Add padding on view programmatically

I am developing Android v2.2 app.

I have a Fragment. In the onCreateView(...) callback of my fragment class, I inflate an layout to the fragment like below:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
	View view = inflater.inflate(R.layout.login, null);
		
	return view;
}

The above inflated layout file is (login.xml):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Username" />

    
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Username" />

</LinearLayout>

I would like to set a paddingTop to the above <LinearLayout> element , and I want to do it in the Java code instead of do it in xml.

How to set paddingTop to <LinearLayout> in my fragment Java class code ??

view.setPadding(0,padding,0,0);

This will set the top padding to padding-pixels.

If you want to set it in dp instead, you can do a conversion:

float scale = getResources().getDisplayMetrics().density;
int dpAsPixels = (int) (sizeInDp*scale + 0.5f);

To answer your second question:

view.setPadding(0,padding,0,0);

like SpK and Jave suggested, will set the padding in pixels. You can set it in dp by calculating the dp value as follows:

int paddingDp = 25;
float density = context.getResources().getDisplayMetrics().density
int paddingPixel = (int)(paddingDp * density);
view.setPadding(0,paddingPixel,0,0);

Hope that helps!

If you store the padding in resource files, you can simply call

int padding = getResources().getDimensionPixelOffset(R.dimen.padding);

It does the conversion for you.

Using Kotlin and the android-ktx library, you can simply do

view.updatePadding(top = 42)

See docs here

You can set padding to your view by pro grammatically throughout below code -

view.setPadding(0,1,20,3);

And, also there are different type of padding available -

Padding

PaddingBottom

PaddingLeft

PaddingRight

PaddingTop

These, links will refer Android Developers site. Hope this helps you lot.

Using TypedValue is a much cleaner way of converting to pixels compared to manually calculating:

float paddingDp = 10f;
// Convert to pixels
int paddingPx = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, paddingDp, context.getResources().getDisplayMetrics());
view.setPadding(paddingPx, paddingPx, paddingPx, paddingPx);

Essentially, TypedValue.applyDimension converts the desired padding into pixels appropriately depending on the current device's display properties.

For more info see: TypedValue.applyDimension Docs.

Kotlin; extension function

fun Float.px(m: DisplayMetrics!): Int
    get() = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, this, m).toInt()

...
val pad = 10.0f.px

use below method for setting padding dynamically

setPadding(int left, int top, int right, int bottom)

Example :

view.setPadding(2,2,2,2);

Write Following Code to set padding, it may help you.

TextView ApplyPaddingTextView = (TextView)findViewById(R.id.textView1);
final LayoutParams layoutparams = (RelativeLayout.LayoutParams) ApplyPaddingTextView.getLayoutParams();

layoutparams.setPadding(50,50,50,50);

ApplyPaddingTextView.setLayoutParams(layoutparams);

Use LinearLayout.LayoutParams or RelativeLayout.LayoutParams according to parent layout of the child view

Context contect=MainActivity.this;
TextView tview=new TextView(context);
tview.setPaddingRelative(10,0,0,0);

This image talks for itself, here you can see in which section the padding is applied

Step 1: First, take the padding value as an integer.

int padding = getResources().getDimensionPixelOffset(R.dimen.padding);

or int padding = 16; [Use any method]

Step 2: Then assign the padding value to the layout.

layout.setPadding(padding, padding, padding, padding);

> layout.setPadding(padding_left, padding_top, padding_right, padding_bottom);

All side different padding can be assigned. layout.setPadding(16, 10, 8, 12);

For removing padding (No Padding) set padding values as 0,

layout.setPadding(0, 0, 0, 0);

The best way is not to write your own funcion.

Let me explain the motivaion - please lookup the official Android source code.

In TypedValue.java we have:

    public static int complexToDimensionPixelSize(int data,
            DisplayMetrics metrics)
    {
        final float value = complexToFloat(data);
        final float f = applyDimension(
                (data>>COMPLEX_UNIT_SHIFT)&COMPLEX_UNIT_MASK,
                value,
                metrics);
        final int res = (int) ((f >= 0) ? (f + 0.5f) : (f - 0.5f));
        if (res != 0) return res;
        if (value == 0) return 0;
        if (value > 0) return 1;
        return -1;
    }

and:

    public static float applyDimension(int unit, float value,
                                       DisplayMetrics metrics)
    {
        switch (unit) {
        case COMPLEX_UNIT_PX:
            return value;
        case COMPLEX_UNIT_DIP:
            return value * metrics.density;
        case COMPLEX_UNIT_SP:
            return value * metrics.scaledDensity;
        case COMPLEX_UNIT_PT:
            return value * metrics.xdpi * (1.0f/72);
        case COMPLEX_UNIT_IN:
            return value * metrics.xdpi;
        case COMPLEX_UNIT_MM:
            return value * metrics.xdpi * (1.0f/25.4f);
        }
        return 0;
    }

As you can see, DisplayMetrics metrics can differ, which means it would yield different values across Android-OS powered devices.

I strongly recommend putting your dp padding in dimen xml file and use the official Android conversions to have consistent behaviour with regard to how Android framework works.

Using Jave's solution.

public static int getResourceDimension(Context context, String name, String defType, String defPackage) {
        int sizeInDp = 0;
        int resourceId = context.getResources().getIdentifier(name, defType, defPackage);
        if (resourceId > 0) {
            sizeInDp = context.getResources().getDimensionPixelSize(resourceId);
        }
        float scale = context.getResources().getDisplayMetrics().density;
        int dpAsPixels = (int) (sizeInDp*scale + 0.5f);

        return dpAsPixels;
    }

then call when needed.

int statusBarHeight = getResourceDimension(getContext(), "status_bar_height",
                "dimen", "android");
        statusBarHeight = (int) (statusBarHeight + getResources().getDimension(R.dimen.fragment_vertical_padding));
        view.setPadding(0, statusBarHeight, 0, 0);

While padding programmatically, convert to density related values by converting pixel to Dp.

    binding.appBarMain.toolbar.setOnApplyWindowInsetsListener { _, insets ->
        val statusBarSize: Int =
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.R) {
                insets.getInsets(WindowInsets.Type.systemBars()).top
            } else {
                insets.systemWindowInsetTop
            }
        binding.appBarMain.appBarLayout.setPadding(0, statusBarSize, 0, 0)
        return@setOnApplyWindowInsetsListener insets
    }