Add mouseDragged handler and add code for freehand drawing and erasing

README.md

@@ -17,8 +17,7 @@ I (Jan) haven't tested the below commands on windows, but they should
 * Multiple windows (so that moving the control window around doesn't move what's
 on the projector.
 * Drawing using primitive shapes (lines, ellipses) and arbitrary colors.
-* Does NOT currently support freeform drawing... should be pretty easy to add though.
-
+* Freehand drawing and erasing
 
 
 ## Compiling

src/DragGetter.java

@@ -0,0 +1,47 @@
+/*
+    Interface for handling mouse drags
+ */
+
+public interface DragGetter {
+    boolean drag(int x1, int y1, int x2, int y2);
+}
+
+
+//public interface Shape {
+//    public int numVertices();
+//}
+//
+//
+//class Circle2 implements Shape {
+//    Circle2() {
+//        blah;
+//    }
+//
+//    int numVertices() {
+//        return 0;
+//    }
+//
+//    void expand() {
+//        blah2;
+//    }
+//}
+//
+//class Square implements Shape {
+//    int numVertices() {
+//        return 4;
+//    }
+//}
+//
+//
+//Shape g = new Circle2();
+////g.expand(); // bad
+//println(g.numVertices()); //good
+//g = new Square();
+//println(g.numVertices());
+//
+//void printNumberOfVertices(Shape s) {
+//    println(s.numVertices());
+//}
+//
+//printNumberOfVertices(new Circle2());
+//printNumberOfVertices(new Square());

src/EuglenaApplet.java

@@ -22,6 +22,7 @@ public class EuglenaApplet extends PApplet {
     Menu menu;
     Calibrator calibrator;
     ClickGetter clickGetter;
+    DragGetter dragGetter;
 
     //Pen
     int penColor = color(200);
@@ -77,7 +78,7 @@ public class EuglenaApplet extends PApplet {
 
 
     @Override
-    public void mouseClicked(){
+    public void mouseClicked() {
         // Ignore mouse clicks in menu area
         if (mouseX > width - menu.width) {
             return;
@@ -92,6 +93,22 @@ public class EuglenaApplet extends PApplet {
         }
     }
 
+    @Override
+    public void mouseDragged() {
+        // Ignore mouse drags from menu area
+        if (pmouseX > width - menu.width) {
+            return;
+        }
+
+        // If we have a clickGetter, use that to handle the mouse click
+        if (dragGetter != null) {
+            boolean done = dragGetter.drag(pmouseX, pmouseY, mouseX, mouseY);
+            if (done) {
+                dragGetter = null;
+            }
+        }
+    }
+
     @Override
     public void keyPressed() {
         /*

src/Freehand.java

@@ -0,0 +1,27 @@
+class Freehand {
+  /*
+    Class for freehand drawing
+   */
+
+  int color, brushSize;
+
+  Freehand(int color, int penWidth) {
+    this.color = color;
+    this.brushSize = penWidth;
+    }
+
+  DragGetter makeDragGetter(ProjectorApplet p) {
+    /*
+      Create a DragGetter which can accept incoming mouse drags
+      and use them to draw lines
+     */
+
+    return (int x1, int y1, int x2, int y2) -> {
+        Line line = new Line(x1, y1, x2, y2, this.color, this.brushSize);
+        p.commandQueue.add(line.makeProjectorCommand());
+
+        // Keep using this DragGetter, don't stop
+        return false;
+    };
+  }
+}

src/Menu.java

@@ -200,6 +200,7 @@ class Menu {
 
         //println(theEvent);
         if (theEvent.isFrom(shapesList)) {
+            parent.dragGetter = null;
             switch((int) shapesList.getValue()) {
                 case 0:
                     parent.clickGetter = new Ellipse(parent.penColor, parent.penWidth)
@@ -215,6 +216,7 @@ class Menu {
                     break;
             }
         } else if (theEvent.isFrom(animateList)){
+            parent.dragGetter = null;
             switch((int) animateList.getValue()) {
                 case 0:
                     parent.clickGetter = new Shrink(parent.operationSpeed)
@@ -275,11 +277,20 @@ class Menu {
                     parent.projectorApplet.calibrator.toggle();
                     break;
 
+                case "Freehand":
+                    parent.clickGetter = null;
+                    parent.dragGetter = new Freehand(parent.penColor, parent.penWidth)
+                                                .makeDragGetter(parent.projectorApplet);
+                    break;
+
                 case "Eraser":
-                    parent.penColor = parent.color(0, 0, 0);
+                    parent.clickGetter = null;
+                    parent.dragGetter = new Freehand(parent.projectorApplet.bgColor, parent.penWidth)
+                                                .makeDragGetter(parent.projectorApplet);
                     break;
 
                 case "Line":
+                    parent.dragGetter = null;
                     parent.clickGetter = new Line(parent.penColor, parent.penWidth)
                                                 .makeClickGetter(parent.projectorApplet);
                     break;