How to add backbutton functionality to app - java

I'm trying to add a backbutton functionality to my app.
However when I try to add the id of the backButton like so,
Button back = findViewById(R.id.backButton);
back.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v) {
finish();
}
}
it just says the symbol for it is missing.
I'm guessing and xml reference to the button is not present, where can I add it. Also the navigation bar (the back and home button and such) is not showing in the bottom of the app in android studio, is there a way to enable that?

What you looking is call BottomNavigationView.
You should place the id in onNavigationItemSelected.
MainActivty
public class MainActivity extends AppCompatActivity {
private TextView mTextMessage;
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_home:
mTextMessage.setText(R.string.title_home);
return true;
case R.id.back:
finish();
return true;
}
return false;
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
BottomNavigationView navView = findViewById(R.id.nav_view);
mTextMessage = findViewById(R.id.message);
navView.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
}
}
activity_main
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="#+id/message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="#dimen/activity_horizontal_margin"
android:layout_marginLeft="#dimen/activity_horizontal_margin"
android:layout_marginTop="#dimen/activity_vertical_margin"
android:text="#string/title_home"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.design.widget.BottomNavigationView
android:id="#+id/nav_view"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="0dp"
android:layout_marginEnd="0dp"
android:background="?android:attr/windowBackground"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:menu="#menu/bottom_nav_menu" />
</android.support.constraint.ConstraintLayout>
Create an xml file under menu folder
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="#+id/navigation_home"
android:icon="#drawable/ic_home_black_24dp"
android:title="#string/title_home" />
<item
android:id="#+id/back"
android:icon="#drawable/back"
android:title="#string/title_dashboard" />
</menu>

Related

BottomNavigationView doesn't appear after running it in the emulator

my BottomNavigationView appear in the preview of the android studio but when i run it in emulator it doesn't appear so it's only the fragment which appear in the emulator and the program isn't give me any error so i tried to switch the home page layout and it also doesn't appear!
and here is my code
in the Home_activity xml
public class HomeActivity extends AppCompatActivity {
#Override
public void onCreate(#Nullable Bundle savedInstanceState, #Nullable PersistableBundle persistentState) {
super.onCreate(savedInstanceState, persistentState);
setContentView(R.layout.activity_home);
BottomNavigationView bottomNavigationView =findViewById(R.id.nav_view);
bottomNavigationView.setOnNavigationItemSelectedListener(navlistener);
}
private BottomNavigationView.OnNavigationItemSelectedListener navlistener = new BottomNavigationView.OnNavigationItemSelectedListener(){
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem menuItem) {
Fragment selectedFragment =null;
switch (menuItem.getItemId()){
case R.id.navigation_home:
selectedFragment=new Home_fragment();
break;
case R.id.navigation_dashboard:
selectedFragment=new Dashboard_fragment();
break;
case R.id.navigation_notifications:
selectedFragment=new Notificatons_fragment();
break;
}
//to show them
getSupportFragmentManager().beginTransaction().replace(R.id.nav_host_fragment,selectedFragment).commit();
return true;
}
};
}
in xml of the home layout page
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="?attr/actionBarSize">
<fragment
android:id="#+id/nav_host_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="#id/nav_view"/>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/nav_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:menu="#menu/bottom_nav_menu"
/>
</RelativeLayout>
Add library in gradle file
dependencies {
implementation 'com.google.android.material:material:1.1.0'
}
Xml file without fragment tag. fragment is giving error on my side.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="?attr/actionBarSize">
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/nav_view"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_alignParentBottom="true"
app:menu="#menu/bottom_nav_menu"
/>
</RelativeLayout>
bottom_nav_menu.xml file in menu folder in res
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="#+id/home"
android:icon="#android:drawable/arrow_down_float"
android:title="home" />
<item
android:id="#+id/id1"
android:icon="#android:drawable/btn_plus"
android:title="deeplink" />
</menu>
You can change your custom icons in menu.
Try it. Hopefully, may resolve you issue your issue. I have tested it
on Android Q emulator. Thanks in advance.

why my other view doesn't move up when the snackbar show after using coordinator layout?

so here is my xml file
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/myCoordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="#+id/button"
android:layout_width="168dp"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:text="Button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent" />
</LinearLayout>
</android.support.design.widget.CoordinatorLayout>
and here is my java file:
public class MainActivity extends AppCompatActivity {
Button myButton;
Snackbar mySnackbar;
CoordinatorLayout myCoordinatorLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myButton = (Button) findViewById(R.id.button);
myCoordinatorLayout = (CoordinatorLayout) findViewById(R.id.myCoordinatorLayout);
myButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mySnackbar = Snackbar.make(myCoordinatorLayout,"Test Snakcbar",BaseTransientBottomBar.LENGTH_INDEFINITE);
mySnackbar.setDuration(8000);
mySnackbar.setAction("OK", new View.OnClickListener() {
#Override
public void onClick(View v) {
mySnackbar.dismiss();
}
});
mySnackbar.show();
}
});
}
}
but my button still stick in the bottom and doesn't move up when the snackbar show. I want my button move up like in this video:
https://developer.android.com/images/training/snackbar/snackbar_button_move.mp4
what should I do ?
You don't need the LinearLayout. Also, you don't need to put constraints, since its coordinator layout and not ConstraintLayout.
Try this instead:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/myCoordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="#+id/button"
android:layout_width="168dp"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:text="Button" />
</android.support.design.widget.CoordinatorLayout>

How to set Menu Items in Custom Toolbar with a activity and a fragment?

before I only used activity's and that worked but when I added the fragments to the activity's the menu icon disappeared and I could find a fix for it
my custom toolbar
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/apptheme"
app:theme="#style/AlertDialog.AppCompat.Light">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:orientation="horizontal"
android:weightSum="100">
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:id="#+id/actionbar_logo_click"
android:paddingLeft="3dp"
android:layout_weight="5">
<ImageView
android:id="#+id/actionbar_logo"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:paddingRight="10dp" />
</FrameLayout>
<TextView
android:id="#+id/actionbar_titel"
style="#style/AudioFileInfoOverlayText"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:paddingTop="7dp"
android:textColor="#color/white"
android:textSize="27dp" />
</LinearLayout>
</android.support.v7.widget.Toolbar>
my menu items
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:icon="#drawable/ic_more_vert_white_24dp"
app:showAsAction="always">
<item
android:id="#+id/menu_rate"
android:title="#string/menu_rate"
/>
<item
android:id="#+id/menu_about"
android:title="#string/menu_about" />
</menu>
my activity xml layout where I add the custom toolbar with the id
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include layout="#layout/app_bar"></include>
<!-- Container for loading and the actual fragment-->
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ProgressBar
android:id="#+id/loading"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:visibility="gone"
android:indeterminate="true" />
</LinearLayout>
</FrameLayout>
my java activity where I call the toolbar and also inflate the menu items
#EActivity(R.layout.activity_main_layout)
public class MainActivity extends BaseActivity {
#ViewById(R.id.adview)
MoPubView mMoPubView;
#ViewById(R.id.app_bar)
Toolbar toolbar;
#ViewById(R.id.actionbar_logo)
ImageView mAactionbarImage;
#ViewById(R.id.actionbar_titel)
TextView mActionbarTitel;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setSupportActionBar(toolbar);
}
#AfterViews
protected void onViewsInitialized() {
gotoFragment(MainFragment_.builder().build(), false);
mAactionbarImage.setImageResource(R.mipmap.ic_launcher);
//Set the titel of the actionbar
mActionbarTitel.setText("How To Twitch");
}
#Override
public void onBackPressed() {
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main_menu, menu);
menu.getItem(0).setIcon(R.drawable.ic_more_vert_white_24dp);
return super.onCreateOptionsMenu(menu);
}
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_rate:
final String appPackageName = getPackageName(); // getPackageName() from Context or Activity object
try {
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=" + appPackageName)));
} catch (android.content.ActivityNotFoundException anfe) {
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("http://play.google.com/store/apps/details?id=" + appPackageName)));
}
break;
case R.id.menu_about:
Intent aboutIntent = new Intent(MainActivity.this, AboutActivity_.class);
startActivity(aboutIntent);
break;
default:
break;
}
return super.onOptionsItemSelected(item);
}
}
for some reason my menu Icon is not showing up in the toolbar so if someone knows what I am doing wrong that would help me alot
I think you are missing an overridden method onPrepareOptionsMenu
Try to add this overridden method and check:
#Override
public void onPrepareOptionsMenu(Menu menu) {
menu.findItem(R.id. menu_rate).setVisible(true);
menu.findItem(R.id. menu_about).setVisible(true);
super.onPrepareOptionsMenu(menu);
}
And add setHasOptionsMenu(true); within onCreateView() of your fragment.

onNavigationItemSelected not being called for Bottom Navigation Bar

I'm trying to implement a bottom nav bar that changes fragments when the nav items are clicked. However, when I click on the nav bar items, the fragments don't change. Using log.d, I noticed onNavigationItemSelected is not being called. How do I fix this?
To note, the startFeedFragment, startScheduleFragment, & startSettingsFragmentare implemented the same way and they work for the buttons in the toolbar. I also referenced this tutorial and this question for help.
MainActivity.java
public class MainActivity extends AppCompatActivity implements BottomNavigationView.OnNavigationItemSelectedListener {
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
setUpRecycler();
startFeedFragment();
BottomNavigationView bottomNavBar = (BottomNavigationView) findViewById(R.id.navigation);
bottomNavBar.bringToFront();
bottomNavBar.setOnNavigationItemSelectedListener(this);
}
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Log.d("NAV BAR", "onNavigationItemSelected hit");
switch (item.getItemId()) {
case R.id.feedMenu:
startFeedFragment();
Log.d("NAV BAR", "feed");
break;
case R.id.myScheduleMenu:
startScheduleFragment();
Log.d("NAV BAR", "schedule");
break;
case R.id.settingsMenu:
startSettingsFragment();
Log.d("NAV BAR", "settings lol");
break;
default:
Log.d("NAV BAR", "false");
return false;
}
return true;
}
/**
* Switches out the fragment for {#link FeedFragment} and sets an appropriate title. startScheduleFragmens & startSettingsFragment are implemented the same way
*/
private void startFeedFragment()
{
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragmentContainer, new FeedFragment());
transaction.commit();
getSupportActionBar().setTitle(R.string.title_fragment_feed);
}
}
Snippet from xml file
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<FrameLayout
android:id="#+id/fragmentContainer"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/navigation"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.design.widget.BottomNavigationView
android:id="#+id/navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:itemBackground="#android:color/white"
app:itemIconTint="#color/colorPrimaryDark"
app:itemTextColor="#color/colorPrimaryDark"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:menu="#menu/bottom_nav"
android:elevation="8dp"/>
</android.support.constraint.ConstraintLayout>
</android.support.design.widget.CoordinatorLayout>
Solved! It was because I had set the buttons in the menu to android:enabled="false". That meant they couldn't be pressed, which is why onNavigationItemSelected wasn't being called. I set all buttons to android:enabled="true" to fix this.
Correct code for bottom_nav.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="#+id/bottom_nav_my_schedule"
android:title="#string/menu_my_schedule"
android:icon="#drawable/ic_event_available_white_24dp"
android:enabled="true"/> <!--make sure enabled is set to true!-->
<item android:id="#+id/bottom_nav_feed"
android:title="#string/menu_feed"
android:icon="#drawable/ic_view_list_white_24dp"
android:enabled="true" /> <!--make sure enabled is set to true!-->
<item android:id="#+id/bottom_nav_settings"
android:title="#string/menu_settings"
android:icon="#drawable/ic_settings_white_24dp"
android:enabled="true"/> <!--make sure enabled is set to true!-->
</menu>
As for me the problem was when my activity main layout was LinearLayout, so I've solved it by changing it to RelativeLayout, I have absolutely no thoughts why it's working, because RelativeLayout layouts reply only for elements location, not its view or something else, but it's working.
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<android.support.v4.view.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<android.support.design.widget.BottomNavigationView
android:id="#+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:itemBackground="#drawable/selector"
android:background="#color/white"
app:menu="#menu/menu_bottom"
app:itemIconTint="#drawable/menu_trainings"
app:labelVisibilityMode="unlabeled"
/>
</RelativeLayout>

How to Set Icon to display on the far right in Java

getSupportActionBar().setLogo(R.drawable.addicon);
The code above seems to place my Icon in the Centre . I would like to place to the far right and make it clickable as well . At the moment it the image for the icon is in the project files as a drawable I have not included it in any xml files.
You can set android:layoutDirection="rtl" in your toolbar xml for place it to right and
set below code for clickable :
getSupportActionbar().setDisplayHomeAsUpEnabled(true);
and :
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
//Do stuff
return true;
default:
return super.onOptionsItemSelected(item);
}
}
There are 2 approaches for doing that.
Option Menus
Creating custom toolbar.
With Option Menus
create main.xml under res/menu.
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.ioa.MainActivity" >
<item
android:id="#+id/action_addition"
android:icon="#drawable/addicon"
android:orderInCategory="100"
android:title="Addition"
app:showAsAction="always"/>
</menu>
and inside your activity create menu like,
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
you can perform Action on particular menu item.
#Override
public boolean onOptionsItemSelected(MenuItem Item) {
if (Item.getItemId() == R.id.action_addition) {
// perform action
}
return super.onOptionsItemSelected(paramMenuItem);
}
With custom toolbar
Create your ToolBar like this,
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/ColorPrimary"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<ImageView
android:id="#+id/add"
android:layout_width="46dp"
android:layout_height="46dp"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginRight="4dp"
android:clickable="true"
android:src="#drawable/ic_launcher" />
</RelativeLayout>
</android.support.v7.widget.Toolbar>
and now you can perform click event of particular ImageView.
ImageView add = (ImageView) findViewById(R.id.add);
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// do work.
}
});
happy Coding.
You Need 3 Things:
A Custom Toolbar Layout
Include the toolbar in your activity
Set the Logo to the toolbar
Create new Resource Layout:
include_toolbar.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:background="?attr/colorPrimaryDark"
android:id="#+id/include_toolbar"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar" />
Change Your Activity File: MainActivity.java
public class BaseActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
Toolbar toolbar = (Toolbar)findViewById(R.id.include_toolbar);
setSupportActionBar(toolbar);
toolbar.setNavigationIcon(R.mipmap_ic_launcher);
}
}
And here's the styles.xml:
<!-- language: xml-->
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#3F51B5</color>
</resources>

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