Multi-tasking with Partial Custom Tabs

By default, Custom Tabs launch as a full-window activity. Starting in Chrome 107, you can use partial Custom Tabs to specify a different launch height in portrait mode such that users can multitask by interacting with your app while viewing web content. Users can expand the Custom Tab to full-screen by dragging the toolbar handle up and restoring the initial launch height by dragging the handle down.

To turn a Custom Tab into a partial Custom Tab, define the initial launch height in pixels by calling the CustomTabBuilder class’s setInitialActivityHeightPx() method. By default, the partial Custom Tab is resizable, but you can pass ACTIVITY\_HEIGHT\_FIXED to disable this behavior:

new CustomTabsBuilder().setInitialActivityHeightPx(
    400,
    ACTIVITY_HEIGHT_FIXED
);

Furthermore, you need to either:

• start a new browser session via a CustomTabsServiceConnection and pass it to the Custom Tabs intent or

• start the Custom Tab activity via startActivityForResult().

Combine both approaches if you want to guarantee a fast startup in case the service connection has not been established yet.

# Launch a partial Custom Tab with an existing session

CustomTabsSession customTabsSession;

// ...

CustomTabsIntent customTabsIntent = new CustomTabsIntent.Builder(customTabsSession)
   .setInitialActivityHeightPx(500)
   .setCloseButtonPosition(CustomTabsIntent.CLOSE_BUTTON_POSITION_END)
   // ...
   .build();

customTabsIntent.launchUrl(context, Uri.parse(url))

# Launch a partial Custom Tab via startActivityForResult

private ActivityResultLauncher<String> mCustomTabLauncher = registerForActivityResult(new ActivityResultContract<String, Integer>() {
    @Override
    public Integer parseResult(int statusCode, @Nullable Intent intent) {
        return statusCode;
    }

    @NonNull
    @Override
    public Intent createIntent(@NonNull Context context, String url) {
        CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder(customTabsSession)
                .setInitialActivityHeightPx(500)
                .setCloseButtonPosition(CustomTabsIntent.CLOSE_BUTTON_POSITION_END)
                .setToolbarCornerRadiusDp(10);
        Intent customTabsIntent = builder.build().intent;
        customTabsIntent.setData(Uri.parse(url));
        return customTabsIntent;
    }
}, new ActivityResultCallback<Integer>() {
    @Override
    public void onActivityResult(Integer statusCode) {
       // ...
    }
});

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    Button selectButton = findViewById(R.id.select_button);
    selectButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View view) {
            mCustomTabLauncher.launch(customTabsIntent.intent);
        }
    });
}

Next up: learn how to measure user engagement in your Custom Tabs.