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No action bar or navigation bar in design view of activity_main.xml

I'm starting out on android and I can't see the top bar nor the bottom buttons that should be viewable if I go to the design tab. As you can see in one of the pictures, I used a WithActionBar theme and still no action bar.

I found the answer, you need to select the eye icon under the blue squares, and select "Show Layout Decorations"

Click the » beside the 28 and select a theme which has an ActionBar.
Maybe get a bigger screen, for not having to search tacked away buttons.

Bottom Navigation View in Support Library v25.0.0 animation?

Reference: Nick Butcher's Tweet
https://twitter.com/crafty/status/789008273949200384
I implemented Bottom Navigation View came out with Android Support Library v25.0.0.
https://github.com/vipulasri/Bottom-Navigation-View-Sample
I am facing following problems:
Floating Action Button overlaps with Bottom Navigation View.
Snackbar displays above Bottom Navigation View.
Bottom Navigation Button doesn't automatically hide or appear on scrolling.
Not able to get the reveal animation like below:

About your third and fourth question. Bottom navigation view is automatically hide title and make animation if you have more then 3 item in it.
And about you first and second question. You can try another root layout, for example CoordinatorLayout.

Maybe it's late, but I made a little project to make reveal animation on background like your example without third part library.
Check it here: https://github.com/GauvainSeigneur/CircularRevealBottomNavigationView

Android Toolbar home as up indicator material design click effect not shown

I'm working on an Android app with some Material Design features. Currently I'm trying to fix the toolbar, but I have one problem, namely: When I press the home as up arrow to go back to the parent activity, it brings me back to the parent activity but doesn't show a ripple effect (so you see that it is clicked..)
The only thing I do to set the home as up arrow is:
this.getSupportActionBar().setDisplayHomeAsUpEnabled(true);
inside my activity.

Found the bug, it was the color of the toolbar. I chose a very dark green color and therefore the click/riffle effect was not visible. Changing the color to something bright fixed the problem for me..

Android: Problems with a Toolbar at the bottom of the screen

I am using the newest AppCompat library and replaced the SupportActionBar with a Toolbar, as suggested by the Android developer's blog. I want to display a second Toolbar at the bottom of the screen, that shows an additional Menu from some xml menu resource, but nothing else.
I have two problems with that:
Although nothing but a Menu is displayed (using Toolbar.inflateMenu()), the Menu occupies only a small space on the right side of the toolbar.
The Overflow Action Menu expands to the bottom of the toolbar and is therefore not shown. It should expand to the top.
Here is a screenshot of the bottom Toolbar:
How can I solve those issues without being forced to create custom views for my Buttons?

How to have the options menu over the custom toolbar?

I have a similar problem as found on this specific question.
I'm using a Toolbar from the v7 support library, and a custom layout. If I have no options menu, I have a result similar to what OP has on the question linked above:
However if I have an options menu, it shifts the toolbar a little bit to the left (start). I would like to have it over the toolbar.
Is it possible? The only way I could hack it is by adding a negative right (end) margin to the toolbar layout, however this moves the menu outside of the screen…

Initially, the whole Toolbar contained several views, so they had to share the width with the action menu.
Now instead I wrapped the Toolbar and the other views in a container (a FrameLayout), so that they overlap without sharing the width. I just need to be careful with the margin at the top so that the other views don't overlap with action icons.