added layout basics

4 files changed, 315 insertions, 0 deletions

diff --git a/examples/layout/button.go b/examples/layout/button.go
new file mode 100644
index 0000000..6c907e3
--- /dev/null
+++ b/examples/layout/button.go
@@ -0,0 +1,64 @@
+package main
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+	"log"
+
+	"github.com/faiface/gui"
+	"github.com/faiface/gui/win"
+)
+
+func Button(env gui.Env, theme *Theme, text string, action func()) {
+	textImg := MakeTextImage(text, theme.Face, theme.Text)
+
+	redraw := func(r image.Rectangle, over, pressed bool) func(draw.Image) image.Rectangle {
+		return func(drw draw.Image) image.Rectangle {
+			var clr color.Color
+			if pressed {
+				clr = theme.ButtonDown
+			} else if over {
+				clr = theme.ButtonOver
+			} else {
+				clr = theme.ButtonUp
+			}
+			draw.Draw(drw, r, &image.Uniform{clr}, image.ZP, draw.Src)
+			DrawCentered(drw, r, textImg, draw.Over)
+			return r
+		}
+	}
+
+	var (
+		r       image.Rectangle
+		over    bool
+		pressed bool
+	)
+
+	for e := range env.Events() {
+		switch e := e.(type) {
+		case gui.Resize:
+			r = e.Rectangle
+			log.Print("button ", e)
+			env.Draw() <- redraw(r, over, pressed)
+
+		case win.MoDown:
+			newPressed := e.Point.In(r)
+			if newPressed != pressed {
+				pressed = newPressed
+				env.Draw() <- redraw(r, over, pressed)
+			}
+
+		case win.MoUp:
+			if pressed {
+				if e.Point.In(r) {
+					action()
+				}
+				pressed = false
+				env.Draw() <- redraw(r, over, pressed)
+			}
+		}
+	}
+
+	close(env.Draw())
+}
diff --git a/examples/layout/main.go b/examples/layout/main.go
new file mode 100644
index 0000000..47364a9
--- /dev/null
+++ b/examples/layout/main.go
@@ -0,0 +1,128 @@
+package main
+
+import (
+	"image"
+	"image/draw"
+	"log"
+	"time"
+
+	"github.com/faiface/gui"
+	"github.com/faiface/gui/fixedgrid"
+	"github.com/faiface/gui/win"
+	"github.com/faiface/mainthread"
+	"golang.org/x/image/colornames"
+	"golang.org/x/image/font/gofont/goregular"
+)
+
+func Blinker(env gui.Env, closed bool) {
+	defer func() {
+		if recover() != nil {
+			log.Print("recovered blinker")
+		}
+	}()
+
+	var r image.Rectangle
+	var visible bool = true
+	// redraw takes a bool and produces a draw command
+	redraw := func() func(draw.Image) image.Rectangle {
+		return func(drw draw.Image) image.Rectangle {
+			if visible {
+				draw.Draw(drw, r, image.White, image.ZP, draw.Src)
+			} else {
+				draw.Draw(drw, r, &image.Uniform{colornames.Firebrick}, image.ZP, draw.Src)
+			}
+			return r
+		}
+	}
+
+	// first we draw a white rectangle
+	env.Draw() <- redraw()
+	go func() {
+		for event := range env.Events() {
+			switch event := event.(type) {
+			case win.MoDown:
+				if event.Point.In(r) {
+					go func() {
+						for i := 0; i < 3; i++ {
+							visible = false
+							env.Draw() <- redraw()
+							time.Sleep(time.Second / 3)
+							visible = true
+							env.Draw() <- redraw()
+							time.Sleep(time.Second / 3)
+						}
+					}()
+				}
+			case gui.Resize:
+				log.Print(event)
+				r = event.Rectangle
+				env.Draw() <- redraw()
+			}
+		}
+	}()
+
+	if closed {
+		time.Sleep(time.Second * 1)
+		close(env.Draw())
+	}
+}
+
+func run() {
+	face, err := TTFToFace(goregular.TTF, 18)
+	if err != nil {
+		panic(err)
+	}
+	theme := &Theme{
+		Face:       face,
+		Background: colornames.White,
+		Empty:      colornames.Darkgrey,
+		Text:       colornames.Black,
+		Highlight:  colornames.Blueviolet,
+		ButtonUp:   colornames.Lightgrey,
+		ButtonDown: colornames.Grey,
+	}
+	w, err := win.New(win.Title("gui test"),
+		win.Resizable(),
+	)
+	if err != nil {
+		panic(err)
+	}
+	mux, env := gui.NewMux(w)
+	gr := fixedgrid.New(mux.MakeEnv(),
+		fixedgrid.Rows(5),
+		fixedgrid.Columns(2),
+		fixedgrid.Gap(10),
+	)
+	log.Print(gr)
+	go Blinker(gr.GetEnv("0;0"), false)
+	go Blinker(gr.GetEnv("0;1"), true)
+	go Blinker(gr.GetEnv("1;1"), false)
+	go Blinker(gr.GetEnv("0;2"), false)
+	go Blinker(gr.GetEnv("0;3"), false)
+	go Blinker(gr.GetEnv("0;4"), false)
+	sgr := fixedgrid.New(gr.GetEnv("1;0"),
+		fixedgrid.Columns(3),
+		fixedgrid.Gap(4),
+		fixedgrid.Background(colornames.Darkgrey),
+	)
+	go Button(sgr.GetEnv("0;0"), theme, "Hey", func() {
+		log.Print("hey")
+	})
+	go Button(sgr.GetEnv("1;0"), theme, "Ho", func() {
+		log.Print("ho")
+	})
+	go Button(sgr.GetEnv("2;0"), theme, "Hu", func() {
+		log.Print("hu")
+	})
+	// we use the master env now, w is used by the mux
+	for event := range env.Events() {
+		switch event.(type) {
+		case win.WiClose:
+			close(env.Draw())
+		}
+	}
+}
+
+func main() {
+	mainthread.Run(run)
+}
diff --git a/examples/layout/theme.go b/examples/layout/theme.go
new file mode 100644
index 0000000..e37c0c0
--- /dev/null
+++ b/examples/layout/theme.go
@@ -0,0 +1,19 @@
+package main
+
+import (
+	"image/color"
+
+	"golang.org/x/image/font"
+)
+
+type Theme struct {
+	Face font.Face
+
+	Background color.Color
+	Empty      color.Color
+	Text       color.Color
+	Highlight  color.Color
+	ButtonUp   color.Color
+	ButtonOver color.Color
+	ButtonDown color.Color
+}
diff --git a/examples/layout/utils.go b/examples/layout/utils.go
new file mode 100644
index 0000000..e799988
--- /dev/null
+++ b/examples/layout/utils.go
@@ -0,0 +1,104 @@
+package main
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+	"sync"
+
+	"github.com/golang/freetype/truetype"
+
+	"golang.org/x/image/font"
+	"golang.org/x/image/math/fixed"
+)
+
+type concurrentFace struct {
+	mu   sync.Mutex
+	face font.Face
+}
+
+func (cf *concurrentFace) Close() error {
+	cf.mu.Lock()
+	defer cf.mu.Unlock()
+	return cf.face.Close()
+}
+
+func (cf *concurrentFace) Glyph(dot fixed.Point26_6, r rune) (dr image.Rectangle, mask image.Image, maskp image.Point, advance fixed.Int26_6, ok bool) {
+	cf.mu.Lock()
+	defer cf.mu.Unlock()
+	return cf.face.Glyph(dot, r)
+}
+
+func (cf *concurrentFace) GlyphBounds(r rune) (bounds fixed.Rectangle26_6, advance fixed.Int26_6, ok bool) {
+	cf.mu.Lock()
+	defer cf.mu.Unlock()
+	return cf.face.GlyphBounds(r)
+}
+
+func (cf *concurrentFace) GlyphAdvance(r rune) (advance fixed.Int26_6, ok bool) {
+	cf.mu.Lock()
+	defer cf.mu.Unlock()
+	return cf.face.GlyphAdvance(r)
+}
+
+func (cf *concurrentFace) Kern(r0, r1 rune) fixed.Int26_6 {
+	cf.mu.Lock()
+	defer cf.mu.Unlock()
+	return cf.face.Kern(r0, r1)
+}
+
+func (cf *concurrentFace) Metrics() font.Metrics {
+	cf.mu.Lock()
+	defer cf.mu.Unlock()
+	return cf.face.Metrics()
+}
+
+func TTFToFace(ttf []byte, size float64) (font.Face, error) {
+	font, err := truetype.Parse(ttf)
+	if err != nil {
+		return nil, err
+	}
+	return &concurrentFace{face: truetype.NewFace(font, &truetype.Options{
+		Size: size,
+	})}, nil
+}
+
+func MakeTextImage(text string, face font.Face, clr color.Color) image.Image {
+	drawer := &font.Drawer{
+		Src:  &image.Uniform{clr},
+		Face: face,
+		Dot:  fixed.P(0, 0),
+	}
+	b26_6, _ := drawer.BoundString(text)
+	bounds := image.Rect(
+		b26_6.Min.X.Floor(),
+		b26_6.Min.Y.Floor(),
+		b26_6.Max.X.Ceil(),
+		b26_6.Max.Y.Ceil(),
+	)
+	drawer.Dst = image.NewRGBA(bounds)
+	drawer.DrawString(text)
+	return drawer.Dst
+}
+
+func DrawCentered(dst draw.Image, r image.Rectangle, src image.Image, op draw.Op) {
+	if src == nil {
+		return
+	}
+	bounds := src.Bounds()
+	center := bounds.Min.Add(bounds.Max).Div(2)
+	target := r.Min.Add(r.Max).Div(2)
+	delta := target.Sub(center)
+	draw.Draw(dst, bounds.Add(delta).Intersect(r), src, bounds.Min, op)
+}
+
+func DrawLeftCentered(dst draw.Image, r image.Rectangle, src image.Image, op draw.Op) {
+	if src == nil {
+		return
+	}
+	bounds := src.Bounds()
+	leftCenter := image.Pt(bounds.Min.X, (bounds.Min.Y+bounds.Max.Y)/2)
+	target := image.Pt(r.Min.X, (r.Min.Y+r.Max.Y)/2)
+	delta := target.Sub(leftCenter)
+	draw.Draw(dst, bounds.Add(delta).Intersect(r), src, bounds.Min, op)
+}