doodle/ui/supervisor.go
Noah Petherbridge b67c4b67b2 Add Initial "Doodad Palette" UX
* Add a tab bar to the top of the Palette window that has two
  radiobuttons for "Palette" and "Doodads"
* UI: add the concept of a Hidden() widget and the corresponding Hide()
  and Show() methods. Hidden widgets are skipped over when evaluating
  Frame packing, rendering, and event supervision.
* The Palette Window in editor mode now displays one of two tabs:
  * Palette: the old color swatch palette now lives here.
  * Doodads: the new Doodad palette.
* The Doodad Palette shows a grid of buttons (2 per row) showing the
  available Doodad drawings in the user's config folder.
* The Doodad buttons act as radiobuttons for now and have no other
  effect. TODO will be making them react to drag-drop events.
* UI: added a `Children()` method as the inverse of `Parent()` for
  container widgets (like Frame, Window and Button) to expose their
  children. The BaseWidget just returns an empty []Widget.
* Console: added a `repl` command that keeps the dev console open and
  prefixes every command with `$` filled out -- for rapid JavaScript
  console evaluation.
2018-10-08 13:06:42 -07:00

120 lines
2.3 KiB
Go

package ui
import (
"sync"
"git.kirsle.net/apps/doodle/events"
"git.kirsle.net/apps/doodle/render"
)
// Event is a named event that the supervisor will send.
type Event int
// Events.
const (
NullEvent Event = iota
MouseOver
MouseOut
MouseDown
MouseUp
Click
KeyDown
KeyUp
KeyPress
)
// Supervisor keeps track of widgets of interest to notify them about
// interaction events such as mouse hovers and clicks in their general
// vicinity.
type Supervisor struct {
lock sync.RWMutex
widgets []Widget
hovering map[int]interface{}
clicked map[int]interface{}
}
// NewSupervisor creates a supervisor.
func NewSupervisor() *Supervisor {
return &Supervisor{
widgets: []Widget{},
hovering: map[int]interface{}{},
clicked: map[int]interface{}{},
}
}
// Loop to check events and pass them to managed widgets.
func (s *Supervisor) Loop(ev *events.State) {
var (
XY = render.Point{
X: ev.CursorX.Now,
Y: ev.CursorY.Now,
}
)
// See if we are hovering over any widgets.
for id, w := range s.widgets {
if w.Hidden() {
// TODO: somehow the Supervisor wasn't triggering hidden widgets
// anyway, but I don't know why. Adding this check for safety.
continue
}
var (
P = w.Point()
S = w.Size()
P2 = render.Point{
X: P.X + S.W,
Y: P.Y + S.H,
}
)
if XY.X >= P.X && XY.X <= P2.X && XY.Y >= P.Y && XY.Y <= P2.Y {
// Cursor has intersected the widget.
if _, ok := s.hovering[id]; !ok {
w.Event(MouseOver, XY)
s.hovering[id] = nil
}
_, isClicked := s.clicked[id]
if ev.Button1.Now {
if !isClicked {
w.Event(MouseDown, XY)
s.clicked[id] = nil
}
} else if isClicked {
w.Event(MouseUp, XY)
w.Event(Click, XY)
delete(s.clicked, id)
}
} else {
// Cursor is not intersecting the widget.
if _, ok := s.hovering[id]; ok {
w.Event(MouseOut, XY)
delete(s.hovering, id)
}
if _, ok := s.clicked[id]; ok {
w.Event(MouseUp, XY)
delete(s.clicked, id)
}
}
}
}
// Present all widgets managed by the supervisor.
func (s *Supervisor) Present(e render.Engine) {
s.lock.RLock()
defer s.lock.RUnlock()
for _, w := range s.widgets {
w.Present(e, w.Point())
}
}
// Add a widget to be supervised.
func (s *Supervisor) Add(w Widget) {
s.lock.Lock()
s.widgets = append(s.widgets, w)
s.lock.Unlock()
}