Simple question. How does android work with drawable folders if any folders are empty ? Lets say I have images only in folder "drawable-hdpi". When I start application on emulator with higher dpi "drawable-xhdpi" it load images from "drawable-hdpi" (of course in bad size). Also when I start application on device with lower dpi "drawable-mdpi" it load images from "drawable-hdpi".
My question is - does it mean if doesn't exist images for current device dpi, android system takes images from other folder it is not empty ? Till today I thought, when images in current dpi are not present, application doesnt work.
It takes the near dpi, and scales the image up or down by the dpi difference between the target dpi and the folder dpi. If in the "drawale" folder (no dpi), no scaling takes place.
http://developer.android.com/training/basics/supporting-devices/screens.html
Note: Low-density (ldpi) resources aren’t always necessary. When you provide hdpi assets, the system scales them down by one half to properly fit ldpi screens.
It works. It first check in the current dpi folder for the resources. If not found then it use other available resources
Related
There are multiple groups of screen densities of Android phones (ldpi, mdpi, hdpi and so on).
I had a folder "drawable" with picture size 1920 x 930 pixels which is for xxxhdpi, I guess.
I want to arrange pictures for all screen densities from xxxhdpi to hdpi. So, I should rename my existing folder: "drawable" -> "drawable-xxxhdpi". Then, I should create 3 additional folders for others. Do I understand it right?
How would actually the program choose proper folder?
For example, I also have smaller pictures now. Should I also resize them? If I don't duplicate them in new folder, will the program crash?
Will the program crash on phones with, for example, hdpi if I don't create a folder for hdpi?
Couldn't get how it works, would be grateful for an explanation.
First of all be sure that you are in the "Project" view because you will not see all the folders if you are in "Android" view. Then instead of renaming drawable folder create the others and keep drawable for some files that doesn't need to resize (for example defining a background). Folders should be:
drawable-hdpi
drawable-mdpi
drawable-xhdpi
drawable-xxhdpi
drawable-xxxhdpi
Selection between them will be done automatically according to the screen of the device you are installing the app. If screen is xxxhdpi and you don't have a file for that resolution the app will take the smaller and so on. Obviously this will not be a great UI performance but you should not have problems with crashes.
There are many online App icons generators in the web so you can take a big icon and put it there so you get the icons for all sizes
I want my app to be as lightweight as possible. So i put all my images inside drawable-xxhdpi and let the Android OS to resize them.
However for the 10 inch mdpi tablets i want to use hdpi images. I know, that it is possible to create drawable-sw720dp-mdpi and put there hdpi images. But this will increase apk size, which is not the option. So, is it possible to make such a change without making drawable copies?
create a drawable folder in res folder of project and paste all images there...it will resize all images according to device size
Let's say you have a set of resources called icon_text.png; and you place one in the drawable-xxhdpi folder and another one in drawable-hdpi folder. That is your scenario, right? Any device that is mdpi (it doesn't matter its size) will pull resources (if available) from the hdpi folder. The system will pick the closest match, and mdpi is closer to hdpi than to xxhdpi.
I have one image that is in all folder except drawable-ldpi folder. Then if i will run my project in ldpi devices then from which folder it will try to find that image? or my app will simply get crash? I am not having this image in my drawable folder,too.
Test case i performed using mdpi device --
Placed image in drawable-xxxhdpi folder only, worked fine.
Placed image in drawable-ldpi folder only, worked fine.
Came to conclusion it perform both scale up and scale down
Regards
It is not required to have images for all the densities, only one is enough. The system will scale it up/down when needed. So the best approach is to have images for the highest density supported (xhdpi or xxhdpi).
It will scale but you might run into problems when a phone with a ldpi tries to load xhdpi or xxhdpi images.
Google's recommended that it is useful when you are creating different images for each resolution and not just resizing it.
And also in present when Eclipse creates launcher icons, it only creates them for mdpi, hdpi, xhdpi, and xxhdpi. Based on that creating ldpi icon is not necessary and that mdpi will be scaled down automatically.
In your case it will try to find image in mdpi folder.
Dont worry, FYI ldpi device is closed before some months and now no any new ldpi device will come in market. But if any user will install your app in ldpi device then it will find closest image as compare to ldpi and will show it.
But that image must be in any of the folder.
If the user is using a device with a low density screen, and a ldpi resource is not found, the resource with the closest density is used and scaled down.
By the way, I wouldn't even bother with mdpi, let alone ldpi.
Your app will not crash until you have the named image in at least one of drawable folders. System will show the closest density image.
So I am learning how to program android apps, and have just barely started. Looking through the developers page I followed a tutorial to add a search bar in the menu. However, it asked to put an image in the res/drawable folder. Upon seeing all these options I just placed it in the first folder, drawable-hdpi, and the app worked. I was just wondering if anyone could explain what the difference in each folder is, and if the icon is placed in the correct folder (even if the app still runs). Whats the most optimal solution?
http://imgur.com/t2r6fS2
Android Tutorial: http://developer.android.com/training/basics/actionbar/adding-buttons.html
Edit: Wow! Thanks for all the responses. You guys are fantastic. I'll mark an answer as soon as it will let me.
The folder names need to be :
/drawable-ldpi For low density screens
/drawable-mdpi For medium density screens
/drawable-hdpi For high resolution screens
/drawable-xhdpi For extra high resolution screens
/drawable should be reserved for assets that you don't either care which device or for xml drawable assets
Then on top of that you can provide different resources based on configuration by using config qualifiers, you can read all about it here http://developer.android.com/guide/topics/resources/providing-resources.html
for instance, you can have high resolution assets for landscape with a folder
/drawable-land-hdpi
Hope that helps
Android devices comes with different screen sizes and different resolutions. To support your application's images with different device's screen size you need to put your image in their respective folders. Following are the screen size supported by Android devices
LDPI ( deprecated )
MDPI : 48x48 Pixel
HDPI : 72x72 Pixel
XHDPI : 96x96 Pixel
XXHDPI : 144x144 Pixel
TVDPI
You can create such sizes images by helping of this site Android Asset Studio
These different folders are for different screen sizes. Here is a link to the android notes, http://developer.android.com/guide/practices/screens_support.html .
In short the ldpi is for low resolution screens, mdpi for medium resolution and so on.
Android different Screen size with different resolutions:
- drawable-ldpi (it need resolution or ppi is ~120)
- drawable-mdpi (it need resolution or ppi is ~160)
- drawable-hdpi (it need resolution or ppi is ~240)
- drawable-xhdpi (it need resolution or ppi is ~320)
If you create big images but less ppi then it will go in this manner. So be aware about this.
this may help you ....
check out the answer in below link
What is the difference between "px", "dp", "dip" and "sp" on Android?
I've only placed mdpi and hdpi images inside each folder, but when I run my app on an ldpi device, it won't pick the images from the mdpi folder, but from the hdpi folder. Why is that? Any ideas on what i'm doing wrong?
P.S. If I place images specifically for the ldpi device inside the ldpi folder, it uses those, but if i delete them, it uses the hdpi ones.
Help.
That is the default behavior of Android. LDPI is basically half of HDPI and ANdroid basically picks images from HDPI, scales it to half the size and uses it.
Read the last note on this link
http://developer.android.com/training/basics/supporting-devices/screens.html
Android checks for the particular density.If the reference of the image is given than it checks for the availability of it and sets the image according to the density but if its not available than it will take the default image which resides in Hdpi folder which is the default behavior of Android.
Take an example of the default image of Android that is ic_launcher,if its present in a single folder,android is going to set it because it first find its availability than density.