Android - Switch ActionBar Back Button to Navigation Button

Question

I am having the following problem:

I know how to set up a toolbar to show a back button icon instead of a burger button icon.

From this:

to this:

using: getSupportActionBar().setDisplayHomeAsUpEnabled(true);

Now, I want to do the reverse action, I want to go from back button icon to burger icon:

to here:

How can I do this?

Update:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setSupportActionBar(mToolbar);
    getSupportActionBar().setDisplayShowTitleEnabled(false);
}

private void enableViews(boolean enable) {
    if(enable) {
        // Enables back button icon
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    } else {
        // TODO: Enables burger icon
    }
}

Solution 1

If I assume you're using android.support.v4.widget.DrawerLayout in your layout, then this approach may work for you; I've only tested on API 21 but given it's mostly using the support libraries, it should work (famous last words) on lower or higher targets.

import android.support.v7.app.ActionBarDrawerToggle
import android.support.v4.widget.DrawerLayout

    ActionBarDrawerToggle mDrawerToggle;
    DrawerLayout drawerLayout;
    private boolean mToolBarNavigationListenerIsRegistered = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setSupportActionBar(mToolbar);
        getSupportActionBar().setDisplayShowTitleEnabled(false);
        // Get DrawerLayout ref from layout
        drawerLayout = (DrawerLayout)findViewById(R.id.drawer);
        // Initialize ActionBarDrawerToggle, which will control toggle of hamburger.
        // You set the values of R.string.open and R.string.close accordingly.
        // Also, you can implement drawer toggle listener if you want.
        mDrawerToggle = new ActionBarDrawerToggle (this, drawerLayout, mToolbar, R.string.open, R.string.close);
        // Setting the actionbarToggle to drawer layout
        drawerLayout.addDrawerListener(mDrawerToggle);
        // Calling sync state is necessary to show your hamburger icon...
        // or so I hear. Doesn't hurt including it even if you find it works
        // without it on your test device(s)
        mDrawerToggle.syncState();
    }

    /**
     * To be semantically or contextually correct, maybe change the name
     * and signature of this function to something like:
     *
     * private void showBackButton(boolean show)
     * Just a suggestion.
     */
     private void enableViews(boolean enable) {

        // To keep states of ActionBar and ActionBarDrawerToggle synchronized,
        // when you enable on one, you disable on the other.
        // And as you may notice, the order for this operation is disable first, then enable - VERY VERY IMPORTANT.
        if(enable) {
            //You may not want to open the drawer on swipe from the left in this case  
            drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED);
            // Remove hamburger
            mDrawerToggle.setDrawerIndicatorEnabled(false);
            // Show back button
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            // when DrawerToggle is disabled i.e. setDrawerIndicatorEnabled(false), navigation icon
            // clicks are disabled i.e. the UP button will not work.
            // We need to add a listener, as in below, so DrawerToggle will forward
            // click events to this listener.
            if(!mToolBarNavigationListenerIsRegistered) {
                mDrawerToggle.setToolbarNavigationClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        // Doesn't have to be onBackPressed
                        onBackPressed();
                    }
                });

                mToolBarNavigationListenerIsRegistered = true;
            }

        } else {
            //You must regain the power of swipe for the drawer. 
            drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED);

            // Remove back button
            getSupportActionBar().setDisplayHomeAsUpEnabled(false);
            // Show hamburger 
            mDrawerToggle.setDrawerIndicatorEnabled(true);
            // Remove the/any drawer toggle listener
            mDrawerToggle.setToolbarNavigationClickListener(null);
            mToolBarNavigationListenerIsRegistered = false;
        }

        // So, one may think "Hmm why not simplify to:
        // .....
        // getSupportActionBar().setDisplayHomeAsUpEnabled(enable);
        // mDrawer.setDrawerIndicatorEnabled(!enable);
        // ......
        // To re-iterate, the order in which you enable and disable views IS important #dontSimplify.
    }

The solution uses ActionBarDrawerToggle.setDrawerIndicatorEnabled to toggle the visibility of the hamburger icon and ActionBar.setDisplayHomeAsUpEnabled for visibility of the Up button, essentially making use of their respective drawable resources.

Other assumptions

• Your Activity theme extends Theme.AppCompat.Light.NoActionBar.

Solution 2

The top solutions did not work in this case:

• One Activity and multiple Fragments
• One Fragment (SettingsFragment) should show the back icon instead of the burger menu
• Using com.google.android.material.appbar.AppBarLayout, androidx.appcompat.widget.Toolbar and ActionBarDrawerToggle

I call this method in my Activity's onCreate():

private fun initBackStackChangeListener() {
    supportFragmentManager.addOnBackStackChangedListener {
        val fragment = supportFragmentManager.findFragmentById(R.id.fragment_container)

        if (fragment is SettingsFragment) {
            menuDrawerToggle?.isDrawerIndicatorEnabled = false
            drawer_layout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED)
            menuDrawerToggle?.setToolbarNavigationClickListener { onBackPressed() }
            supportActionBar?.setDisplayHomeAsUpEnabled(true)
        } else {
            supportActionBar?.setDisplayHomeAsUpEnabled(false)
            drawer_layout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED)
            menuDrawerToggle?.isDrawerIndicatorEnabled = true
            menuDrawerToggle?.toolbarNavigationClickListener = null
            menuDrawerToggle?.syncState()
        }
    }
}

And menuDrawerToggle is this:

menuDrawerToggle = ActionBarDrawerToggle(
        this, drawer_layout, toolbar,
        R.string.navigation_drawer_open,
        R.string.navigation_drawer_close
    ).apply {
        drawer_layout.addDrawerListener(this)
        this.syncState()
    }

Works like a charm. Maybe it helps anybody.

Solution 3

I found flexible solutions in The Google I/O 2017 Android App.

public Toolbar getToolbar() {
    if (mToolbar == null) {
        mToolbar = (Toolbar) findViewById(R.id.toolbar);
        if (mToolbar != null) {
            setSupportActionBar(mToolbar);
            mToolbar.setNavigationContentDescription(R.string.navdrawer_description_a11y);
            mToolbarTitle = (TextView) mToolbar.findViewById(R.id.toolbar_title);
            if (mToolbarTitle != null) {
                int titleId = getNavigationTitleId();
                if (titleId != 0) {
                    mToolbarTitle.setText(titleId);
                }
            }

            // We use our own toolbar title, so hide the default one
            getSupportActionBar().setDisplayShowTitleEnabled(false);
        }
    }
    return mToolbar;
}

/**
 * @param clickListener The {@link android.view.View.OnClickListener} for the navigation icon of
 *                      the toolbar.
 */
protected void setToolbarAsUp(View.OnClickListener clickListener) {
    // Initialise the toolbar
    getToolbar();
    if (mToolbar != null) {
        mToolbar.setNavigationIcon(R.drawable.ic_up);
        mToolbar.setNavigationContentDescription(R.string.close_and_go_back);
        mToolbar.setNavigationOnClickListener(clickListener);
    }
}

So the usage is really simple.

setToolbarAsUp(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        // onBackPressed();
        // or navigate to parent or some other intent
    }
});

Solution 4

The selected answer is too hacky in my opinion.

I tried implementing it, and while doing so I realized that there's actually no good use for the ActionBarDrawerToggle (maybe that is why it was removed from the official android tutorial regarding Navigation Drawer): it doesn't make your life easier when you want to co-ordinate between the navigate drawer and the action bar.

The problem is that you only have 1 home "button", and that it has 2 different functionalities - open the drawer when you are in the main screen, and go up when you are further down in your app. Passing the toolbar as a parameter to ActionBarDrawerToggle constructor, adds the menu icon to it, and calls openDrawer on click event. Now if you want to switch to an up event you have to turn off this special icon, and re-enable the inherent back functionality of the action bar... which is still a mess.

So if ActionBarDrawerToggle doesn't help you (yet, maybe someone will figure out a way where it does), why use it in the first place? Here's how to do it without it:

boolean homeShouldOpenDrawer; // flag for onOptionsItemSelected

@Override
protected void onCreate(Bundle savedInstanceState) {
    ...
    // if you're using NoActionBar theme
    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    ActionBar actionbar = getSupportActionBar();

    // enables the home button with a <-
    actionbar.setDisplayHomeAsUpEnabled(true);

    // replaces the <- with the menu (hamburger) icon 
    // (ic_menu should be in every empty project, and can be easily added)
    actionbar.setHomeAsUpIndicator(R.drawable.ic_menu);

    // I assume your first fragment/state should be main screen, i.e. home = opens drawer
    homeShouldOpenDrawer = true;
    ...
}

private void enableViews(boolean enable) {
    if(enable) {
        // Enables back button icon
        // passing null or 0 brings back the <- icon
        getSupportActionBar().setHomeAsUpIndicator(null);
        homeShouldOpenDrawer = false;
    } else {
        // Enables burger icon
        getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_menu);
        homeShouldOpenDrawer = true;
    }

}

// this is called whenever a selection is made from the action bar
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            if (homeShouldOpenDrawer) {
                drawerLayout.openDrawer(GravityCompat.START);
            } else {
                onBackPressed();
            }
    }

    return super.onOptionsItemSelected(item);
}

Solution 5

you can change the action bar button with:

        getSupportActionBar().setHomeAsUpIndicator(R.drawable.back_button);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

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