Kotlin for Android Developers

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#ff212121
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@android:color/black
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26.1 Creating the settings activity
A new activity will we opened when the settings option is selected in the overflow menu in the
toolbar. So first thing we need is a new
SettingsActivity
:
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class SettingsActivity : AppCompatActivity() {
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override fun onCreate(savedInstanceState: Bundle?) {
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super.onCreate(savedInstanceState)
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setContentView(R.layout.activity_settings)
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setSupportActionBar(toolbar)
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supportActionBar?.setDisplayHomeAsUpEnabled(true)
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}
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override fun onOptionsItemSelected(item: MenuItem) = when (item.itemId) {
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android.R.id.home -> { onBackPressed(); true }
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else -> false
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}
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}
We’ll save the preference when the user gets out of the screen activity, so we’re going to deal with
the
Up
action the same way as the
Back
one, by redirecting the action to
onBackPressed
. By now,
let’s create the XML layout. A simple
EditText
will be enough for the preference:
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---

26 Settings Screen
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xmlns:android="http://schemas.android.com/apk/res/android"
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android:layout_width="match_parent"
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android:layout_height="match_parent">
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android:orientation="vertical"
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android:layout_width="match_parent"
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android:layout_height="match_parent"
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android:layout_marginTop="?attr/actionBarSize"
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android:padding="@dimen/spacing_xlarge">
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android:layout_width="wrap_content"
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android:layout_height="wrap_content"
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android:text="@string/city_zipcode"/>
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android:id="@+id/cityCode"
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android:layout_width="match_parent"
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android:layout_height="wrap_content"
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android:hint="@string/city_zipcode"
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android:inputType="number"/>
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And then just declare the activity in the
AndroidManifest.xml
:
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android:name=".ui.activities.SettingsActivity"
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android:label="@string/settings"/>