For Example... it works if you have to "Port" a Theme/ROM for Nexus S to a Theme/ROM for Galaxy S or a Milestone!
(attention when the former is hdpi and the latter is mdpi, use the function
Toggle to hdpi-to-mdpi, but I don't know how this works)
The Porter works like Metamorph (but all happens on the PC, so out from the phone)!
Metamorph works while the smartphone is active (OS is working)!
With Metamorph I have problems if I try to modify frameork-res.apk, I suppose because OS are using it!
So I use TP without problems!
Theme Porter extracts all the PNG of all the APKs in /OLD and compare them with all the PNG of all the APKs in /NEW!
If there are 2 PNG with the same name in the same place, Theme Porter takes the PNG in /NEW and replace it with the PNG in /OLD!
If the PNG exists only in /OLD, Theme Porter doesn't copy it in /NEW!
If the PNG exists only in /NEW, Theme Porter doesn't replace it (because there's nothing to replace)!
Doesn't matter if you use a Theme or Rom in update.zip, you need only the APKs!
Indeed you only need the png in the apk!
You can use (or make) a nameofapp.zip with inside only the folder /res/drawable/etc.... (or res/drawable-hdpi/pngfiles...etc...), then rename it in .apk and put it in OLD, and Theme Porter works just as well!!
Rename Theme Porter folder in "TP" and put it in C/
So you will have C/TP/new and C/TP/old, it works in this way!
Here I posted a >Video Tutorial< in Italian!
If you want... I can translate the slides in english! (Let me know...)
But it's so easy that it is not necessary translate...
The Theme is an update.zip that contains the Font, Bootanimation, and all the apks of the ROM (wich is based on) but with "themed" png!
The Theme.apk for theme chooser is different and it is only 1 apk that works like metamorph, but in different way because Theme Chooser doesn't replace physically the png in all the system.apk (all the apks of the ROM), but "tell" to the device that the png that are in the system apks are now in the Theme.apk (Theme for Theme Chooser)
You can learn to use Theme.apk for Theme Chooser from
>>>HERE - [GUIDE] T-mobile theme engine for the faint at heart<<<
You could use Theme Porter (TP) between 2 apk for Theme Chooser, but this isn't the same of using TP between 2 ROM/Theme, because 2 apks for Theme Chooser could be very different!!!