Palm webOS in 10 Minutes
Palm webOS in 10 Minutes
(but only if I talk too fast)
Who's This Guy?
Serial enthusiast and general tinkerer at decafbad.com
Author of books, most recently Professional JavaScript Frameworks from Wrox
Jack-of-All-Trades on the Mozilla Webdev team
(I telecommute from my basement in Livonia)
Developer of two small webOS apps released to the homebrew community
What is webOS?
webOS is Palm's new mobile operating system
It's based on embedded Linux
It uses Apple's WebKit as an application runtime
Apps are built using HTML, CSS, and JavaScript
Currently available on the Pre and soon on the Pixi
What about the webOS SDK?
Free to download, cross-platform
Emulator runs as a disk image in VirtualBox
Developer Mode on device (a.k.a. the Konami code) unlocks a Linux shell and full root access
No certificates are required to install & test software
(unlike the iPhone)
What about the webOS SDK?
Basic tools are Java-based shell commands
Use TCP (emulator) or USB (device)
Tools to generate, package, install, and run apps
Inspector connects via TCP to emulator
Inspector allows live DOM/CSS tweaks and JavaScript shell with message log
What about the webOS SDK?
IDE integration is available
Using Eclipse (officially supported)
Using Komodo Edit (community supported)
Personally, I prefer Vim and a makefile
JSLint is highly recommended
(package/install/launch takes longer than a page refresh)
Application runtime
Apple WebKit 3.2 with patches by Palm
Apple's JavaScriptCore replaced by Google V8
AJAX / XMLHttpRequest without domain restrictions
HTML 5 Web Database support
Access to system services via JSON messages
Multitasking UI
One or more cards per app
(think chrome-less browser windows)
One stage per card
(basically the DOM document)
A stack of scenes per stage
(container <div>s inside stage body)
Gestural touch navigation for cards and scenes
(think Minority Report)
Multitasking UI
Growl-like background notifications
Dashboard panels for background interaction
Modal dialog style alerts
Mojo
Palm's mobile MVC framework based on Prototype
Assistants in JS for app, stages, and scenes
(consulted by built-in controller objects)
Common HTML/CSS/JS widgets
(finger-sized and webOS-themed)
Custom events defined for gestures and widgets
(eg. tap, flick, pinch/spread, orientation, shake)
Mojo
Partial HTML templates used for scenes and widgets
CSS used to customize system styles
Access to OS / hardware via JSON messages
(eg. accelerometer, audio, camera, GPS, phone, video,
inter-app messaging, media DB access, etc.)
Prototype provides the rest
(eg. AJAX, DOM, JSON, etc)
Homebrew App Repositories
The official Palm App Catalog is in beta
New apps subject to a backlogged review process
But, adventurous users can install apps from homebrew app repositories like PreCentral and Preware
Palm has done nothing to prevent this
Works great for recruiting early test pilots
webOS Internals Group
Exploring & documenting everything in webOS
(even "private" APIs)
Not supported by Palm, but no efforts to stop them
Almost all Palm code on device is unobfuscated HTML/CSS/JS
Other code is mostly Java, easily reverse engineered
Mods to webOS system files and core apps are distributed as patches and applied with quilt
Embedded Linux & OSS
$ uname -a
Linux castle 2.6.24-palm-joplin-3430 #1 175.1.23 armv7l GNU/Linux
Largely based on Open Source Software packages
Nearly 1700 packages from Optware embedded Linux repository can be installed—and most work
...including a LAMP stack, running WordPress!