*Edit. Sorry, first sentence after "1." should read: IT seems that the fact that 66 pixels shows on my Galaxy as 8mm, when it should be 10mm (based on provided dpi), ISN'T DUE to a false dpi returned from DisplayMetrics.
On May 12, 12:29 pm, Ab <abe.oppenh...@gmail.com> wrote: > Diane, > > Thank you for your reply. I have 2 quick follow up questions: > > 1. I seems that the fact that 66 pixels shows on my Galaxy as 8mm, > when it should be 10mm (based on provided dpi), is do to a false dpi > returned from DisplayMetrics. The Galaxy screen measures 3.5 inches > wide, and the specs that its resolution is 1024 x 600. So, 600/3.5 = > 171.48. Which is close enough to 168.89 that it doesn't explain the > 2mm difference in button size. Am I incorrect in my thought that > there is something else causing this discrepancy? > > 2. What is your recommendation to display a relatively consistently > sized button? Possibly have different layouts for extra large > devices, set the button dimensions to 50dip on regular devices, and > 75dip on extra large devices? > > On May 12, 12:10 pm, Dianne Hackborn <hack...@android.com> wrote: > > > > > > > > > Sorry as things are today you basically can't do this because many devices > > are not reporting the correct true screen dpi. If they did, the correct way > > to do this would be to use a physical unit for your dimensions --- that is > > "10mm" if you want 10mm. But as I say, there are many devices out there > > that are not configured with the correct physical screen dpi do these units > > are at this point not usable. > > > On Thu, May 12, 2011 at 8:50 AM, Ab <abe.oppenh...@gmail.com> wrote: > > > I want to put a toolbar in my application. The toolbar will use > > > ImageViews as application buttons. I would like the ImageViews to be > > > the exact same size regardless device; by "same size" I mean that, > > > when rendered to the screen, if I measure them with a ruler, the > > > dimensions will be the same. I would like this size to be ~10mm (the > > > width of my index finger). > > > > I have been completely unsuccessful in accomplishing this. > > > > I am testing on a MDPI, large screen Acer Iconia Tab and a HDPI medium > > > screen Samsung Galaxy Tab. If I set layout_width="50dip" and > > > layout_height="50dip", the buttons render as ~10mm on the Samsung, and > > > ~8mm on the Acer. If I set the buttons as layout_width="12mm" and > > > layout_height="12mm", they render as 12mm on the Acer and ~9mm on the > > > Galaxy (confusing that 50dip renders bigger on the Galaxy than the > > > Acer, but 12 mm renders smaller on the Galaxy than on the Acer). > > > > If I place a 32pix x 32pix icon in my drawable-mdpi folder (and no > > > equivalent in the drawable-hdpi folder), and set > > > layout_width="wrap_content" and layout_height="wrap_content"; the > > > results are similar to if set to 50dip, the Samsung is about 10mm, the > > > Acer about 8mm. If I add a 48pix x 48pix icon to my drawable-hdpi > > > folder, there is no change; presumably because the Acer still uses the > > > mdpi icon and the Samsung uses the bigger one, but scales it down by > > > 50% because it knows its hdpi (if am confident that this surprising > > > scaling occurs because if I move the 48pix icon to the mdpi folder, > > > and have nothing in the hdpi folder, the icon shows very large on the > > > Samsung). > > > > I then attempted to calculate the number of pixels necessary for 10mm > > > based on the values of xdpi and ydpi from DisplayMetrics: 10 mm in > > > pixels = xdpi * 10 / 25.4. On the galaxy, this is 168.89 * 10 / 25.4 > > > = 66. However, when I set the layout_width to 66, the button measured > > > ~8mm wide. But, at 168.89 dpi, the dots per mm should be 6.64 > > > (168.89/25.4), so 66pixels should be approximately 10mm. So, how > > > could it measure 8mm? The Galaxy must be scaling down the layout > > > parameters somehow. Is there any way to retrieve how much they are > > > scaling down by, so that I can adjust for it? > > > > I am confused and could really use advice. How do I make my button > > > fingertip sized regardless of dpi and screen size? > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "Android Developers" group. > > > To post to this group, send email to android-developers@googlegroups.com > > > To unsubscribe from this group, send email to > > > android-developers+unsubscr...@googlegroups.com > > > For more options, visit this group at > > >http://groups.google.com/group/android-developers?hl=en > > > -- > > Dianne Hackborn > > Android framework engineer > > hack...@android.com > > > Note: please don't send private questions to me, as I don't have time to > > provide private support, and so won't reply to such e-mails. All such > > questions should be posted on public forums, where I and others can see and > > answer them. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
