gmlog

README

Simple logging package for gomobile applications. It supports Print, Printf, Fatal and Fatalf methods.

go get github.com/viru/gmlog

Typical usage (simplified code to show the idea):

package main

import (
	"github.com/viru/gmlog"
	// other imports left out for readibility
)

func main() {
	app.Main(func(a app.App) {
		var glctx gl.Context
		var sz size.Event
		for e := range a.Events() {
			switch e := a.Filter(e).(type) {
			case lifecycle.Event:
				switch e.Crosses(lifecycle.StageVisible) {
				case lifecycle.CrossOn:
					onStart(glctx, sz) // Initialise logger here.
					a.Send(paint.Event{})
				case lifecycle.CrossOff:
					onStop() // Release logger here.
				}
			case size.Event:
				sz = e
			case paint.Event:
				onPaint(glctx, sz) // Make sure logger Draw func is called here.
				a.Publish()
				a.Send(paint.Event{})
			}
		}
	})
}

var (
	images    *glutil.Images
	eng       sprite.Engine
	log       *gmlog.Logger // Global log handler.
)

func onStart(glctx gl.Context, sz size.Event) {
	images = glutil.NewImages(glctx)
	eng = glsprite.Engine(images)
	log = gmlog.New(images, 5)) // Pass your images to logger along with lines limit.
	log.Print("Initialised app") // Now you can print to your logs.
}

func onStop() {
	eng.Release()
	log.Release() // Release logger before releasing images.
	images.Release()
}

func onPaint(glctx gl.Context, sz size.Event) {
	glctx.ClearColor(0, 0, 0, 1)
	glctx.Clear(gl.COLOR_BUFFER_BIT)
	eng.Render(scene, now, sz)
	log.Draw(sz) // Call Draw to display the logs.
}

Logs are added on top of the screen (not configurable at the moment):

Documentation

Overview

Package gmlog implements a simple logging package. It defines a type, Logger, with methods for formatting output. It is anologous to standard library's log package, but prints lines of logs on gomobile application.

Index

• type Logger
  • func New(images *glutil.Images, limit int) *Logger
  • func (l *Logger) Draw(sz size.Event)
  • func (l *Logger) Fatal(v ...interface{})
  • func (l *Logger) Fatalf(format string, v ...interface{})
  • func (l *Logger) Output(msg string)
  • func (l *Logger) Print(v ...interface{})
  • func (l *Logger) Printf(format string, v ...interface{})
  • func (l *Logger) Release()

Types

type Logger

type Logger struct {
	// contains filtered or unexported fields
}

A Logger represents an active logging object that generates lines of output to glutil Images (useful in gomobile applications).

func New

func New(images *glutil.Images, limit int) *Logger

New creates a Logger tied to the current GL images. Limit limits amount of lines to be displayed.

func (*Logger) Draw

func (l *Logger) Draw(sz size.Event)

Draw draws all current logs at the top of the screen.

func (*Logger) Fatal

func (l *Logger) Fatal(v ...interface{})

Fatal is equivalent to l.Print() followed by a call to os.Exit(1).

func (*Logger) Fatalf

func (l *Logger) Fatalf(format string, v ...interface{})

Fatalf is equivalent to l.Printf() followed by a call to os.Exit(1).

func (*Logger) Output

func (l *Logger) Output(msg string)

Output adds formatted message to the buffer.

func (*Logger) Print

func (l *Logger) Print(v ...interface{})

Print adds new message to logger buffer.

func (*Logger) Printf

func (l *Logger) Printf(format string, v ...interface{})

Printf adds new message format and optional arguments to logger buffer.

func (*Logger) Release

func (l *Logger) Release()

Release releases image resources.