move more ui logic into Collection

* Generalize hover detection and move it into ui.Collection
* Implement transparencu for the prompt banner

10 files changed, 277 insertions, 30 deletions

diff --git a/go/ui/button.go b/go/ui/button.go
index 78ab459f..eac3c2e4 100644
--- a/go/ui/button.go
+++ b/go/ui/button.go
@@ -41,13 +41,6 @@ func (b *SimpleButton) render() *ebiten.Image {
 	return img
 }
 
-func (b *SimpleButton) FindObjectAt(x, y int) interface{} {
-	if b.Contains(x, y) {
-		return b
-	}
-	return nil
-}
-
 func (b *SimpleButton) Click(x, y int) {
 	b.OnClick(b)
 }
diff --git a/go/ui/choice.go b/go/ui/choice.go
index bacc6657..28878604 100644
--- a/go/ui/choice.go
+++ b/go/ui/choice.go
@@ -51,16 +51,8 @@ func (c *Choice) Contains(x, y int) bool {
 	return x >= c.X && x <= c.X+c.Width && y >= c.Y && y <= c.Y+height
 }
 
-func (c *Choice) FindObjectAt(x, y int) interface{} {
-	if c.Contains(x, y) {
-		return c
-	}
-	return nil
-}
-
-func (c *Choice) Render() *ebiten.Image {
-	return nil
-}
+func (c *Choice) FindObjectAt(x, y int) interface{} { return nil }
+func (c *Choice) Render() *ebiten.Image             { return nil }
 
 func NewObjectChoice(x, y int, objs []interface{}, onClick func(*Choice, int, int)) *Choice {
 	// TODO: use dynamic with width and height
diff --git a/go/ui/collection.go b/go/ui/collection.go
index ac53ba8c..d75e3267 100644
--- a/go/ui/collection.go
+++ b/go/ui/collection.go
@@ -1,12 +1,20 @@
 package ui
 
 import (
+	"log"
+
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/inpututil"
 )
 
 type Collection struct {
-	widgets []Widget
+	Width, Height int
+	hoverDetector hoverDetector
+	widgets       []Widget
+}
+
+func (c *Collection) Layout() (int, int) {
+	return c.Width, c.Height
 }
 
 func (c *Collection) Widgets() []Widget {
@@ -17,10 +25,40 @@ func (c *Collection) Clear() {
 	c.widgets = []Widget{}
 }
 
+func (c *Collection) ResetHover() {
+	c.hoverDetector.reset(0, 0)
+}
+
 func (c *Collection) AddWidget(w Widget) {
+	if w == nil {
+		log.Panicf("Adding nil widget to collection")
+	}
 	c.widgets = append(c.widgets, w)
 }
 
+func (c *Collection) FindWidget(toFind Widget) int {
+	for i, w := range c.widgets {
+		if w != toFind {
+			continue
+		}
+		return i
+	}
+	return -1
+}
+
+func (c *Collection) RemoveWidget(widget Widget) {
+	idx := c.FindWidget(widget)
+	if idx != -1 {
+		c.RemoveWidgetAt(idx)
+	}
+}
+
+func (c *Collection) RemoveWidgetAt(idx int) {
+	nwidgets := len(c.widgets)
+	c.widgets[idx] = c.widgets[nwidgets-1]
+	c.widgets = c.widgets[:nwidgets-1]
+}
+
 func (c *Collection) Draw(screen *ebiten.Image) {
 	for _, w := range c.widgets {
 		w.Draw(screen)
@@ -39,6 +77,8 @@ func (c *Collection) Update() error {
 		break
 	}
 
+	c.hoverDetector.update(c, x, y, activeWidget)
+
 	if activeWidget == nil {
 		return nil
 	}
@@ -61,7 +101,7 @@ func (c *Collection) Update() error {
 	}
 
 	if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonLeft) {
-		if btn, ok := activeWidget.(Button); ok {
+		if btn, ok := activeWidget.(Clickable); ok {
 			btn.Click(x, y)
 		}
 	}
diff --git a/go/ui/hoverDetector.go b/go/ui/hoverDetector.go
new file mode 100644
index 00000000..49161f4f
--- /dev/null
+++ b/go/ui/hoverDetector.go
@@ -0,0 +1,41 @@
+package ui
+
+// A simple structure to detect if the cursor has not moved or started moving again.
+// hoverDetector.update must be called during each Update invocation to track the
+// frame and the current cursor position.
+type hoverDetector struct {
+	last_x, last_y int
+	ticks          int
+	hovering       Hoverable
+}
+
+func (h *hoverDetector) update(collection *Collection, x, y int, w Widget) {
+	if x == h.last_x && y == h.last_y {
+		h.hover(collection, x, y, w)
+	} else {
+		h.reset(x, y)
+		h.last_x, h.last_y = x, y
+	}
+}
+
+func (h *hoverDetector) hover(collection *Collection, x, y int, w Widget) {
+	h.ticks++
+
+	if w == nil || h.hovering != nil {
+		return
+	}
+
+	if hoverable, ok := w.(Hoverable); ok && hoverable.onHover(h.ticks, x, y, collection) {
+		h.hovering = hoverable
+	}
+}
+
+func (h *hoverDetector) reset(x, y int) {
+	if h.hovering != nil {
+		if !h.hovering.stopHover(h.ticks, x, y) {
+			return
+		}
+		h.hovering = nil
+	}
+	h.ticks = 0
+}
diff --git a/go/ui/hoverable.go b/go/ui/hoverable.go
new file mode 100644
index 00000000..54d4ec15
--- /dev/null
+++ b/go/ui/hoverable.go
@@ -0,0 +1,120 @@
+package ui
+
+import (
+	"muhq.space/muhqs-game/go/game"
+)
+
+const (
+	HOVER_THRESHOLD = 60
+
+	HOVER_CARD_WIDTH  = 500
+	HOVER_CARD_HEIGHT = 700
+)
+
+type Hoverable interface {
+	onHover(ticks int, x, y int, c *Collection) bool
+	stopHover(ticks int, x, y int) bool
+}
+
+type hoverWidget struct {
+	createHint func(x, y int) Widget
+	reset      func()
+	xMax, yMax int
+}
+
+func (h *hoverWidget) showHint(x, y int, c *Collection) {
+	hint := h.createHint(x, y)
+	if hint == nil {
+		return
+	}
+
+	c.AddWidget(hint)
+	h.reset = func() {
+		c.RemoveWidget(hint)
+	}
+}
+
+func (h *hoverWidget) onHover(ticks int, x, y int, c *Collection) bool {
+	if h.xMax == 0 || h.yMax == 0 {
+		width, height := c.Layout()
+		h.xMax = width
+		h.yMax = height
+	}
+
+	if ticks == HOVER_THRESHOLD {
+		h.showHint(x, y, c)
+		return true
+	}
+
+	return false
+}
+
+func (h *hoverWidget) stopHover(ticks int, x, y int) bool {
+	if h.reset != nil {
+		h.reset()
+	}
+	return true
+}
+
+type hoverCardView struct {
+	hoverWidget
+}
+
+func (h *hoverCardView) init(w Widget) {
+	h.createHint = func(x, y int) Widget {
+		card := w.FindObjectAt(x, y).(*game.Card)
+		if card == nil {
+			return nil
+		}
+
+		wx, wy := x, y
+		if x+HOVER_CARD_WIDTH > h.xMax || y+HOVER_CARD_HEIGHT > h.yMax {
+			wx = x - HOVER_CARD_WIDTH
+			wy = y - HOVER_CARD_HEIGHT
+		}
+		if wx < 0 {
+			wx = 0
+		}
+		if wy < 0 {
+			wy = 0
+		}
+
+		return NewScaledCardView(wx, wy, HOVER_CARD_WIDTH, HOVER_CARD_HEIGHT, card.Path())
+	}
+}
+
+type hoverPermInfo struct {
+	hoverWidget
+}
+
+func (h *hoverPermInfo) init(w Widget) {
+	h.createHint = func(x, y int) Widget {
+		obj := w.FindObjectAt(x, y)
+		if obj == nil {
+			return nil
+		}
+
+		perm, ok := obj.(game.Permanent)
+		if !ok {
+			return nil
+		}
+
+		hint := NewPermInfo(x+TILE_WIDTH, y, perm)
+
+		wx, wy := x, y
+		if hint.X+hint.Width > h.xMax || y+hint.Height > h.yMax {
+			wx = x - hint.Width
+			wy = y - hint.Height
+		}
+		if wx < 0 {
+			wx = 0
+		}
+		if wy < 0 {
+			wy = 0
+		}
+
+		hint.X, hint.Y = wx, wy
+
+		return hint
+	}
+}
diff --git a/go/ui/mapView.go b/go/ui/mapView.go
index 155750b4..0553b348 100644
--- a/go/ui/mapView.go
+++ b/go/ui/mapView.go
@@ -23,6 +23,7 @@ const (
 )
 
 type MapView struct {
+	hoverPermInfo
 	gameState            *game.State
 	mapLayer             *ebiten.Image
 	permanentsLayer      *ebiten.Image
@@ -31,14 +32,25 @@ type MapView struct {
 }
 
 func NewMapView(g *game.State) *MapView {
-	vw := MapView{g, nil, nil, []game.Position{}, []game.Permanent{}}
-	return &vw
+	vw := &MapView{gameState: g}
+	vw.hoverPermInfo.init(vw)
+	return vw
 }
 
 func (mv *MapView) Height() int {
 	return len(mv.gameState.Map.Tiles) * TILE_HEIGHT
 }
 
+func (mv *MapView) Width() int {
+	maxWidth := 0
+	for _, row := range mv.gameState.Map.Tiles {
+		if n := len(row); n > maxWidth {
+			maxWidth = n
+		}
+	}
+	return maxWidth * TILE_WIDTH
+}
+
 func rotateStreetImg(x, y int, radian float64, op *ebiten.DrawImageOptions) {
 	// Move the image's center to the screen's upper-left corner.
 	// This is a preparation for rotating. When geometry matrices are applied,
@@ -278,6 +290,12 @@ func (vw *MapView) ClearPermanentsHighlights() {
 	vw.HighlightPermanents([]game.Permanent{})
 }
 
+func (mv *MapView) Contains(x, y int) bool {
+	w := mv.Width()
+	h := mv.Height()
+	return x >= 0 && y >= 0 && x <= w && y <= h
+}
+
 func (*MapView) Render(Widget) *ebiten.Image {
 	return nil
 }
diff --git a/go/ui/prompt.go b/go/ui/prompt.go
index b8d60a49..93c4b4cd 100644
--- a/go/ui/prompt.go
+++ b/go/ui/prompt.go
@@ -1,6 +1,8 @@
 package ui
 
 import (
+	"image/color"
+
 	"github.com/hajimehoshi/ebiten/v2"
 
 	"muhq.space/muhqs-game/go/game"
@@ -42,6 +44,10 @@ func (p *Prompt) Height() int {
 	return PROMPT_HEIGHT
 }
 
+func (p *Prompt) ClearSelections() {
+	p.action.Targets().ClearSelections()
+}
+
 func (p *Prompt) Draw(screen *ebiten.Image) {
 	for _, comp := range p.components {
 		comp.Draw(screen)
@@ -54,3 +60,34 @@ func (p *Prompt) Contains(x, y int) bool {
 
 func (p *Prompt) FindObjectAt(screenX, screenY int) interface{} { return nil }
 func (*Prompt) Render(Widget) *ebiten.Image                     { return nil }
+
+func (p *Prompt) setTextBgAlpha(alpha uint8) {
+	for _, comp := range p.components {
+		textBox, ok := comp.(*TextBox)
+		if !ok {
+			continue
+		}
+		bg := color.RGBAModel.Convert(textBox.bg).(color.RGBA)
+		bg.A = alpha
+		textBox.Bg(bg)
+		textBox.ForceRedraw()
+	}
+}
+
+func (p *Prompt) onHover(ticks int, x int, y int, c *Collection) bool {
+	if ticks == 1 {
+		p.setTextBgAlpha(0x7f)
+		return true
+	}
+
+	return false
+}
+
+func (p *Prompt) stopHover(ticks int, x, y int) bool {
+	if p.Contains(x, y) {
+		return false
+	}
+
+	p.setTextBgAlpha(0xff)
+	return true
+}
diff --git a/go/ui/stateBar.go b/go/ui/stateBar.go
index 93de9af9..1686b5e1 100644
--- a/go/ui/stateBar.go
+++ b/go/ui/stateBar.go
@@ -44,9 +44,7 @@ func (sb *StateBar) Draw(screen *ebiten.Image) {
 	sb.phaseView.Draw(screen)
 }
 
-func (sb *StateBar) FindObjectAt(x, y int) interface{} {
-	return nil
-}
+func (sb *StateBar) FindObjectAt(x, y int) interface{} { return nil }
 
 func (sb *StateBar) ForceRedraw() {
 	if sb.resourceView != nil {
diff --git a/go/ui/textBox.go b/go/ui/textBox.go
index 2635535c..66b90698 100644
--- a/go/ui/textBox.go
+++ b/go/ui/textBox.go
@@ -84,11 +84,20 @@ func NewUnitInfo(x, y int, u *game.Unit) *TextBox {
 	return NewAutoTextBox(x, y, info)
 }
 
-func NewPermInfo(x, y int, p game.Permanent) *TextBox {
+func NewGenericPermInfo(x, y int, p game.Permanent) *TextBox {
 	info := fmt.Sprintf("%s\nDamage: %d", p.String(), p.Damage())
 	return NewAutoTextBox(x, y, info)
 }
 
+func NewPermInfo(x, y int, p game.Permanent) *TextBox {
+	switch p := p.(type) {
+	case *game.Unit:
+		return NewUnitInfo(x, y, p)
+	default:
+		return NewGenericPermInfo(x, y, p)
+	}
+}
+
 func (tb *TextBox) render() *ebiten.Image {
 	var x, y int
 	b := text.BoundString(font.Font24, tb.text)
@@ -115,6 +124,7 @@ func (tb *TextBox) render() *ebiten.Image {
 
 type PocList struct {
 	TextBox
+	hoverCardView
 	centerX int
 	bottomY int
 	poc     game.PileOfCards
@@ -128,6 +138,8 @@ func NewPocList(centerX, bottomY int, poc game.PileOfCards) *PocList {
 		poc:     poc,
 	}
 
+	w.hoverCardView.init(w)
+
 	w.renderImpl = func() *ebiten.Image {
 		w.setText()
 		return w.render()
diff --git a/go/ui/widget.go b/go/ui/widget.go
index cfcdd766..4ee0caac 100644
--- a/go/ui/widget.go
+++ b/go/ui/widget.go
@@ -17,12 +17,8 @@ type WidgetBase struct {
 	renderImpl    func() *ebiten.Image
 }
 
-func renderDummy() *ebiten.Image {
-	return nil
-}
-
 func NewWidgetBase(x, y, width, height int) WidgetBase {
-	return WidgetBase{x, y, width, height, nil, renderDummy}
+	return WidgetBase{X: x, Y: y, Width: width, Height: height}
 }
 
 func (w *WidgetBase) Draw(screen *ebiten.Image) {