Develop Reference

Android graphics for XXHDPI

I'm about to adjust all drawables for an Android app for XXHDPI devices (like sony xperia Z and samsung s4). After thorough reading on Google's documentation, blogs, and SO, I'm confused as to the graphics I'm about to produce.
My concerns are the following:
Google states that I shouldn't worry about this density as it scales up XHDPI graphics - In the same manner, (before XXHDPI devices) why the production of XHDPI graphics was a necessity and it didn't scale up HDPI graphics?
Sony reminds developers not to exclude XXHDPI screens without clarifying if this concerns making adjustments to graphics - Do I have to redesign all graphic elements for XXHDPI?
Based on (2), Sony Xperia Z Ultra has 342dpi density but it is categorized as an XXHDPI device. - If I produce the graphics for an XXHDPI, which is twice the size of an HDPI density, the graphics will scale down by almost 1/3 to match Sony's density and this is undesirable. Why doesn't Xperia Z use the XHDPI drawables? What if I have a pattern and I can't afford any scaling since I'll lose the detail of the pixel-perfect pattern?
Are XXHDPI resources REALLY necessary?
I hope somebody can answer all the questions above.
EDIT
Below are the results of slightly scaling a graphic to adjust to various densities
- xhdpi image (1:1) no scaling
- xhdpi scaled up by 10%
- xhdpi scaled down by 10%
The detail loss is obvious at 2nd and 3rd image.

Unless you actually need your graphics to be "pixel perfect", scaling up from XHDPI will probably be fine for almost all cases. Pixels are so small the user won't be able to tell the difference. Do you actually have an XXHDPI device you can see your graphics on? You might have to provide XXHDPI resources for some drawables, just like you sometimes have to provide MDPI drawables when the HDPI ones don't scale down well.
"do not exclude" in this context means explicitly from the manifest. Some developers target densities in their manifest and that will affect the app not showing in the Play store, this is unrelated to actual graphics.
From that same page, it actually says that the density of that device is 440 dpi? - "One of the awesome features you’ll find in the recently announced Sony Xperia Z is its 5” screen, which boasts a display density of 440 dpi,"

XXHDPI resources are essential for stuff like icons on modern devices. Google will change their story and start to recommend them when they release their own XXHDPI Nexus device.
Think about it this way: xxhdpi devices are pretty much the STANDARD Android devices. Little chance Samsung & HTC are going to roll everything back to XHDPI just because Google can't keep up.

1) Android scales the drawables selecting the drawable that will produce the best result https://stackoverflow.com/a/14004691/936414
2) The post only asks you to include xxhdpi screen support in manifest. All XXHDPI devices take resources from XHDPI and scale them to fit accordingly. So no need of separate resources in XXHDPI folder
3) No need to include resources for XXHDPI.

android app icon missing on certain device

I've recently developed an Android app. For some reason the app icon does not show on the home screen on a HTC One device. The icon shows fine for my other devices.
Reading other forums, I have made sure the app is stored within the phone rather than the SD card, and tried rebooting but these do not seem to fix the issue.
I'm guessing that the HTC One is not picking up the icon file, but I'm not sure why - as the other devices including Galaxsy S3 and other HTC devices do? Any help would be appreciated.
Thanks in advance!

I suppose you've created folders to support various densities? ldpi,mdpi,hdpi,xhdpi? If that's the case, are you sure you've put your icon in XHDPI folder because HTC ONE will read it from there because it has very big density.
For example:
According to GSM Arena, Galaxy S3 Galaxy S3 has 306ppi pixel density. That's high density and this phone will read drawables from hdpi folder.
On the other hand, HTC ONE has 469ppi pixel density. That's extra large density and this phone will read drawables from x-hdpi folder. GSM Arena, HTC ONE
But this may not be the case, because if drawable is missing from one folder will just read it from another available. But please check again your x large folder.

display density and resources usage (ldpi/mdpi/hdpi/xhdpi)

So I got HTC smartphone with 800x480 display. I always thought that it is HDPI device. And I was ensured using the following code:
Display display = activity.getWindowManager().getDefaultDisplay();
DisplayMetrics displayMetrics = new DisplayMetrics();
display.getMetrics(displayMetrics);
displayDensity = displayMetrics.densityDpi;
it says my device is 240dpi. But experimentally I'd discovered that android threats my device only as MDPI. Im sure bout this. I tested the same with another 800x480 (ZTE) and result was the same - it shows 240 in displayDensity but android threats it as MDPI device... But why is it so? On android.devepoler they said that 240dpi is HDPI. I'm totally confused. Why the heck 240 is threated as MDPI?
How I'd discovered that android treats my HTC as MDPI device:
In short what I made to ensure - I put a big image to drawable-hdpi (guessing AOS gonna use it) and smaller one to drawable-mdpi and than ran an app to see which it gonna use. And it always used image from drawable-mdpi instead of drawable-hdpi. To know how which image looks like on my device I ran app previously putting images to drawable folder of project.
However, like I mention above, I was guessing that my 800x480 HTC is HDPI due to code based on displayDensity but not on Configuration. Configuration says my device is Configuration.SCREENLAYOUT_SIZE_NORMAL and seems like thats the reason why AOS treats my device as MDPI only. So in conjunction with DisplayDensity of 240dpi (which must be HDPI instead of MDPI) it really frustrating. So now the question is why with Display density of 240dpi Configuration sets device to MDPI type? Whats the reason of this? I was thinking that the one and only way to detect the device type is its display density. And if it is 240dpi it must be HDPI device instead of MDPI.

You may try to read this page: http://developer.android.com/guide/topics/resources/providing-resources.html , it shows a complete explanation about screen density and others when you want to organize your resource folder.
About device being treated like MDPI it may be like Nexus 7, we were sure that it was MDPI, but it was using images from HDPI and also some values from MDPI/sw600dp (things that you will find better explained at that link above there), because its density, actually was TVDPI and so it's a 'middle' density between HDPI and MDPI. Try to download an app called ScreenInfo, on GooglePlay. It shows various informations about device screen, and may help you to make sure about your HTC.
Hope it helps.

Sorry for delay, so, first of all, you have to decide which public you want. You have to keep in mind that there are inumerous devices around there and it's almost impossible to cover all of them. I'd advise you to start with devices considered normal(screen normal, and MDPI density) because that is the baseline. And then, worry about others, based on that first one. Understand that the differentiation on resources folders are only done if necessary. In most cases, resources used to baseline works well for everyone.
Hope it helps.

how can i develop application for all android devices ? what setting can i put on simulator that work on most devices?

What simulator resolution i should keep when developing application for Samsung galaxy s2 and galaxy s3 ?
What i found that samsung galaxy s2 has 480x800 resolution and s3 has 1280x720 resolution so what i have understood up till now that I should ask my graphics designer to provide me hdpi graphics that contain 480x800 background images and to implement same background image in galaxy s3 mobile, I will use image of size 1280x720 and put in xhdpi folder so that it can work on s3.
The background image is something which covers whole available area for mobile app. so am i right ??

You will need to create several emulators or get various devices.
There are some pretty important ones, so generally you need to make sure you have:
ldpi, mdpi, hdpi, xhdpi
and
small, medium, large, xlarge
Some people choose to exclude certain sizes (like small and ldpi) but htat's up to you,
if you go with some or all of the following, it should be a good start:
480x320 (SE Mini 10), 480x800 (GS2, Desire, etc), 1280x720 (GS3, Galaxy Nexus etc), 1280x800 (Note, Xoom, various other tablets)
HTC ChaCha (because it's landscape default)
You need to make sure you create resources in the relevant folders for each density, usually, I tend to ignore ldpi and just put resources in:
mdpi,hdpi and xhdpi (mdpi will be scaled down for ldpi devices,
automatically)
You may also need to create various portrait and landscape layouts in different sizes.
Reading this page provides most of the necessary information:
http://developer.android.com/guide/practices/screens_support.html
This page also contains important information regarding size distribution and popularity that is constantly up to date:
Android Stats

One thing that Android does for you is that it manages resolution. If you use the proper size formats (dp, sp, etc), your layout will scale to almost all resolutions. If you place images in the proper drawable folders (hdpi, ldpi, mdpi, etc), the OS will also swap those out as necessary.
Also, the emulator should handle resolutions for specific devices, if I recall correctly.

Desing lazout in smart way! Usualy it means don't put to mutch content in one layout.
Make sure that evrything looks good on smallest size and bigest size. It is better to treat tablets separetly. Read how providing alternative resources works, you can build sepereate layouts for each screen size.

Check if the hardware is available on that device before using it. hasSystemFeature() can be used for checking.

Drawables and Layouts for Galaxy Tab and Motorola XOOM

I'm testing my app at Galaxy Tab and Motorola XOOM emulator skins, and I can't understand, why the drawables are taken from the wrong folders. I have drawable-xhdpi folder, where I store big size pictures. However, Tab takes drawables from drawable-hdpi, and XOOM uses the drawable-mdpi folder. So, how do I manage my resources? Thanks in advance.
In addition, it feels like view sizes defined in sp are not ported properly. I have some views which need to be 80sp x 80sp, on phones with mdpi and hdpi screens they look right, but on tablets they look too small. Why can this be?

However, Tab takes drawables from drawable-hdpi, and XOOM uses the drawable-mdpi folder. So, how do I manage my resources?
There is no single "Galaxy Tab" device, so I have no idea which one you are referring to there. The XOOM is an -mdpi device. I would expect that the Galaxy Tab 10.1 would be -mdpi as well. However, in the end, device manufacturers will choose values that they feel deliver the best results for existing applications.

GalaxyTab 7" use "-large-hdpi"; XOOM 10.1" use "-xlarge-mdpi".
check this post for details:
GalaxyTab, Motorola Xoom Screen Desity and Size

I have test with multiple screen resolutions and find out Android use the following qualifier for different screen resolutions:
240x320: -ldpi
320x480: -mdpi
480x800: -hdpi
GalaxyTab7.1 inches: -large
GalaxyTab10.1 inches: -xlarge
Hope this information is useful for you.

Galaxy tab (the old one, running Android 2.x) is indeed not xhdpi. I had success by using the "large" qualifier to identify tablets. Else you can always use an API qualifier such as v11 for Honeycomb only resources.

Rather than using the dpi qualifiers you can use screen size qualifiers instead, theres info here on exactly what tags you can use when selecting which resources to use,
http://developer.android.com/guide/topics/resources/providing-resources.html
It's important to understand the difference between dpi and screen size, dpi tends to be high on phones, like a samsung galaxy s2, but on the big 10 inch tablets it tends to be low(which makes sense if you think about it, the phones squeeze more pixels into a smaller space).