calculate dp for different screen for supporting multiple screens - android

I know there are many questions like this, I have read many blogs and questions on this and I am not satisfied by what I have understand.
I want to support multiple screens and resolutions like hdpi, xxxhdpi etc.
And i am using dimens.xml for this purpose. But m still unclear about how to calculate exact dp value for different screens.
For example if 48dp x 48dp ImageView is proper for hdpi device, what values should i define for xxhdpi device? Is there any fixed calulation just like there is for drawable images?
I am using these folder for trying to support multiple screens :
values-sw320dp-hdpi
values-sw320dp-xhdpi/xxhdpi/xxxhdpi
There are few problems I am facing currently
Though defining values in respective dimens.xml works almost for most of the devices, there are few devices which takes wrong values
For example I have Lg optimus G that is xhdpi device, but it reads values from values-sw320dp-xxxhdpi's dimens.xml instead of xhdpi one
I am not able to calculate the exact value for each resolution (hdpi,xhdpi etc), so the view which looks perfect in hdpi device, seems little large or small in xxxhdpi as I can't guess the value like if hdpi view size is 48dp then xxxhdpi should be of 64dp or something as I don't know the exact approach.
Also while searching for supporting different screens, I read many times about calculating dp at runtime based on density or calulating pixels etc.
I am too confused about all this. Please help me in understanding and learning the proper way of making responsive apps.

You can use resource qualifiers to specify different sizes for Views.
If you want the width of an ImageView to vary based on the size of the screen, create a new dimension in your dimens.xml file called image_view_width (for example).
This then essentially creates a copy of the dimens.xml but adding the 'Size' qualifier. This will create another version of the dimens.xmlfile, and any device that meets your specified qualifications will use that version of dimens.xml. You then add image_view_width to this new file and give it a different (smaller/bigger) value. You can do this as many times as you want and with as many different qualifiers as you want.
Finally, when you want to use this value in your layouts, you only have to type:
android:layout_width="#dimen/image_view_width"
and android will do the rest for you.
Hope this helps!

Related

1080x1920 420dpi screen not accessing from sw420dp

I am creating different values folder for supporting different screen sizes.The following are the folders:
values-sw320dp-hdpi
values-sw320dp-xhdpi
values-sw320dp-xxhdpi
values-sw420dpi
values-sw560dpi
values-sw480dp-hdpi
values-sw480dp-xhdpi
values-sw480dp-xxhdpi
values-sw600dp
values-sw720dp
In the list of devices provided by Android Studio there is 1080x1920 420dpi.It should access dimens values from values-sw420dp.But instead it is accessing from sw320dp-xxhdpi.The layout in 1080x1920 420dpi **looks slightly different from **1080x1920 xxhdpi. Can anyone explain to me why it is not accessing from its own folder?Or could you explain to me the correct way to create a layout so that it support different screen sizes with different densities?I have referred different sites.They are confusing..Please help me!!
I am creating different values folder for supporting different screen sizes.
First, using density qualifiers (e.g., -xhdpi) on resource types other than drawable and mipmap is a serious code smell. Almost assuredly, you are not going to get the results that you expect.
Second, there is no -sw420dpi or -sw560dpi qualifier. You could have -sw420dp or -sw560dp, to say that you want to use these resources for those screen size thresholds. However, such directories would never be used, because of your density qualifiers on directories like values-sw320dp-hdpi.
In the list of devices provided by Android Studio there is 1080x1920 420dpi.It should access dimens values from values-sw420dp
No, it should not.
The smallest width of that screen is 1080px. 1080px, at 420dpi, is 411dp (1080 * 160 / 420). 411 < 420. Hence, anything that is -sw420dp will not qualify.
But instead it is accessing from sw320dp-xxhdpi.
Partially, that is because 411 is lower than 420.
Partially, that is because you are using density qualifiers here, which short-circuit a lot of the "normal" rules for resource selection.
The layout in 1080x1920 420dpi **looks slightly different from **1080x1920 xxhdpi.
Your question has no layouts, so nobody can comment on that.
Can anyone explain to me why it is not accessing from its own folder?
There is no "its own folder".
Or could you explain to me the correct way to create a layout so that it support different screen sizes with different densities?
Use layout resources based on screen size and (perhaps) orientation (e.g., res/layout-sw420dp/)
Use dimen resources measured in sp (for sizing text or things that are dominated by text) or dp (for everything else) in those layout resources (e.g., <dimen name="margin">16dp</dimen>)
Use density qualifiers, and maybe size qualifiers, for drawable and mipmap resources (e.g., res/drawable-hdpi/)
Frequently, that is sufficient.
I have referred different sites.They are confusing
Perhaps consider reading a book.

Different Text Sizes for different Screen Sizes, using what ratio factor?

Hello I am using different textsizes depending on different screen sizes.
Like:
values-small: dimens.xml -> ?
values-normal: dimens.xml -> 10sp
values-large: dimens.xml -> ?
values-xlarge: dimens.xml -> ?
I want to know if there is a formula to set the right sizes depending on small, large, xlarge instead of setting sp size by testing it on different screens^^?
second question: is values-normal neccessary, isnt "values" folder == values-normal?
third question: what happens when I declare dimens.xml for small, normal, and large and the device is a XLARGE device will it use dimens.xml from values? or valuse-normal? or the next smaller one values-large?
thank you
I want to know if there is a formula to set the right sizes depending on small, large, xlarge instead of setting sp size by testing it on different screens
Not really. Many apps do not change their font size at all based on screen size, just as most Web apps do not change their font size based on browser window size. Of course, you are certainly welcome to specify different <dimen> resources for different screen sizes, including dimensions for use with text. And there's nothing stopping you from using an algorithm like the others suggest; just understand that there's no real reason to use that algorithm. To put it another way, a graphic designer should be telling you how big to make the text, not a calculator.
Moreover, the -small, -normal, etc. buckets are not used as much anymore, in favor of the more flexible -wNNNdp, -hNNNdp, and -swNNNdp buckets.
isnt "values" folder == values-normal?
No.
Suppose you have res/values-small/, res/values/, res/values-large/, and res/values-xlarge/. Further suppose that each resource set defines a text_size dimension resource, and you use that in in layouts (e.g., #dimen/text_size).
A -normal device will then pull from res/values-small/, as -small is for small screens or larger. Your res/values/ version of the resource will never be used. Hence, the typical pattern would be not have res/values-small/, putting your -small resources in res/values/, and overriding that default value in res/values-normal/, res/values-large/, and res/values-xlarge/.
what happens when I declare dimens.xml for small, normal, and large and the device is a XLARGE device will it use dimens.xml from values? or valuse-normal? or the next smaller one values-large?
It should pull from res/values-large/, as that is the closest match among the qualifying resource sets.
This is the common problem in majority of Android projects to support varied screen sizes.
In short, you can make use of scalable DP and scalable Font approach.
Android project structure inherently allows specifying different font size (SP) and margin values (DP) by defining them in dimens.xml files for supported screen sizes. But the problem that still remain is - what values to be used ? UX designers normally provide style guides for only one set (e.g. 360x640 DP screen size) and don't provide for all other supported screen sizes. So the problem to use right vlaues for other supported screen sizes still remain unanswered.
One good solution (per my understading) is to use readymade scalable dictionary of dimens.xml files, something similar to the dictionary of files provided by this library. After adding these xml files to project, you just need to use the keys in your layouts, then Android automatically uses font/margin value from respective directory. Please refer here for visual difference - with and without this approach.
I use the ratio 0.75 : 1 : 1.5 : 2 same as for DPIs. It works fine.

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.

Android Text Scaling on different resolutions same density

I have 2 devices, a 1024x600 7" tablet hdpi running Gingerbread and a hub attached to a touchscreen which is 1920x1008 22" in size, hdpi running ICS. The Android OS seems to consider both as "large" (240dp).
So, they have the same actual density (240dpi), same generalized density (hdpi), same generalized size (large) but different actual size (7" vs 22")
The text and spacing dimensions that I specify for my layout work great on the 22", but then on the 7" they look enormous and dont fit on the screen.
I've tried using dp and sp, no difference as I think the problem is that Android sees these things as the same size / density. Does anyone have any recommendations on how I can be able to scale sizes appropriately?
This program wil also eventually need to be supported on a 4.5" handheld as well.
Thanks in advance.
Sorry, my previous answer was completely wrong = )
Ideally, you should be able to design for the 7" tablet and have your layout scale up to the TV. But if that doesn't work you should be able to use something like layout-sw1008dp. The "sw" prefix allows you to specify the minimum dimension of the smallest side of the screen - so in the case of a TV, the height.
I am also facing such problem in my application. But i found a good solution for this.
I have only one layout for tablet and directory name is layout-sw600dp.
Now, when part came to height and width problems, I have created several different values directory in which i place dimensions and font size and other stubs. So there will be no constant value in layout of tablet screen.
androd:layout_width:"60dp" // i drop this scenario
androd:layout_width:"#dimen/tab_width" // i used this scenario
and your values directory name will be like
values-xlarge
values-large
All the values will be fetched from your values directory. It will not create different layout, but one layout can be used multiple times.
See my stack answer which may help you.

Density-specific layouts vs. size-specific layouts in Android

For quite a long time, I have been declaring resource folders for 4 different densities:
drawable-ldpi
drawable-mdpi
drawable-hdpi
drawable-xhdpi
In the layout's XML, I have been using fixed widths (while still density-independent) such as 128dp for those graphics.
However, when more and more large-screen phones, and especially tablets, were introduced, that approach did not work anymore. Although you provide density-independent resources this way, the layout will not look good on large screens.
This is why I think I need to add Dimension resources that depend on the screen size, for use in the XML layouts, e.g.:
values
values-w600dp
values-w720dp
values-w1024dp
But does that mean that I should drop supporting those 4 density containers? Or do I need to provide 16 resource folders, i.e. one for every combination of density and size?
I can't find any good help in the Android documentation as to this topic.
drawables and layouts are different. To answer your question, should you stop support those densities. Yes, but you should still support xdpi and hdpi. Romain Guy recently said that modern devices like the Nexus 7 (at a tvpi) can scale the assets properly enough that mdpi isn't really needed. And nobody uses ldpi anymore. Last I looked is was less than 2% of the market.
About layouts. A Nexus 7 (1280x800 tvdpi) would use something from the values-w1024dp but still get assets from the drawable-hdpi folder. Those two aren't mutually exclusive. Something like a S3 would also pull from the values-w1024dp but use drawable-xdpi. You only need to provide an alternative layout if your use-case calls for it.
So do you need 16 different things? No. You do need xdpi & hdpi (if not mdpi). You may want to include alternative layouts for different sizes. You can be as specific as you want or as generic. Unless you're doing a hybrid app for both phone & tablet (7 & 10 in) you probably don't need a lot of xxxx-sizexxx folders.
In the layout's XML, I have been using fixed widths (while still density-independent) such as 128dp for those graphics.
This is probably a source of your issues. Your layouts should be as fluid as possible using wrap_content and match_parent. Fixed sizes should be reserved for padding around the sides and image where you know the size ahead of time. If you do this, your layout should look decent at any size from a small 320 x 200 to a GTV size.
1) Regarding dimensions in your layouts (values/dimens.xml):
values values-w600dp values-w720dp values-w1024dp
But does that mean that I should drop supporting those 4 density
containers? Or do I need to provide 16 resource folders, i.e. one for
every combination of density and size?
No, you don't need to provide different dimensions per dpi bucket (hdpi/xhdpi), because the dimensions are already being scaled up or down based on the device (if you're using dp instead of px). So for dimensions, you only need to provide values for devices with different sizes (hence the name, values-smallest possible width-600-dp). Because you don't want 16dp padding on a phone AND 16dp on a 10" tablet as well. You'd want 64dp instead. And no, it doesn't matter what density the device has. It still needs to have the same padding on the respective device width. So for dimens, you only need to think about the device's actual physical dimensions.
2) Regarding drawables scaling for different resolutions (drawables/xdpi):
The system scales them appropriately for the device. You don't need to worry about this. Also, you don't need to add any other buckets here. Just use mdpi/hdpi/xhdpi and maybe xxhdpi because many new devices are going to use the new density in the future.
Conclusion: there are 2 different UI building components that vary according to 2 different rules: drawables based on screen density and dimensions based on screen size. Do not mistake one for the other and think you need tens of buckets in the values folder, because that's not only wrong, it's just mind boggling.

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