Develop Reference

get ImageView src programmatically

How to get ImageView src programmatically and set it in another ImageView
Drawable drawable = imageViewA....?
imageViewB.setImageDrawable(drawable);

You can do something like this:
Drawable drawable = imageViewA.getDrawable();
if(drawable != null){
imageViewB.setImageDrawable(drawable);
}

You can use setImageResource(int)
imageView.setImageResource(R.drawable.bg_image);

Instead of get drawable you do...
Bitmap bitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();
and set to new image
newImageView.setImageBitmap(bitmap);

Android - setBackgroundResource on Button

I have some buttons which i set the background with setBackgroundResource(R.drawable.cal_box_center); and the problem I'm having is that my background is a gradient which has this banding effect (annoying) and I've read that in order to remove this you'll need to set the Bitmap.Config.ARGB_8888. I looked into the API and the way to do this is to use decodeStream etc, but how can i use setBackgroundResource and still set the Config to ARGB_8888?
Thanks in advance.

You can use this code snippet:
// create button
Button btn = new Button(getApplicationContext());
//decode the resource(You can also use decodeStream and other decode method of
//BitmapFactory)
Bitmap btm = BitmapFactory.decodeResource(getResources(), R.drawable.cal_box_center);
//create another copy of your bitmap and specify Config
Bitmap newBtm = btm.copy(Bitmap.Config.ARGB_8888, true);
//use your newBtm to create a BitmapDrawable
BitmapDrawable btmDrwble = new BitmapDrawable(newBtm);
// finally set the drawable as your button's background
btn.setBackgroundDrawable(btmDrwble);

Create drawable from layout

Is there a way to generate a drawable object from a layout?
In fact, I need a cropped part of my initial layout, and my idea is to transform the layout into a drawable object and then to crop drawable.

A simple version:
Bitmap snapshot = null;
Drawable drawable = null;
yourView.setDrawingCacheEnabled(true);
yourView.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_LOW); //Quality of the snpashot
try {
snapshot = Bitmap.createBitmap(yourView.getDrawingCache(), sizes and stuff); // You can tell how to crop the snapshot and whatever in this method
drawable = new BitmapDrawable(snapshot)
} finally {
yourView.setDrawingCacheEnabled(false);
}

Copy Bitmap contents of one ImageView to anoher

This has me baffled. I need to copy the Bitmap from one ImageView into another. I do not want to simply copy one ImageView to another because I need to do some changes to the bitmap on its way over.
Here is some code that doesn't work.
ImageView ivSrc = (ImageView) findViewById(R.id.photo);
ivSrc.setDrawingCacheEnabled(true);
Bitmap bmSrc1 = ivSrc.getDrawingCache(); // will cause nullPointerException
Bitmap bmSrc2 = Bitmap.createBitmap(ivSrc.getDrawingCache());//bmSrc2 will be null
View vSrc = (View) ivSrc.getParent();
vSrc.setDrawingCacheEnabled(true);
Bitmap bmSrc3 = Bitmap.createBitmap(vSrc.getDrawingCache()); //black bitmap
//To test the bitmaps:
ImageView ivDest = (ImageView) findViewById(R.id.photo2);
ivDest.setImageBitmap(bmSrc1); //bmSrc1, 2, 3 results shown above
I have to going about this wrong because doing a copy should be so easy. TIA

Not used the drawing cache, but wouldn't you need to call buildDrawingCache() ?
The way I'd do it:
Bitmap bmSrc1 = ((BitmapDrawable)ivSrc.getDrawable()).getBitmap();
Bitmap bmSrc2 = bmSrc1.copy(bmSrc1.getConfig(), true);
Note that bmSrc2 is mutable, i.e. you can stick it in a Canvas and do whatever you like with it before drawing it somewhere.

Android: showing default image in gallery's ImageView while actual image is downloaded

I believe this is pretty trivial but I can't get it to work.
I want to display a default image in gallery elements (ImageViews) while their actual image is being fetched from the net.
Right now, nothing is shown for an ImageView which its image has yet to arrive. Once it arrives it is immediately shown.
What I tried is right after the instantiation of the ImageView to call its setImageResource function like so:
final ImageView i = new ImageView(mContext);
i.setImageResource(R.drawable.loading);
But it doesn't seem to work. Below is the full getView() function.
Any help is appreciated.
Thanks.
public View getView(int position, View convertView, ViewGroup parent) {
final ImageView i = new ImageView(mContext);
i.setImageResource(R.drawable.loading);
// if the drawbale is in the buffer - fetch it from there
Drawable bufferedImage = DataManager.getInstance().getImagesBuffer()[position];
if (bufferedImage != null){
i.setImageDrawable(bufferedImage);
BitmapDrawable drawable = (BitmapDrawable) i.getDrawable();
drawable.setAntiAlias(true);
}
// if drawable is not in buffer - fetch it from the net via AsyncImageLoader
else
{
String imageUrl = DataManager.getInstance().getImageBufferInstance().getImageUrl(position);
Drawable downloadedImage = AsyncImageLoader.getInstance().loadDrawable(imageUrl, new ImageCallback() {
public void imageLoaded(Drawable imageDrawable, String imageUrl) {
if (imageDrawable == null)
{
imageDrawable = getResources().getDrawable(R.drawable.icon);
}
i.setImageDrawable(imageDrawable);
BitmapDrawable drawable = (BitmapDrawable) i.getDrawable();
drawable.setAntiAlias(true);
}
});
i.setImageDrawable(downloadedImage);
}
i.setLayoutParams(new CoverFlow.LayoutParams(Utils.getInstance().getScreenWidth() / 2,
Utils.getInstance().getScreenHeight() / 2));
i.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
return i;
}

Fix your indentation... If I'm reading that correctly, you're only setting the temporary drawable icon in the imageLoaded callback of your (not shown) AsyncImageLoader, which I assume means it's then only being set after the image downloads and is then immediately overwritten with the downloaded image. Try moving the placeholder-setting code into your else block outside the callback.