CODEWITHSUNDEEP
androidwidthpixelunits-of-measurementdensity-independent-pixel
user256239
user256239

Reputation: 18027

Does setWidth(int pixels) use dip or px?

Does setWidth(int pixels) use device independent pixel or physical pixel as unit? For example, does setWidth(100) set the a view's width to 100 dips or 100 pxs?

Thanks.

Upvotes: 101

Views: 84479

Answers (7)

Kasun Thilina
Kasun Thilina

Reputation: 1681

It uses pixels. here's a Kotlin extension function to convert pixels to dp

fun Context.pxToDp(value: Float):Int{
    val r: Resources = resources
    return TypedValue.applyDimension(
        TypedValue.COMPLEX_UNIT_DIP, value, r.displayMetrics
    ).roundToInt()
}

Upvotes: 1

Abhishek Garg
Abhishek Garg

Reputation: 3242

Based on above answers which works fine to me, i generate some helper methods, just add them in your utils to use them in whole project.

   // value in DP
   public static int getValueInDP(Context context, int value){
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, value, context.getResources().getDisplayMetrics());
    }

    public static float getValueInDP(Context context, float value){
        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, value, context.getResources().getDisplayMetrics());
    }

    // value in PX
    public static int getValueInPixel(Context context, int value){
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, value, context.getResources().getDisplayMetrics());
    }

    public static float getValueInPixel(Context context, float value){
        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, value, context.getResources().getDisplayMetrics());
    }

Upvotes: 2

Dan Lew
Dan Lew

Reputation: 87440

It uses pixels, but I'm sure you're wondering how to use dips instead. The answer is in TypedValue.applyDimension(). Here's an example of how to convert dips to px in code:

// Converts 14 dip into its equivalent px
Resources r = getResources();
int px = Math.round(TypedValue.applyDimension(
    TypedValue.COMPLEX_UNIT_DIP, 14,r.getDisplayMetrics()));

Upvotes: 227

pomber
pomber

Reputation: 23980

float dps = 100;
float pxs = dps * getResources().getDisplayMetrics().density;

Source (@Romain Guy)

Upvotes: 6

Nidhin
Nidhin

Reputation: 1838

Method setWidth(100), set 100 px as width(not in dp).So you may face width varying problems on different android phones.So use measurement in dp instead of pixels.Use the below code to get measurement in dp of sample width=300px and height=400px.

int width = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 300, getResources().getDisplayMetrics());

int Height = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 400, getResources().getDisplayMetrics());

Upvotes: 10

SDJMcHattie
SDJMcHattie

Reputation: 1699

The correct way to obtain a constant number of DIPs in code is to create a resources XML file containing dp values a bit like:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <dimen name="image_width">100dp</dimen>
    <dimen name="image_height">75dp</dimen>
</resources>

Then refer to the resource in your code like so:

float width = getResources().getDimension(R.dimen.image_width));
float height = getResources().getDimension(R.dimen.image_height));

The float you have returned will be scaled accordingly for the pixel density of the device and so you don't need to keep replicating a conversion method throughout your application.

Upvotes: 29

Josnidhin
Josnidhin

Reputation: 12504

Pixels of course, the method is asking for pixels as parameter.

Upvotes: 0

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