S08a

.gitignore

@@ -0,0 +1,2 @@
+MagicBoxes.dart.js
+*~

Board.dart

@@ -5,6 +5,7 @@ class Board {
   // The board is redrawn every INTERVAL ms.
   static final int INTERVAL = 8; 
 
+  CanvasElement canvas;
   CanvasRenderingContext2D context;
 
   int width;
@@ -15,14 +16,16 @@ class Board {
 
   Box beforeLastBoxClicked;
   Box lastBoxClicked;
+  Box lastBoxSelected;
+  Line lastLineSelected;
 
   MenuBar menuBar; 
   ToolBar toolBar;
 
   num defaultLineWidth;
 
-  Board(CanvasElement canvas) {
-    context = canvas.getContext("2d");
+  Board(this.canvas) {
+    context = canvas.getContext('2d');
     width = canvas.width;
     height = canvas.height;
     defaultLineWidth = context.lineWidth;
@@ -63,6 +66,17 @@ class Board {
     }
   }
 
+  void printBoxNames() {
+    for (Box box in boxes) {
+      print(box.title);
+    }
+  }
+
+  void saveAsPng() {
+    ImageElement modelImage = document.query('#modelImage');
+    modelImage.src = canvas.toDataURL("image/png");
+  }
+
   void createBoxesInDiagonal() {
     int x = 0; int y = 0;
     while (true) {
@@ -206,6 +220,56 @@ class Board {
     deselectLines();
   }
 
+  void increaseHeightOfSelectedBoxes() {
+    for (Box box in boxes) {
+      if (box.isSelected()) {
+        box.height = box.height + Box.DEFAULT_INCREMENT;
+      }
+    }
+  }
+
+  void decreaseHeightOfSelectedBoxes() {
+    for (Box box in boxes) {
+      if (box.isSelected()) {
+        box.height = box.height - Box.DEFAULT_INCREMENT;
+      }
+    }
+  }
+
+  void increaseWidthOfSelectedBoxes() {
+    for (Box box in boxes) {
+      if (box.isSelected()) {
+        box.width = box.width + Box.DEFAULT_INCREMENT;
+      }
+    }
+  }
+
+  void decreaseWidthOfSelectedBoxes() {
+    for (Box box in boxes) {
+      if (box.isSelected()) {
+        box.width = box.width - Box.DEFAULT_INCREMENT;
+      }
+    }
+  }
+
+  void increaseSizeOfSelectedBoxes() {
+    for (Box box in boxes) {
+      if (box.isSelected()) {
+        box.height = box.height + Box.DEFAULT_INCREMENT;
+        box.width = box.width + Box.DEFAULT_INCREMENT;
+      }
+    }
+  }
+
+  void decreaseSizeOfSelectedBoxes() {
+    for (Box box in boxes) {
+      if (box.isSelected()) {
+        box.height = box.height - Box.DEFAULT_INCREMENT;
+        box.width = box.width - Box.DEFAULT_INCREMENT;
+      }
+    }
+  }
+
   void hideSelectedBoxes() {
     for (Box box in boxes) {
       if (box.isSelected()) {
@@ -248,8 +312,6 @@ class Board {
     showHiddenLines();
   }
 
-  int get nextBoxNo() => boxes.length + 1;
-
   int countSelectedBoxes() {
     int count = 0;
     for (Box box in boxes) {

Box.dart

@@ -1,7 +1,8 @@
 class Box {
 
-  static final int DEFAULT_WIDTH = 100;
-  static final int DEFAULT_HEIGHT = 100;
+  static final int DEFAULT_WIDTH = 120;
+  static final int DEFAULT_HEIGHT = 120;
+  static final int DEFAULT_INCREMENT = 20;
 
   static final int SSS = 6; // selection square size
   static final int TBH = 20; // title box height
@@ -10,25 +11,26 @@ class Box {
 
   final Board board;
 
+  String _name = 'Box';
   int x;
   int y;
   int width;
   int height;
 
-  String textFontSize = 12;
-  String title = "Box";
-  int titleNo;
-  String item = "Item";
+  List<Item> items;
 
   bool _selected = false;
   bool _hidden = false;
   bool _mouseDown = false;
 
+  String textFontSize = 12;
   num defaultLineWidth;
 
   Box(this.board, this.x, this.y, this.width, this.height) {
-    titleNo = board.nextBoxNo;
     defaultLineWidth = board.context.lineWidth;
+
+    items = new List();
+
     draw();
     // Box events (actually, canvas events).
     document.query('#canvas').on.mouseDown.add(onMouseDown);
@@ -39,17 +41,31 @@ class Box {
   void draw() {
     if (!isHidden()) {
       board.context.beginPath();
+      board.context.clearRect(x, y, width, height);
       board.context.rect(x, y, width, height);
       board.context.moveTo(x, y + TBH);
       board.context.lineTo(x + width, y + TBH);
-      board.context.font = "bold " + textFontSize + "px sans-serif";
-      board.context.textAlign = "start";
-      board.context.textBaseline = "top";
-      board.context.fillText(toString(), x + TOS, y + TOS, width - TOS);
-      board.context.fillText(item + 1, x + TOS, y + TOS + TBH, width - TOS);
-      board.context.fillText(item + 2, x + TOS, y + TOS + TBH + IOS, width - TOS);
-      board.context.fillText(item + 3, x + TOS, y + TOS + TBH + 2 * IOS, width - TOS);
-      board.context.fillText(item + 4, x + TOS, y + TOS + TBH + 3 * IOS, width - TOS);
+      board.context.font = 'bold ' + textFontSize + 'px sans-serif';
+      board.context.textAlign = 'start';
+      board.context.textBaseline = 'top';
+      board.context.fillText(title, x + TOS, y + TOS, width - TOS);
+      int i = 0;
+      for (Item item in items) {
+        if (item.category == 'attribute') {
+          board.context.font = '' + textFontSize + 'px sans-serif';
+          board.context.fillText(item.name, x + TOS, y + TOS + TBH + i * IOS, width - TOS);
+        } else if (item.category == 'globally unique') {
+          board.context.font = 'italic ' + textFontSize + 'px sans-serif';
+          board.context.fillText(item.name, x + TOS, y + TOS + TBH + i * IOS, width - TOS);
+        } else if (item.category == 'identifier') {
+          board.context.font = 'bold italic ' + textFontSize + 'px sans-serif';
+          board.context.fillText(item.name, x + TOS, y + TOS + TBH + i * IOS, width - TOS);
+        } else if (item.category == 'required') {
+          board.context.font = 'bold ' + textFontSize + 'px sans-serif';
+          board.context.fillText(item.name, x + TOS, y + TOS + TBH + i * IOS, width - TOS);
+        }
+        i++;
+      }
       if (isSelected()) {
         board.context.rect(x, y, SSS, SSS);
         board.context.rect(x + width - SSS, y, SSS, SSS);
@@ -62,16 +78,60 @@ class Box {
     }
   }
 
-  select() => _selected = true;
-  deselect() => _selected = false;
-  toggleSelection() => _selected = !_selected;
+  void select() {
+    _selected = true;
+    board.lastBoxSelected = this;
+  }
+
+  void deselect() {
+    _selected = false;
+    board.lastBoxSelected = null;
+  }
+
+  void toggleSelection() { 
+    _selected = !_selected;
+    if (_selected) {
+      board.lastBoxSelected = this;
+    } else {
+      board.lastBoxSelected = null;
+    }
+  }
+
   bool isSelected() => _selected;
 
   hide() => _hidden = true;
   show() => _hidden = false;
   bool isHidden() => _hidden;
 
-  String toString() => '$title$titleNo ($x, $y)';
+  void set title(String name) {
+    _name = name;
+  }
+
+  String get title() {
+    return _name;
+  }
+
+  Item findItem(String name) {
+    for (Item item in items) {
+      if (item.name == name) {
+        return item;
+      }
+    }
+    return null;
+  } 
+
+  bool removeItem(Item item) {
+    if (item != null) {
+      int index = items.indexOf(item, 0);
+      if (index >= 0) {
+        items.removeRange(index, 1);
+        return true;
+      }
+    }
+    return false;
+  } 
+
+  String toString() => '$title ($x, $y)';
 
   Point center() {
     int centerX = x + width / 2;
@@ -87,6 +147,36 @@ class Box {
     }
   }
 
+  /**
+   * Return the intersection point of the line between the begin <x1,y1> 
+   * and end <x2,y2> points with this box;
+   * <x1,y1> is inside the box, <x2,y2> may be inside or outside. 
+   * Fast algorithm.
+   */
+  Point getIntersectionPoint(Point lineBeginPoint, Point lineEndPoint) {
+    int x1 = lineBeginPoint.x;
+    int y1 = lineBeginPoint.y;
+    int x2 = lineEndPoint.x;
+    int y2 = lineEndPoint.y;
+    if (x2 == x1) /* vertical line */
+      return new Point(x2, (y2 < y1 ? this.y : this.y + this.height));
+    if (y2 == y1) /* horizontal line */
+      return new Point((x2 < x1 ? this.x : this.x + this.width), y2);
+
+    double m = (y2 - y1) / (x2 - x1);
+    int x = (x2 < x1 ? this.x : this.x + this.width);
+    double fy = m * (x - x2) + y2;
+    int y;
+    /* float comparison, because fy may be bigger than the biggest integer */
+    if (fy >= this.y && fy <= this.y + this.height) {
+      y = fy.toInt();
+    } else {
+      y = (y2 < y1 ? this.y : this.y + this.height);
+      x = ((fy - y2) / m).toInt() + x2;
+    }
+    return new Point(x, y);
+  }
+
   void onMouseDown(MouseEvent e) {
     _mouseDown = true;
     if (board.toolBar.isSelectToolOn() && contains(e.offsetX, e.offsetY)) {

Item.dart

@@ -0,0 +1,14 @@
+class Item {
+
+  final Box box;
+
+  String name;
+  String category;
+
+  Item(this.box, String name, String category) {
+    this.name = name;
+    this.category = category;
+    box.items.add(this);
+  }
+
+}