Author: Alessandro Crugnola

Obtain styleable fields at runtime

Alessandro Crugnola android , ,

Ususally, when we want to get some “R” attributes at runtime, we use the Resources getIdentifier method, which is useful for getting strings, drawables and ids at runtime. Unfortunately this method cannot be used to get the styleable fields. However, using java reflections, there’s another way to solve the problem. With this snippet you can get styleable fields at runtime in your code:

[cce]public static final <T> T getFieldFromStyleable( Context context, String name ) {
try {
// use reflection to access the resource class
Field field = Class.forName( context.getPackageName() + “.R$styleable” ).getField( name );
if ( null != field ) {
return (T) field.get( null );
}
} catch ( Throwable t ) {
t.printStackTrace();
}
return null;
}[/cce]

Which can be used in this way:
[cce]int[] array = getFieldFromStyleable( context, “MyListView” );
array = context.obtainStyledAttributes( attrs, styleableArray, defStyle, 0 );[/cce]

purePDF moved to github

Alessandro Crugnola actionscript, purePDF ,

As you may have noticed I’m not working with flash and actionscript anymore. However I still receive some requests regarding the purePDF library I published, well I don’t remember when exactly 🙂
By the way, I decided to move the code to github, thus it will be easier for anyone still interested in that library to fork and add modifications and share to other people.

Here’s the link to the project: https://github.com/sephiroth74/purePDF

Android Wheel Widget

Alessandro Crugnola android , ,

This is a simple widget I created as part of the Aviary Editor SDK for Android. It creates a wheel-like widet which can be scrolled in both directions.
The idea was to replace the default slider widget and use a more “real world” component.
Moreover if you’ll add the VIBRATE permission into your AndroidManifest.xml file you’ll have also haptics feedback while the wheel is scrolling:
[cce]<uses-permission android:name=”android.permission.VIBRATE” />[/cce]

To include the wheel widget in the current layout, you should add in the layout xml this lines:

<it.sephiroth.android.wheel.view.Wheel
android:id=”@+id/wheel”
xmlns:sephiroth=”http://schemas.android.com/apk/res/it.sephiroth.android.wheel”
android:layout_width=”match_parent”
android:layout_height=”match_parent”
sephiroth:numRotations=”6″
sephiroth:ticks=”28″ />

Where numRotations is the max number of rotations the wheel can perform and ticks is the total number of ticks the wheel will display.

Then in your activity you can add a OnScrollListener listener to the wheel widget, in this way:

mWheel = (Wheel) findViewById( R.id.wheel );
mWheel.setOnScrollListener( new OnScrollListener() {

@Override
public void onScrollStarted( Wheel view, float value, int roundValue ) {
}

@Override
public void onScrollFinished( Wheel view, float value, int roundValue ) {
}

@Override
public void onScroll( Wheel view, float value, int roundValue ) {
}
} );

You can download the source at the gihub project page.

Android Workspace Widget

Alessandro Crugnola android , , ,

 

I was looking for an android widget similar to the launcher workspace widget ( the one used in almost all launchers ), but a bit more customizable and with the possibility to use an Adapter as content provider. So at the end I mixed portion of code from the android launcher Workspace widget, the Gallery widget and the AbsListView widget.

Nothing particular tricky, just a combination of the 3 widgets in order to have the same sliding effect of the workspace ( using custom number of columns and rows ), but at the same time with an ArrayAdapter for creating views, and a little glow effect at start at the end of scrolling for creating the gingerbread style overscroll effect.

This is the source code: workspace

It’s just a first version, so it’s not really optimized…

The adapter used for creating this example looks like this:
[cc]
class WorkspaceAdapter extends ArrayAdapter {

int screenId;
PackageManager pm;
private LayoutInflater mInflater;
private int nCellsPerScreen = 4;

public WorkspaceAdapter( Context context, int textViewResourceId, List objects ) {
super( context, textViewResourceId, objects );
screenId = textViewResourceId;
pm = context.getPackageManager();
nCellsPerScreen = context.getResources().getInteger( R.integer.config_portraitCells ) * context.getResources().getInteger( R.integer.config_portraitRows );
mInflater = (LayoutInflater) context.getSystemService( LAYOUT_INFLATER_SERVICE );
}

@Override
public int getCount() {
return (int) Math.ceil( (double) super.getCount() / nCellsPerScreen );
}

public int getRealCount() {
return super.getCount();
}

@Override
public View getView( int position, View convertView, ViewGroup parent ) {

if ( convertView == null ) {
convertView = mInflater.inflate( screenId, mWorkspace, false );
((CellLayout)convertView).setNumCols( nCellsPerScreen );
}

CellLayout cell = (CellLayout) convertView;

int index = position * nCellsPerScreen;
int realCount = getRealCount();

for ( int i = 0; i < nCellsPerScreen; i++ ) { CellInfo cellInfo = cell.findVacantCell( 1, 1 ); TextView text; if ( cellInfo == null ) { text = (TextView) cell.getChildAt( i ); } else { text = (TextView) mInflater.inflate( R.layout.application_boxed, cell, false ); CellLayout.LayoutParams lp = new CellLayout.LayoutParams( cellInfo.cellX, cellInfo.cellY, cellInfo.spanH, cellInfo.spanV ); cell.addView( text, i, lp ); } if ( index + i < realCount ) { ApplicationInfo appInfo = getItem( index + i ); CharSequence label = appInfo.loadLabel( pm ); Drawable bm = appInfo.loadIcon( pm ); text.setCompoundDrawablesWithIntrinsicBounds( null, bm, null, null ); // new text.setText( label ); text.setClickable( true ); text.setFocusable( true ); text.setVisibility( View.VISIBLE ); } else { text.setVisibility( View.INVISIBLE ); } } return convertView; } } [/cc]  

Compile skia for android on Mac Lion

Alessandro Crugnola android, general , , ,

Some time ago I started to look at skia as possible solution for graphics 2D editing for a native android project I was developing.
Well, even if skia is part of the android system and it’s used everywhere by android itself, trying to include skia in my project was quite an hell..
Looking for resources I just found old examples and tips, and every try was just a failure.. but since android uses skia internally to do graphics operations I decided to look into the android project.

After downloading the skia module from the android git repository I just realized it couldn’t be compiled by itself because it has external dependencies. So next step was to download and compile the whole android source code. Easy task? not at all, at least if you’re on a mac running Lion!

At the end I managed to compile everything and build the skia module as static module, in this way now my project can link the skia library and include correctly the skia headers.

Ok, I don’t have the whole procedure step by step here, first of all because it depends on the android version you’re going to compiled, second and most important because I didn’t write down all the steps 🙂 So this is more a sort of list of notes about compiling android on Lion and a reminder for myself too. ( I was trying to compile android 2.2 using “generic-user” as lunch configuration )

Build Android: http://source.android.com/source/initializing.html

To get rid of clearsilver errors: http://code.google.com/p/android/issues/detail?id=993#c27

Java 1.5 version complaining: http://wiki.oneswarm.org/index.php/OS_X_10.6_Snow_Leopard

Well, the first time you’ll try to “make” everything probably you’ll get this error:

[cc]
./external/elfutils/config-compat-darwin.h:42: error: static declaration of ‘strnlen’ follows non-static declaration
[/cc]

modify ./external/elfutils/config-compat-darwin.h.
replace:
[cc lang=”c”]
static inline size_t strnlen (const char *__string, size_t __maxlen)
{
int len = 0;
while (__maxlen– && *__string++)
len++;
return len;
}
[/cc]

with:
[cc lang=”c”]
#if 0
static inline size_t strnlen (const char *__string, size_t __maxlen)
{
int len = 0;
while (__maxlen– && *__string++)
len++;
return len;
}
#endif
[/cc]

Well, at the end of the process I just edited the Android.mk makefile into external/skia adding a new entry for BUILD_STATIC_LIBRARY and the next command was simply:

[cc]mmm external/skia[/cc]

which produced the required libskia.a file to be linked in my project.

QuickActionView in Android

Alessandro Crugnola android ,

While I was searching for an custom implementation of the QuickContactBadge for Android, I went into this interesting post ( Lorenz’s Blog ), which had a custom widget called QuickAction.
While it’s a very nice widget, it didn’t fit my needs because I had the necessity of create different action layouts ( horizontal, vertical, grid.. ), so I made a very quick modification to the above code and I ended with this implementation.
Basically I removed from the original Class the ActionItem list and set a BaseAdapter as content source. In this way it’s more simple and easy to add more and different views to the widget.
Moreover I added the support for columns ( both fixed and automatic ).
Here you can see a snippet code of the QuickActionView creation:

[cc lang=”java”]
public void onButtonClick( View v ) {

// create the quick action view, passing the view anchor
QuickActionView qa = QuickActionView.Builder( v );

// set the adapter
qa.setAdapter( new CustomAdapter( this ) );

// set the number of columns ( setting -1 for auto )
qa.setNumColumns( (int) (2 + (Math.random() * 10)) );
qa.setOnClickListener( new DialogInterface.OnClickListener() {

@Override
public void onClick( DialogInterface dialog, int which ) {
dialog.dismiss();
Toast.makeText( getBaseContext(), “Selected item: ” + which, Toast.LENGTH_SHORT ).show();
}
} );

// finally show the view
qa.show();
}
[/cc]

Here some Screenshots:

And here you can find the source code: source code

FBTracer updated to Firefox 5

Alessandro Crugnola firefox , ,

FBTracer in action

FBTracer aka Flash Tracer has been just updated to version 0.1.3 ( also thanks to Daniel D. Vanzin ) which is now compatible with the new Firefox 5.

If you already have the extension installed it’s just a matter of check updates from the addons firefox page, otherwise you can download the extension from this page: http://blog.sephiroth.it/firefox-extensions/flash-tracer-for-firebug/

Note. After a fresh install or update of the plugin, sometimes the fbtracer panel doesn’t refresh itself… in that case a firefox restart will fix the problem.