FrameLayout is designed to block out an area on the screen to display a single item. You can add multiple children to a FrameLayout, but all children are pegged to the top left of the screen. Children are drawn in a stack, with the most recently added child on top. The size of the frame layout is the size of its largest child (plus padding), visible or not (if the FrameLayout's parent permits). Views that are GONE are used for sizing only if setConsiderGoneChildrenWhenMeasuring() is set to true.

You can define attributes in the top <resources> element or inside of a <declare-styleable> element. If I'm going to use an attr in more than one place I put it in the root element. Note, all attributes share the same global namespace. That means that even if you create a new attribute inside of a <declare-styleable> element it can be used outside of it and you cannot create another attribute with the same name of a different type.

An <attr> element has two xml attributes name and format. name lets you call it something and this is how you end up referring to it in code, e.g., R.attr.my_attribute. The format attribute can have different values depending on the 'type' of attribute you want. reference - if it references another resource id (e.g, "@color/my_color", "@layout/my_layout") color boolean dimension float integer string fraction enum - normally implicitly defined flag - normally implicitly defined You can set the format to multiple types by using |, e.g., format="reference|color".

Once you have installed these components, open your SDK directory and navigate to docs/sdk/ and open index.html in your browser.

Renderscript is a key new Honeycomb feature which we haven’t yet discussed in much detail

Renderscript is a new API targeted at high-performance 3D rendering and compute operations. The goal of Renderscript is to bring a lower level, higher performance API to Android developers. The target audience is the set of developers looking to maximize the performance of their applications and are comfortable working closer to the metal to achieve this

Renderscript has been used in the creation of the new visually-rich YouTube and Books apps. It is the API used in the live wallpapers shipping with the first Honeycomb tablets.