Cocoa-touch – how to set image for uitabbarcontroller in cocoa code

To fix the OutOfMemory error, you should do something like this:

BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;
Bitmap preview_bitmap = BitmapFactory.decodeStream(is, null, options);

This inSampleSize option reduces memory consumption.

Here's a complete method. First it reads image size without decoding the content itself. Then it finds the best inSampleSize value, it should be a power of 2, and finally the image is decoded.

// Decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f) {
    try {
        // Decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f), null, o);

        // The new size we want to scale to
        final int REQUIRED_SIZE=70;

        // Find the correct scale value. It should be the power of 2.
        int scale = 1;
        while(o.outWidth / scale / 2 >= REQUIRED_SIZE && 
              o.outHeight / scale / 2 >= REQUIRED_SIZE) {
            scale *= 2;
        }

        // Decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    } catch (FileNotFoundException e) {}
    return null;
}

I had a similar question, but wasn't satisfied with the answer (or any I could find on the net), so I tried it in practice and here is what I got:

• init does not cause layoutSubviews to be called (duh)
• addSubview: causes layoutSubviews to be called on the view being added, the view it’s being added to (target view), and all the subviews of the target
• view setFrame intelligently calls layoutSubviews on the view having its frame set only if the size parameter of the frame is different
• scrolling a UIScrollView causes layoutSubviews to be called on the scrollView, and its superview
• rotating a device only calls layoutSubview on the parent view (the responding viewControllers primary view)
• Resizing a view will call layoutSubviews on its superview (Important: views with an intrinsic content size will re-size if the content that determines their size changes; for example, updating the text on a UILabel will cause the intrinsic content size to be updated and thus call layoutSubviews on its superview)

My results - http://blog.logichigh.com/2011/03/16/when-does-layoutsubviews-get-called/