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src/Area.vala

@@ -3,38 +3,126 @@ namespace CairoChart {
 	/**
 	 * Area rectangle.
 	 */
-	[Compact]
 	public class Area {
 
+		double _x0 = 0;
+		double _x1 = 1;
+		double _y0 = 0;
+		double _y1 = 1;
+		double _zx0 = 0;
+		double _zx1 = 1;
+		double _zy0 = 0;
+		double _zy1 = 1;
+
 		/**
 		 * Left bound.
 		 */
-		public double x0 = 0;
+		public double x0 {
+			get {
+				return _x0;
+			}
+			set {
+				_zx0 = _x0 = value;
+			}
+		}
 
 		/**
 		 * Top bound.
 		 */
-		public double y0 = 0;
+		public double y0 {
+			get {
+				return _y0;
+			}
+			set {
+				_zy0 = _y0 = value;
+			}
+		}
 
 		/**
 		 * Right bound.
 		 */
-		public double x1 = 1;
+		public double x1 {
+			get {
+				return _x1;
+			}
+			set {
+				_zx1 = _x1 = value;
+			}
+		}
 
 		/**
 		 * Bottom bound.
 		 */
-		public double y1 = 1;
+		public double y1 {
+			get {
+				return _y1;
+			}
+			set {
+				_zy1 = _y1 = value;
+			}
+		}
+
+		/**
+		 * Zoomed Left bound.
+		 */
+		public double zx0 {
+			get {
+				return _zx0;
+			}
+			set {
+				if (_x0 <= value <= _x1)
+					_zx0 = value;
+			}
+		}
+
+		/**
+		 * Zoomed Top bound.
+		 */
+		public double zy0 {
+			get {
+				return _zy0;
+			}
+			set {
+				if (_y0 <= value <= _y1)
+					_zy0 = value;
+			}
+		}
+
+		/**
+		 * Zoomed Right bound.
+		 */
+		public double zx1 {
+			get {
+				return _zx1;
+			}
+			set {
+				if (_x0 <= value <= _x1)
+					_zx1 = value;
+			}
+		}
+
+		/**
+		 * Zoomed Bottom bound.
+		 */
+		public double zy1 {
+			get {
+				return _zy1;
+			}
+			set {
+				if (_y0 <= value <= _y1)
+					_zy1 = value;
+			}
+		}
 
 		/**
 		 * ``Area`` width.
 		 */
 		public double width {
 			get {
-				return x1 - x0;
+				return _x1 - _x0;
 			}
 			set {
-				x1 = x0 + value;
+				_zx1 = _x1 = _x0 + value;
 			}
 		}
 
@@ -43,10 +131,36 @@ namespace CairoChart {
 		 */
 		public double height {
 			get {
-				return y1 - y0;
+				return _y1 - _y0;
 			}
 			set {
-				y1 = y0 + value;
+				_zy1 = _y1 = _y0 + value;
+			}
+		}
+
+		/**
+		 * ``Area`` zoomed width.
+		 */
+		public double zwidth {
+			get {
+				return _zx1 - _zx0;
+			}
+			set {
+				if (_zx0 <= _zx0 + value <= _x1)
+					_zx1 = _zx0 + value;
+			}
+		}
+
+		/**
+		 * ``Area`` zoomed height.
+		 */
+		public double zheight {
+			get {
+				return _zy1 - _zy0;
+			}
+			set {
+				if (_zy0 <= _zy0 + value <= _y1)
+					_zy1 = _zy0 + value;
 			}
 		}
 
@@ -111,5 +225,15 @@ namespace CairoChart {
 		public Area copy () {
 			return new Area.with_area(this);
 		}
+
+		/**
+		 * Unzooms ``Area``.
+		 */
+		public void unzoom () {
+			_zx0 = x0;
+			_zy0 = y0;
+			_zx1 = x1;
+			_zy1 = y1;
+		}
 	}
 }

src/Range.vala

@@ -3,28 +3,85 @@ namespace CairoChart {
 	/**
 	 * Linear range.
 	 */
-	[Compact]
 	public class Range {
 
+		double _low = 0;
+		double _high = 1;
+		double _zlow = 0;
+		double _zhigh = 1;
+
 		/**
 		 * Low bound.
 		 */
-		public double low = 0;
+		public double low {
+			get {
+				return _low;
+			}
+			set {
+				_zlow = _low = value;
+			}
+		}
 
 		/**
 		 * High bound.
 		 */
-		public double high = 1;
+		public double high {
+			get {
+				return _high;
+			}
+			set {
+				_zhigh = _high = value;
+			}
+		}
+
+		/**
+		 * Zoomed low bound.
+		 */
+		double zlow {
+			get {
+				return _zlow;
+			}
+			set {
+				if (_low <= value <= _high)
+					_zlow = value;
+			}
+		}
+
+		/**
+		 * Zoomed high bound.
+		 */
+		double zhigh {
+			get {
+				return _zhigh;
+			}
+			set {
+				if (_low <= value <= _high)
+					_zhigh = value;
+			}
+		}
 
 		/**
 		 * ``Range`` value.
 		 */
 		public double range {
 			get {
-				return high - low;
+				return _high - _low;
 			}
 			set {
-				high = low + value;
+				_zhigh = _high = _low + value;
+			}
+		}
+
+		/**
+		 * ``Range`` zoomed value.
+		 */
+		public double zrange {
+			get {
+				return _zhigh - _zlow;
+			}
+			set {
+				if (_zlow <= _zlow + value <= _high)
+					_zhigh = _zlow + value;
 			}
 		}
 
@@ -63,5 +120,13 @@ namespace CairoChart {
 		public Range copy () {
 			return new Range.with_range(this);
 		}
+
+		/**
+		 * Unzooms ``Range``.
+		 */
+		public void unzoom () {
+			_zlow = low;
+			_zhigh = high;
+		}
 	}
 }