Android Action Bar Ch 16

Front 1

options menu

Back 1

options menu: name of the menu that can appear on the action bar. options typically refer to entire screen or entire app

Front 2

What's the first step to creating a menu?

Back 2

they're a resource similar to layouts, so create a res/menu subdirectory and then create a new xml file with an item that has a title, id, showAsAttribute

Front 3

showAsAttribute

Back 3

determines whether the menu item appears on the action bar itself or on the overflow menu. don't use always > better to use "ifRoom" and let OS decide

Front 4

What kinds of items should you put on the action bar?

Back 4

only ones that users will use frequently --> avoid cluttering the screen

Front 5

system icon

Back 5

icon that is found on the device rather than in the project's resources. Fine for prototype but better to have it in your own resources if meant for release --> control what the user sees

(can copy the system icons directly into project's resources)

Front 6

Two options menu callbacks you'll need in a fragment for implementing an Options menu

Back 6

public void onCreateOptionsMenu(Menu, MenuInflater)

public boolean onOptionsSelected(MenuItem item)

Front 7

Code to override onCreateOptionsMenu(...)

Back 7

@Overridepublic void onCreateOptionsMenu(Menu menu, MenuInflater inflater)

{

super.onCreateOptionsMenu(menu, inflater); inflater.inflate(R.menu.fragment_crime_list, menu);

}

Front 8

What do you do after overriding onCreateOptionsMenu(...)?

Back 8

Tell the FragmentManager that the fragment should receive a call to onCreateOptionsMenu(...) by adding:

setHasOptionsMenu(true)

in onCreate(...) for the fragment

Front 9

How do you determine which menu item has been selected?

Back 9

Check its id

item.getItemId()

Front 10

temporal navigation

Back 10

what you get when you use the back button. takes you to where you were last

Front 11

ancestral navigation

Back 11

aka hierarchical navigation: takes you up the app hierarchy

Front 12

Android's recommendation for ancestral navigation

Back 12

implement the app icon to go "up" one level to the parent of the current activity

Front 13

How do you visually let the user know the icon is enabled as a "home" button for ancestral navigation?

Back 13

caret pointing to the left

@TargetApi(11)

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){ getActivity().getActionBar().setDisplayHomeAsUpEnabled(true);}

//this just enables the caret. it doesn't do the actual wiring

Front 14

How do you respond to an enabled app icon?

Back 14

treat as if it were an existing options menu item: override onOptionsItemSelected(MenuItem)

Front 15

What's the resource id for the android home icon?

Back 15

android.R.id.home

Front 16

Best way to implement ancestral navigation

Back 16

use navUtils and add metadata to the manifest

Front 17

How do you add parent activity metadata in the manifest?

Back 17

< meta-data android:name="android.support.PARENT_ACTIVITY" android:value=".CrimeListActivity" />

(basically creating a name-value pair that the NavUtils class can recognize)

Front 18

After you've added parent activity metadata to the manifest, how do you check whether there's a parent activity and, if so, go back to it?

Back 18

if (NavUtils.getParentActivityName(getActivity()) != null){ NavUtils.navigateUpFromSameTask(getActivity());}

Front 19

Why is it better to use NavUtils than starting the parent activity yourself?

Back 19

short and easy

centralizes relationship between activities in the manifest