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I'm trying to position a view in the center to make it look good by adding 130 (margin-top) programmatically, however, I'm not sure how to give other android devices such as tablets to look the same? adding 130 to the margin-top looks good on the normal android phone but will look different on a tablet. How will I able to make a logic to give a margin-top that will provide the same look on all devices? Some examples or tip would be great! I would love to hear from you! 

margin_top = 130 // How to make this look good on all devices? 

ViewGroup.MarginLayoutParams p = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
p.setMargins(0, margin_top, 0, 0);
v.requestLayout();
Phantômaxx
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Jennifer
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  • What kind of layout is the parent layout? –  Aug 06 '18 at 15:15
  • Why don't you use `FrameLayout`/`LinearLayout` with `gravity=center`. Or `RelativeLayout` with `alignSelf=parentBottom`, or Constraint layout? – Khemraj Sharma Aug 06 '18 at 15:16
  • A view that is an imageView is in a LinearLayout and that LinearLayout is inside a RelativeLayout. I want to know if it's possible to make a margin that can suit all devices. – Jennifer Aug 06 '18 at 15:17
  • I think you can use the `height` or `weight` of the device and a percent for creating the top margin. Something like top margin should be `0.15 * height`. – grrigore Aug 06 '18 at 15:18
  • So the center of the parent Linear Layout may not be the center of the Relative Layout? –  Aug 06 '18 at 15:21
  • @grrigore I feel that the thing you are thinking might be a key for me! Do you know any sample for it? – Jennifer Aug 06 '18 at 15:22
  • @mTak Yes, the center of the parent linearlayout is not the center this time! – Jennifer Aug 06 '18 at 15:22
  • @user3264924 check out [this](https://stackoverflow.com/questions/10172657/how-to-get-device-height-and-width-at-runtime) answer. – grrigore Aug 06 '18 at 15:23
  • @grrigore Thanks for the answer, but since I'm a noob with android I'm not sure what the 0.15 * device height meant. This time I felt that the 130 margin top looked good on the phone, then, in this case, how should I calculate? – Jennifer Aug 06 '18 at 15:25
  • @user3264924 This also means that if the parent linearlayout does not cover the necessary area around the center then this problem is unsolvable. –  Aug 06 '18 at 15:26
  • @user3264924 well, if you know the phone height you can calculate a ratio (phone weight/130) and then try it on a tablet or something (the ration * the device height). I don't know if this works, it was just something that came to my mind. **LE:** I also think everything has to be in pixels. If you can tell me the phone's height I might write an answer and you can try it. – grrigore Aug 06 '18 at 15:27

1 Answers1

1

My approach to this is the following:

1). Get the device height. Also check this answer.

DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
int height = displayMetrics.heightPixels;

2). Calculate the ratio.

You have set a top margin of 130dp I assume. Using pixplicity I managed to convert it to px.

dp to px

Your phone has a resolution height x weight in pixels. Let's define height as phoneHeight.

Here it becomes a little tricky for me too. As you can see 130dp has different pixel values for ldpi, mdpi, etc. I personally don't know which one you should use, you might try the mdpi one. (I'll try to research more and come back with an answer).

LE:

You can use this method to convert dp to pixels according to your phone. (See this answer).

public static float convertDpToPixel(float dp, Context context){
    Resources resources = context.getResources();
    DisplayMetrics metrics = resources.getDisplayMetrics();
    float px = dp * ((float)metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT);
    return px;
}

Use the returned px into the formula below. (let's call the returned px - convertedPx.

3). The formula for the top margin's value.

If we use the value of 130dp for mdpi from the table we get 130px. So the formula would be:

margin_top = (convertedPx / phoneHeight) * height

with phoneHeight the height of the phone you are currently testing on and height the height of the device using displayMetrics.

NOTICE: convertedPx will be a constant. You only have to run this method (convertDpToPixel) on your phone to find out how much 130dp mean in pixels.

grrigore
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  • If it's something unclear, please let me know. I'm quite tired and might not explain it very well. – grrigore Aug 06 '18 at 15:58
  • **NOTICE:** `convertedPx / phoneHeight` raport must be extracted while testing on your phone as a ratio and use this ratio as a constant. Moreover, you might have to convert margin_top to dp again (as `setMargins` method uses dp) , check [this](https://stackoverflow.com/questions/4605527/converting-pixels-to-dp/9563438#9563438) answer for a method. – grrigore Aug 06 '18 at 16:05
  • Thank you so much!!!! I will check it out! Yes, I will let you know if I find something unclear! – Jennifer Aug 06 '18 at 16:15
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    Thank you so much! Your solution was the best! Problem solved! – Jennifer Aug 09 '18 at 14:50
  • What is difference between phoneHeight and height? – Pir Shukarullah Shah Oct 24 '18 at 09:16
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    @PirShukarullahShah `phoneHeight` - the height of the phone you are currently testing on (let's say your phone is 120x350) -> `phoneHeight` is 120. `height` - the height of the device using `displayMetrics` (you get this value using the method described in **1).**) – grrigore Oct 24 '18 at 09:27
  • Sorry for this question but how to get phoneHeight? I am using displayMetrics as phoneHeight. – Pir Shukarullah Shah Oct 24 '18 at 09:39
  • @PirShukarullahShah Yes, use the method from the **1).** step and save `height` value (write it on a paper) this is `phoneHeight`. – grrigore Oct 24 '18 at 09:53
  • Hi, I know that this answer is really old, but I have one question, DisplayMetrics calculates the whole screen height (including the not usable part like the navigation bar). Wouldn't be better to make exactly the same but calculating the usable screen height using `configuration.screenHeightDp` and later converting it to px as `configuration.screenHeightDp` displays the usable screen height in dp units? And later using the converted px in `height` and also the ` phoneHeight` would be better to calculate it with configuration and later converting it to px also. Right? – sacacorchos Dec 27 '22 at 12:49