How can i override drawer navigation button behaviour and change the icon?

0
votes

I have application that uses drawer navigation to show different fragments with main topics. Drawer navigation

And in Home fragment i display different categories(those colourful boxes) and when i choose one category it displays new fragment with daily and general details of that category.(lets call this Detail fragment) Home fragment

What i want and cannot figure out how to accomplish, is in that Detail fragment, i want there to be back arrow that takes me back to Home fragment not the hamburger menu icon that opens the drawer navigation. Detail fragment

3
javaandroidkotlin

3 Answers

1
votes

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.setDrawerListener(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.

0
votes

You can do it by adding toolbar to the main activity dynamically rather than using in built navigation drawer, make it from scratch. when you add fragments add toolbar on the fragments. Toolbar myChildToolbar = (Toolbar) findViewById(R.id.my_child_toolbar); setSupportActionBar(myChildToolbar);

// Get a support ActionBar corresponding to this toolbar
ActionBar ab = getSupportActionBar();

// Enable the Up button
ab.setDisplayHomeAsUpEnabled(true);

Then you would be able to override the method on Button navigation up method to enable back button you want on toolbar.

0
votes

Thanks for your help, I got some ideas from your answers and some other posts in Stackoverflow. If you think this is bad solution, please let me know. This is how I was able to make it work with quite simple solution(Kotlin):

Put this in your activitys onCreate

supportFragmentManager.addOnBackStackChangedListener {
       actionBarDrawerToggle?.isDrawerIndicatorEnabled = supportFragmentManager.backStackEntryCount <= 0
}

and override onSupportNavigateUp():

override fun onSupportNavigateUp(): Boolean {
    supportFragmentManager.popBackStack()
    return super.onSupportNavigateUp()
}