Android resolutions and emulator not choosing correct image - android

I have a quick question regarding Android resolutions and how it is represented on the emulator. I have set up a test project to test many different resolutions and how they look on each orientation. So I have created drawable-land-ldpi,mdpi,hdpi-xhpdi and done the same thing for drawable-port. I also have all the layout folders, i.e. small med large x large, small-land,med-land,large-land, x-land
I have created 8 test images, that just say small port, land, medium port, land etc and so on just to check Android is choosing the correct image. I have also created a layout file for each layout folder, in the layout files I have a text field which just specifies the folder name so I know which layout folder is being used.
I have two questions, first is am I creating the correct image size for each folder. The image sizes I have created as are follows
drawable-land-ldpi - 320 * 240
drawable-port-ldpi - 240 * 320
drawable-land-mdpi - 480 * 320
drawable-port-mdpi - 320 * 480
drawable-land-hdpi - 800 * 480
drawable-port-hdpi - 480 * 800
drawable-land-xhdpi - 1080 * 720
drawable-port-xhdpi - 720 * 1080
And my second question is why do these not seem to represent properly on the emulator? Example, I have created an Android app with one screen and the images in the appropriate folders. I have created two emulators, one is 2.3.3, and one is a 3.0 tablet.
If I run the device on my device which, it uses the image from the medium resolution folder and uses the medium layout folder. So if it is port it will use the layout from the default layout folder and the image from the drawable-port-mdpi and if its landscape it will use the layout from the default land folder and the image from the drawable-land-mdpi.
However if I run this on the emulator, on the 2.3.3 device, it uses the layout folder from the medium layout folder, but the image from the drawable-hdpi-port and if its landscape uses the medium landscape layout folder, but the image from the drawable-hdpi-land. If I run it on the 3.0 tablet emulator, it uses the correct layout from the xLarge port and xLarge land, but it uses the image from the drawable-mdpi folders.
I have set up in the manifest to support all resolutions and layouts. Is there any reason why the emulator is doing this? I don't have an Android tablet on me at present to test this as friend forgot to bring it, so I can't test if this works fine on the tablet yet.
I would like to be able to use the emulator to try out a range of devices to test, but if it is not choosing the correct image then I cannot rely on it. Anyone else have issues like this? Or am I doing something wrong?
Any information would be much appreciated!!

Pixel density matters. For instance, your hdpi images may be the right size, but with an incorrect pixel density, they will still get scaled in those folders. For instance, your hdpi images should have a pixel density of ~240dpi. Check the developer guide for supporting multiple screen sizes:
http://developer.android.com/guide/practices/screens_support.html
Another issue is that the screens may be a variety of sizes, along with different pixel densities, e.g., a tablet could be 10 inches (X-Large), but still have a medium pixel density (1280x800). At the same time, you could have another tablet that's also 10" with xhdpi, if the resolution was something like 2560x1600.
It might be better for you to specify your actual layout folders based on pixel density. i.e., you can make folders:
res/layout-sw600dp/main_activity.xml # For 7” tablets (600dp wide and bigger)
res/layout-sw720dp/main_activity.xml # For 10” tablets (720dp wide and bigger)
And you can still apply port and land to them. Read up on the page about supporting multiple screen sizes, it will probably really help to answer a lot of your questions.

Related

Android : Screen Size

I'm working on android application and got in trouble of multiple screen support. I developed the app for 1080x1920 and when i tested the app on my friends Micromax Unite 2 with resolution of 480x800, it was something else. So i made two folders in the layout as:
layout-1080x1920
layout-480x800
thinking that the 480x800 device will pick up the layout-480x800 folder. But no it used the layout-1080x1920. So what should i do? So that the device having resolution of 480x800 works on layout-480x800
I suggest naming the folders as such:
layout-sw600dp
Where sw600dp means Screen Width 600dp. This layout folder will be used by devices with screen widths of 600dp or more (typically all 7-10 inch tablets, or just very dense screen). And when you are targeting for the phone use just the layout folder without any specified criteria. All phones not matching the sw600dp will use the default layout resources. Possibly also consider using
layout-sw600dp-port
if you need to use specific layouts for portrait orientation, likewise you can do
layout-sw600dp-land
if you wanted to specified layouts for landscape.
The link cricket_007 provided is where I learned this information
Note that 1080x1920 equates to about 540 x 960 dp in dp measurement, which is why I suggested to use the particular 600dp for width
giving the folder names pixel according to android screen support dev page. Even if you know all possible resolutions for every device, the android system takes those *xml files/drawables etc specified by their DPI, not PX. Those dpi resolutions still can change on runtime, such as, when your activity uses a tool bar (which is not part of your dpi resolution). Name your folders layout-xlarge, layout-large, layout-normal, layout-small for *xml layouts. I suggest to put 4 different xml files with same name in each of them and try it again for different devices.

Problems in supporting multiple resolutions

I am having trouble managing my application layouts in three different resolutions; 720x1280, 1080x1920 and 1440x2560.
In drawable-xhdpi folder is the corresponding images to 720x1280 resolution.
The folder drawable-xxhdpi is the corresponding images to 1080x1920 resolution and in drawable-xxxhdpi to 1440x2560.
I began to adjust the screens in layout folders. The layout-sw360dp was setting screens for 720x1280 and the layout-sw480dp the 1080x1920.
When testing in the emulator 720x1280 all settings worked perfectly.
But to test the emulator 1080x1920, oddly taking this information in layout-sw360dp folder and not the layout-sw480dp.
In the case of adjusting each folder layout-sw360dp and layout-sw480dp, I'm using margin with values ​​in 'dp' and emulator higher values ​​(layout-sw480dp) are being dropped are being used and the values ​​of the layout-sw360dp.
How can I manage three screen sizes correctly?
Well designed Android applications cater for varying screen sizes, the screen size being a function of both resolution and density. Using several layout-sw###dp folders allows you to vary the layout according to the width of the display, e.g. showing fewer elements and controls on a small screen and perhaps more detail on a large one.
The 'sw' in the layout folder name is the 'shortest width' a display must have in device independent pixels (dip). One dip = 1 real pixel on a 160 density screen. So on a 320 density screen, 2 real pixels make up one dip.
Your nexus 5 has 480/160 = 3 real pixels per dip. So with a width resolution of 1080, that is 360dip wide.
Your nexus 4 has 320/160 = 2 real pixels per dip. So with a width resolution of 768, that is 384dip wide.
Neither device is more than 480 dip wide so both use the sw360dp folder.
Both devices are physically very similar in size. The Nexus 5 (5.4inch screen) has more pixels than the Nexus 4 (4.7inch screen) but the pixels are physically smaller. So it is correct that the same layout is used for both. The UI should look the same on both devices, assuming you correctly specify the size and layout of your various UI elements in dip.
As a further example, I have an old tablet (10inch screen) with a resolution of 800x1280 and a low density of 149, hence is 859dip wide. You can comfortably display far more info on a screen that size than on a Nexus 4/5, hence you might consider creating a layout-sw720dp for that.
So you appear to be doing exactly the right thing already by designing different layouts for different screen sizes. Just remember that resolution is not the same thing as screen size. Screen size is a combination of resolution and density.
As for your drawables, you are also already doing the right thing by using drawable-xhdpi, drawable-xxhdpi etc with appropriate resolution images in each one. So for example a small device with an extremely high density would likely use the 1440x2560 images and the sw360dp layout. My low res tablet would use the 720x1280 images, unless you'd put something in drawable-mdpi which is where it would look first.
So firstly you'd create appropriate resolution images in the drawable folders so that they would look as good as possible on different resolution screens. Then create appropriate swxxxdp for your layouts so they take up the appropriate space depending on the physical screen size, i.e. make good use of available screen space on large devices and don't clutter up small ones. It's likely you would want to go further and create -land and -port versions of each as well.
It is worth noting that even if you only have one layout folder and one drawable folder, your application will still work on all devices. Android simply looks for the best choice and if there is only one, it'll use that. Adding in the various folders simply allows you to make your app look as good as possible on a range of devices.
Everything I have discussed here and more is explained in detail at http://developer.android.com/guide/practices/screens_support.html.

The process of creating Android layout files

I am in the process of creating layouts for a new application and I am interested to know how you are usually approach this process.
Obviously it's a very general question, but I think we can get a lot of ideas from different developers' perspectives. As creating perfect layouts in Android, in my opinion, is one of the most difficult tasks in the app development process, I think the answers can be of value.
The assumption is that we want to support all device sizes with the least number of XML files, without compromising the application design quality.
In my case the designer of the app designed it with Galaxy S3 dimensions in mind (720 x 1280px).
Considering the 3:4:6:8 ratio -
What will be the base device you'll do the design for, so one layout file will look good on all normal size devices?
How would you handle the difference in device dimensions, thinking in dp -
Eg.
480 X 800 hdpi = 320 X 533dp
320 X 480 mdpi = 320 X 480dp
720 x 1280 xhdpi = 360 X 640dp
How will you still use the extra dp, so there won't be to many empty spaces, without making the layout not appropriate for 320 X 480 device?
When the designer marks a margin of 20px, how would you interpret it in the xml?
Taking into consideration he designed it on a 720 x 1280px canvas.
Start with some screen size as your base target device for e.g. 4.7 inch (hdpi) and create a single layout for default screens in layout folder and declare dimensions in dimens.xml in values folder.
Next, let's say you want your layouts for a 7" device, create values-sw320dp folder for 7" in portrait orientation and declare separate dimensions in dimens.xml in this folder.
Next, let's say you want your layouts for a 10" device, create values-sw720dp folder for 10" in portrait orientation and declare separate dimensions in dimens.xml in this folder.
PS: For landscape orientation, add -land in the end of folder names.
Next, let's say you have new devices such as xhdpi and xxhdpi devices, you can create values-xhdpi and values-xxhdpi folders.
Since you have defined dimensions in values folder, when you run the App, most of the dimensions will be used from here only. And you can add/update the dimensions in respective folders for screen-size and resolutions on which there is any mismatch.
Also, if you have got separate drawables for various size like mdpi, hdpi, etc you can place them under drawable-mdpi, drawable-hdpi, etc.
The Android system will take care of loading correct resources at run-time.
Note: On Android versions < 3.2, the folder naming was little different, you can refer that here.
Hope this helps.
Android automatically scales layouts to fit the current device. One way to make the solution more elegant would be to create separate folders drawable-ldpi, drawable-mdpi, drawable-hdpi, drawable-xhdpi and drawable-xxhdpi to hold the drawable resources - this is to make sure the same resource does not get used across all the different resolutions where it might not be so clear.
Do not use px (pixels) for measurements in the layout file - use dip (or density independent pixels) which allows to scale according to device pixel density.
The other extreme would be to have different layouts for different resolutions though this is is not advisable.

Android layout editor devices not holding their place for each different layout

I am trying to design different layouts for different screen sizes. I have created layout files for sw240dp, and I am now trying to design layouts for sw480dp. My problem involves the list of devices in the layout editor. I am trying to select a 3.7 inch device to design on, but the software keeps jumping over to the sw240dp layout file every time I select the 3.7 inch device for sw480dp. I don't understand what I'm doing wrong here. Is there something wrong with my eclipse software, or am I doing something wrong?
What resolution and density are you selecting for the emulated device? The DP is determined by the density and resolution. So for 480 DP, here is the mapping from density to required pixel resolution:
MDPI (160) : 480px
HDPI (240) : 720px
XHDPI(320) : 960px
So if you're picking a 3.7" 480x800 device at HDPI, that's not going to fall into the sw480dp bucket. You'd need to create it as an MDPI device (i.e. density of 160).

Application Skeleton to support multiple screens

As we know Android coming with various device which having different
Features, Resolution, and Screen-size so while developing an Application which support
multiple (small and big) screen there is an obstacle of size and layout.
This leads to different combinations of screen sizes, resolutions, and DPIs and creates quite a challenge when designing and developing for Android devices. While some other Manufacturer (non Android) have different resolutions and DPI, they share the same screen size and the resolutions follow the same aspect ratio. Therefore, an image can be created to fit the non Android devices.
My question is that is there a proper flow or architecture that one should follow to meet the requirement?
Remember we do have Tablets of different Size and Resolution.
I'm aware that Android Developer contains this information but my view is from implementation.
From my knowledge what I understood is that for designing Android graphics even Programmer must know the designing concept.
Finally created a structure which handle layouts and icon for multiple screen.
Android generalises device displays into categories based on two parameters:
Screen size, the physical size of the display (measured diagonally)
Screen density, the physical pixel density of the display (in pixels-per-inch, or ppi)`
To determine screen size & density quickly, please install "What's my Size" app for Android.
Screen size
Android defines four generalised screen sizes:
Qualifier Size
small ~3 inches (approx)
normal ~4 inches (approx)
large Exceeds 4 inches
xlarge Exceeds 7 inches
Most phones are classified as small or normal (roughly 3 to 4 inches diagonally). But now, there are many phones with large screen such as Galaxy S4, HTC One, Xperia Z
A small tablet like the Samsung Galaxy Tab is classified as large (larger than 4 inches)
Extra-large applies to large devices, for example large tablets
Android defines four generalised screen densities:
Qualifier Description Nominal value
ldpi low density 120 ppi
mdpi medium density 160 ppi
hdpi high density 240 ppi
xhdpi extra high density 320 ppi
Typically:
screen size has most impact on your app layouts
screen density has most impact on your image and graphic resources
It is listed here the percentage difference of device screen
Ldpi- 75%
Mdpi- 100% (base according to Android developer site)
Hdpi- 150%
XHdpi- 200%
But as we know now most of device coming with 480X800 so I'm consider this as based device, so our new calculation will like this
Ldpi- 50%
Mdpi- 66.67%
Hdpi- 100%
XHdpi- 133.33%
which means that first icon and design will be created for 480X800 only and then for rest ones(i.e. Ldpi, Mdpi, Xhdpi).
There are images which are common for all layout and must uniform in color and shape(no complex shape, no curve) so for this kind of image we are creating 9patch which to be put in “drawable(no-suffix)” folder. To create 9Patch image you can either use DrawNinePatch or BetterNinePatch
Now just rename your images based on Android's standards and complete your application with hdpi and then just take drawable-hdpi folder and Open Adode Photoshop(recommended)
create Action of multiple size(just change the size according to percentage ratio) once Action created for all size then just do Batch Automate and give source(drawable-hdpi) and destination(drawable-ldpi, drawable-mdpi, drawable-xdpi).
The reason I insist you to use Photoshop because it will resize automatically your image with Actions and one more plus point is that you need not to rename the file(it will assign same name as original one).
once you completed with creation of all images, refresh your project and test it.
Sometimes there may be possibility that the layout which support screen(xhdpi, hdpi, mdpi) may be get cut in small screen(ldpi) so for handling this just create separate Layout folder(layout-small) for it and add ScrollView(mostly). Thats it.
Tablet
Tablets are categorized into two size.
7"(1024X(600-48(navigation bar))) = 1024X552 (drawable-large)
10"(1280X(800-48(navigation bar))) = 1280X752 (drawable-xlarge)
In this we need to create image for both the screen and just put them accordingly
So all in all we will have this folder in our application to support multiple screen.
drawable
drawable-ldpi
drawable-mdpi
drawable-hdpi
drawable-xhdpi
drawable-large
drawable-xlarge
will be more qualifier combination with Screen size and Screen density
drawable-large-ldpi
drawable-large-mdpi
drawable-large-hdpi
drawable-large-xhdpi
more qualifier with Screen density and Version
drawable-ldpi-v11
drawable-mdpi-v11
drawable-hdpi-v11
drawable-xhdpi-v11
and more qualifier with Screen size and Version
drawable-large-v11
drawable-xlarge-v11
and more qualifier with Smallest width concept(SW)
drawable-sw???dp
Further more in Android V3.0 Honeycomb they introduced new concept of SW(smallest width) in which device are categorized into screen width, so if we are creating a folder named drawable-sw360dp then the device with 720dp(either width or height) will use resource from the this folder.
for example to find the Samsung Galaxy S3 dp to suffix to drawable-sw?dp
With reference of DP Calculation, If you want to support your layout or drawable to S3 then the calculation says
px= Device's width = 720
dpi= Device's density= 320
formula given
px = dp * (dpi / 160)
interchanging formula because we have px's value
dp = px / (dpi / 160)
now putting value,
dp= 720 / (320/160);
dp=360.
so drawable-sw360dp will do the job
Get you Device configuaration from GsmArena
Sameway you can also create folder according to Device's Android API version i.e. drawable-hdpi-v11` so the device which is having API11 and it is Hdpi then it will use this resources.
Additional Tips:
Use relative layouts, dp, sp, and mm
dp units - device independent pixels normalised to 1 physical pixel on a 160 ppi screen i.e. medium density. Scaled at runtime. Use for screen element dimensions
sp units - scaled pixels, specified as floating point values, based on dp units but additionally scaled for the user's font-size preference setting. Scaled at runtime. Use for font sizes
you should always use RelativeLayout for layouts; AbsoluteLayout is deprecated and should not be used.
Use appropriate image formats - PNG versus JPEG
Android "prefers" PNG for bitmap image files, "accepts" JPEG, and "discourages" GIF.
However, PNG and JPEG are not equivalents. They have different quality trade offs, and PNG is not always best:
JPEG can offer up to 50% file-size reductions over PNG, which is significant if your app is image-intensive
A higher quality "lossy" JPEG may look better than a highly compressed "lossless" PNG, for the same file size
Add labels to your images and graphics for debugging
Use the supports-screens element
Configure your emulators with real device values
Conventionally, desktop systems display at 72ppi (Mac), or 96ppi (Windows, Linux). Compared with mobile, desktop displays are always low density.
Always configure your Android emulators to mimic real device values, and always set them to scale to emulate device density.
In Eclipse, it's easy to create multiple emulators (from the Eclipse menu bar, select Window > AVD Manager > New) configured with values for real devices:
Name the emulator for the real device it's emulating
Specify Resolution, don't use Built-in generic sizes
Set the device density to match the real device (in the Hardware pane set Abstracted LCD Property to the real density, always an integer value)
When you launch the device, always select Scale display to real size, and type in the real screen dimension in inches.
If you don't set the device density, the emulator defaults to low density, and always loads ldpi-specific resources. Resolution (pixel dimensions) will be correct, but your density-dependent image resources will not display as intended.
Of course, nothing you do will reproduce higher density image quality on a lower density desktop display.
Here is the Data collected during a 7-day period ending on October 1, 2012. To see the latest statistic about Android platform version, go to here
Based on Screen Size
Based on Screen Density
Designers should create base designs of
base size of mdpi devices * density conversion factor of highest supported density bucket
size.Base screen size is 320 X 480 px and density buckets are as follows:
ldpi: 0.75
mdpi: 1.0 (base density)
hdpi: 1.5
xhdpi: 2.0
xxhdpi: 3.0
xxxhdpi: 4.0
And to tackle extra available space on Android devices should use stretchable components in both the directions (horizontally and vertically). Detailed info is available here:
http://vinsol.com/blog/2014/11/20/tips-for-designers-from-a-developer/

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