Question

I’ve asked a similar question about the Android ActionBar before: Change ActionBar Tabs background color

I still don’t have an answer to the question: when will the two line design/when the one line design used? I’ve set a custom divider to my tab bar and it’s also being used in the horizontal layout. However to create drawables/styles based on the orientation/screen size etc I need to know when which layout is being used. Looking through the Android source it seems they are using the same drawables for both layouts, so that doesn’t really help me. The same problem applies when changing the font color of the Tab View.

I fear that it’ll be decided in code which format is being used, so there’s not really any way around this. Can anyone confirm this? Or is there at least a way to find out in code if the Action bar is one lined or two lined?

Answer 1

Android will stack tabs beneath the action bar when it deems the screen size/orientation to be narrow (like on a normal sized screen in portrait, or on a small sized screen regardless of orientation). Similarly if there are many tabs, in some cases they will appear as a drop-down list in order to ensure the best fit in the action bar.

The Action bar is a highly adaptive UI control. If you are going to use its navigation modes I would strongly suggest not trying to anticipate their configuration or attempt to apply styles that are specific to each one. Your tab drawables will always need to be 9patch anyway because the base action bar height will also vary across orientations and screen sizes (notice its height is slightly smaller in landscape).

That said, you can query the action bar height at runtime using its getHeight() method. This Honeycomb Gallery example included in the SDK uses a bunch of logic in an OnGlobalLayoutListener to ensure that the Fragment layout responds to the various action bar sizes appropriately.