# How to Implement a New Two-State Player Action in SmartTube
> Learn how to implement a new two-state player action in SmartTube. Extend TwoStateAction, register it in VideoPlayerGlue, and define XML resources and flags.
- Repository: [Yuriy L/SmartTube](https://github.com/yuliskov/SmartTube)
- Tags: how-to-guide
- Published: 2026-09-14
---
**To implement a new two-state player action in SmartTube, extend the `TwoStateAction` class, register the instance in `VideoPlayerGlue`, and define the corresponding XML resources and configuration flags.**
SmartTube is an open-source Android TV YouTube client that uses the Android Leanback library for its playback interface. Every toggle-style control—from thumbs up/down to screen dimming—is implemented as a specialized **two-state player action**. This guide explains the exact source files and method calls required to add your own toggle control to the player UI.
## Understanding the TwoStateAction Architecture
The foundation for all toggle controls is the **`TwoStateAction`** class located at [`smarttubetv/src/main/java/com/liskovsoft/smartyoutubetv2/tv/ui/playback/actions/TwoStateAction.java`](https://github.com/yuliskov/SmartTube/blob/main/smarttubetv/src/main/java/com/liskovsoft/smartyoutubetv2/tv/ui/playback/actions/TwoStateAction.java). This class extends `PlaybackControlsRow.MultiAction` and manages two distinct visual states through array indexing:
- **`INDEX_OFF` (0)** – Displays the outline icon and "off" label.
- **`INDEX_ON` (1)** – Displays the solid, highlighted icon and "on" label.
When an action transitions to **on**, the class can automatically force a *bound* counterpart action to turn **off**, which is how mutually exclusive toggles like thumbs-up and thumbs-down are implemented. The current state is stored in the action's index and is accessible through the `VideoPlayerGlue` interface.
## Step-by-Step Implementation Guide
### 1. Create a TwoStateAction Subclass
Create a new Java file in the actions package at `smarttubetv/src/main/java/com/liskovsoft/smartyoutubetv2/tv/ui/playback/actions/`. Your class must extend `TwoStateAction` and call the super constructor with a unique action ID and an outline drawable resource.
```java
public class MyNewToggleAction extends TwoStateAction {
public MyNewToggleAction(Context context) {
// R.id.action_my_new_toggle defined in ids.xml, R.drawable.lb_ic_my_toggle is the outline icon
super(context, R.id.action_my_new_toggle, R.drawable.lb_ic_my_toggle);
String[] labels = new String[2];
labels[INDEX_OFF] = context.getString(R.string.my_toggle_off);
labels[INDEX_ON] = context.getString(R.string.my_toggle_on);
setLabels(labels);
}
}
```
The outline icon you provide is automatically highlighted in the active state using `ActionHelpers.getIconHighlightColor()`.
### 2. (Optional) Bind the Action to a Counterpart
If your toggle must be mutually exclusive with another action—similar to how like/dislike works—instantiate both actions and bind them using `setBoundAction()`:
```java
MyNewToggleAction on = new MyNewToggleAction(context);
AnotherToggleAction off = new AnotherToggleAction(context);
on.setBoundAction(off);
off.setBoundAction(on);
```
The binding logic inside `TwoStateAction.setIndex()` ensures that turning one action **on** forces its bound partner to turn **off**.
### 3. Register the Action in VideoPlayerGlue
Open [`smarttubetv/src/main/java/com/liskovsoft/smartyoutubetv2/tv/ui/playback/other/VideoPlayerGlue.java`](https://github.com/yuliskov/SmartTube/blob/main/smarttubetv/src/main/java/com/liskovsoft/smartyoutubetv2/tv/ui/playback/other/VideoPlayerGlue.java). In the constructor (approximately lines 115-136), register your action by adding it to the internal `mActions` map:
```java
putAction(new MyNewToggleAction(context));
```
This step is required for `VideoPlayerGlue.getButtonState()` and `VideoPlayerGlue.setButtonState()` to recognize your action ID.
### 4. Expose the Action in UI Configuration
SmartTube allows users to enable or disable controls via the player tweaks menu. You must define the following resources:
- **Action ID**: Add a unique ID in [`res/values/ids.xml`](https://github.com/yuliskov/SmartTube/blob/main/res/values/ids.xml):
```xml