From 1223e277009005337243ca991cb54dd75bf723a7 Mon Sep 17 00:00:00 2001
From: Clement Benard <contact@clementbenard.com>
Date: Tue, 9 Jul 2019 10:59:38 +0200
Subject: Layout system remaking

---
 layout/layout.go | 168 ++++---------------------------------------------------
 1 file changed, 11 insertions(+), 157 deletions(-)

(limited to 'layout/layout.go')

diff --git a/layout/layout.go b/layout/layout.go
index 3601629..987ee24 100644
--- a/layout/layout.go
+++ b/layout/layout.go
@@ -3,163 +3,17 @@ package layout
 import (
 	"image"
 	"image/draw"
-	"sync"
-
-	"github.com/faiface/gui"
 )
 
-type Layout struct {
-	masterEnv *MuxEnv
-	inEvent   chan<- gui.Event
-
-	mu         sync.Mutex
-	lastResize gui.Event
-	eventsIns  map[string]chan<- gui.Event
-	draw       chan<- func(draw.Image) image.Rectangle
-
-	Lay    func(image.Rectangle) map[string]image.Rectangle
-	Redraw func(draw.Image, image.Rectangle)
-}
-
-func New(
-	env gui.Env,
-	lay func(image.Rectangle) map[string]image.Rectangle,
-	redraw func(draw.Image, image.Rectangle),
-) *Layout {
-
-	mux := &Layout{
-		Lay:    lay,
-		Redraw: redraw,
-	}
-	drawChan := make(chan func(draw.Image) image.Rectangle)
-	mux.draw = drawChan
-	mux.masterEnv = mux.makeEnv("master", true)
-	mux.inEvent = mux.masterEnv.In
-	mux.eventsIns = make(map[string]chan<- gui.Event)
-	go func() {
-		for d := range drawChan {
-			env.Draw() <- d
-		}
-		close(env.Draw())
-	}()
-
-	go func() {
-		for e := range env.Events() {
-			mux.inEvent <- e
-		}
-	}()
-
-	go func() {
-		for e := range mux.masterEnv.Events() {
-			mux.mu.Lock()
-			if resize, ok := e.(gui.Resize); ok {
-				mux.lastResize = resize
-				rect := resize.Rectangle
-
-				mux.draw <- func(drw draw.Image) image.Rectangle {
-					mux.Redraw(drw, rect)
-					return rect
-				}
-				l := mux.Lay(rect)
-
-				for key, eventsIn := range mux.eventsIns {
-					func(rz gui.Resize) {
-						rz.Rectangle = l[key]
-						eventsIn <- rz
-					}(resize)
-				}
-			} else {
-				for _, eventsIn := range mux.eventsIns {
-					eventsIn <- e
-				}
-			}
-			mux.mu.Unlock()
-		}
-		mux.mu.Lock()
-		for _, eventsIn := range mux.eventsIns {
-			close(eventsIn)
-		}
-		mux.mu.Unlock()
-	}()
-
-	return mux
-}
-
-func (mux *Layout) GetEnv(name string) gui.Env {
-	return mux.makeEnv(name, false)
-}
-
-type MuxEnv struct {
-	In     chan<- gui.Event
-	events <-chan gui.Event
-	draw   chan<- func(draw.Image) image.Rectangle
-}
-
-func (m *MuxEnv) Events() <-chan gui.Event                      { return m.events }
-func (m *MuxEnv) Draw() chan<- func(draw.Image) image.Rectangle { return m.draw }
-
-// We do not store master env
-func (mux *Layout) makeEnv(envName string, master bool) *MuxEnv {
-	eventsOut, eventsIn := gui.MakeEventsChan()
-	drawChan := make(chan func(draw.Image) image.Rectangle)
-	env := &MuxEnv{eventsIn, eventsOut, drawChan}
-
-	mux.mu.Lock()
-	if !master {
-		mux.eventsIns[envName] = eventsIn
-	}
-
-	// make sure to always send a resize event to a new Env if we got the size already
-	// that means it missed the resize event by the root Env
-	if mux.lastResize != nil {
-		eventsIn <- mux.lastResize
-	}
-	mux.mu.Unlock()
-
-	go func() {
-		func() {
-			// When the master Env gets its Draw() channel closed, it closes all the Events()
-			// channels of all the children Envs, and it also closes the internal draw channel
-			// of the Mux. Otherwise, closing the Draw() channel of the master Env wouldn't
-			// close the Env the Mux is muxing. However, some child Envs of the Mux may still
-			// send some drawing commmands before they realize that their Events() channel got
-			// closed.
-			//
-			// That is perfectly fine if their drawing commands simply get ignored. This down here
-			// is a little hacky, but (I hope) perfectly fine solution to the problem.
-			//
-			// When the internal draw channel of the Mux gets closed, the line marked with ! will
-			// cause panic. We recover this panic, then we receive, but ignore all furhter draw
-			// commands, correctly draining the Env until it closes itself.
-			defer func() {
-				if recover() != nil {
-					for range drawChan {
-					}
-				}
-			}()
-			for d := range drawChan {
-				mux.draw <- d // !
-			}
-		}()
-		if master {
-			mux.mu.Lock()
-			for _, eventsIn := range mux.eventsIns {
-				close(eventsIn)
-			}
-			mux.eventsIns = nil
-			close(mux.draw)
-			mux.mu.Unlock()
-		} else {
-			mux.mu.Lock()
-			delete(mux.eventsIns, envName)
-
-			close(eventsIn)
-			mux.mu.Unlock()
-		}
-		if mux.lastResize != nil {
-			mux.inEvent <- mux.lastResize
-		}
-	}()
-
-	return env
+// Layout represents any graphical layout
+//
+// A Layout needs to be able to redraw itself with the Redraw method.
+// Redraw() only draws the background or frame of the Layout, not the childs.
+//
+// Lay represents the way to divide space among your childs.
+// It takes a parameter of how much space is available,
+// and returns where exactly to put its childs.
+type Layout interface {
+	Lay(image.Rectangle) []image.Rectangle
+	Redraw(draw.Image, image.Rectangle)
 }
-- 
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