// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// +build linux,!android

package app

// Simple on-screen app debugging for X11. Not an officially supported
// development target for apps, as screens with mice are very different
// than screens with touch panels.

/*
#cgo LDFLAGS: -lEGL -lGLESv2 -lX11

void runApp(void);
*/
import "C"
import (
	"runtime"
	"sync"

	"code.google.com/p/go.mobile/event"
	"code.google.com/p/go.mobile/geom"
)

var cb Callbacks

func run(callbacks Callbacks) {
	runtime.LockOSThread()
	cb = callbacks
	C.runApp()
}

//export onResize
func onResize(w, h int) {
	// TODO(nigeltao): don't assume 72 DPI. DisplayWidth / DisplayWidthMM
	// is probably the best place to start looking.
	geom.Scale = 1
	geom.Width = geom.Pt(w)
	geom.Height = geom.Pt(h)
}

var events struct {
	sync.Mutex
	pending []event.Touch
}

func sendTouch(ty event.TouchType, x, y float32) {
	events.Lock()
	events.pending = append(events.pending, event.Touch{
		Type: ty,
		Loc: geom.Point{
			X: geom.Pt(x),
			Y: geom.Pt(y),
		},
	})
	events.Unlock()
}

//export onTouchStart
func onTouchStart(x, y float32) { sendTouch(event.TouchStart, x, y) }

//export onTouchMove
func onTouchMove(x, y float32) { sendTouch(event.TouchMove, x, y) }

//export onTouchEnd
func onTouchEnd(x, y float32) { sendTouch(event.TouchEnd, x, y) }

//export onDraw
func onDraw() {
	events.Lock()
	pending := events.pending
	events.pending = nil
	events.Unlock()

	for _, e := range pending {
		if cb.Touch != nil {
			cb.Touch(e)
		}
	}
	if cb.Draw != nil {
		cb.Draw()
	}
}