Noah Petherbridge
5434484b6e
The `level.Canvas` is a widget that holds onto its Palette and Grid and has interactions to allow scrolling and editing the grid using the swatches available on the palette. Thus all of the logic in the Editor Mode for drawing directly onto the root SDL surface are now handled inside a level.Canvas instance. The `level.Canvas` widget has the following properties: * Like any widget it has an X,Y position and a width/height. * It has a Scroll position to control which slice of its drawing will be visible inside its bounding box. * It supports levels having negative coordinates for their pixels. It doesn't care. The default Scroll position is (0,0) at the top left corner of the widget but you can scroll into the negatives and see the negative pixels. * Keyboard keys will scroll the viewport inside the canvas. * The canvas draws only the pixels that are visible inside its bounding box. This feature will eventually pave the way toward: * Doodads being dropped on top of your map, each Doodad being its own Canvas widget. * Using drawings as button icons for the user interface, as the Canvas is a normal widget.
114 lines
2.1 KiB
Go
114 lines
2.1 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 {
|
|
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()
|
|
}
|