Dedexer in Softpedia

Wow, I got an e-mail that dedexer 1.5 got included into Softpedia. The funny thing is that it got included into the Mac development tool section. I have already got a number of questions from Android developers working on Mac. Is it so that Mac is a favourite platform for Android developers or is it just my fortune? Any opinions?

Fancy graphs

It seems that a sure sign of the maturity of an application platform when graph libraries start to appear. Android definitely got to this stage with aiCharts.

I didn't discover it myself. I got a mail from the authors. Even though aiCharts is a commercial product, the Android component market is still nascent enough so that they deserve advertising (even if it is only my lame advertising).

aiCharts comes with flashy demonstrations and a number of demo programs.


There was only one limitation I was able to discover: the demo programs require the latest API version and according to the authors, aiChart will not run with lower than Android 1.1. Another limitation is that ArtfulBits obviously wants to make money out of the product so the thing is protected by license key.

I also received this chart from them that I now share with you. If you need a chart library, at least you know what options to choose from.

Feature name	aiCharts, Artfulbits v1.0.0	Rchart, java4less, v1.0.0	chart4j, Google, v1.2	jFreeChart, Jfree, v1.0.13	AChartEngine, 4viewsoft, v0.3.0
Chart types
Area	+	+	-	+	+
Bar	+	+	+	+	+
Bubble	+	+	+	+	-
Box and Whiskers	-	-	-	+	-
Candle stick	+	+	-	+	+
Column	+	+	+	+	-
Doughnut	-	-	-	+	-
Fast line	+	-	-	+	-
Funnel	+	-	-	-	-
Gantt	-	-	-	+	-
HiLo Open Close	+	+	-	+	-
HiLo	+	+	-	+	-
Histogram	-	-	-	+	-
Kagi	-	-	-	-	-
Line	+	+	+	+	+
Pie	+	+	+	+	+
Point	+	+	+	+	-
Polar	+	+	+	+	-
Point and Figure	-	-	-	-	-
Pyramid	+	-	-	-	-
Renko	-	-	-	-	-
Spline Area	+	-	-	+	-
Spline	+	+	+	+	-
100% Stacked Area	+	-	-	+	-
Stacked Area	+	-	-	+	-
Stacked Bar	+	+	-	+	+
100% Stacked Column	+	-	-	+	-
Stacked Column	+	-	-	+	-
Step Line	+	-	-	+	-
Step Area	-	-	-	+	-
Three line break	-	-	-	-	-
Tornado		-	-	-	-
3D Charts	-	+	pseoudo	+	-
Annotations	+	+	+	+	-
Multiple series	+	+	+	+	+
Multiple areas	+	-	-	-	-
Legend	+	+	+	+	-
Multiple legends	+	-	-	-	-
Legend dock	+	+	+	+	-
Legend alignment	+	+	-	-	-
Custom legend items	+	-	-	+	-
Axis
Logarithmic axes	-	+	-	+	-
Multiple axes	-	+	-	+	-
Axis label position	+	-	-	+	-
Axis label alignment	+	-	-	+	-
Labels mode	+	-	+	+	-
Date values	+	+	+	+	-
Axis scale	+	+	+	+	-
Custom labels format	+	-	+	-	-
Nice range calculation	+	+	+	+	-
Zoom/Scroll	+	+	+	+	-
Striplines	+	+	+	+	-
Series
SQL data source	+	-	-	-	-
Series drawables	+	-	-	-	-
Per point style	+	-	-	-	-
XML data source	+	-	-	-	-
Visual customization
Themes	-	-	-	+	-
Chart background	+	+	-	+	-
Axes customization
Series customization
Annotations customization	+	+	+	+	-
Saving chart to image/stream	+	+	+	+	-
XML inflation	+	-	-	-	-
Multiple titles	+	-	-	-	-
Events on chart objects clicks	+	-	-	-	-
Specially writtern for Android	+	-	-	-	-
APIs Documentation	+	+	-	+	-
Intuitive architecture	+	-	-	-	-
Summary for features	61	38	25	53	9

Dedexer annotation support

Just a short post for those few who do Dalvik bytecode analysis: dedexer has now full annotation support! For example it now decompiles "throws" and inner class annotation, along with custom annotations. Go for 1.5 release to get it.

It's that simple

Like many, I also thought that this project was a joke. Somebody obviously created something like the Visual Basic and made it work on Android. Then from this blog post, it became clear that Simple is dead serious.

Simple tries to replicate the 20 year old Microsoft idea about high-performance components and a script language binding them into applications. There is one thing, however, that caught my attention. Why not Python or any other "real" script language? Why this Basic afterthought?

The intriguing fact is that Android's virtual machine, Dalvik just got another language beside Java. The Simple compiler takes the Simple code and compiles directly into Dalvik bytecode, without going through Java. For example there is this Simple subroutine (remember the term "subroutine" ages ago? :-)).

Sub PreviewBrick(brick As Brick, orientation As Integer)

The Simple compiler turns it into a proper Dalvik method (Simple compiler's DEX output decompiled by Dedexer):

.method public PreviewBrick(Lcom/google/devtools/simple/samples/tetris/Brick;I)V

There is a runtime for Simple programs but it is not really an interpreter, it is just a glue between the standard Android classes and the Simple event system. That may explain, why the scripting language is not Python; a real scripting language may be too dynamic to compile.

There have been similar attempts for Java proper but the JVM was never designed to run anything other than Java. When .Net appeared, Microsoft claimed that the .Net Common Language Runtime is much more suitable running certain languages than the Java bytecode. This may or may not be true, the fact remains that CLR runs mostly C# and Visual Basic.NET programs.

From this demonstration with Simple, it is clear that Dalvik can also run a script language (Simple) and a component language (Java). Whether developers will find attractive enough to work in a script language that needs time-consuming compilation and deployment before running it (one huge advantage of scripting languages is that the program can be executed immediately after modification) or whether experimenting software experts want to use a rather obsolete language (like this BASIC clone) for binding their components is yet to be seen.

New DEX assembler/disassembler pair

Dedexer got competition! Not one but immediately two - smali and baksmali is a DEX assembler/disassembler pair. The programs are brand new and - like Dedexer - they are also based on a Jasmin-like format. I tried them very shortly, the disassembler - baksmali - worked correctly and indeed produced an output similar to dedexer but I could not compile the output of baksmali back to DEX format with the assembler - smali. The disassembler does not handle ODEX files either.

The initiative is indeed valuable, however, and I encourage every reverse engineer out there give the new tools a try.

Custom adapter in color

I got a comment on this blog with relation to an old sin of mine, the custom adapter example program. That example was about custom views in a list adapter. The comment was innocent enough: is there a way to change the colors of that list? I thought it was a 5 minute task to answer that question, in the end I had to deal with a topic I never wanted to know about: themes.

Click here to download the example program.

It turned out that the color scheme used by ListView is eventually taken from the active theme. It is possible to change it programmatically but it is quite complicated to do so. Meanwhile, with themes, it is relatively easy. If you know the information source. The Android development guide is almost completely useless regarding themes, for example sample themes don't work. This blog entry from Brainflush is much more informative, at least its examples work. The source that helped me the most was the actual Android XML fileset that defines the themes. If you have access to the Android source tree, the Android system resources can be found under the platform\frameworks\base\core\res\res directory. The relevant files are styles.xml under the values subdirectory and the content of the drawable subdirectory.

If you check the styles.xml in the res/values directory in our example program, you will see that modifying the color scheme of the ListView is a quite complicated, multi-step process. First of all, in res/values/styles.xml, the ListView style is overridden with the android:listViewStyle property. The ListViewStyle (MyListView) in turn references a list selector (android:listSelector) that is stored in the res/drawable directory. That selector defines color schemes for all the possible state combination of the list row. To increase the fun, the resource compiler screwed up the image IDs in the R.java file if the weather icon image files were not at the beginning of the file name list, hence the bizarre names in the drawable subdirectory. Now what we need more is a transition that refers a 9-patch background image (block blue in our case) for the selected row and we are ready.

Don't say that it was not easy.

PS: I apologize for the hideous colors. :-)

Assets

Let's have something lighter than the application separation stuff was in the previous entry.

I got a mail from someone who wanted to embed raw files into the APK file so that they are available for the application when it is executing. I have never done such a thing but I remembered faintly something about the res/raw directory where such resources reside. They are still there but now there is a better thing: assets. The difference between a raw resource in res/raw directory and an asset is that assets behave like a file system, they can be listed, iterated over, discovered, just like files while for raw resources, you need the resource ID.

Click here to download the example program.

This simple application iterates over the files in the asset directory, reads their contents and sets three TextFields according to the content of these files. Assets go into the ./assets directory in the project root and can contain any files. The AssetManager class provides access to assets as InputStreams.