Atomized the functionality of the base tomo package

layouts/layout.go

@@ -0,0 +1,37 @@
+package layouts
+
+import "image"
+import "git.tebibyte.media/sashakoshka/tomo/elements"
+
+// LayoutEntry associates an element with layout and positioning information so
+// it can be arranged by a Layout.
+type LayoutEntry struct {
+	elements.Element
+	Bounds image.Rectangle
+	Expand bool
+}
+
+// Layout is capable of arranging elements within a container. It is also able
+// to determine the minimum amount of room it needs to do so.
+type Layout interface {
+	// Arrange takes in a slice of entries and a bounding width and height,
+	// and changes the position of the entiries in the slice so that they
+	// are properly laid out. The given width and height should not be less
+	// than what is returned by MinimumSize.
+	Arrange (entries []LayoutEntry, margin int, bounds image.Rectangle)
+
+	// MinimumSize returns the minimum width and height that the layout
+	// needs to properly arrange the given slice of layout entries.
+	MinimumSize (entries []LayoutEntry, margin int) (width, height int)
+
+	// FlexibleHeightFor Returns the minimum height the layout needs to lay
+	// out the specified elements at the given width, taking into account
+	// flexible elements.
+	FlexibleHeightFor (
+		entries []LayoutEntry,
+		margin int,
+		squeeze int,
+	) (
+		height int,
+	)
+}