so, I've created a project where I use an image in the action bar, but android only scaled it to the folders -mdpi, -hdpi, -xhdpi, -xxhdpi, why isn't it scaling to the low density folder ?
Btw, what if I want to use an image that is going to be the same size no matter what screen resolution is being used, should I create a folder just for this images ?
I believe they removed ldpi because there are so few ldpi devices out and they can make use of mdpi anyway.
Having an image the same size on any resolution is what these folders are for!! If you put an image in the static drawable folder its size will be different depending on what device you use because the pixel density is the same in the picture but it has to be scaled differently on screen to adjust for the larger or smaller density of the screen
go read the introductory android tutorials to learn more about screen density
Related
I realise that Android will try it's best if it does not find an icon in the required folder but I see someplaces they suggest all of the above and in others they don't include drawable ?
So should I populate drawable as well if all the others are filled with my tab icon images?
If you use a VectorDrawable, you don't need to add a Resource for every density (mdpi, xhdpi etc). VectorDrawable is supported since API 21 (Lollipop) or with Support Library (or AndroidX).
For simple types of images (usually icons), you can avoid creating separate images for each density by using vector graphics. Because vector graphics define the illustration with geometric line paths instead of pixels, they can be drawn at any size without scaling artifacts.
For images (PNG) on the other hand, you must add proper icons for every density because Android will try to scale the images (so they can proportionally occupy same area in all devices). When scaling, the image may become blurred reducing the quality of your UI.
To provide good graphical qualities on devices with different pixel densities, you should provide multiple versions of each bitmap in your app—one for each density bucket, at a corresponding resolution. Otherwise, Android must scale your bitmap so it occupies the same visible space on each screen, resulting in scaling artifacts such as blurring.
You can read more HERE and HERE
EDIT
Maybe, you don't need to duplicate ALL icons. A lot of factors can lead to different experiences such as using wrap_content or a specific dimension to control the icon size or even using a different scaleType in your ImageView. So, maybe, you can start by adding icons for xhdpi or xxhdpi folders only and check your screen in different screen (small display, large displays, low-resolution displays, high-resolution displays etc). Then, you can "duplicate" only the necessary icons... But if your project or APK size is relatively small, don't mind to duplicate the icons.
There's even some online tools to generate the assets for every density from a single PNG such Android Asset Studio website..
If you are adding all resolution drawable icon like :
drawable-mdpi
drawable-hdpi
drawable-xhdpi
drawable-xxhdpi
drawable-xxxdpi
then you need not to add any extra icons on drawable folder
because all the device resolution covers under the above drawable folders
I can't wrap my head around the folders mdpi, hdpi, xhdpi and xxhdpi, are they meant for every kind of images or only for icons? The sizes in which my images are stored in there are really small, as you can see in this cheatsheet (click to enlarge):
xhdpi is 96px. In my app 96px looks really blurry (click to enlarge):
So how should I store my image then?
the folders mdpi hdpi xhdpi and xxhdpi, are they meant for every kind of images or only for icons?
Most bitmap drawable resources should get density-specific versions, at least for a few densities.
as you can see in this cheatsheet xhdpi is 96px
I see nothing in there saying that every image must be 96px for xhdpi. The standard action bar height and tab bar heights for xhdpi are 96px. That's it.
In my app 96px looks really blurry.
That image should have a higher resolution, as you are using it in a UI element that is far larger than the action bar or a tab bar.
So how should I store my image then?
Step #1: Determine your desired size for the image, in inches.
Step #2: Determine the resolution for the image in dp, by multiplying the size in inches from Step #1 by 160.
Step #3: Choose what densities you want to create specific artwork for. You might use the "Screen Sizes and Densities" section of the Android device dashboard to give you some ideas.
Step #4: Determine the density-specific resolution for the image in px, for the densities from Step #3, by multiplying the dp value from Step #2 by the size factor shown in the upper-left infographic of that cheatsheet.
Step #5: Create drawable directories for the densities from Step #3 and create your artwork in those, sized based on the values from Step #4.
Drawable folders are meant for all kind of images.
hdpi,mdpi,xhdpi,xxhdpi.xxhdpi are generally used to cover each and every device available in the market place.
nodpi folder is used to store images that can be used in any resolutions
For adding app icon try using the mipmap folders with all these above qualifiers for different size.
placing correct size images in correct folder will definitely work.
This question already has answers here:
Android screen size HDPI, LDPI, MDPI [duplicate]
(4 answers)
Closed 9 years ago.
I have to manage different screen sizes and different densities in my Android app.
I am not getting directory structure properly.
What I understand so far is there are four types of screen sizes:
small
normal
large
xlarge
and different densities as well:
ldpi
mdpi
hdpi
xhdpi
Now each device size (small , normal , large and xlarge) shall map against each density. Because every size can have different density, right?
If yes, then we can say small screen have all the density i.e ( ldpi , mdpi , hdpi , xhdpi)
same for normal, large and xlarge.
The point is how I'll manage them in my drawable directories.
Will there be four folders for small screen size with different size (drawable-small-ldpi, drawable-small-mdpi, drawable-small-hdpi, drawable-small-xhdpi)?
And same for other screen sizes as well.
If not then how I'll manage all the image in ( drawable-ldpi , drawable-mdpi , drawable-hdpi , drawable-xhdpi) folder because different screen size I'll have different size of images. Then how can a small device with different density and large device with a different size be manageable in same density folder.
Please don't give me reference of any Android document as I read all that stuff.
If any one can't get my point, then please let me know. I'm very confused.
When I have started development in Android, I was confused about same issue.But now I have figured it out and I'm doing pretty well.
Anyways, You are absolutely right.you can provide different images by 4 folders for each.i.e.: drawable-small-ldpi, drawable-small-mdpi, drawable-small-hdpi, drawable-small-xhdpi
But it is just waste of your time.because you don't need to worry this much about it.Android can scale up/scale down according to the device configuration.so just provide extra images for those devices only if you don't get desired outputs for them.
As far as I know, supporting multiple devices, you have to consider few general criteria in your mind.
Density qualifiers: ldpi,mdpi,hdpi,xhdpi,etc are generally used when you want to provide different resolution images.
Size qualifiers + Orientation qualifiers: small,normal,large,xlarge,sw600dp,normal-land,normal-port,etc are generally used when you want to provide different layout designs.
i.e.: single pane layout,multi-pane layout,different elements in layouts according to different screen sizes.
For reference: Download the example app from here and try to understand how it is being supported for multiple screens.
I hope it will be helpful !!
Here are official docs for you to read about the subject: Supporting Multiple Screens then Supporting Different Screen Sizes
Put your all image in all different folder that is drawable-hdpi, drawable-ldpi, drawable-mdpi, drawable-xhdpi and drawable-xxhdpi. android will take care of it.
What I always do is just put all my images in one folder (usually xhdpi). The Android system will scale them for you so you don't have to worry about what to put in what folder.
Heres what Android says about this:
Provide different bitmap drawables for different screen densities
By
default, Android scales your bitmap drawables (.png, .jpg, and .gif
files) and Nine-Patch drawables (.9.png files) so that they render at
the appropriate physical size on each device. For example, if your
application provides bitmap drawables only for the baseline, medium
screen density (mdpi), then the system scales them up when on a
high-density screen, and scales them down when on a low-density
screen. This scaling can cause artifacts in the bitmaps. To ensure
your bitmaps look their best, you should include alternative versions
at different resolutions for different screen densities. The
configuration qualifiers you can use for density-specific resources
are ldpi (low), mdpi (medium), hdpi (high), and xhdpi (extra high).
For example, bitmaps for high-density screens should go in
drawable-hdpi/.
You can find the documentation here:
https://developer.android.com/guide/practices/screens_support.html
Hope this helps
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.
This might be a quick answer but I must not know what to search for as I can't find anyone talking about it! I have some png files in my drawables folder that are 88x88 pixels. I run my app and have a log print out the size of the images and it claims they are 176x176. What gives? Is something expanding my images before they go into the apk or is my phone really only half the resolution it claims?
BitmapFactory.decodeResource scales images in the Drawable folder according to the DPI of the device (it generates a higher resolution image for high resolution screens).
If you don't want the image to be scaled on decoding, place it in the folder Drawable-nodpi
From this guide:
"By default, Android scales your bitmap drawables (.png, .jpg, and .gif files) and Nine-Patch drawables (.9.png files) so that they render at the appropriate physical size on each device. For example, if your application provides bitmap drawables only for the baseline, medium screen density (mdpi), then the system scales them up when on a high-density screen, and scales them down when on a low-density screen. This scaling can cause artifacts in the bitmaps. To ensure your bitmaps look their best, you should include alternative versions at different resolutions for different screen densities."
So yes, your screen is probably xhdpi with density 2, so size of your image from unspecified drawables folder would be x2.