CODEWITHSUNDEEP
androidandroid-layout
Wallyworld
Wallyworld

Reputation: 53

When Extending LinearLayout Child Views are not visible

Alright. So I start my activity in Main, grab the FragmentManager and instantiate a Fragment which needs to return a View. OK. So I extended a LinearLayout in order to have something to return. My Activity and Fragment are happy but I am not.

Three LinearLayouts which I create in the parent ViewGroup are there (code below). I have verified this by counting children and by setting the background colors to contrast one another. The parent also changes size depending on how tall I make the children (when I don't declare any LayoutParams on the parent).

public class Mainmenu extends LinearLayout {
private ArrayList<LinearLayout> panes = new ArrayList<LinearLayout>();
private Context context;
private final int
    LEFT = 0, CENTER = 1, RIGHT = 2;

public Mainmenu(Context c) {
    super(c);
    context = c;
    setBackgroundColor(Color.WHITE);
    setOrientation(HORIZONTAL);
    setLayoutParams(
            new LinearLayout.LayoutParams(
                    LinearLayout.LayoutParams.FILL_PARENT,
                    LinearLayout.LayoutParams.FILL_PARENT));


    for(int i=0;i<=RIGHT;i++){                                      //Create the (3) Panes
        LinearLayout ll = new LinearLayout(context);
        ll.setLayoutParams(
                new LinearLayout.LayoutParams(300,
                        LinearLayout.LayoutParams.FILL_PARENT));
        switch(i){
        case LEFT | RIGHT:
            ll.setBackgroundColor(Color.DKGRAY);
        default:
            ll.setBackgroundColor(Color.BLACK);
        }
        ll.setOrientation(LinearLayout.VERTICAL);
        ll.setVisibility(VISIBLE);
        ll.setWillNotDraw(false);
        panes.add(i, ll);
        addView(ll);
    }

    LinearLayout.LayoutParams buttons =
        new LinearLayout.LayoutParams(100, 50);
    buttons.setMargins(15, 5, 5, 0);

    TextView tv1 = new TextView(context);
    tv1.setText("hello");
    tv1.setTextColor(Color.RED);
    panes.get(LEFT).addView(tv1, buttons);

    Button button = new Button(context);
    button.setText("Launch Editor");
    button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v){
        }
    });
    panes.get(CENTER).addView(button);
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    // TODO Auto-generated method stub

}

}

Nothing is null, all my elements (3 ViewGroups and 2 Views) are present in the tree but not visible. I've tried bringing children to the front through the parent and the children, creating them in different super.methods and invalidating the view in a similarly shotgunned fashion. What's going on? Is it as simple as not having any idea what I'm doing?

Upvotes: 5

Views: 3404

Answers (1)

sksamuel
sksamuel

Reputation: 16387

The problem is simply because you are overriding onLayout and doing nothing with it. You only need to override this if you want to layout the children yourself (ie, you were designing some unique custom layout). In this case just remove that method, or call super.onLayout.

Upvotes: 3

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