Layout usage in Android - android

I am new to android.
As far as I know, there are different layouts like the liner layout, the table layout, and some others. I would like to know in which case what layout would be suitable.
I am unable to categorize the exact differences between the layouts.
Also, can someone please tell me what the specific meanings of the attributes like fill_parent, wrap_parent are?

What type of layout to use really depends on how the layout you are trying to build looks. If you have a simple layout of items one after another, a LinearLayout usually is the best choice. It's easy to work with, but the drawback is that you can't really customize the layout very much. All your views will just end up in a horizontal or vertical list. A RelativeLayout gives you a better way of adding Views that are right/left/top/bottom aligned compared to its parent view. And last but not least, the TableLayout is really great if you are building a grid of views.

All layouts have specific uses. Read android.developers.com, fill parent means your view will cover whole screen area, wrap-content covers that much area that is occupied by the layout's child views. Match - parent takes area equal to its parent area.But using match parent is not good.

Related

Should I always use ConstraintLayout for everything?

just a simple question, should we always use Constraint Layout for everything? why another layout still used today?
I want to make a simple login layout like this, should I use Linear Layout or Constraint Layout?
usually, I make every layout with Constraint Layout but my friend told me to use Linear Layout for the login, is it wrong if I use Constraint Layout? thanks before!
ConstraintLayout helps you to avoid using nested layouts and it causes better performance. it's not wrong to use it for everything but if you know that you are not going to have nested layouts, for example, three Textviews respectively, you can use LinearLayout. ConstraintLayout needs more XML code than LinearLayout for simple structures, and using LinearLayout is better for these situations.
I would say ConstraintLayout is more versatile and has better performance compared to RelativeLayout, But LinearLayout has its own significance in android you can specify weights of view using LinearLayout and for complex UIs I would say going with ConstarintLayout is a better option because of its performance and in ConstarintLayout you can specify the view positions, heights, widths, margins and paddings based on screen sizes rather than hard coding the values to fixed dp
https://android.jlelse.eu/constraint-layout-performance-870e5f238100
The above link gives more overview of LinearLayout vs ConsrainLayout performances.
No it it's depends on your need, if you want to make complex layout and want to make them responsive then you can.

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.

Android Relative layout Usage

Suggest me on this
I have to use some header and body part in android screen design, Can i use plain Linear layout for screen design or can i use relative layout or else both layout combined together.For the header bar im using a gradient image and application runs both in vertical and horizontal orientation.
As of now im using two main linear layouts for the first one im using a height of 40 dp and for the second i just used 0dip is this a correct way of approach or i have change anything.
Don't mix concept of RelativeLayout and LinearLayout. RelativeLayout is preferred because it reduces extra lines as compared to LinearLayout. In RelativeLayout views are placed relative to each other i.e. left, right, top and bottom unlike LinearLayout where you can't place view in respect of some other view. Both have its own advantages. As Weight concept is not supported by RelativeLayout but LinearLayout.
Depending on the complexity of layout both are chosen. One thing to avoid is un-necessary nesting of layouts which reduces performance. I would recommend read concepts of RelativeLayout, LinearLayout and weight first then you will be able to judge which layout to use on your own. Till then use RelativeLayout as it requires minimum number of lines.
You can use Linear-Linear, Linear-Relative or Relative-Relative. Anything you want.
Your question is hard to understand. From what i get, i think your approach is fine. You should let the Screen design (second layout) use "match_parent". It will take up remaining part. For your header layout using "40dp" is fine. I made app with Header, and i used this approach.
If in Header, you are adding images as well as TextView, it is advisable to use RelativeLayout. In the rest part, use however you need it.

which layout should be used for this example

Which Android layout would be best suited for this example. Inside each box would be a picture. I am mainly wondering what would be the best parent layout for the entire screen.
I was probably going to use TableLayout for each of the rows of boxes. Then have each column in the TableLayout be a FrameLayout. Then have each FrameLayout contain the picture.
But i am not sure what parent Layout i should use to contain the entire screen.
I would like this to be able to fit in Landscape on the majority of the phones on the market. Maybe it resizes everything to fit those screens in landscape.
I would also like there to be spacing between those TableLayouts.
Any assistance is greatly appreciated.
Thanks.
If I were building that, and the number of images/boxes in each set was static, I would probably use RelativeLayout as the parent and LinearLayout for each of the "rows." Then just use ImageView directly as children of the LinearLayout. RelativeLayout allows you to position things relative to each other or the parent.
Either RelativeLayout or GridView whichever fulfills the exact requirement.

Android Layouts, Table, Relative and Linear, i am confused in their differences

I have read many articles regarding layout, but I am still quitely confused. My questions are:
When to use relative layout? Example?
When to use table layout and why we can't use it instead of relative layout?
When to use linear layout?
I just need brief answers.
When use which layout?
I think It depends on your UI, and most important thing that how you create optimized layout.
From definition : -
LinearLayout – designed to display child View controls in a single row or column. This is a very handy layout method for creating forms.
RelativeLayout – designed to display child View controls in relation to each other. For instance, you can set a control to be positioned “above” or “below” or “to the left of” or “to the right of” another control, referred to by its unique identifier. You can also align child View controls relative to the parent edges.
TableLayout – designed to organize child View controls into rows and columns. Individual View controls are added within each row of the table using a TableRow layout View (which is basically a horizontally oriented LinearLayout) for each row of the table.
References :
Creating Efficient Layouts
Common Layout Objects
And most important Hierarchy Viewer
at first there is some confusion about these layouts but as you start playing with these three layouts u will get idea where to use what.. I worked on relative-layout the most.
Consider i want to use a widget always at bottom of screen then with table or linear layout this is not possible always.. without feeling screen other two can not make item at bottom but relative can do.use of any type of layout depends on your screen requirements.
I started out using relativelayout. But recently I've switched to using mostly linearlayout.
The reason is kind of hard to explain, but take this as an example: Say I want a layout that has two images centered in the middle of the screen. Both images should take up 1/4 of the screen width and 1/4 of the screen height. This is impossible to do with relativelayout assuming you want it to work exactly the same on all devices. But you can do this with Linearlayout. By creating vertical and horizontal parents, you can create "boxes". To accomplish this you must learn about weigthsum and weigth. Parent layouts should have the weigthsum attribute and children should have the weight attribute.
Anyway, my point: Relativelayout is easy to use but it's also deceptive. You may think that your layout will look exactly alike on all device, but most likely, they won't look alike. The reason for this is:
With relativelayout you must define size with either dp or px(assuming you don't fill parent or wrap content).
Different devices have different aspect ratios.
I hoped that helped in terms of understanding relative and linearlayout.

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