To use instances of ImageDetectionFilter, we make the same kind of modifications to CameraActivity that we did to the other filters in the previous chapter. Recall that all our filter classes implement the Filter interface so that CameraActivity can use them all in similar ways.
First, we need to define some text (for the menu button) in res/values/strings.xml:
<string name="menu_next_image_detection_filter">Next
Tracker</string>Next, we need to define the menu button itself in res/menu/activity_camera.xml:
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/menu_next_image_detection_filter"
app:showAsAction="ifRoom|withText"
android:title="@string/menu_next_image_detection_filter" />
<!-- ... -->
</menu>The rest of our modifications pertain to CameraActivity.java. We need to add new member variables...