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/buttons.go

@@ -0,0 +1,136 @@
+package ui
+
+import (
+	"image"
+
+	"code.ur.gs/lupine/ordoor/internal/assetstore"
+	"code.ur.gs/lupine/ordoor/internal/menus"
+)
+
+func init() {
+	registerBuilder(menus.TypeSimpleButton, registerSimpleButton)
+	registerBuilder(menus.TypeInvokeButton, registerInvokeButton)
+	registerBuilder(menus.TypeMainButton, registerMainButton)
+}
+
+// A button without hover animation
+type button struct {
+	path string
+
+	baseSpr   *assetstore.Sprite
+	clickSpr  *assetstore.Sprite
+	frozenSpr *assetstore.Sprite
+
+	clickImpl
+	freezeImpl
+	hoverImpl
+}
+
+// A button with hover animation
+type mainButton struct {
+	hoverAnim animation
+
+	button
+}
+
+func registerSimpleButton(d *Driver, r *menus.Record) error {
+	return registerButton(d, r, r.SpriteId[0])
+}
+
+func registerInvokeButton(d *Driver, r *menus.Record) error {
+	return registerButton(d, r, r.Share)
+}
+
+func registerMainButton(d *Driver, r *menus.Record) error {
+	sprites, err := d.menu.Sprites(r.Share, 3) // base, pressed, disabled
+	if err != nil {
+		return err
+	}
+
+	hovers, err := d.menu.Images(r.SpriteId[0], r.DrawType)
+	if err != nil {
+		return err
+	}
+
+	btn := &mainButton{
+		hoverAnim: animation(hovers),
+		button: button{
+			path:      r.Path(),
+			baseSpr:   sprites[0],
+			clickSpr:  sprites[1],
+			frozenSpr: sprites[2],
+			hoverImpl: hoverImpl{text: r.Desc},
+		},
+	}
+
+	d.clickables = append(d.clickables, btn)
+	d.freezables = append(d.freezables, btn)
+	d.hoverables = append(d.hoverables, btn)
+	d.paintables = append(d.paintables, btn)
+
+	return nil
+}
+
+func registerButton(d *Driver, r *menus.Record, spriteId int) error {
+	sprites, err := d.menu.Sprites(spriteId, 3) // base, pressed, disabled
+	if err != nil {
+		return err
+	}
+
+	btn := &button{
+		path:      r.Path(),
+		baseSpr:   sprites[0],
+		clickSpr:  sprites[1],
+		frozenSpr: sprites[2],
+		hoverImpl: hoverImpl{text: r.Desc},
+	}
+
+	d.clickables = append(d.clickables, btn)
+	d.freezables = append(d.freezables, btn)
+	d.hoverables = append(d.hoverables, btn)
+	d.paintables = append(d.paintables, btn)
+
+	return nil
+}
+
+func (b *button) id() string {
+	return b.path
+}
+
+func (b *button) bounds() image.Rectangle {
+	return b.baseSpr.Rect
+}
+
+func (b *button) mouseDownState() bool {
+	if b.isFrozen() {
+		return false
+	}
+
+	return b.clickImpl.mouseDownState()
+}
+
+func (b *button) registerMouseClick() {
+	if !b.isFrozen() {
+		b.clickImpl.registerMouseClick()
+	}
+}
+
+func (b *button) regions(tick int) []region {
+	if b.isFrozen() {
+		return oneRegion(b.bounds().Min, b.frozenSpr.Image)
+	}
+
+	if b.mouseDownState() {
+		return oneRegion(b.bounds().Min, b.clickSpr.Image)
+	}
+
+	return oneRegion(b.bounds().Min, b.baseSpr.Image)
+}
+
+func (m *mainButton) regions(tick int) []region {
+	if !m.isFrozen() && !m.mouseDownState() && m.hoverState() {
+		return oneRegion(m.bounds().Min, m.hoverAnim.image(tick))
+	}
+
+	return m.button.regions(tick)
+}