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|
// SPDX-License-Identifier: Unlicense OR MIT
package router
import (
"image"
"io"
"gioui.org/f32"
"gioui.org/internal/ops"
"gioui.org/io/event"
"gioui.org/io/pointer"
"gioui.org/io/semantic"
"gioui.org/io/transfer"
)
type pointerQueue struct {
hitTree []hitNode
areas []areaNode
cursors []cursorNode
cursor pointer.CursorName
handlers map[event.Tag]*pointerHandler
pointers []pointerInfo
transfers []io.ReadCloser // pending data transfers
scratch []event.Tag
semantic struct {
idsAssigned bool
lastID SemanticID
// contentIDs maps semantic content to a list of semantic IDs
// previously assigned. It is used to maintain stable IDs across
// frames.
contentIDs map[semanticContent][]semanticID
}
}
type hitNode struct {
next int
area int
// For handler nodes.
tag event.Tag
pass bool
}
type cursorNode struct {
name pointer.CursorName
area int
}
type pointerInfo struct {
id pointer.ID
pressed bool
handlers []event.Tag
// last tracks the last pointer event received,
// used while processing frame events.
last pointer.Event
// entered tracks the tags that contain the pointer.
entered []event.Tag
dataSource event.Tag // dragging source tag
dataTarget event.Tag // dragging target tag
}
type pointerHandler struct {
area int
active bool
wantsGrab bool
types pointer.Type
// min and max horizontal/vertical scroll
scrollRange image.Rectangle
sourceMimes []string
targetMimes []string
offeredMime string
data io.ReadCloser
}
type areaOp struct {
kind areaKind
rect f32.Rectangle
}
type areaNode struct {
trans f32.Affine2D
area areaOp
// Tree indices, with -1 being the sentinel.
parent int
firstChild int
lastChild int
sibling int
semantic struct {
valid bool
id SemanticID
content semanticContent
}
}
type areaKind uint8
// collectState represents the state for pointerCollector.
type collectState struct {
t f32.Affine2D
// nodePlusOne is the current node index, plus one to
// make the zero value collectState the initial state.
nodePlusOne int
pass int
}
// pointerCollector tracks the state needed to update an pointerQueue
// from pointer ops.
type pointerCollector struct {
q *pointerQueue
state collectState
nodeStack []int
}
type semanticContent struct {
tag event.Tag
label string
desc string
class semantic.ClassOp
gestures SemanticGestures
selected bool
disabled bool
}
type semanticID struct {
id SemanticID
used bool
}
const (
areaRect areaKind = iota
areaEllipse
)
func (c *pointerCollector) resetState() {
c.state = collectState{}
}
func (c *pointerCollector) setTrans(t f32.Affine2D) {
c.state.t = t
}
func (c *pointerCollector) clip(op ops.ClipOp) {
kind := areaRect
if op.Shape == ops.Ellipse {
kind = areaEllipse
}
c.pushArea(kind, frect(op.Bounds))
}
func (c *pointerCollector) pushArea(kind areaKind, bounds f32.Rectangle) {
parentID := c.currentArea()
areaID := len(c.q.areas)
areaOp := areaOp{kind: kind, rect: bounds}
if parentID != -1 {
parent := &c.q.areas[parentID]
if parent.firstChild == -1 {
parent.firstChild = areaID
}
if siblingID := parent.lastChild; siblingID != -1 {
c.q.areas[siblingID].sibling = areaID
}
parent.lastChild = areaID
}
an := areaNode{
trans: c.state.t,
area: areaOp,
parent: parentID,
sibling: -1,
firstChild: -1,
lastChild: -1,
}
c.q.areas = append(c.q.areas, an)
c.nodeStack = append(c.nodeStack, c.state.nodePlusOne-1)
c.addHitNode(hitNode{
area: areaID,
pass: true,
})
}
// frect converts a rectangle to a f32.Rectangle.
func frect(r image.Rectangle) f32.Rectangle {
return f32.Rectangle{
Min: fpt(r.Min), Max: fpt(r.Max),
}
}
// fpt converts a point to a f32.Point.
func fpt(p image.Point) f32.Point {
return f32.Point{
X: float32(p.X), Y: float32(p.Y),
}
}
func (c *pointerCollector) popArea() {
n := len(c.nodeStack)
c.state.nodePlusOne = c.nodeStack[n-1] + 1
c.nodeStack = c.nodeStack[:n-1]
}
func (c *pointerCollector) pass() {
c.state.pass++
}
func (c *pointerCollector) popPass() {
c.state.pass--
}
func (c *pointerCollector) currentArea() int {
if i := c.state.nodePlusOne - 1; i != -1 {
n := c.q.hitTree[i]
return n.area
}
return -1
}
func (c *pointerCollector) addHitNode(n hitNode) {
n.next = c.state.nodePlusOne - 1
c.q.hitTree = append(c.q.hitTree, n)
c.state.nodePlusOne = len(c.q.hitTree) - 1 + 1
}
// newHandler returns the current handler or a new one for tag.
func (c *pointerCollector) newHandler(tag event.Tag, events *handlerEvents) *pointerHandler {
areaID := c.currentArea()
c.addHitNode(hitNode{
area: areaID,
tag: tag,
pass: c.state.pass > 0,
})
h, ok := c.q.handlers[tag]
if !ok {
h = new(pointerHandler)
c.q.handlers[tag] = h
// Cancel handlers on (each) first appearance, but don't
// trigger redraw.
events.AddNoRedraw(tag, pointer.Event{Type: pointer.Cancel})
}
h.active = true
h.area = areaID
return h
}
func (c *pointerCollector) inputOp(op pointer.InputOp, events *handlerEvents) {
areaID := c.currentArea()
area := &c.q.areas[areaID]
area.semantic.content.tag = op.Tag
if op.Types&(pointer.Press|pointer.Release) != 0 {
area.semantic.content.gestures |= ClickGesture
}
area.semantic.valid = area.semantic.content.gestures != 0
h := c.newHandler(op.Tag, events)
h.wantsGrab = h.wantsGrab || op.Grab
h.types = h.types | op.Types
h.scrollRange = op.ScrollBounds
}
func (c *pointerCollector) semanticLabel(lbl string) {
areaID := c.currentArea()
area := &c.q.areas[areaID]
area.semantic.valid = true
area.semantic.content.label = lbl
}
func (c *pointerCollector) semanticDesc(desc string) {
areaID := c.currentArea()
area := &c.q.areas[areaID]
area.semantic.valid = true
area.semantic.content.desc = desc
}
func (c *pointerCollector) semanticClass(class semantic.ClassOp) {
areaID := c.currentArea()
area := &c.q.areas[areaID]
area.semantic.valid = true
area.semantic.content.class = class
}
func (c *pointerCollector) semanticSelected(selected bool) {
areaID := c.currentArea()
area := &c.q.areas[areaID]
area.semantic.valid = true
area.semantic.content.selected = selected
}
func (c *pointerCollector) semanticDisabled(disabled bool) {
areaID := c.currentArea()
area := &c.q.areas[areaID]
area.semantic.valid = true
area.semantic.content.disabled = disabled
}
func (c *pointerCollector) cursor(name pointer.CursorName) {
c.q.cursors = append(c.q.cursors, cursorNode{
name: name,
area: len(c.q.areas) - 1,
})
}
func (c *pointerCollector) sourceOp(op transfer.SourceOp, events *handlerEvents) {
h := c.newHandler(op.Tag, events)
h.sourceMimes = append(h.sourceMimes, op.Type)
}
func (c *pointerCollector) targetOp(op transfer.TargetOp, events *handlerEvents) {
h := c.newHandler(op.Tag, events)
h.targetMimes = append(h.targetMimes, op.Type)
}
func (c *pointerCollector) offerOp(op transfer.OfferOp, events *handlerEvents) {
h := c.newHandler(op.Tag, events)
h.offeredMime = op.Type
h.data = op.Data
}
func (c *pointerCollector) reset() {
c.q.reset()
c.resetState()
c.nodeStack = c.nodeStack[:0]
c.ensureRoot()
}
// Ensure implicit root area for semantic descriptions to hang onto.
func (c *pointerCollector) ensureRoot() {
if len(c.q.areas) > 0 {
return
}
c.pushArea(areaRect, f32.Rect(-1e6, -1e6, 1e6, 1e6))
// Make it semantic to ensure a single semantic root.
c.q.areas[0].semantic.valid = true
}
func (q *pointerQueue) assignSemIDs() {
if q.semantic.idsAssigned {
return
}
q.semantic.idsAssigned = true
for i, a := range q.areas {
if a.semantic.valid {
q.areas[i].semantic.id = q.semanticIDFor(a.semantic.content)
}
}
}
func (q *pointerQueue) AppendSemantics(nodes []SemanticNode) []SemanticNode {
q.assignSemIDs()
nodes = q.appendSemanticChildren(nodes, 0)
nodes = q.appendSemanticArea(nodes, 0, 0)
return nodes
}
func (q *pointerQueue) appendSemanticArea(nodes []SemanticNode, parentID SemanticID, nodeIdx int) []SemanticNode {
areaIdx := nodes[nodeIdx].areaIdx
a := q.areas[areaIdx]
childStart := len(nodes)
nodes = q.appendSemanticChildren(nodes, a.firstChild)
childEnd := len(nodes)
for i := childStart; i < childEnd; i++ {
nodes = q.appendSemanticArea(nodes, a.semantic.id, i)
}
n := &nodes[nodeIdx]
n.ParentID = parentID
n.Children = nodes[childStart:childEnd]
return nodes
}
func (q *pointerQueue) appendSemanticChildren(nodes []SemanticNode, areaIdx int) []SemanticNode {
if areaIdx == -1 {
return nodes
}
a := q.areas[areaIdx]
if semID := a.semantic.id; semID != 0 {
cnt := a.semantic.content
nodes = append(nodes, SemanticNode{
ID: semID,
Desc: SemanticDesc{
Bounds: f32.Rectangle{
Min: a.trans.Transform(a.area.rect.Min),
Max: a.trans.Transform(a.area.rect.Max),
},
Label: cnt.label,
Description: cnt.desc,
Class: cnt.class,
Gestures: cnt.gestures,
Selected: cnt.selected,
Disabled: cnt.disabled,
},
areaIdx: areaIdx,
})
} else {
nodes = q.appendSemanticChildren(nodes, a.firstChild)
}
return q.appendSemanticChildren(nodes, a.sibling)
}
func (q *pointerQueue) semanticIDFor(content semanticContent) SemanticID {
ids := q.semantic.contentIDs[content]
for i, id := range ids {
if !id.used {
ids[i].used = true
return id.id
}
}
// No prior assigned ID; allocate a new one.
q.semantic.lastID++
id := semanticID{id: q.semantic.lastID, used: true}
if q.semantic.contentIDs == nil {
q.semantic.contentIDs = make(map[semanticContent][]semanticID)
}
q.semantic.contentIDs[content] = append(q.semantic.contentIDs[content], id)
return id.id
}
func (q *pointerQueue) SemanticAt(pos f32.Point) (SemanticID, bool) {
q.assignSemIDs()
for i := len(q.hitTree) - 1; i >= 0; i-- {
n := &q.hitTree[i]
hit := q.hit(n.area, pos)
if !hit {
continue
}
area := q.areas[n.area]
if area.semantic.id != 0 {
return area.semantic.id, true
}
}
return 0, false
}
func (q *pointerQueue) opHit(pos f32.Point) []event.Tag {
// Track whether we're passing through hits.
pass := true
hits := q.scratch[:0]
idx := len(q.hitTree) - 1
for idx >= 0 {
n := &q.hitTree[idx]
hit := q.hit(n.area, pos)
if !hit {
idx--
continue
}
pass = pass && n.pass
if pass {
idx--
} else {
idx = n.next
}
if n.tag != nil {
if _, exists := q.handlers[n.tag]; exists {
hits = addHandler(hits, n.tag)
}
}
}
q.scratch = hits[:0]
return hits
}
func (q *pointerQueue) invTransform(areaIdx int, p f32.Point) f32.Point {
if areaIdx == -1 {
return p
}
return q.areas[areaIdx].trans.Invert().Transform(p)
}
func (q *pointerQueue) hit(areaIdx int, p f32.Point) bool {
for areaIdx != -1 {
a := &q.areas[areaIdx]
p := a.trans.Invert().Transform(p)
if !a.area.Hit(p) {
return false
}
areaIdx = a.parent
}
return true
}
func (q *pointerQueue) reset() {
if q.handlers == nil {
q.handlers = make(map[event.Tag]*pointerHandler)
}
for _, h := range q.handlers {
// Reset handler.
h.active = false
h.wantsGrab = false
h.types = 0
h.sourceMimes = h.sourceMimes[:0]
h.targetMimes = h.targetMimes[:0]
}
q.hitTree = q.hitTree[:0]
q.areas = q.areas[:0]
q.cursors = q.cursors[:0]
q.semantic.idsAssigned = false
for k, ids := range q.semantic.contentIDs {
for i := len(ids) - 1; i >= 0; i-- {
if !ids[i].used {
ids = append(ids[:i], ids[i+1:]...)
} else {
ids[i].used = false
}
}
if len(ids) > 0 {
q.semantic.contentIDs[k] = ids
} else {
delete(q.semantic.contentIDs, k)
}
}
for _, rc := range q.transfers {
if rc != nil {
rc.Close()
}
}
q.transfers = nil
}
func (q *pointerQueue) Frame(events *handlerEvents) {
for k, h := range q.handlers {
if !h.active {
q.dropHandler(nil, k)
delete(q.handlers, k)
}
if h.wantsGrab {
for _, p := range q.pointers {
if !p.pressed {
continue
}
for i, k2 := range p.handlers {
if k2 == k {
// Drop other handlers that lost their grab.
dropped := q.scratch[:0]
dropped = append(dropped, p.handlers[:i]...)
dropped = append(dropped, p.handlers[i+1:]...)
for _, tag := range dropped {
q.dropHandler(events, tag)
}
break
}
}
}
}
}
for i := range q.pointers {
p := &q.pointers[i]
q.deliverEnterLeaveEvents(p, events, p.last)
q.deliverTransferDataEvent(p, events)
}
}
func (q *pointerQueue) dropHandler(events *handlerEvents, tag event.Tag) {
if events != nil {
events.Add(tag, pointer.Event{Type: pointer.Cancel})
}
for i := range q.pointers {
p := &q.pointers[i]
for i := len(p.handlers) - 1; i >= 0; i-- {
if p.handlers[i] == tag {
p.handlers = append(p.handlers[:i], p.handlers[i+1:]...)
}
}
for i := len(p.entered) - 1; i >= 0; i-- {
if p.entered[i] == tag {
p.entered = append(p.entered[:i], p.entered[i+1:]...)
}
}
}
}
// pointerOf returns the pointerInfo index corresponding to the pointer in e.
func (q *pointerQueue) pointerOf(e pointer.Event) int {
for i, p := range q.pointers {
if p.id == e.PointerID {
return i
}
}
q.pointers = append(q.pointers, pointerInfo{id: e.PointerID})
return len(q.pointers) - 1
}
func (q *pointerQueue) Push(e pointer.Event, events *handlerEvents) {
if e.Type == pointer.Cancel {
q.pointers = q.pointers[:0]
for k := range q.handlers {
q.dropHandler(events, k)
}
return
}
pidx := q.pointerOf(e)
p := &q.pointers[pidx]
p.last = e
switch e.Type {
case pointer.Press:
q.deliverEnterLeaveEvents(p, events, e)
p.pressed = true
q.deliverEvent(p, events, e)
case pointer.Move:
if p.pressed {
e.Type = pointer.Drag
}
q.deliverEnterLeaveEvents(p, events, e)
q.deliverEvent(p, events, e)
if p.pressed {
q.deliverDragEvent(p, events)
}
case pointer.Release:
q.deliverEvent(p, events, e)
p.pressed = false
q.deliverEnterLeaveEvents(p, events, e)
q.deliverDropEvent(p, events)
case pointer.Scroll:
q.deliverEnterLeaveEvents(p, events, e)
q.deliverScrollEvent(p, events, e)
default:
panic("unsupported pointer event type")
}
if !p.pressed && len(p.entered) == 0 {
// No longer need to track pointer.
q.pointers = append(q.pointers[:pidx], q.pointers[pidx+1:]...)
}
}
func (q *pointerQueue) deliverEvent(p *pointerInfo, events *handlerEvents, e pointer.Event) {
foremost := true
if p.pressed && len(p.handlers) == 1 {
e.Priority = pointer.Grabbed
foremost = false
}
for _, k := range p.handlers {
h := q.handlers[k]
if e.Type&h.types == 0 {
continue
}
e := e
if foremost {
foremost = false
e.Priority = pointer.Foremost
}
e.Position = q.invTransform(h.area, e.Position)
events.Add(k, e)
}
}
func (q *pointerQueue) deliverScrollEvent(p *pointerInfo, events *handlerEvents, e pointer.Event) {
foremost := true
if p.pressed && len(p.handlers) == 1 {
e.Priority = pointer.Grabbed
foremost = false
}
var sx, sy = e.Scroll.X, e.Scroll.Y
for _, k := range p.handlers {
if sx == 0 && sy == 0 {
return
}
h := q.handlers[k]
// Distribute the scroll to the handler based on its ScrollRange.
sx, e.Scroll.X = setScrollEvent(sx, h.scrollRange.Min.X, h.scrollRange.Max.X)
sy, e.Scroll.Y = setScrollEvent(sy, h.scrollRange.Min.Y, h.scrollRange.Max.Y)
e := e
if foremost {
foremost = false
e.Priority = pointer.Foremost
}
e.Position = q.invTransform(h.area, e.Position)
events.Add(k, e)
}
}
func (q *pointerQueue) deliverEnterLeaveEvents(p *pointerInfo, events *handlerEvents, e pointer.Event) {
var hits []event.Tag
if e.Source != pointer.Mouse && !p.pressed && e.Type != pointer.Press {
// Consider non-mouse pointers leaving when they're released.
} else {
hits = q.opHit(e.Position)
if p.pressed {
// Filter out non-participating handlers,
// except potential transfer targets when a transfer has been initiated.
var hitsHaveTarget bool
if p.dataSource != nil {
transferSource := q.handlers[p.dataSource]
for _, hit := range hits {
if _, ok := firstMimeMatch(transferSource, q.handlers[hit]); ok {
hitsHaveTarget = true
break
}
}
}
for i := len(hits) - 1; i >= 0; i-- {
if _, found := searchTag(p.handlers, hits[i]); !found && !hitsHaveTarget {
hits = append(hits[:i], hits[i+1:]...)
}
}
} else {
p.handlers = append(p.handlers[:0], hits...)
}
}
// Deliver Leave events.
for _, k := range p.entered {
if _, found := searchTag(hits, k); found {
continue
}
h := q.handlers[k]
e.Type = pointer.Leave
if e.Type&h.types != 0 {
e.Position = q.invTransform(h.area, e.Position)
events.Add(k, e)
}
}
// Deliver Enter events and update cursor.
q.cursor = pointer.CursorDefault
for _, k := range hits {
h := q.handlers[k]
for i := len(q.cursors) - 1; i >= 0; i-- {
if c := q.cursors[i]; c.area == h.area {
q.cursor = c.name
break
}
}
if _, found := searchTag(p.entered, k); found {
continue
}
e.Type = pointer.Enter
if e.Type&h.types != 0 {
e.Position = q.invTransform(h.area, e.Position)
events.Add(k, e)
}
}
p.entered = append(p.entered[:0], hits...)
}
func (q *pointerQueue) deliverDragEvent(p *pointerInfo, events *handlerEvents) {
if p.dataSource != nil {
return
}
// Identify the data source.
for _, k := range p.entered {
src := q.handlers[k]
if len(src.sourceMimes) == 0 {
continue
}
// One data source handler per pointer.
p.dataSource = k
// Notify all potential targets.
for k, tgt := range q.handlers {
if _, ok := firstMimeMatch(src, tgt); ok {
events.Add(k, transfer.InitiateEvent{})
}
}
break
}
}
func (q *pointerQueue) deliverDropEvent(p *pointerInfo, events *handlerEvents) {
if p.dataSource == nil {
return
}
// Request data from the source.
src := q.handlers[p.dataSource]
for _, k := range p.entered {
h := q.handlers[k]
if m, ok := firstMimeMatch(src, h); ok {
p.dataTarget = k
events.Add(p.dataSource, transfer.RequestEvent{Type: m})
return
}
}
// No valid target found, abort.
q.deliverTransferCancelEvent(p, events)
}
func (q *pointerQueue) deliverTransferDataEvent(p *pointerInfo, events *handlerEvents) {
if p.dataSource == nil {
return
}
src := q.handlers[p.dataSource]
if src.data == nil {
// Data not received yet.
return
}
if p.dataTarget == nil {
q.deliverTransferCancelEvent(p, events)
return
}
// Send the offered data to the target.
transferIdx := len(q.transfers)
events.Add(p.dataTarget, transfer.DataEvent{
Type: src.offeredMime,
Open: func() io.ReadCloser {
q.transfers[transferIdx] = nil
return src.data
},
})
q.transfers = append(q.transfers, src.data)
p.dataTarget = nil
}
func (q *pointerQueue) deliverTransferCancelEvent(p *pointerInfo, events *handlerEvents) {
events.Add(p.dataSource, transfer.CancelEvent{})
// Cancel all potential targets.
src := q.handlers[p.dataSource]
for k, h := range q.handlers {
if _, ok := firstMimeMatch(src, h); ok {
events.Add(k, transfer.CancelEvent{})
}
}
src.offeredMime = ""
src.data = nil
p.dataSource = nil
p.dataTarget = nil
}
func searchTag(tags []event.Tag, tag event.Tag) (int, bool) {
for i, t := range tags {
if t == tag {
return i, true
}
}
return 0, false
}
// addHandler adds tag to the slice if not present.
func addHandler(tags []event.Tag, tag event.Tag) []event.Tag {
for _, t := range tags {
if t == tag {
return tags
}
}
return append(tags, tag)
}
// firstMimeMatch returns the first type match between src and tgt.
func firstMimeMatch(src, tgt *pointerHandler) (first string, matched bool) {
for _, m1 := range tgt.targetMimes {
for _, m2 := range src.sourceMimes {
if m1 == m2 {
return m1, true
}
}
}
return "", false
}
func (op *areaOp) Hit(pos f32.Point) bool {
pos = pos.Sub(op.rect.Min)
size := op.rect.Size()
switch op.kind {
case areaRect:
return 0 <= pos.X && pos.X < size.X &&
0 <= pos.Y && pos.Y < size.Y
case areaEllipse:
rx := size.X / 2
ry := size.Y / 2
xh := pos.X - rx
yk := pos.Y - ry
// The ellipse function works in all cases because
// 0/0 is not <= 1.
return (xh*xh)/(rx*rx)+(yk*yk)/(ry*ry) <= 1
default:
panic("invalid area kind")
}
}
func setScrollEvent(scroll float32, min, max int) (left, scrolled float32) {
if v := float32(max); scroll > v {
return scroll - v, v
}
if v := float32(min); scroll < v {
return scroll - v, v
}
return 0, scroll
}
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