Develop Reference

Android menu icons scaling issue

I am using the onCreateOptionsMenu method to create a toolbar with icons in the MainActivity of my app. I am testing on different screen sizes and pixel densities with Android Studio's emulator. The documentation states, "Based on the density of the current screen, the system uses any density-specific resources from your app. If resources are not available in the correct density, the system loads the default resources and scales them up or down as needed." I've tried putting all of my vector icons the default drawable directory, but the system does not scale them for different screen sizes or densities at all. Nor does onCreateOptionsMenu scale the height of the toolbar or the title text. Is it supposed to? Because of this, I have also tried using different density buckets to address that problem. However, I'm running into an issue with greatly varying screen sizes sharing the same density bucket.
As an example, I'm testing on Pixel 3 (5.5" phone) and Pixel C (10" tablet). They are using the same density bucket (xhdpi) so if I use a 24dp x 24dp icon for the phone, then it looks way too small on the tablet. How do I work around this?

You can string together multiple qualifiers and create a custom bucket. So in addition to the drawable-xhdpi bucket I added a drawable-sw720dp-xhdpi bucket with larger icons for the 10" tablet. Now tablet displays the slightly larger icons while the phone still uses the standard bucket. The solution can be found in the comments of the selected answer in this post by #Theo. Unfortunately the documentation does not state that multiple qualifiers are supported.

Can we consider different drawable folders for tablets?

I have read many articles on "How to make a responsive app in android" everyone has suggested to use "multiple bitmaps" for each screen. I just want to know that
(1) Can we consider different drawable folders(drawable-hdpi,drawable-xdpi,drawable-xxdpi etc) in-supporting of tablets? or just these folders are designed for smart phones in order to get responsiveness?

In Android you have 2 type of qualifiers for image sizes:
Screen pixel density (dpi): Is the screen resolution. i.e. hdpi, xhdpi, tvdpi.
Screen size: Is the phisical size of the screen. i.e. small, normal, large, xlarge.
Some tablets have big screens, but with low dpi, there so they use images from mdpi or hdpi folder. But you can create special folders for tablets using the screen size qualifier to assign images. For example you can have:
res/
drawable-mdpi/
drawable-hdpi/
drawable-xhdpi/
drawable-xxhdpi/
drawable-xlarge-mdpi/
drawable-xlarge-hdpi/
drawable-xlarge-xhdpi/
drawable-xlarge-xxhdpi/
Your tablet will use the resources from drawable-xlarge- according to the dpi resolution.
To learn more about this refer to:
https://developer.android.com/guide/topics/resources/providing-resources.html

Responsive app is not just about using different Drawables. It contains Layouts and Dimensions too.
I advise you to read these two articles from google :
Designing for Multiple Screens
Supporting Multiple Screens

Android different screen size and different densities [duplicate]

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

What resolution of Drawables i should use for this display metrics?

I want to make my application to multiple screen support. so to achieve this i read the Android developers guildeline https://developer.android.com/guide/practices/screens_support.html and i have created the different drawable and layout folders to put different size of images.
I tested the application in different devices and it looks fine in those devices, while i found that in one of 7" tablet the images are too small. to confirm this i created simple project and put same name of images in different folder and found that this device uses ldpi drawables and in generally the size of ldpi drawable used to be 36x36 and that causes the issue, if i increase this drawable size then it will not compatible with other low-density devices.
Here is the Dispaly Metrics of the device in which i am having a problem.
{density=0.75, width=800, height=444, scaledDensity=0.75, xdpi=160.0, ydpi=160.42105}
How to deal with this problem ? if anyone have this issue before then please give me some advice. any idea and help will be appreciated.
Thanks & Regards

You can get more control over this:
Specify multiple different images for different screen resolutions and densities. To do so read supporting multiple screens. If you need even more precision in image scaling and quality you can use the fundamental size of screen attribute which is sw<N>dp - you can specify the smallest width of the screen where your image should be used. This is a qualifier name for a resource folder.
Some values you might use here for common screen sizes:
320, for devices with screen configurations such as:
240x320 ldpi (QVGA handset)
320x480 mdpi (handset)
480x800 hdpi (high density handset)
480, for screens such as 480x800 mdpi (tablet/handset).
600, for screens such as 600x1024 mdpi (7" tablet).
720, for screens such as 720x1280 mdpi (10" tablet).
Just specify your device width and put your edited image that fits the best in corresponding sw<N>dp folder in your case sw<444>dp.
You should also have a look at other qualifiers that make Android choosing image at runtime (screen density, Available width, Available height, Screen size or Screen aspect). By combining these qualifiers and testing carefully you will be sure that the user has the best experience on each device.
Shortly, put your image under drawable-sw<444>dp folder. (444-smaller screen metric)

how to get same sized launcher icons on different emulator skins…(android)

have a look at figure 2. in the link given below.. http://developer.android.com/guide/practices/screens_support.html..
there it is being mentioned that ,The platform provides density independence to applications by default.(launcher icons are displayed at the same physical sizes, although screen sizes, aspect ratios, and densities are different.)
and showed with 3 emulator screens namely WVGA high density (left), HVGA medium density (center), and QVGA low density (right)...
i have created these 3 avd's and tested but the launcher icons are different in different emulator..can any one knows why it so and how should i get same sized launcher icons on those emulators...

you should refer this:
http://developer.android.com/guide/practices/ui_guidelines/icon_design.html

you have 3 different drawable folder name drawable-mdpi/,drawable-hdpi, drawable-ldpi/ in your res/ folder and each of them have different size icon. if you want same size icon in each emulator then put the same size icon in all three folders.

Keep in mind that your monitor is of a fixed pixel density, while these various devices will have differing pixel density. That means the same number of pixels will be a different physical size on your monitor than it will be on an Android device (which will typically have much smaller pixels than your monitor).