How to set columnWeight of cardView programmatically

Question

I am using GridLayout which contains 3 cardviews initially. Now when user clicks last card I want to add one more card to GridLayout.

But in the initial 3 cards which I created in xml file contains attribute 'columnweight'. So i want to set this attribute to the newly created cardview after onClick.

I have seen some question related to this. But they are creating their gridlayout also programmatically and don't want to create gridLayout programmatically. How can I do this?

Note :- My each CradView structure is like this :- Cardview->LinearLayout->TextView

I have went through the below link this

But as I said they created gridLayout programmatically and I want to do that.

My initial Layout with GridView containg 3 cardViews is

<?xml version="1.0" encoding="utf-8"?>

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fillViewport="true">

    <LinearLayout android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:orientation="vertical"
        android:id="@+id/activity_manager"
        android:weightSum="10">

        <Space
            android:layout_height="30dp"
            android:layout_width="wrap_content"/>

        <GridLayout
            android:id="@+id/mainGrid"
            android:columnCount="2"
            android:alignmentMode="alignMargins"
            android:columnOrderPreserved="false"
            android:layout_weight="5"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="14dp" >

            <android.support.v7.widget.CardView
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_columnWeight="1"
                android:layout_rowWeight="1"
                app:cardElevation="8dp"
                android:layout_marginRight="16dp"
                android:layout_marginLeft="16dp"
                android:layout_marginBottom="16dp"
                app:cardCornerRadius="8dp"
                android:padding="0dp">

                <LinearLayout
                    android:layout_gravity="center_horizontal|center_vertical"
                    android:layout_margin="4dp"
                    android:orientation="vertical"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content">

                    <TextView
                        android:text="Mumbai Hackathon"
                        android:textAlignment="center"
                        android:layout_marginTop="6dp"
                        android:textColor="@color/colorPrimary"
                        android:textSize="18sp"
                        android:textStyle="bold"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content" />

                </LinearLayout>

            </android.support.v7.widget.CardView>

            <android.support.v7.widget.CardView
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_columnWeight="1"
                android:layout_rowWeight="1"
                app:cardElevation="8dp"
                android:layout_marginRight="16dp"
                android:layout_marginLeft="16dp"
                android:layout_marginBottom="16dp"
                app:cardCornerRadius="8dp"
                android:padding="0dp">

                <LinearLayout
                    android:layout_gravity="center_horizontal|center_vertical"
                    android:layout_margin="4dp"
                    android:orientation="vertical"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content">

                    <TextView
                        android:text="Game of Codes (GOC)"
                        android:layout_marginTop="6dp"
                        android:textAlignment="center"
                        android:textColor="@color/colorPrimary"
                        android:textSize="18sp"
                        android:textStyle="bold"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content" />

                </LinearLayout>

            </android.support.v7.widget.CardView>

            <android.support.v7.widget.CardView
                android:id="@+id/add_file"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_columnWeight="1"
                android:layout_rowWeight="1"
                app:cardElevation="8dp"
                android:layout_marginRight="16dp"
                android:layout_marginLeft="16dp"
                android:layout_marginBottom="16dp"
                app:cardCornerRadius="8dp">

                <LinearLayout
                    android:layout_gravity="center_horizontal|center_vertical"
                    android:layout_margin="4dp"
                    android:orientation="vertical"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content">

                    <TextView
                        android:text="+\nAdd New File"
                        android:layout_marginTop="6dp"
                        android:textAlignment="center"
                        android:textColor="@color/colorPrimary"
                        android:textSize="18sp"
                        android:textStyle="bold"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content" />

                </LinearLayout>

            </android.support.v7.widget.CardView>

        </GridLayout>
    </LinearLayout>
</ScrollView>

Answer 1

Source: GridLayout (not GridView) how to stretch all children evenly

UPDATE: Weights are supported as of API 21. See PaulT's answer for more details. END UPDATE There are limitations when using the GridLayout, the following quote is taken from the documentation.

"GridLayout does not provide support for the principle of weight, as defined in weight. In general, it is not therefore possible to configure a GridLayout to distribute excess space in non-trivial proportions between multiple rows or columns ... For complete control over excess space distribution in a row or column; use a LinearLayout subview to hold the components in the associated cell group."

Here is a small example that uses LinearLayout subviews. (I used Space Views that takes up unused area and pushes the buttons into desired position.)

<GridLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:columnCount="1"
>
    <TextView
        android:text="2x2 button grid"
        android:textSize="32dip"
        android:layout_gravity="center_horizontal" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content" android:orientation="horizontal">
        <Space
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1" />
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button 1" />
        <Space
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1" />
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="start"
            android:text="Button 2" />
        <Space
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
    >
        <Space
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1" />
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button 3" />
        <Space
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1" />
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="start"
            android:text="Button 4" />
        <Space
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1" />
    </LinearLayout>
</GridLayout>