Question or issue of Kotlin Programming:
I’m trying to use the new Android P FloatingActionButton that’s part of the com.google.android.material.floatingactionbutton.FloatingActionButton and I’m getting this warning:
import com.google.android.material.floatingactionbutton.FloatingActionButton
import android.view.View
class MainActivity : AppCompatActivity() {
lateinit var demoFab: FloatingActionButton
override fun onCreate(savedInstanceState: Bundle?) {
demoFab = findViewById(R.id.demoFab)
demoFab.visibility = View.VISIBLE // the warning is here
}
}
I’ve tried searching and the only search result is in regards to responding to UI visibility changes:
Respond to UI visibility changes
I tried exploring how I could to see if there was a VISIBLE int value in that com.google.android.material package and the only one I found was com.google.android.material.floatingactionbutton.FloatingActionButton.VISIBLE, but the warning still remains.
buildscript {
ext.kotlin_version = '1.2.41'
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.2.0-alpha14'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
classpath "com.google.gms:oss-licenses:0.9.2"
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
mavenCentral()
maven { url "http://oss.sonatype.org/content/repositories/snapshots/" }
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'com.google.gms.oss.licenses.plugin'
android {
compileSdkVersion 'android-P'
defaultConfig {
applicationId "com.codeforsanjose.maps.pacmap"
minSdkVersion 21
targetSdkVersion 'P'
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
splits {
abi {
enable true
reset()
include 'arm64-v8a', 'armeabi', 'armeabi-v7a', 'mips', 'x86', 'x86_64'
universalApk false
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
buildTypes {
release {
minifyEnabled true
shrinkResources true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'androidx.appcompat:appcompat:1.0.0-alpha1'
implementation 'androidx.constraintlayout:constraintlayout:1.1.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.1.0-alpha2'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha2'
implementation 'com.mapbox.mapboxsdk:mapbox-android-sdk:5.5.2'
//implementation 'com.mapbox.mapboxsdk:mapbox-android-sdk:6.1.0'
implementation 'com.mapbox.mapboxsdk:mapbox-android-plugin-locationlayer:0.5.0'
implementation 'com.mapbox.mapboxsdk:mapbox-android-navigation:0.13.0'
implementation 'com.mapbox.mapboxsdk:mapbox-android-navigation-ui:0.13.0'
implementation 'com.google.android.gms:play-services-oss-licenses:15.0.1'
implementation 'com.google.code.gson:gson:2.8.2'
implementation 'com.squareup.moshi:moshi:1.5.0'
implementation 'com.squareup.okhttp3:logging-interceptor:3.10.0'
implementation 'com.squareup.retrofit2:converter-gson:2.3.0'
implementation 'com.squareup.retrofit2:converter-moshi:2.4.0'
implementation "com.squareup.retrofit2:adapter-rxjava2:2.3.0"
implementation 'com.squareup.retrofit2:retrofit:2.4.0'
implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'
implementation 'io.reactivex.rxjava2:rxkotlin:2.2.0'
}
I should note that I’m using Android Studio version 3.2 canary 14. It seems there have been some reported bugs for this version, and I suspect this is one of them.
Issue still exists with Android Studio version 3.2 canary 15, but I found a workaround for it using show() and hide()
override fun onCreate(savedInstanceState: Bundle?) {
demoFab = findViewById(R.id.demoFab)
demoFab.show() // this works and doesn't have the warning
}
How to solve this issue?
Solution no. 1:
Using Method 1
demoFab.show(); // in place of visible demoFab.hide(); // in place of Invisible suppress the warning/error for me.
and Method 2
@SuppressLint("RestrictedApi") // also suppressed the warning
private void setUp() {
....
}
update:
Method 3:
demoFab.setVisibility(View.GONE); demoFab.setVisibility(View.INVISIBLE); demoFab.setVisibility(View.VISIBLE);
Method 4:
demoFab.visibility = View.GONE demoFab.visibility = View.INVISIBLE demoFab.visibility = View.VISIBLE
Solution no. 2:
Seems to work fine just to cast it to a view.
(mFloatingActionButton as View).visibility = INVISIBLE
Of course you need to remember that the visibility may affect other components, so you should probably use show() and hide() at the same time to make sure other components are notified of the change.
Solution no. 3:
Use:
myButton.hide(); myClearButton.hide();
A typical example would be:
Hiding and showing buttons when user is typing or has focus on a EditText resource:
check if user is typing or has focus:
mCommentField.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View view, boolean hasFocus) {
if (hasFocus) {
//user has focused
showBts();
} else {
//focus has stopped perform your desired action
hideButtons();
}
}
});
Hide and Show button methods:
private void hideButtons() {
mCommentButton.hide();
mClearButton.hide();
}
private void showBts() {
mCommentButton. show();
mClearButton.show();
And in your xml, set the buttons to invisible by default so that they only display/show when a user has focus or is typing:
android:visibility="invisible"
Best practice:
android:visibility="Gone"
Using visibility gone means your view is doesn’t take up any space on your layout while “invisible” will take up unnecessary space on your layout
In this example:My Views are in a ViewHolder and iam referencing the buttons from a a fragment with a recylerview
Solution no. 4:
This also works:
findViewById(R.id.fab).setVisibility(View.GONE);
Solution no. 5:
For me above methods did not work so I created an extension function to make it work.
fun View.showView() {
this.visibility = View.VISIBLE
}
fun View.hideView() {
this.visibility = View.GONE
}
now call like
binding.fabAdded.showView()
Solution no. 6:
For Kotlin I have an extension method
fun viewsVisibility(visibility: Int, vararg views: View) {
for (view in views) { view.visibility = visibility }
}
Then in then in the code you can do the following
viewsVisibility(View.VISIBLE, demoFab) viewsVisibility(View.GONE, demoFab) viewsVisibility(View.INVISIBLE, demoFab, addFab, removeFab)
The error will be gone and this gives the flexibility for any visibility state along with taking in a list of views to handle. There are a lot of times I need to handle more than one view at a time as shown in the final example line.
Solution no. 7:
if(data){
fragmentPendingApprovalDetailsBinding.fabPendingList.show();
}else {
fragmentPendingApprovalDetailsBinding.fabPendingList.hide();
}
Solution no. 8:
For com.google.android.material.floatingactionbutton.FloatingActionButton
Visibility
Use the show and hide methods to animate the visibility of a FloatingActionButton. The show animation grows the widget and fades it in, while the hide animation shrinks the widget and fades it out.
Source: https://material.io/develop/android/components/floating-action-button/
For android.support.design.widget.FloatingActionButton
use setVisibility() Method
