Develop Reference

Application to support multiple screen resolutions

I have 3 layout folders in my project:
1. layout
2. layout-large
3. layout-small
and as of now i don't have anything in layout-small but layout has layouts with small dimensions and layout-large has layouts with large dimensions.
The problem is:
when i test my app on a 240x320 it uses layouts from layout
when i test my app on a 480x800 even now it uses layouts from layout
Is it because thought i have layout-large, 480x800 doesn't fall into large screens, hence uses the default layout folder?
If that is the case, how can i make layouts for Normal Screens there is nothing like layout-normal or layout-medium.
Moreover, if i design my layout for HVGA (320x480) it should work perfectly for WVGA800 (480x800) since they both fall under same screen size, only density changes. And i am using dp everywhere. Am i right?
any help appreciated.

When it comes to xlarge, large and small then it is depending on size(inches) not on dpi of your device
see below for specification
Additionally DPI is basically for Drawables while SIZE is for Layout.

Just use the following details it may work but i am not sure..
res/layout/my_layout.xml // layout for normal screen size ("default")
res/layout-small/my_layout.xml // layout for small screen size
res/layout-large/my_layout.xml // layout for large screen size
res/layout-xlarge/my_layout.xml // layout for extra large screen size
res/layout-xlarge-land/my_layout.xml // layout for extra large in landscape orientation
res/drawable-mdpi/my_icon.png // bitmap for medium density
res/drawable-hdpi/my_icon.png // bitmap for high density
res/drawable-xhdpi/my_icon.png // bitmap for extra high density
Just try....

You should check this developer page out it helped me alot. http://developer.android.com/guide/practices/screens_support.html
Even if they have different resolution or screen size that doesnt mean that they have different pixel density. For example a large screen may have less pixel density than a smaller screen.
Another example would be the Samsung Galaxy tab which is 10.1 inch but is still mdpi-large and Nexus One which is less than 5 inch but uses hdpi.
Best of luck

I think I got what is going wrong with you........ lets try this.
suppose you are going to make the application compatible for 480x800 resolution.So for that first of all create two folder for it i.e.
1.layout-sw480dp this is for landscape.
2.layout-sw480dp-port for portrait mode.
Now,put all layout of the resolution of 480X800 in it.you see it will run easily on the particular resolution.
Note:- point here to be noted that for any device resolution let A X B. the name of the layout folder is goes like this.
1.layout-swAdp.
2.layout-swAdp-port.
here "A" is the screen resolution height value of device.
i hope it work for you.

Background images for different screens

In my application I have a background for activity. This is an image, I am going to use fitXY for it. I am ok if it will be resized a little (keeping aspect ration is not very important) but not very much.
I am going to prepare few images with different size and for both Portrait and Landscape orientation. I am going to cover about 90% of devices.
My question is the following:
What images sizes I need for background?
What folders under "res" I should put these images?
I would like to get very specific file sizes and folder name where to put these files.
The solution should work on tablets as well.

I just used two images with maximum sizes (one portrait and one landscape). Then android resized the to smaller and it looks quite good for me.
I have one background with resolution: 800*1200 px in drawable folder
and another with resolution: 1200*800 px in drawable-land folder
This works pretty fine on tablets.

You have to create multiple resources for your app. Android has 4 resolutions (ldpi,mdpi,hdpi and xhdpi) and 4 generalized screen sizes (small, medium, large and extra large). So you have to make 4 layouts (or 3 if you don't plan on supporting tablets, since tablets come under the extra large category) to support the screen sizes.
Here's a general guide:
put layouts for small, medium, large and extra large in your res/ folder as follows:
res/layout/sample_layout.xml // default layout
res/layout-small/sample_layout.xml // layout for small screen size
res/layout-large/sample_layout.xml // layout for large screen size
res/layout-xlarge/sample_layout.xml // layout for extra large screen size
you can also use
res/layout-land/sample_layout.xml for landscape orientation for all screen sizes or you can target landscape layouts for specific screen sizes as res/layout-medium-land/sample_layout.xml
note that all the layouts have the same name.
once you have your layouts ready, you need to take care of image resolutions also
once again in your res/ folder add images like this:
res/drawable-ldpi/sample_image.png // low density
res/drawable-mdpi/sample_image.png // medium density
res/drawable-hdpi/sample_image.png // high density
res/drawable-xhdpi/sample_image.png // extra high density
once again, all the images have the same name.
general guidelines for designing images are:
ldpi is 0.75x dimensions of mdpi
hdpi is 1.5x dimensions of mdpi
xhdpi is 2x dimensinons of mdpi
generally, I design mdpi images for a 320x480 screen and then multiply the dimensions as per the above rules to get images for other resolutions.
Android will automatically select the best combination of layout and image depending on the device. For example, for a high resolution medium size device, layout-medium and high density image will be displayed to the user.
Make sure you create emulators for all these combinations and test your app thoroughly. here's the official docs for more info:
https://developer.android.com/guide/practices/screens_support.html

m/h/xh dpi are the most important. Combine that with the (most common) resolutions and you should be fine for your "90%" target.

Using different resources for different layouts. Layout distinctions

I've got a layout-normal and layout-large. Additionally, I provide several splash images with different resolution: 480x800 and 1280x800.
My problems are:
In my task it's said that I must distinguish layouts based on device resolutions(one for 480x800 and the other for 1280x800). Is there any possibility to implement it ? Taking in consideration an assumption that handsets have 480x800 resolutions and tablets - 1280x800 and higher, I could implement this scheme but I'm not sure that it's true.
I've created a test project where I attempted to distinguish layouts based on size, but I can't make android use 480x800 image for layout-normal and 1280x800 image for layout-large: in both cases it shows the 480x800 image. I guess, it's because of size, in case of a device, not equals resolution, in case of an image. However, I need to provide completely different looks for 480x800 and 1280x800. what are my options here ?
Thanks.
PS I'm building against Android 2.3.

You have the "Supporting Multiple screens" documentation that helps on that matter.
For example, the following is a list of resource directories in an application that provides different layout designs for different screen sizes and different bitmap drawables for medium, high, and extra high density screens.
res/layout/my_layout.xml // layout for normal screen size ("default")
res/layout-small/my_layout.xml // layout for small screen size
res/layout-large/my_layout.xml // layout for large screen size
res/layout-xlarge/my_layout.xml // layout for extra large screen size
res/layout-xlarge-land/my_layout.xml // layout for extra large in landscape orientation
res/drawable-mdpi/my_icon.png // bitmap for medium density
res/drawable-hdpi/my_icon.png // bitmap for high density
res/drawable-xhdpi/my_icon.png // bitmap for extra high density

how to i develop android application to work in different screen resolutions

I,m working on android project.
Actually i have develop on small app in honeycomb with resolution(1024*600), when am running the same app in different resolution let say android 2.2(froyo) screen the alignment of images in app screen changes.
Note:Images that are place in xml file are manual arranged(no wrapper thing used for width and height)
Please help me out this question asap..
regards,
Murali...G

Mainly we need to look up is the usage of UI patterns like action bar, Dashboard etc.
But the key point is you should use less static images and as you also use tablet. You should've used Fragments(Of course you would ve done. In case if you have done. Please do it).
Also use 9 patch images or colors for backgrounds. If you are using different images then. You need to keep images for different density.
Maybe all I say is abstract as this question is a abstract one. There is no one line answer for this. As this is a process by itself.

//design your xml in this way
res/layout/my_layout.xml // layout for normal screen size ("default")
res/layout-small/my_layout.xml // layout for small screen size
res/layout-large/my_layout.xml // layout for large screen size
res/layout-xlarge/my_layout.xml // layout for extra large screen size
res/layout-xlarge-land/my_layout.xml // layout for extra large in landscape orientation
Low density Small screens QVGA 240x320
res/layout-small-ldpi
res/layout-small-land-ldpi
Low density Normal screens WVGA400 240x400 (x432)
res/layout-ldpi
res/layout-land-ldpi
Medium density Normal screens HVGA 320x480
res/layout-mdpi
res/layout-land-mdpi
Medium density Large screens HVGA 320x480
res/layout-large-mdpi
res/layout-large-land-mdpi
High density Normal screens WVGA800 480x800 (x854)
res/layout-hdpi
res/layout-land-hdpi
Xoom (medium density large but 1280x800 res)

Check this Android class:
http://developer.android.com/training/multiscreen/index.html

Multiple screen support do we need different layouts for each screen

For Multiple screen support do we need different layouts for each screen which goes in hdpi, ldpi and mdpi folders, I read this on android site, but not sure how to implement this one.
Thanks
Max

The following is a list of resource directories in an application that provides different layout designs for different screen sizes and different bitmap drawables for medium, high, and extra high density screens.
res/layout/my_layout.xml // layout for normal screen size ("default")
res/layout-small/my_layout.xml // layout for small screen size
res/layout-large/my_layout.xml // layout for large screen size
res/layout-xlarge/my_layout.xml // layout for extra large screen size
res/layout-xlarge-land/my_layout.xml // layout for extra large in landscape orientation
res/drawable-mdpi/my_icon.png // bitmap for medium density
res/drawable-hdpi/my_icon.png // bitmap for high density
res/drawable-xhdpi/my_icon.png // bitmap for extra high density
This information are already given at Android developer site: http://developer.android.com/guide/practices/screens_support.html
Alternative drawables => Screen densities:

Screen resolution (screen density) does affect the appearance of components. To support different screen densities, similarly to the solution given by Ash, have the following folders:
res/values-ldpi for low-density (ldpi) screens (~120dpi)
res/values-mdpi for medium-density (mdpi) screens (~160dpi)
res/values-hdpi for high-density (hdpi) screens (~240dpi)
res/values-xhdpi for extra high-density (xhdpi) screens (~320dpi)
res/values-nodpi for all

Let's assume that you have a default, good-looking layout in the layout folder. In most cases, Android will be able to adjust it properly. In my practice, only large screens require a new layout parameters.
To avoid layout duplication, we use the following layout structure:
res/layout/foo.xml -- layout file
res/values/foo_styles_default.xml -- default styles (component sizes, margins, etc.)
res/values-large/foo_styles_large.xml -- styles for large screen
res/values-xlarge/foo_styles_xlarge.xml -- styles for very large screen
Screen-size-dependent parameters in the 'foo.xml' layout are set via the 'style' attribute, thus allowing us to avoid creating multiple layout files.

As per my observation most of screen will work for different screen size. Please test for app in different screen sizes and if you find issue than place layout in specific folder as diffined above.