Develop Reference

Supporting multiple screen size - Android

I am going to develop new application in Android. This application should only work in portrait (even for tablet). Also the UI and layout design should be similar on phones and tablet. We can't change the layout design for tablet as it has huge area to use. We have to stretch all the images to match phones. We can use nine patch. But I am little bit confused of using images in multiple drawables.
As per my analysis (may be wrong.. : ) ) the screens are divided into density and sizes. We can use the scaling ratio of 3:4:6:8. But this ratio is based on the density. But in my case I have to stretch the entire UI to fill the Tablet screen.
So what are the drawables that can be used for a app like this which can support multiple devices. And what are the screen sizes for which we have to design.
And this application needs nearly 100 layouts. So I am planning to maintain single layout and designing the layout using weight for each layout instead of using dimension.
Also if I used multiple APKs to support different screen size what are the drawables used to support
1. Small and Normal
2. Large
3. Xlarge

I just did something very similar. To stretch the app without creating new layouts I used dimensions set in XML
res/values/dimensions.xml
res/values-sw600dp/dimensions.xml -> 7+ inches
res/values-sw720dp/dimensions.xml -> 10+ inches
Dimensions are resources files:
<dimen name="default_padding">11dp</dimen>
You can increase the dimensions by about 30% in the 600 and 720 file.
Then simply used #dimen/default_padding in your layout and it will be scaled
Regarding images, either you make sure you have all your assets in all densities, or you set fixed size to you ImageView's and appropriate scaleType

Firstly, you do NOT want to create multiple APKs to support multiple screen densities. Android provides all of the framework you need to support everything within one build, you just need to create the right resource hierarchy drawables with your desired densities.
So what exactly do you need... based on your question the following:
portrait mode: you can specify this in each Activity declared in your AndroidManifest file using the following:
<activity android:name=".MainActivity"
android:label="#string/app_name"
android:configChanges="orientation" >
...
</activity>
NOTE: Per the Android docs, if you're targeting API >= 13, and you use the android:configChanges attribute you should also use the android:screenSize attribute to help specify size changes.
dimension sizes for various screens: as touched upon, this can also be handled in resources. This is your best way to use one common layout file but configure the layout for use on numerous devices. See http://developer.android.com/guide/topics/resources/more-resources.html#Dimension for how to use dimensions if you're unfamiliar
drawables: it sounds like this is the crux of your question. As you mentioned, using nine-patches will help you reduce your app footprint and fill in extra space (see here and here for more on nine-patches). The sizes you should support and the densities needed for those sizes are discussed in great detail in Android design docs, so much detail I could not even do it justice rehashing it here. I've provided links below to as many places as I could remember that this is discussed.
Good luck!
Here are links to Android design docs that you will find useful (some of which have been mentioned):
http://developer.android.com/guide/topics/resources/providing-resources.html#AlternativeResources
http://developer.android.com/training/multiscreen/index.html
http://developer.android.com/guide/practices/screens_support.html
http://developer.android.com/design/style/devices-displays.html

In addition to the pixel density specific folders, you can specify screen-size specific folders
drawable/
drawable-large/
drawable-xlarge/
drawable-hdpi/
drawable-large-hdpi/
drawable-xlarge-hdpi/
drawable-xhdpi/
drawable-large-xhdpi/
drawable-xlarge-xhdpi/
So you could design scale appropriate graphics for the various screen sizes and densities. Please note that a give screen size category (e.g. "large") will only give you a rough idea as to the actual device pixel dimensions of the device, but you'll get good guidelines for min/max dp ranges.
For example, you might have a 100x100 image you want to display on phones (screen size "normal"), you'd create image assets at 100x100, 150x150, 200x200 for drawable, drawable-hdpi, drawable-xhdpi folders respectively. But on 7" tablets, i.e. "large" screen size devices, you might display this same image at 200x200, so your "drawable-large" folder assets would be 200x200, 300x300, 400x400, and on 10" tablets, i.e. "xlarge" screens, you might display the same image at 300x300, 450x450, 600x600, so these go in "drawable-xlarge-*" folders.
All the details are here:
http://developer.android.com/guide/practices/screens_support.html

First you need all the possible screen layouts
drawable
drawable-ldpi
drawable-mdpi
drawable-hdpi
drawable-xhdpi
drawable-xxhdpi // phones like s4
drawable-xlarge
drawable-tvdpi // nexus 7 etc
drawable-xlarge-xhdpi //tablet like nexus 10
layout : for phone
layout-sw600dp
layout-sw720dp
then you need to put all use 9- patch images for buttons etc ... you can also make your custom drawable it would be easy and handy to work on ..Also you can take dpi for each screen by using switch and scale it the layout accordingly.
As, in one of my project I had used this technique for showing respective thing to each resolution device .
DisplayMetrics metrics = getResources().getDisplayMetrics();
int densityDpi = (int) metrics.density ;
switch (densityDpi) {
case (int) 1.5:
break;
case (int) 2: //1.75 will be 2 in INT.
break;
default:
break;
}
also keep all the values you are going to used for margin padding etc values-sw600dp for tvdpi tablet ,value-sw720dp for tablets
Last but not least keep all thing generic as much as you can and put it in drawable ..
I have seen some ppl who used background patterns of different dpi's and put it in respective drawable .. if there is such thing like pattern make your custom drawble and repeat it accordingly
that will save your time .. hope it may help you

In order to stretch all the images to match phones you can specify the image size using the sdp size unit. This size unit is relative to the screen size so it can fulfill your requirement.

Is it correct way to create separate layout file for supporting different screens? [duplicate]

I'm really feeling confused. From the docs at developer.android.com, it seems in order to keep my images scaled correctly (aspect ratio too) across all current Android devices I need all these layouts below. Is that really what everyone is doing? Am I missing something, or should I be going about this a different way?
Low density Small screens QVGA 240x320
------------------------------------------------
layout-small-ldpi
layout-small-land-ldpi
Low density Normal screens WVGA400 240x400 (x432)
------------------------------------------------
layout-ldpi
layout-land-ldpi
Medium density Normal screens HVGA 320x480
------------------------------------------------
layout-mdpi
layout-land-mdpi
Medium density Large screens HVGA 320x480
------------------------------------------------
layout-large-mdpi
layout-large-land-mdpi
High density Normal screens WVGA800 480x800 (x854)
------------------------------------------------
layout-hdpi
layout-land-hdpi
Xoom (medium density large but 1280x800 res)
------------------------------------------------
layout-xlarge
layout-xlarge-land

Your app will work on 100% of the devices with the classic layout.
You can just add some buttons or change the layout in landscape mode by adding some qualifiers but that's up to you!
For instance, on LDPI (small resolution) device, you may want to adjust some buttons or change a little bit to fit the small screen.
You may also want to put some buttons on the right in landscape mode and in the bottom of your layout in portrait!
You do not "have to" use them.

According to Android Dev Protip from Roman Nurik about screen size qualifiers:
If you have custom layouts for larger screen devices such as tablets,
now's the time to stop using the -large or -xlarge resource qualifier
and switch to using -swXXdp or -wXXdp qualifiers. The latter were
introduced in API level 13, which basically all tablets now have
support for according to the latest platform version charts1.
means that for basically all cases where -large would have any effect,
-swXXdp can be used instead to provide more granularity.
So which actual sw or w qualifiers should you use? Here's a quick
just-give-me-something starting point:
7" tablets: Instead of layout-large, use layout-sw600dp.
Example: Nexus 7 = 960×600 dp; the smaller of the two dimensions is
600.
10" tablets: Instead of layout-xlarge, use layout-sw720dp.
Example: Nexus 10 = 1280×800 dp; the smaller of the two dimensions is
800. Some 10" tablets are a bit more narrow so 720 is a commonly used switching point.
There's more to it than just that (you really want to choose switching
points based on your content's minimum requirements, not on device
form factor), but that's a #Protip for another day (::cough:: +Nick
Butcher ::cough::).

In the layout if you do not use AbsoluteLayout, you application is going to be resized to fit the screen.
But in some cases, for smaller screens you need declare a new layout with less components for example.
For images:
You has some options.
Simple ignore some resolutions and let the device choose the best image to it.
Declare on AndroidManifest for wich sizes you want to support.
Or has just one and let the resize screw your application.

Yes. You should define different layout for different screen resolution.
When you are supposed to work with tablet kind of application. That time really you feel that. There is a need of different layout. Because Tablets always comes in different size.
One more thing, When you are working on android, means you should always taste your app with real device. And also test with different size emulators.

In Android, image sizing while supporting multiple screen sizes

In my android app, I want to support multiple screen sizes. I realize that for Android "large" means a lot of the current phone screens at 480 x 800 pixels as well as a 7" tablet like the Nexus 7 which has 800 x 1280 pixels. But I'd like to create 2 separate layouts for those two display sizes. I've found that rather than using res/layout-large, using res/layout-h800dp gives me greater control of which size screen uses what layout. (I'm using a portrait orientation, hence h800dp) The problem I'm having is this: sometimes the h800dp layout uses the images in the drawable-mdpi folder, and sometimes it uses the images in the drawable-hdpi folder. I'm using the same syntax in the xml to call the images: `android:src="#drawable/image", but in one activity it looks in the mdpi drawable folder, and in the next activity, it looks in the ldpi drawable folder. Is there any way to get the h800dp layouts to always look in the ldpi folder?

This link explains nearly everything regarding screen properties (DPI, physical size, resolution, etc.)
What you may be able to do is specify folders like layout-large-hdpi, layout-large-mdpi, and layout-large-ldpi.
Experiment with blending these types together in folder names.

Resolutions and densities

I am developing for android and my code runs perfect on nexus or any 3.7 inch device.
If I run it on tablet (7 or 10.1 inch) then the fonts and buttons are very small and the spacing is way too big.
If I run it on 2.7 QVGA then the buttons are too big and overlap.
I am using dp and sp all over the layout so I am surprised it didn't adjust according to different screen size/density.
Does that mean that I have to wrte the same XML layout in 3 layout folders (large, medium and small) and put my drawable in 3 different density folders?
Or am I amissing something here. Yes I read the "Supporting multiple screen" document and it just loses me with the details (but I did follow the tips of using dp and sp). I am looking for more of a summary/general approach answer.

dp and sp adjusts according to screen density. Therefore, a screen with 500 dpi and 4000 dpi but with the same SCREEN DIMENTIONS will looks the same.
If they have different screen sizes, it won't fit as you want. If you want to support multiple screen sizes, you'd have to use weights or percentages.
The key is that dp = device independent pixel and it only adjusts according to density, not screen size.

In the most cases if you don't make a tablet app, you don't need to make more than one XML layout for different densities/sizes. All you must do is define dimensions with DP and SP as you said.
But is necessary to provide different images in the drawable folder to show one or other in function on screen size/density.
If you put all images in drawable folder (without specify hdi,ldi or mdi) Android will try to adjust the images but not always works fine.
Hope it helps.

Supporting Multiple resolution devices Android

I am stuck in a situation.
I created an application for Samsung Galaxy Tab 7". The same application when i run on the HTC Flyer it shows very small fonts.
I tried following :
I thought may be the screen of HTC Flyer is xhdmi so i crated folders accordingly
res -> values-large-xhdmi -> styles.xml -> <item textsize>20</item>
res -> values-large-> styles.xml -> <item textsize>16</item>
this is not working.. :(
any help will be highly appreciable in this regard.
Thanks.

Check out this recent blog post on sizes: http://android-developers.blogspot.com/2011/07/new-tools-for-managing-screen-sizes.html
A typical 7” tablet has a 1024x600 mdpi screen. This also counts as a
large screen.
The original Samsung Galaxy Tab is an interesting case. Physically it
is a 1024x600 7” screen and thus classified as “large”. However the
device configures its screen as hdpi, which means after applying the
appropriate ⅔ scaling factor the actual space on the screen is 682dp x
400dp. This actually moves it out of the “large” bucket and into a
“normal” screen size. The Tab actually reports that it is “large”;
this was a mistake in the framework’s computation of the size for that
device that we made. Today no devices should ship like this.
So you need to think of the Galaxy as a large sized screen but with hdpi.
THe HTC Flyer will be large sized screen but with mdpi.
When specifying sizes you need to stick with dp, as this normalizes all sizes to scale appropriately for the different density screens. Use a dimension to specify in a xml value resource.
As milind hinted (i think), it is probably better to use the same style for these two screen sizes and specify a dimen resource. This resource can then be customized for the different displays.
The bottom line, however, is that you are using text size differences based on the screen size. The text size should be indicated in dp, so it will scale accordingly to any screen density. Really, the only resources that should be based on screen size are layouts.

If you are plan to make Multiple resolution Supporting android application just you have care about image and xml no other needs that you have same images with three different size putting in different folders like drawable-hdpi, drawable-ldpi, drawable-mdpi. you can make style.xml common for all.
Thanks