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How to measure the layout performance in android?

I had been using nested views in one of the screens in my android app. Now that I have removed all of them and used a ConstraintLayout for performance gains, I want to measure how much the performance has increased. Is there a way to measure the performance gain?

The easiest way is probably just to profile the app using a profiler using the old code and the new and see how much inclusive time is spent in onLayout in both versions.
Expect the difference to be less dramatic than you expect. The reality is your main thread is going to be idle most of the time, improving layout efficiency is really rarely a big factor in your app's performance. I would never refactor a nested design for that, I'd refactor a nested design if using constraint layout gave me cleaner XML for my view. Also remember that depending on what features you use, constraint view may not be faster. Its quicker to layout a nested linear layout than it is to calculate a whole bunch of constraints on multiple inner views, for example.

Is there any determining factor for selecting a specific layout in Android?

I'm familiar with almost all the basic layouts in Android & understand when they are to be used. I know that a RelativeLayout is to be used when elements in the UI are to positioned relative to each other, that a LinearLayout is to be used when UI elements are to be displayed vertically or horizontally. So I was wondering if the ease of development was the only factor that determined what layout should be selected or if there was any performance factor involved. I mean I can lay out two ImageViews vertically in Android using both LinearLayout and RelativeLayout, so why use a particular layout then?

There are some performance gains for avoiding certain things, such as nesting RelativeLayout (see this question). Also, the docs recommend making layouts shallow and wide, which can facilitated with RelativeLayout, again for performance reasons.
However, often thinking about such things will be premature optimization for simple layouts, and you should use whatever makes the most sense for the situation.

How to compare the efficiency of different layouts?

Currently I am running into a performance issue, with one of my activitys.
In this Activity I am inflating a lot.
So beside optimizing the code I would like to optimize the layout, too.
The basic ideas are clear (avoid nesting, flat hirachie, viewStub where usefull, merge for the basic frame, ...). But still at some points you have to choose (like do I use a relative layout or a linear layout, a table layout or even a gridlayout).
Here is where my questions fit in:
How do I compare the efficiency of differend ways (that are giving me a similar layout)?
What I am already doing is to check the layout with the Hierarchy View, which gives me a general idea, which parts of the layout are expensive and which aren't.
BUT:
It does not give me an accurate comparission between different ways to do one thing. One and the same layout inflation can vary between 1ms and 20ms, even if it is the same layout only at a different time.
So my question: How do I compare different ways to achieve a layout for their efficiency, regardless of external circumstances?

Try using the layoutopt tool for the layout optimization.
If the view layout optimized enough then at runtime creating more views with the same layout should be optimized.

Complex RelativeLayout-based View - performance issue

Got a performance issue when lots of nested RelativeLayouts are used.
For example if we have some RelativeLayout as a UI root, and every container(button, label, textview, imageview) is a RelativeLayout + Android based component (ex. aButton = RelativeLayout + ImageView + TextView), then in a complex view of 4 buttons, 3 images and 6 labels we get ~15 nested RelativeLayouts.
RelativeLayout has a very complex onMeasure method, that calculates size of every child to determine the size of layout. Calculating size of a complex view of 15-20 nested RelativeLayouts costs ~5 seconds, that's too much. onMeasure is most expensive of all calls, even drawing finished much faster then measurement.
<=UPD=>
To prevent appearing suggestions to use native android views to build something complex: Ability to add everything to everything is required. That's why every container has to be not just View, but ViewGroup. And RelativeLayout features like gravity and alignment can also help alot, that's why lot's of RelativeLayouts are used.
<=/UPD=>
Had anyone got these performance problems?
Should replacing RelativeLayout with some other Layout solve issue?
Or removing all these nested layouts is the only way to deal with the problem?
Does anyone know how much layouts can be nested without some performance problems appearing?

It definitely depends on your testing device. But you should check the hierarchyviewer (within the tools directory) for unneccessary nests of views in order to remove them.
Also your aButton sounds like a stock ImageButton. So you could replace at least that with a standard solution.
If you posted some code it might be easier to tell whether there are more items that could be replaced by stock solutions.

After a few tests came to conclusion that having more that 12 nested layouts does a great impact on performance.
On average 10-11 nested layouts should work fine.
For example 12 nested layouts with 12 children on each display in 6 seconds on device, and in 9 on emulator.

It was my understanding that the whole point of relativelayout is that you don't have to nest them to the nth degree. Why not just use a few RelativeLayout s rather than 1 per component?

Managing Android layouts, there must be a better way

I'm trying to sort the layout for one of my Android apps, but I'm finding layouts a nightmare.
Principally I have to have a portrait and landscape layout for normal, small and large screens. So thats 6 layouts to maintain to start with, let alone having to launch the app on three emulators each time because my UI widets don't load in the built in previewer.
I might be showing my ignorance as a fairly new developer, but there must be a better way!
Are there any tools out there to help with Android layouts?
Thanks

You dont need to have that many layouts. Design only as many as you need, and never use absolute values, aditionally try to make everything look nice using fill_parent and wrap_content for you layout_width & layout_height tags. Android does most of the work it self.
This article contains a lot of usefull info:
Supportng multiple screens

You may find this applicaiton helpful for designing your layouts:
http://www.droiddraw.org/
Also, if you don't specify a layout for each rotation, android will use one - infact it can use one for everything. If you use fixed values it makes it much harder. Try using fill_parent and wrap_content, you android will take care of scaling the view for each screen type and rotation too.
As a tip, don't forget to include:
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
above your relative or linear layout, and:
</ScrollView>
at the end - that way if the view doesn't fit on the screen (ie too much content) it will allow the user to scroll.

Eclipse's built in layout "editor" shows a reasonably good example of what a layout looks like. I would assume you're writing your application in Eclipse. If not, I highly recommend it. While not perfect, it's the best environment I've found.

you just need to master the proper use of RelativeLayout's and LinearLayout's. Almost all of my Layouts will start with a Relative and have Linear nested inside.
I generally don't use LinearLayouts without having either height or width set to 0 and using the weight attribute to make everything the same size.