Added Stacks of controls.

1 files changed, 73 insertions, 0 deletions

diff --git a/stack.go b/stack.go
new file mode 100644
index 0000000..ed8d608
--- /dev/null
+++ b/stack.go
@@ -0,0 +1,73 @@
+// 13 february 2014
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+// Orientation defines the orientation of controls in a Stack.
+type Orientation int
+const (
+	Horizontal Orientation = iota
+	Vertical
+)
+
+// A Stack stacks controls horizontally or vertically within the Stack's parent, alotting each the same size.
+type Stack struct {
+	// The controls of the Stack. Once the Window containing the Stack has been created, this should not be modified.
+	Controls		[]Control
+
+	lock			sync.Mutex
+	created		bool
+	orientation	Orientation
+}
+
+// NewStack creates a new Stack with the specified orientation.
+func NewStack(o Orientation) *Stack {
+	if o != Horizontal && o != Vertical {
+		panic(fmt.Sprintf("invalid orientation %d given to NewStack()", o))
+	}
+	return &Stack{
+		orientation:	o,
+	}
+}
+
+// TODO adorn errors with which stage failed
+func (s *Stack) apply(window *sysData) error {
+	for _, c := range s.Controls {
+		err := c.apply(window)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// TODO adorn errors with which stage failed
+func (s *Stack) setRect(x int, y int, width int, height int) error {
+	var dx, dy int
+
+	if len(s.Controls) == 0 {		// do nothing if there's nothing to do
+		return nil
+	}
+	switch s.orientation {
+	case Horizontal:
+		dx = width / len(s.Controls)
+		width = dx
+	case Vertical:
+		dy = height / len(s.Controls)
+		height = dy
+	default:
+		panic(fmt.Sprintf("invalid orientation %d given to Stack.setRect()", s.orientation))
+	}
+	for _, c := range s.Controls {
+		err := c.setRect(x, y, width, height)
+		if err != nil {
+			return err
+		}
+		x += dx
+		y += dy
+	}
+	return nil
+}