Code Salvage

- Integrated some code from the (soon to be obsolete) 2.0.0 branch,
  which is general in nature and will be needed.
- And the corresponding unit tests.

src/Rectangle.cpp

@@ -0,0 +1,126 @@
+////////////////////////////////////////////////////////////////////////////////
+// taskwarrior - a command line task list manager.
+//
+// Copyright 2006 - 2010, Paul Beckingham, Federico Hernandez.
+// All rights reserved.
+//
+// This program is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free Software
+// Foundation; either version 2 of the License, or (at your option) any later
+// version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+// details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program; if not, write to the
+//
+//     Free Software Foundation, Inc.,
+//     51 Franklin Street, Fifth Floor,
+//     Boston, MA
+//     02110-1301
+//     USA
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include "Rectangle.h"
+
+////////////////////////////////////////////////////////////////////////////////
+Rectangle::Rectangle ()
+: left (0)
+, top (0)
+, width (0)
+, height (0)
+{
+}
+
+////////////////////////////////////////////////////////////////////////////////
+Rectangle::Rectangle (int l, int t, int w, int h)
+{
+  left   = l;
+  top    = t;
+  width  = w;
+  height = h;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+Rectangle::Rectangle (const Rectangle& other)
+{
+  *this = other;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+Rectangle& Rectangle::operator= (const Rectangle& other)
+{
+  if (this != &other)
+  {
+    left   = other.left;
+    top    = other.top;
+    width  = other.width;
+    height = other.height;
+  }
+
+  return *this;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+bool Rectangle::operator== (const Rectangle& other) const
+{
+  if (left   == other.left   &&
+      top    == other.top    &&
+      width  == other.width  &&
+      height == other.height)
+    return true;
+
+  return false;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+bool Rectangle::operator!= (const Rectangle& other) const
+{
+  return !(*this == other);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Algorithm:
+//   Find the conditions at which the rectangles do not intersect and then
+//   negate the result.
+bool Rectangle::intersects (const Rectangle& other) const
+{
+  return ! (other.left                   > left + width - 1 ||
+            other.left + other.width - 1 < left             ||
+            other.top                    > top + height - 1 ||
+            other.top + other.height - 1 < top);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+bool Rectangle::contains (const Rectangle& other) const
+{
+  if (other.left                >= left         &&
+      other.left + other.width  <= left + width &&
+      other.top                 >= top          &&
+      other.top  + other.height <= top + height)
+    return true;
+
+  return false;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Adjacent rectangles must not intersect, but must have at top/bottom,
+// bottom/top, left/right or right/left adjacency.
+bool Rectangle::adjacentTo (const Rectangle& other) const
+{
+  if (! this->intersects (other))
+    if (top + height   == other.top                 ||
+        top            == other.top  + other.height ||
+        left + width   == other.left                ||
+        left           == other.left + other.width)
+      return true;
+
+  return false;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+