Rework the UI framework

Interface is now Driver, and Widget is now a set of interfaces with a
struct per widget type. This should make it easier to add other types.

internal/ui/widget.go

@@ -1,109 +0,0 @@
-package ui
-
-import (
-	"image"
-
-	"github.com/hajimehoshi/ebiten"
-
-	"code.ur.gs/lupine/ordoor/internal/assetstore"
-	"code.ur.gs/lupine/ordoor/internal/menus"
-)
-
-// Widget represents an interactive area of the screen. Backgrounds and other
-// non-interactive areas are not widgets.
-type Widget struct {
-	// Position on the screen in original (i.e., unscaled) coordinates
-	Bounds  image.Rectangle
-	Tooltip string
-	Value   string // #dealwithit for bools and ints and so on :p
-
-	OnHoverEnter func()
-	OnHoverLeave func()
-
-	// Mouse up can happen without a click taking place if, for instance, the
-	// mouse cursor leaves the bounds while still pressed.
-	OnMouseDown  func()
-	OnMouseClick func()
-	OnMouseUp    func()
-
-	disabled      bool
-	disabledImage *ebiten.Image
-
-	// These are expected to have the same dimensions as the Bounds
-	hoverAnimation animation
-	hoverState     bool
-
-	// FIXME: We assume right mouse button isn't needed here
-	// TODO: down, up, and click hooks.
-	mouseButtonDownImage *ebiten.Image
-	mouseButtonState     bool
-
-	path   string
-	record *menus.Record
-	sprite *assetstore.Sprite
-
-	valueToImage func() *ebiten.Image
-}
-
-func (w *Widget) Disable() {
-	w.hovering(false)
-	w.mouseButton(false)
-
-	w.disabled = true
-}
-
-func (w *Widget) hovering(value bool) {
-	if w.OnHoverEnter != nil && !w.hoverState && value {
-		w.OnHoverEnter()
-	}
-
-	if w.OnHoverLeave != nil && w.hoverState && !value {
-		w.OnHoverLeave()
-	}
-
-	w.hoverState = value
-
-	return
-}
-
-func (w *Widget) mouseButton(value bool) {
-	if w.OnMouseDown != nil && !w.mouseButtonState && value {
-		w.OnMouseDown()
-	}
-
-	if w.mouseButtonState && !value {
-		if w.OnMouseClick != nil && w.hoverState {
-			w.OnMouseClick()
-		}
-
-		if w.OnMouseUp != nil {
-			w.OnMouseUp()
-		}
-	}
-
-	w.mouseButtonState = value
-}
-
-func (w *Widget) Image(aniStep int) (*ebiten.Image, error) {
-	if w.disabled {
-		if w.disabledImage != nil {
-			return w.disabledImage, nil
-		}
-
-		return w.sprite.Image, nil
-	}
-
-	if w.mouseButtonDownImage != nil && w.hoverState && w.mouseButtonState {
-		return w.mouseButtonDownImage, nil
-	}
-
-	if w.hoverState && w.hoverAnimation != nil {
-		return w.hoverAnimation.image(aniStep), nil
-	}
-
-	if w.valueToImage != nil {
-		return w.valueToImage(), nil
-	}
-
-	return w.sprite.Image, nil
-}