Move most properties from Button to parent Widget

These properties will be globally useful to all sorts of Widgets and
have been moved from the Button up into the Common widget, and its
interface extended to configure these:
* Padding int32
* Background color
* Foreground color
* Border size, color and style (default solid; raised; sunken)
* Outline size and color

The button adjusts its border style from "raised" to "sunken" for
MouseDown events and its Background color for MouseOver events. Other
widgets such as Labels and Frames will be able to have borders, paddings
and outlines too, but they will be off by default.

render/interface.go

@@ -63,6 +63,32 @@ func (c Color) String() string {
 	)
 }
 
+// Add a relative color value to the color.
+func (c Color) Add(r, g, b, a int32) Color {
+	var (
+		R = int32(c.Red) + r
+		G = int32(c.Green) + g
+		B = int32(c.Blue) + b
+		A = int32(c.Alpha) + a
+	)
+
+	cap8 := func(v int32) uint8 {
+		if v > 255 {
+			v = 255
+		} else if v < 0 {
+			v = 0
+		}
+		return uint8(v)
+	}
+
+	return Color{
+		Red:   cap8(R),
+		Green: cap8(G),
+		Blue:  cap8(B),
+		Alpha: cap8(A),
+	}
+}
+
 // Point holds an X,Y coordinate value.
 type Point struct {
 	X int32

render/sdl/sdl.go

@@ -131,17 +131,7 @@ func (r *Renderer) Poll() (*events.State, error) {
 				}
 
 				if eventName != "" {
-					log.Debug("tick:%d  Mouse Button1 %s BEFORE: %+v",
-						r.ticks,
-						eventName,
-						s.Button1,
-					)
 					s.Button1.Push(eventName == "DOWN")
-					log.Debug("tick:%d  Mouse Button1 %s AFTER: %+v",
-						r.ticks,
-						eventName,
-						s.Button1,
-					)
 
 					// Return the event immediately.
 					return s, nil

ui/button.go

@@ -9,15 +9,6 @@ import (
 type Button struct {
 	BaseWidget
 	Label Label
-	Padding int32
-	Border  int32
-	Outline int32
-
-	// Color options.
-	Background     render.Color
-	HighlightColor render.Color
-	ShadowColor    render.Color
-	OutlineColor   render.Color
 
 	// Private options.
 	hovering bool
@@ -28,29 +19,31 @@ type Button struct {
 func NewButton(label Label) *Button {
 	w := &Button{
 		Label: label,
-		Padding: 4, // TODO magic number
-		Border:  2,
-		Outline: 1,
-
-		// Default theme colors.
-		Background:     theme.ButtonBackgroundColor,
-		HighlightColor: theme.ButtonHighlightColor,
-		ShadowColor:    theme.ButtonShadowColor,
-		OutlineColor:   theme.ButtonOutlineColor,
 	}
 
+	w.SetPadding(4)
+	w.SetBorderSize(2)
+	w.SetBorderStyle(BorderRaised)
+	w.SetOutlineSize(1)
+	w.SetOutlineColor(theme.ButtonOutlineColor)
+	w.SetBackground(theme.ButtonBackgroundColor)
+
 	w.Handle("MouseOver", func(p render.Point) {
 		w.hovering = true
+		w.SetBackground(theme.ButtonHoverColor)
 	})
 	w.Handle("MouseOut", func(p render.Point) {
 		w.hovering = false
+		w.SetBackground(theme.ButtonBackgroundColor)
 	})
 
 	w.Handle("MouseDown", func(p render.Point) {
 		w.clicked = true
+		w.SetBorderStyle(BorderSunken)
 	})
 	w.Handle("MouseUp", func(p render.Point) {
 		w.clicked = false
+		w.SetBorderStyle(BorderRaised)
 	})
 
 	return w
@@ -67,8 +60,8 @@ func (w *Button) Compute(e render.Engine) {
 	w.Label.Compute(e)
 	size := w.Label.Size()
 	w.Resize(render.Rect{
-		W: size.W + (w.Padding * 2) + (w.Border * 2) + (w.Outline * 2),
+		W: size.W + w.BoxThickness(2),
-		H: size.H + (w.Padding * 2) + (w.Border * 2) + (w.Outline * 2),
+		H: size.H + w.BoxThickness(2),
 	})
 }
 
@@ -76,55 +69,20 @@ func (w *Button) Compute(e render.Engine) {
 func (w *Button) Present(e render.Engine) {
 	w.Compute(e)
 	P := w.Point()
-	S := w.Size()
 
-	box := render.Rect{
+	// Draw the widget's border and everything.
-		X: P.X,
+	w.DrawBox(e)
-		Y: P.Y,
-		W: S.W,
-		H: S.H,
-	}
 
-	// Draw the outline layer as the full size of the widget.
+	// Offset further if we are currently sunken.
-	e.DrawBox(w.OutlineColor, render.Rect{
+	var clickOffset int32
-		X: P.X - w.Outline,
-		Y: P.Y - w.Outline,
-		W: S.W + (w.Outline * 2),
-		H: S.H + (w.Outline * 2),
-	})
-
-	// Highlight on the top left edge.
-	color := w.HighlightColor
 	if w.clicked {
-		color = w.ShadowColor
+		clickOffset++
-	}
-	e.DrawBox(color, box)
-	box.W = S.W
-
-	// Shadow on the bottom right edge.
-	box.X += w.Border
-	box.Y += w.Border
-	box.W -= w.Border
-	box.H -= w.Border
-	color = w.ShadowColor
-	if w.clicked {
-		color = w.HighlightColor
-	}
-	e.DrawBox(color, box)
-
-	// Background color of the button.
-	box.W -= w.Border
-	box.H -= w.Border
-	if w.hovering {
-		e.DrawBox(render.Yellow, box)
-	} else {
-		e.DrawBox(w.Background, box)
 	}
 
 	// Draw the text label inside.
 	w.Label.MoveTo(render.Point{
-		X: P.X + w.Padding + w.Border + w.Outline,
+		X: P.X + w.BoxThickness(1) + clickOffset,
-		Y: P.Y + w.Padding + w.Border + w.Outline,
+		Y: P.Y + w.BoxThickness(1) + clickOffset,
 	})
 	w.Label.Present(e)
 }

ui/theme/theme.go

@@ -4,8 +4,7 @@ import "git.kirsle.net/apps/doodle/render"
 
 // Color schemes.
 var (
-	ButtonBackgroundColor = render.RGBA(250, 250, 250, 255)
+	ButtonBackgroundColor = render.RGBA(200, 200, 200, 255)
-	ButtonHighlightColor  = render.RGBA(128, 128, 128, 255)
+	ButtonHoverColor      = render.RGBA(200, 255, 255, 255)
-	ButtonShadowColor     = render.RGBA(20, 20, 20, 255)
 	ButtonOutlineColor    = render.Black
 )

ui/widget.go

@@ -1,6 +1,18 @@
 package ui
 
-import "git.kirsle.net/apps/doodle/render"
+import (
+	"git.kirsle.net/apps/doodle/render"
+)
+
+// BorderStyle options for widget.SetBorderStyle()
+type BorderStyle string
+
+// Styles for a widget border.
+const (
+	BorderSolid  BorderStyle = "solid"
+	BorderRaised             = "raised"
+	BorderSunken             = "sunken"
+)
 
 // Widget is a user interface element.
 type Widget interface {
@@ -13,6 +25,28 @@ type Widget interface {
 	Handle(string, func(render.Point))
 	Event(string, render.Point) // called internally to trigger an event
 
+	// Thickness of the padding + border + outline.
+	BoxThickness(multiplier int32) int32
+	DrawBox(render.Engine)
+
+	// Widget configuration getters.
+	Padding() int32               // Padding
+	SetPadding(int32)             //
+	Background() render.Color     // Background color
+	SetBackground(render.Color)   //
+	Foreground() render.Color     // Foreground color
+	SetForeground(render.Color)   //
+	BorderStyle() BorderStyle     // Border style: none, raised, sunken
+	SetBorderStyle(BorderStyle)   //
+	BorderColor() render.Color    // Border color (default is Background)
+	SetBorderColor(render.Color)  //
+	BorderSize() int32            // Border size (default 0)
+	SetBorderSize(int32)          //
+	OutlineColor() render.Color   // Outline color (default Invisible)
+	SetOutlineColor(render.Color) //
+	OutlineSize() int32           // Outline size (default 0)
+	SetOutlineSize(int32)         //
+
 	// Run any render computations; by the end the widget must know its
 	// Width and Height. For example the Label widget will render itself onto
 	// an SDL Surface and then it will know its bounding box, but not before.
@@ -28,6 +62,14 @@ type BaseWidget struct {
 	width        int32
 	height       int32
 	point        render.Point
+	padding      int32
+	background   render.Color
+	foreground   render.Color
+	borderStyle  BorderStyle
+	borderColor  render.Color
+	borderSize   int32
+	outlineColor render.Color
+	outlineSize  int32
 	handlers     map[string][]func(render.Point)
 }
 
@@ -62,6 +104,159 @@ func (w *BaseWidget) Resize(v render.Rect) {
 	w.height = v.H
 }
 
+// BoxThickness returns the full sum of the padding, border and outline.
+// m = multiplier, i.e., 1 or 2
+func (w *BaseWidget) BoxThickness(m int32) int32 {
+	if m == 0 {
+		m = 1
+	}
+	return (w.Padding() * m) + (w.BorderSize() * m) + (w.OutlineSize() * m)
+}
+
+// DrawBox draws the border and outline.
+func (w *BaseWidget) DrawBox(e render.Engine) {
+	var (
+		P           = w.Point()
+		S           = w.Size()
+		outline     = w.OutlineSize()
+		border      = w.BorderSize()
+		borderColor = w.BorderColor()
+		highlight   = borderColor.Add(20, 20, 20, 0)
+		shadow      = borderColor.Add(-20, -20, -20, 0)
+		color       render.Color
+		box         = render.Rect{
+			X: P.X,
+			Y: P.Y,
+			W: S.W,
+			H: S.H,
+		}
+	)
+
+	// Draw the outline layer as the full size of the widget.
+	e.DrawBox(w.OutlineColor(), render.Rect{
+		X: P.X - outline,
+		Y: P.Y - outline,
+		W: S.W + (outline * 2),
+		H: S.H + (outline * 2),
+	})
+
+	// Highlight on the top left edge.
+	if w.BorderStyle() == BorderRaised {
+		color = highlight
+	} else if w.BorderStyle() == BorderSunken {
+		color = shadow
+	} else {
+		color = borderColor
+	}
+	e.DrawBox(color, box)
+	box.W = S.W
+
+	// Shadow on the bottom right edge.
+	box.X += border
+	box.Y += border
+	box.W -= border
+	box.H -= border
+	if w.BorderStyle() == BorderRaised {
+		color = shadow
+	} else if w.BorderStyle() == BorderSunken {
+		color = highlight
+	} else {
+		color = borderColor
+	}
+	e.DrawBox(color.Add(-20, -20, -20, 0), box)
+
+	// Background color of the button.
+	box.W -= border
+	box.H -= border
+	// if w.hovering {
+	// 	e.DrawBox(render.Yellow, box)
+	// } else {
+	e.DrawBox(color, box)
+}
+
+// Padding returns the padding width.
+func (w *BaseWidget) Padding() int32 {
+	return w.padding
+}
+
+// SetPadding sets the padding width.
+func (w *BaseWidget) SetPadding(v int32) {
+	w.padding = v
+}
+
+// Background returns the background color.
+func (w *BaseWidget) Background() render.Color {
+	return w.background
+}
+
+// SetBackground sets the color.
+func (w *BaseWidget) SetBackground(c render.Color) {
+	w.background = c
+}
+
+// Foreground returns the foreground color.
+func (w *BaseWidget) Foreground() render.Color {
+	return w.foreground
+}
+
+// SetForeground sets the color.
+func (w *BaseWidget) SetForeground(c render.Color) {
+	w.foreground = c
+}
+
+// BorderStyle returns the border style.
+func (w *BaseWidget) BorderStyle() BorderStyle {
+	return w.borderStyle
+}
+
+// SetBorderStyle sets the border style.
+func (w *BaseWidget) SetBorderStyle(v BorderStyle) {
+	w.borderStyle = v
+}
+
+// BorderColor returns the border color, or defaults to the background color.
+func (w *BaseWidget) BorderColor() render.Color {
+	if w.borderColor == render.Invisible {
+		return w.Background()
+	}
+	return w.borderColor
+}
+
+// SetBorderColor sets the border color.
+func (w *BaseWidget) SetBorderColor(c render.Color) {
+	w.borderColor = c
+}
+
+// BorderSize returns the border thickness.
+func (w *BaseWidget) BorderSize() int32 {
+	return w.borderSize
+}
+
+// SetBorderSize sets the border thickness.
+func (w *BaseWidget) SetBorderSize(v int32) {
+	w.borderSize = v
+}
+
+// OutlineColor returns the background color.
+func (w *BaseWidget) OutlineColor() render.Color {
+	return w.outlineColor
+}
+
+// SetOutlineColor sets the color.
+func (w *BaseWidget) SetOutlineColor(c render.Color) {
+	w.outlineColor = c
+}
+
+// OutlineSize returns the outline thickness.
+func (w *BaseWidget) OutlineSize() int32 {
+	return w.outlineSize
+}
+
+// SetOutlineSize sets the outline thickness.
+func (w *BaseWidget) SetOutlineSize(v int32) {
+	w.outlineSize = v
+}
+
 // Event is called internally by Doodle to trigger an event.
 func (w *BaseWidget) Event(name string, p render.Point) {
 	if handlers, ok := w.handlers[name]; ok {