refactor all container widgets into subpackage

cwidgets/expanded/hist.go

@@ -0,0 +1,74 @@
+package expanded
+
+type IntHist struct {
+	data   []int
+	labels []string
+}
+
+func NewIntHist(max int) IntHist {
+	return IntHist{
+		data:   make([]int, max),
+		labels: make([]string, max),
+	}
+}
+
+func (h IntHist) Append(val int) {
+	if len(h.data) == cap(h.data) {
+		h.data = append(h.data[:0], h.data[1:]...)
+	}
+
+	h.data = append(h.data, val)
+}
+
+type FloatHist struct {
+	data   []float64
+	labels []string
+}
+
+func NewFloatHist(max int) FloatHist {
+	return FloatHist{
+		data:   make([]float64, max),
+		labels: make([]string, max),
+	}
+}
+
+func (h FloatHist) Append(val float64) {
+	if len(h.data) == cap(h.data) {
+		h.data = append(h.data[:0], h.data[1:]...)
+	}
+	h.data = append(h.data, val)
+}
+
+type DiffHist struct {
+	data    []int // data point derivatives
+	srcData []int // principal input data
+	labels  []string
+}
+
+func NewDiffHist(max int) DiffHist {
+	return DiffHist{
+		data:    make([]int, max),
+		srcData: make([]int, max),
+		labels:  make([]string, max),
+	}
+}
+
+// return most recent value
+func (h DiffHist) Last() int {
+	return h.data[len(h.data)-1]
+}
+
+func (h DiffHist) Append(val int) {
+	if len(h.data) == cap(h.data) {
+		h.data = append(h.data[:0], h.data[1:]...)
+	}
+	if len(h.srcData) == cap(h.srcData) {
+		h.srcData = append(h.srcData[:0], h.srcData[1:]...)
+	}
+
+	diff := val - h.srcData[len(h.srcData)-1]
+	if diff != val { // skip adding to data if this is the initial update
+		h.data = append(h.data, diff)
+	}
+	h.srcData = append(h.srcData, val)
+}