Android: How to Programmatically set the size of a Layout

Question

As part of an Android App I am building a button set. The buttons are part of a nested set of LinearLayouts. Using weight I have the set resizing itself automatically based on the size of the containing parent LinearLayout. The idea is, based on the pixel count and density of the screen, to set the size of the containing layout to a number of pixels; and have the button set resize itself based on that change.

The question then is: How to resize the layout.

I have tried several suggested techniques, and none come close to working. Here is a subset of the XML that builds the button set:

    <LinearLayout android:layout_height="104pt" android:id="@+id/numberPadLayout" android:orientation="horizontal" android:layout_width="104pt"
    android:background="#a0a0a0"
    android:layout_alignParentBottom="true" 
    android:layout_centerHorizontal="true"
>

    <LinearLayout android:layout_weight="2" android:layout_height="fill_parent" android:id="@+id/linearLayout1" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="1" android:id="@+id/button1" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="4" android:id="@+id/button4" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="7" android:id="@+id/button7" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="-" android:id="@+id/buttonDash" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
    </LinearLayout>
    <LinearLayout android:layout_weight="2" android:layout_height="fill_parent" android:id="@+id/linearLayout2" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="2" android:id="@+id/button2" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="5" android:id="@+id/button5" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="8" android:id="@+id/button8" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="0" android:id="@+id/button0" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
    </LinearLayout>

    <LinearLayout android:layout_weight="2" android:layout_height="fill_parent" android:id="@+id/linearLayout3" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="3" android:id="@+id/button3" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="6" android:id="@+id/button6" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="9" android:id="@+id/button9" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="." android:id="@+id/buttonDot" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
    </LinearLayout>
    <LinearLayout android:layout_weight="2" android:layout_height="fill_parent" android:id="@+id/linearLayout4" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="/" android:id="@+id/buttonBack" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="" android:id="@+id/buttonEnter" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
    </LinearLayout>

</LinearLayout>    

The two questions are: 1) how do I get access to numberPadLayout from Java. And once I have access to the view, 2) how do I change the height and width of the layout.

Any suggestions will be appreciated.

Answer 1

Java

This should work:

// Gets linearlayout
LinearLayout layout = findViewById(R.id.numberPadLayout);
// Gets the layout params that will allow you to resize the layout
LayoutParams params = layout.getLayoutParams();
// Changes the height and width to the specified *pixels*
params.height = 100;
params.width = 100;
layout.setLayoutParams(params);

If you want to convert dip to pixels, use this:

int height = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, <HEIGHT>, getResources().getDisplayMetrics());

Kotlin