android-behavioral

Android behaviors for activities and fragments logic composition.

Provide consistency and reusability to your activities and fragments using this framework.

Gradle

repositories {
	maven { url 'https://jitpack.io' }
}
dependencies {
	implementation "com.github.fsbarata:android-behavioral:$behaviors_version"
}

Behaviors

Menu Items

Before:

override fun onCreateOptionsMenu(menu: Menu): Boolean {
    menuInflater.inflate(R.menu.main, menu)
    return true
}

override fun onOptionsItemSelected(item: MenuItem) =
	when (item.itemId) {
		R.id.action_settings -> ...
		...
		else -> super.onOptionsItemSelected(item)
	}

After:

init {
	addBehavior(MenuBehavior(this, R.menu.main,
			R.id.action_settings to { item -> ... }
			...
	))
}

Toolbar Back Arrow

Before:

override fun onCreate(savedInstanceState: Bundle?) {
	super.onCreate(savedInstanceState)
	...

	setSupportActionBar(findViewById<Toolbar>(mToolbarId))
	supportActionBar?.setDisplayShowHomeEnabled(true)
	supportActionBar?.setDisplayHomeAsUpEnabled(true)
	...
}

override fun onSupportNavigateUp(): Boolean {
	activity.onBackPressed()
	return true
}

After:

init {
	addBehavior(ToolbarBackActivityBehavior(this, R.id.toolbar))
}

Action Drawer

Before:

private val drawer by lazy { findViewById<DrawerLayout>(R.id.drawer_layout) }
private val toolbar by lazy { findViewById<Toolbar>(R.id.toolbar) }

override fun onPostCreate(savedInstanceState: Bundle?) {
	super.onPostCreate(savedInstanceState)
	// Sync the toggle state after onRestoreInstanceState has occurred.
	actionBarDrawerToggle.syncState()
}

override fun onBackPressed() {
	if (drawer.isDrawerOpen(GravityCompat.START)) {
		drawer.closeDrawer(GravityCompat.START)
	} else {
		super.onBackPressed()
	}
}

override fun onNavigationItemSelected(item: MenuItem): Boolean {
	when (item.itemId) {
		...
	}

	drawer.closeDrawer(GravityCompat.START)
	return true
}

private fun setupNavigation() {
	actionBarDrawerToggle = ActionBarDrawerToggle(
			this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close)
	drawer.addDrawerListener(actionBarDrawerToggle)
	navigationView.setNavigationItemSelectedListener(this)
}

After

init { 
	addBehavior(ToolbarActionDrawerActivityBehavior(this,
			R.id.drawer_layout, R.id.toolbar, R.id.nav_view,
			R.string.navigation_drawer_open, R.string.navigation_drawer_close,
			navigationItemSelectedListener = { false }))
}

Write your own

Before

@Inject
lateinit var presenter: MainPresenter

override fun onCreate() {
	...
	getInjector().inject(this);
}

override fun onStart() {
	super.onStart()
	presenter.start()
}

override fun onStop() {
	presenter.stop()
	super.onStop()
}

After

init {
	addBehavior(PresenterBehavior { presenter })
}

@Inject
lateinit var presenter: MainPresenter

override fun onCreate() {
	...
	getInjector().inject(this);
}

Where:

class PresenterBehavior(
	presenterProvider: () -> Presenter
) : AbstractLifecycleBehavior(), ILifecycleBehavior {
	lateinit var presenter: Presenter

	override fun onStart() {
		super.onStart()
		presenter = presenterProvider()
		presenter.start()
	}

	override fun onStop() {
		presenter.stop()
		super.onStop()
	}
}