Density in AVD manager

hackhack · Jun 19, 2011

When you make a new virtual device you have to enter a density - how important is that? And how do you figure out what it is?

Erel · Jun 20, 2011

The density is very important. Device resolution is made of Height, width and density (or scale).
See this page for common values. Note that the resolution should be 120 (scale = 0.75), 160 (scale = 1.0) , 240 (scale = 1.5) or 320 (scale = 2.0). Not any other value.

nfordbscndrd · Jun 20, 2011

It looks like Erel's page link didn't make it. He may have been referring to this page.

hackhack · Jun 20, 2011

Erel said:
The density is very important. Device resolution is made of Height, width and density (or scale).
See this page for common values. Note that the resolution should be 120 (scale = 0.75), 160 (scale = 1.0) , 240 (scale = 1.5) or 320 (scale = 2.0). Not any other value.

Did you forget to include a link to a page?

This is my biggest conceptual problem - I don't comprehend this at all.
I'm not sure what density means, to me it would be how closely the pixles are in the display and that would affect how it looks to a human, but not the actual drawing of the graphics?

My HTC Desire has 480×800 so to me that would be the only thing mattering - except you say density is important *sigh* :sign0085:

hackhack · Jun 20, 2011

nfordbscndrd said:
It looks like Erel's page link didn't make it. He may have been referring to this page.

Thanks, I'll see if i can grasp it

nfordbscndrd · Jun 20, 2011

hackhack said:
My HTC Desire has 480×800 so to me that would be the only thing mattering - except you say density is important *sigh*

Density is simply a function of device size and resolution. If you had a device that was 1"x1" and a resolution of 240x240, then its density would be 240 dpi (dots per inch), which is referred to as a density of 1.5 based on a "standard" density of 160 dpi.

If you created a layout on that device and then ran it on a device that was 1"x1" with a resolution of 160x160 (denisty of 1), then your 240x240 layout wouldn't fit on it (obviously) without some adjustment.

If you are writing an app just for your own use, then density doesn't matter (assuming you got the layout working on your device). What's written at the link that I posted is aimed at people developing apps for distribution to others, in which case you must make adjustments to have the app run on devices of all different sizes and resolution.

hackhack · Jun 20, 2011

nfordbscndrd said:
Density is simply a function of device size and resolution.

'does not compute' "a function?" :BangHead:

nfordbscndrd said:
If you had a device that was 1"x1" and a resolution of 240x240, then its density would be 240 dpi (dots per inch), which is referred to as a density of 1.5 based on a "standard" density of 160 dpi.

If you created a layout on that device and then ran it on a device that was 1"x1" with a resolution of 160x160 (denisty of 1), then your 240x240 layout wouldn't fit on it (obviously) without some adjustment.

Yeah, still don't get - different resolutions yield different amounts of space - sure. Get that. But I don't understand why we have to talk about density.

nfordbscndrd said:
If you are writing an app just for your own use, then density doesn't matter (assuming you got the layout working on your device). What's written at the link that I posted is aimed at people developing apps for distribution to others, in which case you must make adjustments to have the app run on devices of all different sizes and resolution.

Yeah, I have a phone and tablet - but it would be nice if it would generally work everywhere.
Perhaps I can just avoid the designer and calculate positions of buttons and everything and set it at run time.

klaus · Jun 20, 2011

You could also have a look at the Beginner's Guide.
Chapters:
5 Screen sizes and resolutions
8.6 Layout Variants.

Best regards.

hackhack · Jun 20, 2011

klaus said:
You could also have a look at the Beginner's Guide.
Chapters:
5 Screen sizes and resolutions
8.6 Layout Variants.

Best regards.

Yeah thanks, but it just repeats what I don't understand.

klaus · Jun 20, 2011

There are lots of explanations in the documentation we suggested you.
What exactly do you not understand ?

Best regards.

hackhack · Jun 20, 2011

klaus said:
There are lots of explanations in the documentation we suggested you.
What exactly do you not understand ?

Well, as i've said I don't understand why density matters (and how to calculate) - I only see how resolution matters.

agraham · Jun 20, 2011

You don't calculate the density, it is a property of the device and is determined by the device manufacturer. It sorts of corresponds to the dots per inch of the display. A font size that renders 12 pixels high on a density 1 device will render 18 pixels high on a density 1.5 device.

A layout will look the same on a 320 x 480 density 1 device as on a 480 x 720 density 1.5 device but the latter will look better because of the increased resolution.

klaus · Jun 20, 2011

The density is the number of pixels per inch.
You could have two different devices with the same resolution for example 640*960 pixels but with different physical sizes, a 3.5'' and a 7'' screen.
The device with the 3.5'' screen has a density of 320 pixels/inch
and the tablet with the 7'' screen has a density of 160 pixels/inch.
If you design one layout file for both you will get all views shown proportional to the physical screen size, a same button will have its physical width and hight double on the 7'' screen than on the 3.5'' screen.

In case above I would make two different layout files because the big physical difference. You can put much more views, with a same physical dimensions, on a 7'' tablet screen than on a 3.5'' screen with the higher density.
So one layout file with 640*960 density 320 for the 3.5'' screen
and a second one withe 640*960 density 160 for the 7'' screen.

Best regards.

hackhack · Jun 20, 2011

agraham said:
You don't calculate the density, it is a property of the device and is determined by the device manufacturer.

Thank you, brief and factual. Now i know that at least. Density can't be calculated, I have to look it.
So now i have to look up my phone to figure out what its density is.

agraham said:
It sorts of corresponds to the dots per inch of the display. A font size that renders 12 pixels high on a density 1 device will render 18 pixels high on a density 1.5 device.

So you took 12 and multiplied it by 1.5?

agraham said:
A layout will look the same on a 320 x 480 density 1 device as on a 480 x 720 density 1.5 device but the latter will look better because of the increased resolution.

So you multiply the base density value with width and height to get new values for other densitys?

hackhack · Jun 20, 2011

klaus said:
The density is the number of pixels per inch.
You could have two different devices with the same resolution for example 640*960 pixels but with different physical sizes, a 3.5'' and a 7'' screen.
The device with the 3.5'' screen has a density of 320 pixels/inch
and the tablet with the 7'' screen has a density of 160 pixels/inch.
If you design one layout file for both you will get all views shown proportional to the physical screen size, a same button will have its physical width and hight double on the 7'' screen than on the 3.5'' screen.

In case above I would make two different layout files because the big physical difference. You can put much more views, with a same physical dimensions, on a 7'' tablet screen than on a 3.5'' screen with the higher density.
So one layout file with 640*960 density 320 for the 3.5'' screen
and a second one withe 640*960 density 160 for the 7'' screen.

So if I would want to make a layout for 480×800 and for 1280x800 it would be better to make two different layout files?

klaus · Jun 20, 2011

So you took 12 and multiplied it by 1.5?

Yes.

So you multiply the base density value with width and height to get new values for other densitys?

Yes, but the OS will do it for you. The only difference could be different width/height ratios as explained in chapter '5 Screen sizes and resolutions' in the Beginner's Guide.

So if I would want to make a layout for 480×800 and for 1280x800 it would be better to make two different layout files?

Yes. For two reasons:
- the physical size difference
- the different width/height ratios

Best regards.

hackhack · Jun 21, 2011

klaus said:
Yes. For two reasons:
- the physical size difference
- the different width/height ratios

Is there a function to read the density when running on a given device?

nfordbscndrd · Jun 21, 2011

hackhack said:
Is there a function to read the density when running on a given device?

Dim dens As Float
dens = Density

hackhack · Jun 21, 2011

nfordbscndrd said:
Dim dens As Float
dens = Density

Holy heck there is more code rendering your message than the actual info
Thanks

hackhack · Jun 21, 2011

klaus said:
Yes.

Yes. For two reasons:
- the physical size difference
- the different width/height ratios

Ok, but lets say I don't care about the look, I make a button in the default emulator - what if I just want that button to scale and look huge on a tablet 1280x800 ? Adding it as a variant (scale 1, 160 dpi ) doesn't work, it just runs as a button in the upper left corner.

Density in AVD manager

Active Member

B4X founder

Well-Known Member

Active Member

Active Member

Well-Known Member

Active Member

Expert

Active Member

Expert

Active Member

Expert

Expert

Active Member

Active Member

Expert

Active Member

Well-Known Member

Active Member

Active Member

Similar Threads

Privacy & Transparency

Privacy & Transparency