Change to Data Provider Model

Author: UltimatePea

src/paintcomponents/DataFromPoint.java

@@ -11,10 +11,9 @@
  *
  */
 public class DataFromPoint<T> extends SimplePoint {
-	
-	
-	DataLineSegment<T> lineSegment;
-	Queue<T> datas;
+
+	private DataLineSegment<T> lineSegment;
+	private DataFromPointDataProvider<T> provider;
 
 	/**
 	 * @return the lineSegment
@@ -33,20 +32,32 @@ public void setLineSegment(DataLineSegment<T> lineSegment) {
 
 	public DataFromPoint(int x, int y) {
 		super(x, y);
-		datas = new LinkedBlockingQueue<>();
-	}
-	
-	public void offer(T data){
-		this.datas.offer(data);
 	}
-	
+
 	/**
-	 * Fetches the data, users should not try to call this method, except from DataToPoint class
-	 * returns null if the underlying queue is empty.
+	 * Fetches the data, users should not try to call this method, except from
+	 * DataToPoint class
+	 * 
 	 * @param data
+	 * @throws DataFromPointNoDataProviderException if provider for this method is not set
+	 * @throws DataFromPointProviderCannotProvideDataException if the provider cannot provide such information
 	 */
-	protected T poll(){
-		return this.datas.poll();
+	protected T getData() throws DataFromPointNoDataProviderException, DataFromPointProviderCannotProvideDataException {
+		if (this.provider == null){
+			throw new DataFromPointNoDataProviderException();
+		}
+		if (!this.provider.canProvideInformationToDataFromPoint(this)){
+			throw new DataFromPointProviderCannotProvideDataException();
+		}
+		return this.provider.provideInformationToDataFromPoint(this);
+	}
+
+	public DataFromPointDataProvider<T> getProvider() {
+		return provider;
+	}
+
+	public void setProvider(DataFromPointDataProvider<T> provider) {
+		this.provider = provider;
 	}
 
 }

src/paintcomponents/DataFromPointDataProvider.java

@@ -0,0 +1,11 @@
+package paintcomponents;
+
+
+public interface DataFromPointDataProvider<T> {
+
+	public T provideInformationToDataFromPoint(DataFromPoint<T> dataFromPoint);
+	public boolean canProvideInformationToDataFromPoint(DataFromPoint<T> dataFromPoint);
+		
+	
+	
+}

src/paintcomponents/DataFromPointNoDataProviderException.java

@@ -0,0 +1,5 @@
+package paintcomponents;
+
+public class DataFromPointNoDataProviderException extends Exception {
+
+}

src/paintcomponents/DataFromPointProviderCannotProvideDataException.java

@@ -0,0 +1,5 @@
+package paintcomponents;
+
+public class DataFromPointProviderCannotProvideDataException extends Exception {
+
+}

src/paintcomponents/DataInputTextfieldPaintComponent.java

@@ -12,7 +12,7 @@
  * @author chenzb
  *
  */
-public class DataInputTextfieldPaintComponent extends DataTextPaintComponent {
+public class DataInputTextfieldPaintComponent extends DataTextPaintComponent implements DataFromPointDataProvider<String> {
 
 
 	private static final int HORIZONTAL_OFFSET = 10;
@@ -22,6 +22,7 @@ public DataInputTextfieldPaintComponent(String displayingText, int x,
 			int y) {
 		super(displayingText, x, y);
 		this.fromPoint = new DataFromPoint<>(x, y);
+		fromPoint.setProvider(this);
 	}
 
 	@Override
@@ -60,8 +61,19 @@ public boolean contains(int x, int y) {
 	}
 
 	public void inputData(String s) {
-		fromPoint.offer(s);
 		this.setDisplayingText(s);
 	}
+
+	@Override
+	public String provideInformationToDataFromPoint(
+			DataFromPoint<String> dataFromPoint) {
+		return displayingText;
+	}
+
+	@Override
+	public boolean canProvideInformationToDataFromPoint(
+			DataFromPoint<String> dataFromPoint) {
+		return displayingText == null;
+	}
 
 }

src/paintcomponents/DataToPoint.java

@@ -37,11 +37,13 @@ public DataToPoint(int x, int y) {
 	 * 
 	 * @throws NoConnectingLineSegmentException when this point is not connected to a valid line segment
 	 * @throws NoSuchElementException when the connecting in point does not have a data to offer
+	 * @throws DataFromPointProviderCannotProvideDataException  when the connecting dataInputPoint's data provider cannot provide a information
+	 * @throws DataFromPointNoDataProviderException  when the connecting DataInputPoint does not have a data provider associated
 	 */
-	public T fetchData() throws NoConnectingLineSegmentException, NoSuchElementException{
+	public T fetchData() throws NoConnectingLineSegmentException, NoSuchElementException, DataFromPointNoDataProviderException, DataFromPointProviderCannotProvideDataException{
 		if(this.lineSegment == null) throw new NoConnectingLineSegmentException();
 
-		T returnVal = lineSegment.getFromPoint().poll();
+		T returnVal = lineSegment.getFromPoint().getData();
 		if(returnVal == null) throw new NoSuchElementException();
 		return returnVal;