1.getFeatureID( modelNumber, i);
switch( V1.getFeatureType( modelNumber, ID)) {
case FEATURE_SLOT:
features[i]= new V1Slot( modelNumber, ID);
break;
case FEATURE_HOLE:
features[i]= new V1Hole( modelNumber, ID);
break;
// Other cases
}
}
}
}
Example 4-2: Implementation of V1 Methods
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// myModelNumber and myID are private members containing
// information about the model and feature (in V1) this
// feature corresponds to
public class V1Slot extends SlotFeature {
. . .
public double getX1 () {
return V1.getX1forSlot( myModelNumber, myID);
}
public double getX2 () {
return V1.getX2forSlot( myModelNumber, myID);
}
}
public class V1Hole extends HoleFeature {
. . .
public double getXLoc () {
return V1.getXforHole( myModelNumber, myID);
}
}
Example 4-3: Instantiating the V2 Features
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// segment of code that instantiates the features
// no error checking provided--for illustration
// purposes only
public class V2Model extends Model {
static public Model buildV2Model (String modelName) {
// open model
V2Model myModel= new V2Model();
if (!myModel.openModel( modelName)) return null;
myModel.buildModel();
return myModel;
}
private void buildModel () {
// each feature object needs to know the feature in the
// V2 system it corresponds to in order to retrieve
// information when requested. Note how this information
// is passed into each object's constructor
nElements= getNumberOfElements();
OOGFeature oogF;
// do for each feature in the model
int i;
for (i= 0; i < nElements; i++) {
// determine feature present and create
// appropriate feature object
oogF= getElement(i);
switch(oogF.getType()) {
case OOG_SLOT:
features[i]= new V2Slot( oogF);
break;
case OOG_HOLE:
features[i]= new V2Hole( oogF);
break;
// other cases
}
}
}
}
Example 4-4: Implementation of V2 Methods
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// oogF is a reference to the feature object in V2 that
// the object containing it corresponds to
public class V2Slot extends SlotFeature {
. . .
public double getX1 () throws Exception {
// call appropriate method on oogF to
// get needed information.
return myOogF.getX1Loc();
}
public double getX2 () throws Exception {
// call appropriate method on oogF to
// get needed information.
return myOogF.getX2Loc();
}
}
public class V2Hole extends HoleFeature {
. . .
public double getXLoc () throws Exception {
// call appropriate method on oogF to
// get needed information.
return myOogF.getXLoc();
}
}
