[android] Android custom dropdown/popup menu

How do I do a custom dropdown/popup menu anchored to a button?

I need it to work like the popup menu (anchored to a view), and do something when I click an item from the menu.

How do I add items to the menu by code, keeping menu's height and make it scrollable if there are more than 5 items. I don't need to add any images, just text.

First, create a folder named “menu” in the “res” folder.

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/search"
        android:icon="@android:drawable/ic_menu_search"
        android:title="Search"/>
    <item
        android:id="@+id/add"
        android:icon="@android:drawable/ic_menu_add"
        android:title="Add"/>
    <item
        android:id="@+id/edit"
        android:icon="@android:drawable/ic_menu_edit"
        android:title="Edit">
        <menu>
            <item
                android:id="@+id/share"
                android:icon="@android:drawable/ic_menu_share"
                android:title="Share"/>
        </menu>
    </item>

</menu>

Then, create your Activity Class:

public class PopupMenu1 extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.popup_menu_1);
    }

    public void onPopupButtonClick(View button) {
        PopupMenu popup = new PopupMenu(this, button);
        popup.getMenuInflater().inflate(R.menu.popup, popup.getMenu());

        popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
            public boolean onMenuItemClick(MenuItem item) {
                Toast.makeText(PopupMenu1.this,
                        "Clicked popup menu item " + item.getTitle(),
                        Toast.LENGTH_SHORT).show();
                return true;
            }
        });

        popup.show();
    }
}

I know this is an old question, but I've found another answer that worked better for me and it doesn't seem to appear in any of the answers.

Create a layout xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingTop="5dip"
    android:paddingBottom="5dip"
    android:paddingStart="10dip"
    android:paddingEnd="10dip">

<ImageView
    android:id="@+id/shoe_select_icon"
    android:layout_width="30dp"
    android:layout_height="30dp"
    android:layout_gravity="center_vertical"
    android:scaleType="fitXY" />

<TextView
    android:id="@+id/shoe_select_text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:textSize="20sp"
    android:paddingStart="10dp"
    android:paddingEnd="10dp"/>

</LinearLayout>

Create a ListPopupWindow and a map with the content:

ListPopupWindow popupWindow;
List<HashMap<String, Object>> data = new ArrayList<>();
HashMap<String, Object> map = new HashMap<>();
    map.put(TITLE, getString(R.string.left));
    map.put(ICON, R.drawable.left);
    data.add(map);
    map = new HashMap<>();
    map.put(TITLE, getString(R.string.right));
    map.put(ICON, R.drawable.right);
    data.add(map);

Then on click, display the menu using this function:

private void showListMenu(final View anchor) {
    popupWindow = new ListPopupWindow(this);

    ListAdapter adapter = new SimpleAdapter(
            this,
            data,
            R.layout.shoe_select,
            new String[] {TITLE, ICON}, // These are just the keys that the data uses (constant strings)
            new int[] {R.id.shoe_select_text, R.id.shoe_select_icon}); // The view ids to map the data to

    popupWindow.setAnchorView(anchor);
    popupWindow.setAdapter(adapter);
    popupWindow.setWidth(400);
    popupWindow.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            switch (position){
                case 0:
                    devicesAdapter.setSelectedLeftPosition(devicesList.getChildAdapterPosition(anchor));
                    break;
                case 1:
                    devicesAdapter.setSelectedRightPosition(devicesList.getChildAdapterPosition(anchor));
                    break;
                default:
                    break;
            }
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    devicesAdapter.notifyDataSetChanged();
                }
            });
            popupWindow.dismiss();
        }
    });
    popupWindow.show();
}

The Kotlin Way

fun showPopupMenu(view: View) {
    PopupMenu(view.context, view).apply {
                menuInflater.inflate(R.menu.popup_men, menu)
                setOnMenuItemClickListener { item ->
                    Toast.makeText(view.context, "You Clicked : " + item.title, Toast.LENGTH_SHORT).show()
                    true
                }
            }.show()
}

UPDATE: In the above code, the apply function returns this which is not required, so we can use run which don't return anything and to make it even simpler we can also remove the curly braces of showPopupMenu method.

Even Simpler:

fun showPopupMenu(view: View) = PopupMenu(view.context, view).run {
            menuInflater.inflate(R.menu.popup_men, menu)
            setOnMenuItemClickListener { item ->
                Toast.makeText(view.context, "You Clicked : ${item.title}", Toast.LENGTH_SHORT).show()
                true
            }
            show()
        }