How to set Layoutparams height/width in dp value?

Question

I tried setting height/width manually in button but it didn't work. Then implemented Layoutparams. But size shows small and not getting required dp value.

XML

 <Button
    android:id="@+id/itemButton"
    android:layout_width="88dp"
    android:layout_height="88dp"
    android:layout_marginRight="5dp"
    android:layout_marginBottom="5dp"
    android:background="#5e5789"
    android:gravity="bottom"
    android:padding="10dp"
    android:text=""
    android:textColor="#FFF"
    android:textSize="10sp" />

Constructor:

  public Item (int id, String name, String backgroundColor, String textColor, int width, int height){
    this.id = id;
    this.name = name;
    this.backgroundColor = backgroundColor;
    this.textColor = textColor;
    this.width = width;
    this.height = height;

}

Adapter:

@Override public void onBindViewHolder(final ViewHolder holder, int position) {
    final Item item = items.get(position);
    holder.itemView.setTag(item);
    holder.itemButton.setText(item.getName());
    holder.itemButton.setTextColor(Color.parseColor(item.getTextColor()));
    holder.itemButton.setBackgroundColor(Color.parseColor(item.getBackgroundColor()));
    ViewGroup.LayoutParams params = holder.itemButton.getLayoutParams();
    params.width = item.getWidth();
    params.height = item.getHeight();
    holder.itemButton.setLayoutParams(params);

}

Tellurium

Answer 1

When you specify values programmatically in the LayoutParams, those values are expected to be pixels.

To convert between pixels and dp you have to multiply by the current density factor. That value is in the DisplayMetrics, that you can access from a Context:

float pixels =  dp * context.getResources().getDisplayMetrics().density;

So in your case you could do:

.
.
float factor = holder.itemView.getContext().getResources().getDisplayMetrics().density;
params.width = (int)(item.getWidth() * factor);
params.height = (int)(item.getHeight() * factor);
.
.

Scriber

Your explanation is very clear and precise! Thanks man! It worked! – Tellurium

did not work for me... Calculations are off on different devices .. – Turtledove

Answer 2

Option 1: Use dimens.xml

view.updateLayoutParams {
    width = resources.getDimensionPixelSize(R.dimen.my_width)
    height = resources.getDimensionPixelSize(R.dimen.my_height)
}

Option 2: Dispense with dimens.xml

/** Converts dp to pixel. */
val Int.px get() = (this * Resources.getSystem().displayMetrics.density).toInt()

view.updateLayoutParams {
    width = 100.px
    height = 100.px
}

Ish

Answer 3

I believe you should be using a dp value defined in dimens along with getDimensionPixelSize. In a custom view, the Kotlin implementation would look like:

val layoutParams = layoutParams
val width = context.resources.getDimensionPixelSize(R.dimen.width_in_dp)
layoutParams.width = width

Daglock

Answer 4

  ViewGroup.LayoutParams params = ListView.getLayoutParams();
        params.height = (int) (50 * customsDebts.size() * (getResources().getDisplayMetrics().density));
        params.width = ViewGroup.LayoutParams.MATCH_PARENT;
        ListView.setLayoutParams(params);

Parkerparkhurst