add layout from Keitio

1 files changed, 26 insertions, 0 deletions

diff --git a/gui/layout/split.go b/gui/layout/split.go
new file mode 100644
index 0000000..db04225
--- /dev/null
+++ b/gui/layout/split.go
@@ -0,0 +1,26 @@
+package layout
+
+import "fmt"
+
+// SplitFunc represents a way to split a space among a number of elements.
+// The length of the returned slice must be equal to the number of elements.
+// The sum of all elements of the returned slice must be eqal to the space.
+type SplitFunc func(elements int, space int) []int
+
+var _ SplitFunc = EvenSplit
+
+// EvenSplit is a SplitFunc used to split a space (almost) evenly among the elements.
+// It is almost evenly because width may not be divisible by elements.
+func EvenSplit(elements int, width int) []int {
+	if elements <= 0 {
+		panic(fmt.Errorf("EvenSplit: elements must be greater than 0"))
+	}
+	ret := make([]int, elements)
+	for elements > 0 {
+		v := width / elements
+		width -= v
+		elements -= 1
+		ret[elements] = v
+	}
+	return ret
+}