Dynamic GridLayout

Question

I made an error in another class, that's why it didn't work. The code below seems to be correct

I'm trying to create a dynamic GridLayout. Inside another class, not this one, I have a method that designs rows and cols of my gridlayout. In the class below, i add some buttons to my GridLayout:

int buttons= 6;//the number of bottons i have to put in GridLayout
int buttonsForEveryRow = 3; // buttons i can put inside every single row
int buttonsForEveryRowAlreadyAddedInTheRow =0; // count the buttons added in a single rows
int columnIndex=0; //cols index to which i add the button
int rowIndex=0; //row index to which i add the button

for(int i=0; i < buttons;i++){          
    /*if numeroBottoniPerRigaInseriti equals numeroBottoniPerRiga i have to put the other buttons in a new row*/
    if(buttonsForEveryRowAlreadyAddedInTheRow ==buttonsForEveryRow ){
        rowIndex++; //here i increase the row index
        buttonsForEveryRowAlreadyAddedInTheRow  =0;  
        columnIndex=0; 
    }   

    Spec row = GridLayout.spec(rowIndex, 1); 
    Spec colspan = GridLayout.spec(columnIndex, 1);
    GridLayout.LayoutParams gridLayoutParam = new GridLayout.LayoutParams(row, colspan);
    gridLayout.addView(button_to_add,gridLayoutParam);

    buttonsForEveryRowAlreadyAddedInTheRow ++;
    columnIndex++;

In the following image you can see what i get: Buttons 3 and 6 are missing. I'm afraid I am not using GridLayout.spec properly.

Answer 1

Using below code you can add image views to grid layout dynamically with column span and row span.

    gridLayout = (GridLayout) findViewById(R.id.gridview);

    gridLayout.removeAllViews();

    int total = 10;
    int column = 3;
    int row = total / column;
    gridLayout.setColumnCount(column);
    gridLayout.setRowCount(row + 1);
    for (int i = 0, c = 0, r = 0; i < total; i++, c++) {
        if (c == column) {
            c = 0;
            r++;
        }
        ImageView oImageView = new ImageView(this);
        oImageView.setImageResource(R.drawable.ic_launcher);            

        oImageView.setLayoutParams(new LayoutParams(100, 100));

        Spec rowSpan = GridLayout.spec(GridLayout.UNDEFINED, 1);
        Spec colspan = GridLayout.spec(GridLayout.UNDEFINED, 1);
        if (r == 0 && c == 0) {
            Log.e("", "spec");
            colspan = GridLayout.spec(GridLayout.UNDEFINED, 2);
            rowSpan = GridLayout.spec(GridLayout.UNDEFINED, 2);
        }
        GridLayout.LayoutParams gridParam = new GridLayout.LayoutParams(
                rowSpan, colspan);
        gridLayout.addView(oImageView, gridParam);


    }

Answer 2

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.)

<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>