Develop Reference

dimension folder for different screen sizes [duplicate]

I am creating different values folders in my app (values, values-ldpi, values-mdpi, values-hdpi, values-xhdpi, values-nodpi, values-w360dp-mdpi). But some devices that belong same category. But having different screen sizes. But I see give font size according to device densities in this the answer provided by #PankajSharma suggest to create folders like-
res/values/dimens.xml
res/values-small/dimens.xml
res/values-normal/dimens.xml
res/values-xlarge/dimens.xml
I want to know what is the difference b/w my way and the other way? I think the answer provided by #PankajSharma is easy. I also want to know which way is better?

The approach you are using is a valid approach, but a little outdated. From HoneyComb, there is a new way to fix all of this. Your resources folder should now look like this:
Please refer to the link I have posted and familiarize yourself with Smallest Width concept.
Hope this helps :)
EDIT: Adding to this post, try to establish some kind of standardization in your dimens.xml, something like this:
Doing this makes it easier to maintain code, plus it reduces the number of dimen folders. Normally rather than having values-hdpi, values-xhdpi, etc. files like values-sw480dp-xhdpi might have more values to adjust, but then again all of this is contextual.

Create a Single layout for default screens 4.7 inch (hdpi) in layout folder and dimensions in values folder. This is your Superset.
Now let say you want your layouts for 7inch devices. Create values-sw600dp folder for 7inch in Portrait orientation
Now lets say you want your layouts for 10 inch devices Create values-dw720dp folder
NOTE :- For landscape just add "-land" in front of folder names.
Now lets say you have new devices such as Xperia SP (4.7' and XHDPI) and Nexus 5(5" and XXHDPI).
For these, you can create values-xhdpi and values-xxhdpi folders and similary add -land for landscape orientation..
I hope you got the point of how to create folders..
Now your superset is defined in values folder. Most of the dimensions will be used from here only. Now run your app in other devices. Whatever mismatch is occuring just add that specific dimension in their respective values folder
To check from which folder your layouts, images are used, use my trick.
Create five same strings and put in it all the values folders like this :-
Default Screen
Screen 4.7
XHDPI Screen
MDPI Screen
Create five drawable folders, most of them will be already there : - drawable-hdpi, drawable-mdpi, drawable-xhdpi, drawable-xxhdpi, drawable-xxxhdpi
Put the screenshots below in their respective folder under the same name
This is how my res folder looks like and i am supporting all the devices from 4.7 screen and above :-

app's UI is not proper in a 220 dpi screen

hi I'm new in android developing and it's my first app.
I have made these folders in address : app\src\main\res for supporting multiple phone and tablet screens and put proper dimens.xml files in them.
values-ldpi
values-mdpi
values-hdpi
values-xhdpi
values-xxhdpi
values-xxxhdpi
values-sw600dp
values-sw768dp
values-sw800dp
first of all, are they complete or am I missing some screen sizes?
second, I've tested the app on several devices and it's working fine and has proper user interface in all phones but on the Galaxy Grand Prime which has a 5 inch 540 x 960 pixels display that means 220 dpi. this phone using hdpi dimens but UI is a bit messy.
The following pictures may make my point better :
Proper UI , as it is shown in other devices
VS
UI in galaxy grand prime 220 dpi display
as UI is completely OK in other devices, I thought I should make a specific dimens.xml file for that kind of dpi, so I made values-sw220dp. but after that other phones used this dimens instead of hdpi dimens and problem got worse because UI was fine in the galaxy phone and was not proper in other hdpi displays. and now I don't know what should I do.
can anyone help me in this issue?
at last sorry because of flaws in my english , as you can guess I'm not a native.

are they complete or i'm missing some screen sizes?
If you read the guides which I mentioned at the end of my answer you will find that there are very many possibilities of defining resources folders. I think nobody will want to implement all of them.
Usually you look at your app and then decide on maybe three or four screen sizes you want to support. I think "sw220dp" is important, if only to show a message that your app needs more space :-).
So there could well be three to five layout folders (sw220dp, sw320dp, maybe sw480dp, sw600dp, maybe sw820dp). If you need orientation-dependent layouts, then the number will be twice that much. (Why ? That's explained very well in the guides linked below)
You already know that there are different types of resources. Some of them do not depend on the screen resolution (e.g. layout files), some do (drawable resources).
So first of all you decide which screen sizes you want to support. Let's say they are "phone", "tablet" and "220dp". You create three layout files by the same name "my_activity.xml" and put them in three folders
for the really small window: res/layout-sw220dp
for the mobile phone: res/layout-sw320dp
for the tablet: res/layout-sw600dp
By the way, "sw" stands for smallest width which is the minimum length of the screen, no matter what the orientation is currently.
Now let's assume you have created three different layout files and all of them contain an ImageView like this:
<ImageView
android:layout_width="24dp"
android:layout_height="24dp"
android:src="#drawable/my_picture" />
This is where the screen resolution comes into play: 24dp is a size value in "density-independent pixels". It will be resolved depending on the screen resolution of the device. So you need different versions of my_picture.png, and for this you need different folders for drawables. They are named after the different categories for screen resolution so the runtime knows which png file to pick:
res/drawable/ldpi (although I read somewhere you can skip that because the pictures will be scaled down from hdpi nicely)
res/drawable (here go the resources for res/drawable-mdpi as well as every drawable resource for which resolution does not matter, e.g. drawables defined via xml files)
res/drawable-hdpi
res/drawable-xhdpi
res/drawable-xxhdpi
res/drawable-xxxhdpi
Helpful links:
Providing Resources
Supporting Multiple Screens

Different values folders in android

I am creating different values folders in my app (values, values-ldpi, values-mdpi, values-hdpi, values-xhdpi, values-nodpi, values-w360dp-mdpi). But some devices that belong same category. But having different screen sizes. But I see give font size according to device densities in this the answer provided by #PankajSharma suggest to create folders like-
res/values/dimens.xml
res/values-small/dimens.xml
res/values-normal/dimens.xml
res/values-xlarge/dimens.xml
I want to know what is the difference b/w my way and the other way? I think the answer provided by #PankajSharma is easy. I also want to know which way is better?

The approach you are using is a valid approach, but a little outdated. From HoneyComb, there is a new way to fix all of this. Your resources folder should now look like this:
Please refer to the link I have posted and familiarize yourself with Smallest Width concept.
Hope this helps :)
EDIT: Adding to this post, try to establish some kind of standardization in your dimens.xml, something like this:
Doing this makes it easier to maintain code, plus it reduces the number of dimen folders. Normally rather than having values-hdpi, values-xhdpi, etc. files like values-sw480dp-xhdpi might have more values to adjust, but then again all of this is contextual.

Create a Single layout for default screens 4.7 inch (hdpi) in layout folder and dimensions in values folder. This is your Superset.
Now let say you want your layouts for 7inch devices. Create values-sw600dp folder for 7inch in Portrait orientation
Now lets say you want your layouts for 10 inch devices Create values-dw720dp folder
NOTE :- For landscape just add "-land" in front of folder names.
Now lets say you have new devices such as Xperia SP (4.7' and XHDPI) and Nexus 5(5" and XXHDPI).
For these, you can create values-xhdpi and values-xxhdpi folders and similary add -land for landscape orientation..
I hope you got the point of how to create folders..
Now your superset is defined in values folder. Most of the dimensions will be used from here only. Now run your app in other devices. Whatever mismatch is occuring just add that specific dimension in their respective values folder
To check from which folder your layouts, images are used, use my trick.
Create five same strings and put in it all the values folders like this :-
Default Screen
Screen 4.7
XHDPI Screen
MDPI Screen
Create five drawable folders, most of them will be already there : - drawable-hdpi, drawable-mdpi, drawable-xhdpi, drawable-xxhdpi, drawable-xxxhdpi
Put the screenshots below in their respective folder under the same name
This is how my res folder looks like and i am supporting all the devices from 4.7 screen and above :-

How does Android uses values folders?

I have the font size defined in my dimens.xml (e.g <dimen name="name_text_size">12sp</dimen>)
Since this size wasn't ok on all screens I created some additional folders with different values:
values-xhdpi
values-xlarge-mdpi
values-large-mdpi
I thought this should be enough, since before creating this layouts the text look ok on ldpi, mdpi and hdpi screens, but actually the font became too large. The problem is that I am not able to figure out from which file it takes the value now for these screens. Initially, I thought it uses the default value from the folder "values", but actually no layout is using that value. Can somebody help me understand(I sow Providing documentaion and Support Multiple Screens) how this folders are working and how could I optimize the number of defined resources (e.g. xhdpi and large-mdpi have the same values)?
The solution is simple create the following folders:
values-ldpi
values-mdpi
values-hdpi
But I don't want to make things more complicated than they must be.
Thanks in advance :)

You can provide the different string text in each Values-folder. Once it will run you can check from which folder its taking the string values.
You can achieve this by this trick.

Like layout-sw600dp,alternative for drawable

My question is straight forward and simple, Like there is layout-sw600dp,values-sw600dp, for layout and values respectively, what is there for drawable folder in relative to size of screen.
I read in various document that if we want to use any screen more than or equal to 7 inches we can use layout-sw600dp folder, and for any lesser screen size device, layout folder will be taken into consideration. So how we can make use of same concept for images also. Right now there are ldpi, mdpi, hdpi folder, but images are taken in accordance of screen density not with screen size.Now if I am developing an app which work both on device and phone, what should be my probable approach for images.
Thanks in advance, please guide me.

you can also use the same concept for drawable like drawable-sw600dp,drawable-sw600dp-mdpi etc. I have used this in my application .

I'm not 100% on this one, but I think you can also use the same convention with drawables. Try drawable-sw600dp-hdpi or something similar. Though I also do have a few questions you may want to answer before proceeding:
Why would you want a different image (not resolution) for a bigger screen size?
As you already know, a 7-inch device would be using the layout-sw600dp folder, so why not have a different name for a different drawable? That would look a lot cleaner, imo.