Develop Reference

Hide a view when a dependent view is hidden in ConstraintLayout

Is it possible in ContraintLayout to hide/show a view when a dependent view is gone/visible?
Obviously it's possible by using CoordinatorLayout with a custom behavior or by using an wrapped layout, however the mentioned approaches involve additional layouts. I would like to see such an approach that doesn't introduce additional layouts

You should be able to group the views together using the new "group" feature of ConstraintLayout 1.1.x. See this posting on Medium.
Groups, like the Guidelines, are widgets with size 0. But Group helps to apply some action to a set of widgets. The most common case, is to control a visibility of a collection of widgets.

You can do this programmatically.
When you set the vivisiblity of a compounant in your code, change the visibility value of the dependent view.

What is the difference between a layout and a container in Android?

In android studio, in design section, Layouts and Containers are categorized separately.
What is the fundamental difference between them?

Layouts all directly extend ViewGroup. The Layout suffix is part of the class name for classes in this group, e.g. LinearLayout, RelativeLayout.
Containers is a bucket description for Views that wrap dynamic content. They are more specialized than Layouts and can but don't have to extend a Layout. Some extend ViewGroup indirectly e.g ListView, some don't e.g. VideoView. The Container label is used in Android Studio but is not part of the class name.

I would define the differences as follows:
Layouts are general-purpose ViewGroups dealing directly with graphical views. They have no requirements on what kind of children they can manage.
Containers fulfill more specific tasks, that's why they have additional requirements on how many and which kind of children they can accept. Because of that most containers require writing Adapter classes in order to express those requirements.

A container is a view used to contain other views. Android offers a collection of view classes that act as containers for views. These container classes are called layouts, and as the name suggests, they decide the organization, size, and position of their children views.
Layouts are basically containers for other items known as Views, which are displayed on the screen. Layouts help manage and arrange views as well. Layouts are defined in the form of XML files that cannot be changed by our code during runtime.

When is it better to not use RelativeLayout?

My boss refuses to let me use RelativeLayout. Everything is done using LinearLayout and minimal use of RelativeLayout, such that the layout that I could run with two levels of nesting with RelativeLayout, I now have to do with four using LinearLayout. Any comments on this? What links can share?
In my opinion it would be better to combine these two elements to get the perfect layout.

It depends on the level of nesting indeed. Android suggests to use a minimum Layouts in Layouts as possible, and if you can achieve with one layout, what you want to do with 3, why not?
The app will run faster for it, though with 2-3 nestings you wont see it.
I for example, create a bunch of included layouts, which i reuse in other layouts.
And the level of nesting could get very deep with that

With the LinearLayout we get the clear separation of view or we can say that each layout is separate. With the Linearlayout each UI element us independent of the other. You get the maximum flexibility. It enables to give the vertical and horizontal orientation.
Linearlayout you can control look more and make it almost similar even
on the device change. And also, using LinearLayout is simpler though
starting phase can be quite confusing
From the Docs
A Layout that arranges its children in a single column or a single
row. The direction of the row can be set by calling setOrientation().
You can also specify gravity, which specifies the alignment of all the
child elements by calling setGravity() or specify that specific
children grow to fill up any remaining space in the layout by setting
the weight member of LinearLayout.LayoutParams.
LinearLayout is a view group that aligns all children in a single
direction, vertically or horizontally. You can specify the layout
direction with the android:orientation attribute.
Again it depends upon your need..I also agree with #Lena Bru answer.

What Is A Relative Layout?
After linear layouts, which display controls in a single row or column, relative layouts are one of the more common types of layouts used by Android user interface designers. Much like other layouts, relative layouts can be defined within XML layout resources or programmatically in the application's Java code. The relative layout works much as its name implies: it organizes controls relative to one another, or to the parent control itself.
Get to love the RelativeLayout. It will make your life much easier, when designing for multiple resolutions/densities. If you have an old SDK, update your eclipse plugin. It has graphical snap-lines for RelativeLayouts similar to designing a form in Visual Studio, so you can see what is anchored where. It's really quite good.
google says:
Layouts are a key part of Android applications that directly affect the user experience. If implemented poorly, your layout can lead to a memory hungry application with slow UIs. The Android SDK includes tools to help you identify problems in your layout performance, which when combined the lessons here, you will be able to implement smooth scrolling interfaces with a minimum memory footprint.

FrameLayout vs RelativeLayout for overlays

I need to implement an overlay (translucent) screen for my app, something similar to Showcase View
My guess was to use FrameLayout for this usecase, because it is used to stack items on top of each other. But I was surprised to see that the above library uses RelativeLayout.
My question is when to use FrameLayout then, if not in cases like this? What are the disadvantages if I go the FrameLayout way?

A common rule of thumb when choosing layouts is to select the combination that results in the smallest number of nested layout views.
Specific to your question, RelativeLayout is larger and more capable than the much simpler FrameLayout. So for simple layouts, the latter is probably more efficient. But if using RelativeLayout and it's added positioning options allows you to implement your GUI in a smaller number of layout views, then that would likely be a better choice.
Here's a page that discusses some trade-offs and demonstrates some helpful tools to use when designing your layouts. It mostly talks about RelativeLayout and LinearLayout, but is also apropos to your choice between RelativeLayout and Framelayout. Just keep in mind that FrameLayout is an even simpler layout.
Edit (2017): For even more complicated layouts, you may be able to avoid nested layouts by using ConstraintLayout.

How adjust Android listview column width at runtime?

Does the Android listview has a method to achieve this goal?
I would like to implement the function like listview in C# or vb. There users can adjust the
column width by themselves.

I don't believe you can specifically set the width on a ListView element. That kinda defeats the purpose of Android's layout system. Similar to WPF, Android lays out its UI's in a fluid and dynamic way so that it can intelligently lay out all the children within a View based on their relationships. That's why views are added to layout containers. Maybe if you describe what it is you're trying to do, there might be a more Android-like solution than explicitly setting the width after the view has already been drawn or measured.
Here's a good link to read when thinking about Android layouts and views:
How Android Draws Views