androidandroid-fragmentsandroid-actionbarback

Reputation: 43

How to add a back button to action bar / toolbar

I have written a piece of code as part of an app where I want to implement a back button on the action bar/tool bar such that when the button is pressed, the previous page (the page/fragment immediately before the current page/fragment) will be displayed.

This is the code for the ToolBar, DrawerLayout, NavigationView and getSupportActionBar():

final DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
final NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);

android.support.v7.widget.Toolbar toolbar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
toolbar.setVisibility(View.VISIBLE);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setLogo(R.mipmap.ic_launcher);
getSupportActionBar().setDisplayUseLogoEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);

I am unable to use ActionBar. For some reason (I don't know why), my Android studio/ program, will not allow me to use the ActionBar. So I am substituting that with the set/getSupportActionBar().

The function used in relation to this are:

@Override
public boolean onCreateOptionsMenu(Menu menu) {
     MenuInflater inflater = getMenuInflater();
     inflater.inflate(R.menu.menu_settings, menu);
     return true;
}        

@Override
public boolean onOptionsItemSelected(MenuItem item) {

     // Handle action bar item clicks here. The action bar will
     // automatically handle clicks on the Home/Up button, so long
     // as you specify a parent activity in AndroidManifest.xml.

     int id = item.getItemId();

     switch (id) {
         case android.R.id.home:
             onBackPressed();
             return true;
         default:
             return super.onOptionsItemSelected(item);
         }
    }        

@Override
public void onBackPressed() {

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();        
    }
}

My activity_main.xml file is:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    android:id="@+id/activity_main"
    android:orientation="vertical"
    tools:openDrawer="start"
    tools:context="com.example.albin.settings_menu.SettingsActivity">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#fff">

    <android.support.v7.widget.Toolbar
            xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:app="http://schemas.android.com/apk/res-auto"
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
            app:title="Settings"/>

    <android.support.v4.widget.DrawerLayout
            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/drawer_layout"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

        <FrameLayout
        android:id="@+id/frame"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/toolbar">

        </FrameLayout>

            <android.support.design.widget.NavigationView
                xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:app="http://schemas.android.com/apk/res-auto"
                android:id="@+id/nav_view"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_gravity="start"
                android:fitsSystemWindows="true"
                android:layout_marginTop="-24dp"
                app:menu="@menu/options_menu" />


        </android.support.v4.widget.DrawerLayout>

    </RelativeLayout>
    </LinearLayout>

The problem is that I don't know which is the useful code, which is the useless code and how to mix/join/(add additional codes to) these (codes, methods, variables/objects, fragments, xml layouts) to get the desired outcome, that is, the application of a back button on the action bar/tool bar.

Most of the code above is implemented for the up button, not the back button. I have read at several places that up and back buttons are not the same.

I tried several links on internet as well as on this site, but none of them has just what I need.

Hope someone can give me an clear answer...

Upvotes: 4

Answers (6)

geniushkg

Reputation: 706

The simplest way would be to add parent activity in manifest file as developer docs suggest.

 <activity 
    android:name=".ChildActivity"
    android:parentActivityName=".ParentActivity" >

and java code you already have done it, setSupportActionbar and setHomeAsUpEnabled.

Edited : its necessary to add up action for icon to be visible, as mentioned in Android Developer Docs

Upvotes: 1

Carlos Daniel

Reputation: 2699

If you are referencing some actions from the action bar, such as a Save action or a Share one, and you are overriding onOptionsItemSelected method, then you need to define the behavior when the back or home button is clicked:

@Override public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
      case R.id.action_save:
        //save stuff
      break;

      //this is what you need to add to reference again back/home button
      case android.R.id.home:
        //do your stuff here, usually back to the home or close the current activity
        getActivity().finish();
      break;

      default:
      break;
    }
    return true;

Upvotes: 0

Satan Pandeya

Reputation: 3815

You can include the back icon in ToolBar:

Initialize ToolBar:

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

You can use an drawable icon as a back button.

toolbar.setNavigationIcon(R.drawable.your_drawable_icon);

toolbar.setNavigationOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        // what do you want here
    }
});

If you do not want to use drawable icon then:

getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);

toolbar.setNavigationOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        // what do you want here
    }
});

Upvotes: 9

Rajesh

Reputation: 2618

Actually your layout having that issue because you have added toolbar in RelativeLayout so drawer layout is overlapping on it that's why you would not able to click on back arrow, i have fix your layout see below

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    android:orientation="vertical">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        app:navigationIcon="@drawable/ic_back_black"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:title="Settings" />

    <android.support.v4.widget.DrawerLayout
        android:id="@+id/drawer_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <FrameLayout
            android:id="@+id/frame"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/toolbar" />

        <android.support.design.widget.NavigationView
            android:id="@+id/nav_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="start"
            android:fitsSystemWindows="true"
            app:menu="@menu/options_menu" />
    </android.support.v4.widget.DrawerLayout>
</LinearLayout>

Upvotes: 2

Sridhar S

Reputation: 126

Add a navigation click listener to your toolbar , like below

toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            onBackPressed();
        }
    });

Upvotes: 0

Nayan Srivastava

Reputation: 3725

So toolbar gives added flexibility to modify title-bar in Android.

As far as why getActionBar is not working and you are compelled to use getSupportActionBar is because you must be using SupportLibrary. SupportLibrary gives backward compatibility to earlier SDK versions.

If you want to modify your title-bar/header/action-bar extensively then use toolbar otherwise use action-bar.

Upvotes: 0

How to add a back button to action bar / toolbar

Answers (6)

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