updates.

box.go

@@ -0,0 +1,65 @@
+package chart
+
+import "fmt"
+
+// Box represents the main 4 dimensions of a box.
+type Box struct {
+	Top    int
+	Left   int
+	Right  int
+	Bottom int
+}
+
+// IsZero returns if the box is set or not.
+func (b Box) IsZero() bool {
+	return b.Top == 0 && b.Left == 0 && b.Right == 0 && b.Bottom == 0
+}
+
+// String returns a string representation of the box.
+func (b Box) String() string {
+	return fmt.Sprintf("Box(%d,%d,%d,%d)", b.Top, b.Left, b.Right, b.Bottom)
+}
+
+// GetTop returns a coalesced value with a default.
+func (b Box) GetTop(defaults ...int) int {
+	if b.Top == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return 0
+	}
+	return b.Top
+}
+
+// GetLeft returns a coalesced value with a default.
+func (b Box) GetLeft(defaults ...int) int {
+	if b.Left == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return 0
+	}
+	return b.Left
+}
+
+// GetRight returns a coalesced value with a default.
+func (b Box) GetRight(defaults ...int) int {
+	if b.Right == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return 0
+	}
+	return b.Right
+}
+
+// GetBottom returns a coalesced value with a default.
+func (b Box) GetBottom(defaults ...int) int {
+	if b.Bottom == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return 0
+	}
+	return b.Bottom
+}