ui: move ops reader to ui package

To prepare support for cached OpBlock to refer to other Ops lists.

The exposure of OpsReader is alleviated by the removal of the Refs
and Data accessors for Ops.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

ui/pointer/queue.go

@@ -12,7 +12,7 @@ type Queue struct {
 	hitTree  []hitNode
 	handlers map[Key]*handler
 	pointers []pointerInfo
-	reader   ops.Reader
+	reader   ui.OpsReader
 	scratch  []Key
 }
 
@@ -37,7 +37,7 @@ type handler struct {
 	wantsGrab bool
 }
 
-func (q *Queue) collectHandlers(r *ops.Reader, t ui.Transform, layer int) {
+func (q *Queue) collectHandlers(r *ui.OpsReader, t ui.Transform, layer int) {
 	for {
 		data, ok := r.Decode()
 		if !ok {
@@ -116,7 +116,7 @@ func (q *Queue) Frame(root *ui.Ops) {
 		}
 	}
 	q.hitTree = q.hitTree[:0]
-	q.reader.Reset(root.Data(), root.Refs())
+	q.reader.Reset(root)
 	q.collectHandlers(&q.reader, ui.Transform{}, 0)
 }