1package core
2
3import (
4 "math"
5 "slices"
6 "time"
7
8 "github.com/bnema/neferwl/internal/ports"
9)
10
11// A three-finger swipe follows the fingers: sideways it scrolls the columns,
12// up or down it slides between workspaces. Each swipe moves one step at
13// most (snapswipe.go): the next column edge or the next workspace. When
14// the fingers lift, a quick swipe goes on to that step, a slow one settles
15// on the closest, and a spring takes the view there (motion.go). Sideways
16// over the shown stash the swipe slides the stash the same way, one window
17// at most. Where the view cannot slide (fixed overflow, a float, a
18// fullscreen window), the swipe runs one focus action instead.
19// In the overview, three fingers use distance-based selection during movement.
20
21const (
22 // swipeDecide is the touchpad distance before the swipe picks its axis
23 // (GNOME Shell's threshold).
24 swipeDecide = 16.0
25 // viewSwipeMovement is the touchpad distance that scrolls the columns by
26 // one usable width.
27 viewSwipeMovement = 1200.0
28 // workspaceSwipeMovement is the touchpad distance that slides one
29 // workspace.
30 workspaceSwipeMovement = 300.0
31 // stashSwipeMovement is the touchpad distance that slides the stash by
32 // one window.
33 stashSwipeMovement = 300.0
34)
35
36type swipeMode uint8
37
38const (
39 swipeUndecided swipeMode = iota
40 swipeColumns
41 swipeWorkspaces
42 swipeDiscrete
43 // swipeNavigation navigates overview cards during a three-finger gesture.
44 swipeNavigation
45 // swipeOverview is a vertical four-finger swipe: up opens the
46 // overview, down closes it on the selection (niri's gesture). With
47 // the overview closed, down shows or hides the stash, and up hides
48 // it when it is shown, else opens the overview.
49 swipeOverview
50 // swipeStash is a sideways swipe over the shown stash: its view
51 // follows the fingers, with a stop on each window, and lands on a
52 // neighbor of the selection at most.
53 swipeStash
54 // swipeDropped ignores the rest of a swipe whose workspace changed.
55 swipeDropped
56)
57
58// swipeGesture is the swipe in progress, on the screen focused when it began.
59type swipeGesture struct {
60 screen *screen
61 fingers int
62 mode swipeMode
63 horizontal bool
64 cx, cy float64
65 // snap follows the movement along the chosen axis, natural scroll
66 // applied: positive scrolls right or down. Its view is absolute: the
67 // columns' x in pixels or the monitor's fractional workspace index,
68 // so a focus change during the swipe does not move the fingers' view.
69 // A discrete or overview swipe counts steps of -1, 0 or 1.
70 snap snapSwipe
71 // ws is the workspace whose columns scroll, or the active one when a
72 // workspace slide began.
73 ws *Workspace
74 // points are ws's column snap points when a column swipe began: the
75 // swipe ends if the layout no longer has them.
76 points []float64
77 // list is the numbered workspaces when a workspace slide began: the
78 // slide indexes it, so it ends if the list changes.
79 list []*Workspace
80 // ids and home are the stash windows and the selection when a stash
81 // swipe began: it ends if either changes.
82 ids []WindowID
83 home int
84 // opens is the monitor's overviewOpens when the swipe picked its
85 // mode: a slide the overview opened over is dropped, even once the
86 // overview closed again.
87 opens int
88}
89
90// listChanged reports whether the numbered workspaces or the active one
91// changed since a workspace slide began, or the overview opened over it.
92func (g *swipeGesture) listChanged(m *Monitor) bool {
93 return m.overviewOpens != g.opens || m.shown != nil || m.Workspaces[m.Active] != g.ws || g.horizontal != (g.ws.policy().workspace == horizontalAxis) || !slices.Equal(m.Workspaces, g.list)
94}
95
96// columnsChanged reports whether a column swipe lost its workspace: it is
97// no longer shown or slidable, its snap points moved (an output resize, a
98// panel, a window mapped or resized, other gaps), or the overview opened
99// over it.
100func (g *swipeGesture) columnsChanged(m *Monitor) bool {
101 if m.overviewOpens != g.opens || m.Current() != g.ws || !g.ws.slidable() || g.horizontal != (g.ws.policy().content == horizontalAxis) {
102 return true
103 }
104 if g.ws.policy().wraps {
105 n, spacing := g.ws.cascadeBands()
106 if len(g.points) != n {
107 return true
108 }
109 for i, p := range g.points {
110 if p != float64(i*spacing) {
111 return true
112 }
113 }
114 return false
115 }
116 return !slices.Equal(g.ws.snapPoints(), g.points)
117}
118
119// stashChanged reports whether a stash swipe lost its stash: it is no
120// longer shown or focused, its windows or selection changed, or the
121// overview opened over it.
122func (g *swipeGesture) stashChanged(m *Monitor) bool {
123 w := g.ws
124 return m.overviewOpens != g.opens || m.Current() != w || !w.stashFocused() || w.floatFocus || !w.stashShown() || w.stashAt != g.home ||
125 !slices.EqualFunc(w.Stash, g.ids, func(f Float, id WindowID) bool { return f.ID == id })
126}
127
128// swipeSign turns finger movement into view movement: natural scroll moves
129// the content with the fingers.
130func (c *Core) swipeSign() float64 {
131 if c.cfg.Touchpad.NaturalScroll {
132 return -1
133 }
134 return 1
135}
136
137// swipeBegin starts a swipe. Input streams one swipe at a time; one still
138// running (its end was lost) ends cancelled first: its slide settles back.
139func (c *Core) swipeBegin(b ports.SwipeBegin) bool {
140 changed := false
141 if c.swipe != nil {
142 c.swipeEnd(ports.SwipeEnd{Cancelled: true, Time: b.Time})
143 changed = true
144 }
145 c.swipe = &swipeGesture{screen: c.cur(), fingers: b.Fingers}
146 if b.Fingers == 3 && c.cur().mon.ov.open && !c.overviewKeyboardTaken() {
147 c.scrollStop(ports.PointerAxis{Horizontal: ports.ScrollAxis{Stop: true}})
148 c.swipe.mode = swipeNavigation
149 }
150 return changed
151}
152
153// swipeUpdate moves the swipe; it reports whether the scene changed.
154func (c *Core) swipeUpdate(u ports.SwipeUpdate) bool {
155 g := c.swipe
156 if g == nil {
157 return false
158 }
159 if !c.hasScreen(g.screen) {
160 // Its screen went: let go of what it moved, or that stays shifted.
161 c.dropSwipe()
162 c.swipe = nil
163 return false
164 }
165 if g.mode == swipeNavigation {
166 m := g.screen.mon
167 if !m.ov.open || c.cur() != g.screen || c.overviewKeyboardTaken() {
168 g.mode = swipeDropped
169 return false
170 }
171 now := c.now()
172 shots := c.snapshot(now)
173 changed := m.overviewScroll(ports.PointerAxis{Source: ports.AxisFinger,
174 Horizontal: ports.ScrollAxis{Set: true, Value: u.DX * c.swipeSign()},
175 Vertical: ports.ScrollAxis{Set: true, Value: u.DY * c.swipeSign()}})
176 if changed {
177 c.keyboard.takeBack()
178 c.transition(shots, now)
179 }
180 return changed
181 }
182 if g.mode == swipeUndecided {
183 g.cx += u.DX
184 g.cy += u.DY
185 if g.cx*g.cx+g.cy*g.cy < swipeDecide*swipeDecide {
186 return false
187 }
188 c.decide(g)
189 }
190 d := u.DY
191 if g.horizontal {
192 d = u.DX
193 }
194 if g.mode == swipeOverview {
195 // Like niri, the overview gesture ignores natural scroll: the
196 // fingers going up open it.
197 g.snap.push(d, u.Time)
198 return false
199 }
200 g.snap.push(d*c.swipeSign(), u.Time)
201 m := g.screen.mon
202 switch g.mode {
203 case swipeColumns:
204 if g.columnsChanged(m) {
205 g.ws.view.stop()
206 g.mode = swipeDropped
207 return true
208 }
209 g.ws.view.off = g.snap.pos() - float64(g.ws.View)
210 return true
211 case swipeWorkspaces:
212 if g.listChanged(m) {
213 m.stopSwitch()
214 g.mode = swipeDropped
215 return true
216 }
217 m.switchView.off = g.snap.pos() - float64(m.Active)
218 return true
219 case swipeStash:
220 if g.stashChanged(m) {
221 g.ws.stashView.stop()
222 g.mode = swipeDropped
223 return true
224 }
225 g.ws.stashView.off = g.snap.pos() - float64(g.ws.stashAt)
226 return true
227 }
228 return false
229}
230
231// decide picks the swipe's axis and what it moves. A running slide stops
232// where it is: the fingers take it from there.
233func (c *Core) decide(g *swipeGesture) {
234 g.horizontal = math.Abs(g.cx) > math.Abs(g.cy)
235 m := g.screen.mon
236 g.opens = m.overviewOpens
237 w := m.Current()
238 switch {
239 case g.fingers == 4 && !g.horizontal:
240 g.mode, g.snap = swipeOverview, newStepSwipe()
241 case g.fingers == 4:
242 // Four fingers sideways do nothing.
243 g.mode = swipeDropped
244 case m.ov.open:
245 // Overview navigation is chosen at begin, never on release.
246 g.mode = swipeDropped
247 case !c.animOn():
248 // With animations off nothing slides: the swipe runs a
249 // focus action when the fingers lift.
250 g.mode, g.snap = swipeDiscrete, newStepSwipe()
251 case g.horizontal && w.stashFocused() && !w.floatFocus && w.stashShown():
252 g.mode, g.ws, g.home = swipeStash, w, w.stashAt
253 g.ids = make([]WindowID, 0, len(w.Stash))
254 for _, f := range w.Stash {
255 g.ids = append(g.ids, f.ID)
256 }
257 w.stashView.motion = motion{}
258 g.snap = newSnapSwipe(float64(w.stashAt)+w.stashView.off, float64(w.stashAt), 1/stashSwipeMovement, indexPoints(len(w.Stash)), workspaceBand)
259 case g.horizontal == (w.policy().content == horizontalAxis) && w.slidable():
260 g.mode, g.ws, g.points = swipeColumns, w, w.snapPoints()
261 w.view.motion = motion{}
262 g.snap = newSnapSwipe(float64(w.View)+w.view.off, float64(w.View), w.swipeScale(), g.points, workspaceBand.scaled(float64(w.policy().content.span(w.Usable))))
263 case g.horizontal == (w.policy().workspace == horizontalAxis) && m.shown == nil:
264 // A landing slide measured in an older list lands at once first.
265 if m.switchList != nil && !slices.Equal(m.switchList, m.Workspaces) {
266 m.stopSwitch()
267 }
268 g.mode, g.ws = swipeWorkspaces, m.Workspaces[m.Active]
269 axis := w.policy().workspace
270 if m.switchView.busy() && m.switchAxis != axis {
271 m.stopSwitch()
272 }
273 m.switchAxis = axis
274 g.list = slices.Clone(m.Workspaces)
275 m.switchView.motion, m.switchList = motion{}, nil
276 g.snap = newSnapSwipe(float64(m.Active)+m.switchView.off, float64(m.Active), 1/workspaceSwipeMovement, indexPoints(len(m.Workspaces)), workspaceBand)
277 default:
278 g.mode, g.snap = swipeDiscrete, newStepSwipe()
279 }
280}
281
282// swipeEnd lands the swipe. shown reports that another workspace came on
283// screen.
284func (c *Core) swipeEnd(e ports.SwipeEnd) (shown bool) {
285 g := c.swipe
286 if g != nil && !c.hasScreen(g.screen) {
287 c.dropSwipe()
288 }
289 c.swipe = nil
290 if g == nil || !c.hasScreen(g.screen) {
291 return false
292 }
293 now := c.now()
294 m := g.screen.mon
295 switch g.mode {
296 case swipeNavigation:
297 c.scrollStop(ports.PointerAxis{Horizontal: ports.ScrollAxis{Stop: true}})
298 return false
299 case swipeColumns:
300 w := g.ws
301 if g.columnsChanged(m) {
302 w.view.stop()
303 return false
304 }
305 shown := float64(w.View) + w.view.off
306 target, velocity := g.snap.end(e.Cancelled, e.Time)
307 if !e.Cancelled {
308 view := int(math.Round(target))
309 focus := w.snapFocus(view, target >= shown)
310 if focus != w.Focus && w.policy().equalCells {
311 w.unmaximize()
312 }
313 w.Focus = focus
314 w.View = view
315 // A column wider than the view aligns as focus moves align it.
316 w.scroll()
317 c.focusScreen = c.screenIndex(g.screen.name())
318 c.keyboard.takeBack()
319 }
320 w.view.off = shown - float64(w.View)
321 if c.animOn() {
322 w.view.motion = c.spring(viewSpring(w.view.off, velocity), now)
323 } else {
324 w.view.stop()
325 }
326 case swipeWorkspaces:
327 if g.listChanged(m) {
328 m.stopSwitch()
329 return false
330 }
331 cur := float64(m.Active) + m.switchView.off
332 target, velocity := g.snap.end(e.Cancelled, e.Time)
333 idx := m.Active
334 if !e.Cancelled {
335 idx = int(math.Round(target))
336 }
337 // Focus may drop the empty workspace left behind and renumber the
338 // list: the slide keeps measuring in the list it began on.
339 off := cur - float64(idx)
340 if idx != m.Active {
341 m.Focus(idx)
342 shown = true
343 }
344 if !e.Cancelled {
345 c.focusScreen = c.screenIndex(g.screen.name())
346 c.keyboard.takeBack()
347 }
348 m.switchView.off, m.switchList = off, g.list
349 if c.animOn() {
350 m.switchView.motion = c.spring(m.switchSpring(off, velocity), now)
351 } else {
352 m.stopSwitch()
353 }
354 case swipeStash:
355 w := g.ws
356 if g.stashChanged(m) {
357 w.stashView.stop()
358 return false
359 }
360 drawn := float64(w.stashAt) + w.stashView.off
361 target, velocity := g.snap.end(e.Cancelled, e.Time)
362 dir := 0
363 if !e.Cancelled {
364 dir = int(math.Round(target)) - w.stashAt
365 }
366 if c.cur() == g.screen && dir != 0 {
367 // The landing is the focus action's: the selection, the focus
368 // and the veils move as a bind moves them.
369 a := ActionFocusColumnRight
370 if dir < 0 {
371 a = ActionFocusColumnLeft
372 }
373 c.keyboard.takeBack()
374 c.applyAction(a)
375 }
376 w.stashView.off = drawn - float64(w.stashAt)
377 if c.animOn() {
378 w.stashView.motion = c.spring(w.stashSpring(w.stashView.off, velocity), now)
379 } else {
380 w.stashView.stop()
381 }
382 // The stash never brings another workspace on screen.
383 return false
384 case swipeOverview:
385 step := g.snap.step(e.Cancelled, e.Time)
386 if step == 0 {
387 return false
388 }
389 if !m.ov.open && (step > 0 || m.Current().stashShown()) {
390 return c.swipeStash(g, now)
391 }
392 if (step < 0) == m.ov.open {
393 return false
394 }
395 before := m.Current()
396 shots := c.snapshot(now)
397 m.ToggleOverview()
398 c.focusScreen = c.screenIndex(g.screen.name())
399 c.keyboard.takeBack()
400 c.transition(shots, now)
401 return m.Current() != before
402 case swipeDiscrete:
403 step := g.snap.step(e.Cancelled, e.Time)
404 if step == 0 {
405 return false
406 }
407 w := g.screen.mon.Current()
408 p := w.policy()
409 workspace := g.horizontal == (p.workspace == horizontalAxis)
410 a := ActionFocusColumnRight
411 if step < 0 {
412 a = ActionFocusColumnLeft
413 }
414 if workspace {
415 a = ActionFocusWorkspaceNext
416 if step < 0 {
417 a = ActionFocusWorkspacePrev
418 }
419 } else if p.wraps {
420 // A content swipe cannot escape the last band to another workspace.
421 if w.onFloat() || w.fullscreen != 0 || w.bandNeighbor(step) < 0 {
422 return false
423 }
424 }
425 // Focus actions act on the focused screen: the swipe's, unless the
426 // pointer took the focus to another output meanwhile.
427 if c.cur() != g.screen {
428 return false
429 }
430 if c.cur().mon.ov.open {
431 return false
432 }
433 before := c.cur().mon.Current()
434 shots := c.snapshot(now)
435 c.keyboard.takeBack()
436 if p.wraps && !workspace {
437 w.focusBand(step)
438 } else {
439 c.applyAction(a)
440 }
441 c.transition(shots, now)
442 return c.cur().mon.Current() != before
443 }
444 return shown
445}
446
447// swipeStash runs toggle-stash-visible for a four-finger swipe down, or up
448// while the stash is shown, with the overview closed, on the swipe's screen
449// unless the pointer took the focus to another output meanwhile. It reports
450// whether the stash showed or hid: an empty stash stays as it is.
451func (c *Core) swipeStash(g *swipeGesture, now time.Time) bool {
452 if c.cur() != g.screen {
453 return false
454 }
455 w := g.screen.mon.Current()
456 hidden, over := w.stashHidden, w.stashOver
457 shots := c.snapshot(now)
458 c.keyboard.takeBack()
459 c.applyAction(ActionToggleStashVisible)
460 c.transition(shots, now)
461 return w.stashHidden != hidden || w.stashOver != over
462}
463
464// swipedWorkspace is the workspace on the swipe's screen, or nil without
465// a swipe.
466func (c *Core) swipedWorkspace() *Workspace {
467 if c.swipe == nil {
468 return nil
469 }
470 return c.swipe.screen.mon.Current()
471}
472
473// dropSwipe lets go of the swipe in progress: a bind changed the workspace
474// on its screen. Its slide stops where the bind left the view; the rest of
475// the swipe is ignored, even if a later bind shows its workspace again.
476func (c *Core) dropSwipe() {
477 g := c.swipe
478 if g == nil {
479 return
480 }
481 switch g.mode {
482 case swipeColumns:
483 g.ws.view.stop()
484 case swipeWorkspaces:
485 g.screen.mon.stopSwitch()
486 case swipeStash:
487 g.ws.stashView.stop()
488 }
489 g.mode = swipeDropped
490}
491
492func (c *Core) hasScreen(s *screen) bool {
493 for _, v := range c.screens {
494 if v == s {
495 return true
496 }
497 }
498 return false
499}
500
501// animOn reports whether transitions run (animations = on).
502func (c *Core) animOn() bool { return c.cfg.Animations.On }
503
504// spring starts s at now, stretched by animations.speed (Slowdown). Every motion
505// core creates goes through it, except a retarget, which keeps the slowdown
506// of the motion it replaces.
507func (c *Core) spring(s spring, now time.Time) motion {
508 return newMotion(s, now, c.cfg.Animations.Slowdown)
509}
510
511// stopAnimations settles every running spring where it is going and stops
512// the frame timer: a session lock or a switch to animations = off. A swipe
513// in progress keeps its fingers' view: only running springs stop. Per-window
514// rect motions stop too.
515func (c *Core) stopAnimations() {
516 for _, sc := range c.screens {
517 sc.stopAnimations()
518 }
519 c.stopFrame()
520}
521
522// stopAnimations settles the screen's running springs where they are going.
523func (s *screen) stopAnimations() {
524 if s.mon.switchView.motion.on {
525 s.mon.stopSwitch()
526 }
527 for w := range s.mon.all() {
528 if w.view.motion.on {
529 w.view.stop()
530 }
531 if w.stashView.motion.on {
532 w.stashView.stop()
533 }
534 }
535 s.stopRects()
536}
537
538// animate moves the running springs to now; settled ones stop. A non-nil only
539// limits it to that screen (its own page flip); nil moves every screen.
540func (c *Core) animate(now time.Time, only *screen) {
541 for _, sc := range c.screens {
542 if only != nil && sc != only {
543 continue
544 }
545 m := sc.mon
546 if m.switchView.motion.on {
547 m.switchView.step(now)
548 if !m.switchView.motion.on {
549 m.switchList = nil
550 }
551 }
552 for w := range m.all() {
553 w.view.step(now)
554 w.stashView.step(now)
555 }
556 for id, rm := range sc.rects {
557 rm.advance(now)
558 if rm.on() {
559 sc.rects[id] = rm
560 } else {
561 delete(sc.rects, id)
562 }
563 }
564 }
565}
566
567// sliding reports whether a spring runs on the named output.
568func (c *Core) sliding(output string) bool {
569 i := c.screenIndex(output)
570 return i >= 0 && (c.screens[i].springing() || c.pulsing(c.screens[i]))
571}
572
573// animating reports whether a spring or the focus pulse runs on any output.
574func (c *Core) animating() bool {
575 if c.pulse.id != 0 {
576 return true
577 }
578 for _, sc := range c.screens {
579 if sc.springing() {
580 return true
581 }
582 }
583 return false
584}
585
586func (m *Monitor) springing() bool {
587 if m.switchView.motion.on {
588 return true
589 }
590 for w := range m.all() {
591 if w.view.motion.on || w.stashView.motion.on {
592 return true
593 }
594 }
595 return false
596}
597
598// frameFallback is how long core waits for a page flip before it moves a
599// running slide on its own (an output that stopped flipping).
600func (c *Core) frameFallback() time.Duration {
601 refresh := 60000
602 for _, sc := range c.screens {
603 if r := sc.info.RefreshMilli; r > 0 && (sc.springing() || c.pulsing(sc)) {
604 refresh = min(refresh, r)
605 }
606 }
607 return 2 * time.Second * 1000 / time.Duration(refresh)
608}
609
610// armFrame starts the fallback timer of a running slide. The timer is made
611// on the first arm and reset afterwards (Go 1.23 timers deliver nothing
612// stale after a Stop or Reset), so a frame costs no allocation.
613func (c *Core) armFrame() {
614 d := c.frameFallback()
615 if c.frameTimer == nil {
616 c.frameTimer = newPortTimer(c.opts.Clock, d)
617 } else {
618 c.frameTimer.Stop()
619 c.frameTimer.Reset(d)
620 }
621 c.frameC = c.frameTimer.C()
622}
623
624func (c *Core) stopFrame() {
625 if c.frameC != nil {
626 c.frameTimer.Stop()
627 }
628 c.frameC = nil
629}