Merge branch 'develop' of https://github.com/UCSDOalads/JavaSketchPad into updateMenuBarbyKent

Author: kent0318

src/actions/ConstructLineSegmentAction.java

@@ -1,5 +1,6 @@
 package actions;
 
+import java.awt.Component;
 import java.util.ArrayList;
 
 import paintcomponents.LineSegment;
@@ -20,12 +21,32 @@ public boolean canPerformAction() {
 		//only two points can be selected
 		if(items.size() != 2) return false;
 		//selected component must be of type point
+		
 		for (PaintComponent paintComponent : items) {
 			if(!(paintComponent instanceof SimplePoint)){
 				return false;
 			}
 		}
-		//TODO If line segment already exists, do not add again!!!
+		
+		//check if line segment already exist
+		// if exists, then it will not form a new line segment
+		ArrayList<PaintComponent> components = panel.getPaintComponents();
+		LineSegment line = null;
+		
+		//get all paintComponents
+		for(PaintComponent paintComponent : components) {
+			if( paintComponent instanceof LineSegment ) {
+				line = (LineSegment) paintComponent;
+				//check front point and to point similarities
+				if(items.get(0) == line.getFromPoint() && 
+					items.get(1) == line.getToPoint())
+					return false;
+				if(items.get(1) == line.getFromPoint() && 
+					items.get(0) == line.getToPoint())
+					return false;
+			}
+		}
+		
 		//TODO Do not allow adding two line segments connecting the same point
 		return true;
 

src/ui/PaintPanel.java

@@ -177,6 +177,10 @@ public void addPaintComponent(PaintComponent comp) {
 		components.add(comp);
 
 	}
+	
+	public ArrayList<PaintComponent> getPaintComponents() {
+		return components;
+	}
 
 	/**
 	 * Returns the topmost component under a given point