
## Introduction
The [DeviceSourceManager](/api/classes/babylon.devicesourcemanager) is a class that will manage the connections for various user input devices and provide methods of querying those devices for their current state.  
This class supports several methods of input:
- **Keyboard** *(DeviceType: BABYLON.DeviceType.Keyboard, Inputs: number)*
- **Mouse** *(DeviceType: BABYLON.DeviceType.Mouse, Inputs: BABYLON.PointerInput)*
- **Touch** *(DeviceType: BABYLON.DeviceType.Pointer, Inputs: BABYLON.PointerInput)*
- **DualShock Gamepad** *(DeviceType: BABYLON.DeviceType.DualShock, Inputs: BABYLON.DualShockInput)*
- **Xbox Gamepad, One or 360** *(DeviceType: BABYLON.DeviceType.Xbox, Inputs: BABYLON.XboxInput)*
- **Switch Gamepad, L+R JoyCon Grip or Pro Controller** *(DeviceType: BABYLON.DeviceType.Switch, Inputs: BABYLON.SwitchInput)*
- **Generic/Other Gamepad** *(DeviceType: BABYLON.DeviceType.Generic, Inputs: number)*

Here's an example of the DeviceSourceManager in use
<Playground id="#C7PM2B#18" title="DeviceSourceManager Example" description="Simple example showing how to use the DeviceSourceManager in your scene." image="/img/playgroundsAndNMEs/pg-C7PM2B-17.png"/>

To use the DeviceSourceManager, first create an instance of it.  You will need to provide an engine object.
```javascript
var deviceSourceManager = new BABYLON.DeviceSourceManager(scene.getEngine());
```

Within your scene's render/game loop, you can query the DeviceSourceManager for the current state of a specific input.  First, you will need to get the DeviceSource object.  With this object, you can then query for a specific input's status.

```javascript
// If the device has been registered in the DeviceSourceManager
if (deviceSourceManager.getDeviceSource(BABYLON.DeviceType.Xbox)) {
    // And the A button was pressed
    if (deviceSourceManager.getDeviceSource(BABYLON.DeviceType.Xbox).getInput(BABYLON.XboxInput.A) == 1) {
        // Do something
    }
}
```

It should also be noted that you can use optional chaining to make checks fit into a single line
```javascript
if (deviceSourceManager.getDeviceSource(BABYLON.DeviceType.Xbox)?.getInput(BABYLON.XboxInput.A) == 1) {
    // Do something
}
```

## Events and Observables
You can use the following Observables to work with identifiers for a given device
```javascript

// When a device is registered in the DeviceSourceManager
onDeviceConnectedObservable.add((device) => {
    // You can get the device type by using device.deviceType
    // You can also get the device slot by using device.deviceSlot (default is 0 for keyboard and 1 for mouse)
    // "device" is of Type DeviceSource do you can also access the getInput function or add an observable for onInputChangedObservable
});

// When a device is unregistered in the DeviceSourceManager
onDeviceDisconnectedObservable.add((device) => {
    // You can get the device type by using device.deviceType
    // You can also get the device slot by using device.deviceSlot (default is 0 for keyboard and 1 for mouse)
    // "device" is of Type DeviceSource
});
```

For Keyboards and Pointers, you can use an event based system to get the current input and previous input when an input is activated
```javascript
deviceSourceManager.getDeviceSource(BABYLON.DeviceType.Keyboard).onInputChangedObservable.add((device) => {
    // device.inputIndex is the activated input
    // device.currentState is the current value
    // device.previousState is the previous value (before activation)
});
```



## Gamepad Manager
First create a GamepadManager:
```javascript
var gamepadManager = new BABYLON.GamepadManager();
```
Listen to the manager's onGamepad Connected/Disconnected events:
```javascript
gamepadManager.onGamepadConnectedObservable.add((gamepad, state)=>{
});
gamepadManager.onGamepadDisconnectedObservable.add((gamepad, state)=>{
});
```

## Gamepad events
Once a gamepad is available, event listeners can be added to handle the gamepad's inputs
```javascript
gamepadManager.onGamepadConnectedObservable.add((gamepad, state)=>{
    gamepad.onButtonDownObservable.add((button, state)=>{
        //Button has been pressed
        console.log(button)
    })
    gamepad.onleftstickchanged((values)=>{
        //Left stick has been moved
        console.log(values.x+" "+values.y)
    })
}
```

## Gamepad types
Depending on the type of controller, handle any of it's unique properties:
```javascript
gamepadManager.onGamepadConnectedObservable.add((gamepad, state)=>{
    if (gamepad instanceof BABYLON.Xbox360Pad) {
        gamepad.onButtonDownObservable.add((button, state)=>{
            console.log(BABYLON.Xbox360Button[button])
        })
    }
    if (gamepad instanceof BABYLON.PoseEnabledController) {
        gamepad.onMainButtonStateChangedObservable.add((button, state)=>{
            console.log(button.value)
        })
        var position = gamepad.devicePosition
        var rotation = gamepad.deviceRotationQuaternion
    }
}
```

## Check a gamepad's current state
At any time, a gamepad's current state can be checked with the gamepads properties:
```javascript
scene.registerBeforeRender(function () {
    if(gamepad instanceof BABYLON.Xbox360Pad){
        if(gamepad.buttonA){
            sphere.position.y+=0.05
        }
        sphere.position.x+=gamepad.leftStick.x*0.05
    }
}
```

<Playground id="#U3XJTB#38" title="Gamepad Example" description="Simple example of enabling gamepad support to your scene." image=""/>


## VirtualJoystick
Create virtual joysticks for the left and right side of the screen
```
var leftJoystick = new BABYLON.VirtualJoystick(true);
var rightJoystick = new BABYLON.VirtualJoystick(false);
```

Get joystick value
```
leftJoystick.deltaPosition.x
leftJoystick.deltaPosition.y
```

<Playground id="#PRQU53#7" title="VirtualJoystick Example" description="Simple example showing how to add a VirtualJoystick to your scene." image="/img/playgroundsAndNMEs/divingDeeperVirtualJoystick1.jpg"/>

Note: This will create an overlay canvas on top of the canvas for the scene. This will disable interaction with the Babylon GUI elements and scene pointer events. To avoid this the overlay joystick canvas's z index can be modified to toggle between scene interaction and joysticks input as seen in the playground above. Another option would be to create a custom joystick using the Babylon GUI as described below. 

## Custom joystick

To create a custom virtual joystick and modify it to suit specific use cases, the Babylon GUI can be used.

<Playground id="#C6V6UY#5" title="Custom Joystick Example" description="Simple example showing how to add a Custom Joystick to your scene." image="/img/playgroundsAndNMEs/divingDeeperVirtualJoystick2.jpg"/>

As seen in this example, no overlay canvas is used so other GUI elements will continue to function and the visuals can be modified/positioned if needed.



## How To Use Babylon 3D GUI

The Babylon.js 3D GUI library is an extension you can use to generate 3D interactive user interface.

The latest version can be found [here](https://github.com/BabylonJS/Babylon.js/tree/master/dist/preview%20release/gui)

And the source code is available on the main [Babylon.js GUI3D repo](https://github.com/BabylonJS/Babylon.js/tree/master/gui/src/3D)

## Introduction

Babylon.GUI uses meshes to create an interactive user interface, which is fully integrated in your scene.

## GUI3DManager

To begin with 3D GUI, you need to instantiate a `GUI3DManager` which will be responsible for connecting all the controls together:

```javascript
var manager = new BABYLON.GUI.GUI3DManager(scene);
```

The manager only requires the scene to work on. Once instantiated, the manager will create a utility layer which is a specific child scene that will host all the meshes used to render the controls. This way, your main scene won't get populated by the utility meshes.

You can reach the utility layer with `manager.utilityLayer`.

Once you have a manager, you can start adding controls with `manager.addControl(control)`. All controls will be added to the `manager.rootContainer`.

Please also note that the following functions are available:

- `containsControl()`: Gets a boolean indicating if the given control is in the root child list.
- `removeControl()`: Removes a control from the root child list.

## Containers

A container is used to organize controls in the scene. The base class for all containers is the `Container3D` class. The `manager.rootContainer` is a `Container3D` object.

All containers provide the following functions to handle controls:

- `addControl()`: Adds a control to the children of this container
- `containsControl()`: Gets a boolean indicating if the given control is in the root child list
- `removeControl()`: Removes a control from the root child list

By default, all containers will update their layout everytime you add a new control to it. But you can optimize this behavior if you plan to add multiple controls in a row with `container.blockLayout = true`:

```javascript
panel.blockLayout = true;
for (var index = 0; index < 30; index++) {
  var button = new BABYLON.GUI.Button3D("click me");
  panel.addControl(button);
}
panel.blockLayout = false;
```

The `Container3D` class will do nothing regarding layout of its controls. You need to use one of its children to get a specialized layout mechanism.

All specialized containers must implement the following function to provide layout mechanism:

- `_arrangeChildren()`: This function will be called everytime a new control is added. This is where children class can decide how to organize controls

### StackPanel

The `StackPanel` container can be used to stack items either horizontally or vertically:

```javascript
var panel = new BABYLON.GUI.StackPanel3D();
panel.isVertical = true;
```

The panel will automatically arrange its content every time you add a new control.

You can specify the distance between elements with `panel.margin = 0.02`.

See it in action here: <Playground id="#HJZBRG#0" title="3D GUI StackPanel" description="Simple example showing how to add a 3D GUI StackPanel to your scene." image="/img/playgroundsAndNMEs/divingDeeperBabylon3DGUI1.jpg"/>

### VolumeBasedPanel

VolumeBasedPanel are containers used to dispatch items on the surface of a volume (like sphere or cylinder).

The panels will automatically arrange its content every time you add a new control.

The panels can either be row or column first depending on which property you use:

```javascript
panel.columns = 5; // The panel will automatically compute the number of rows based on number of child controls
```

or

```javascript
panel.rows = 5; // The panel will automatically compute the number of columns based on number of child controls
```

By default a VolumeBasedPanel is set up with panel.columns = 10;

You can specify the distance between elements with `panel.margin = 0.02`.

You can also control how each cell is oriented:

| Value | Type                                                | Description                                                     |
| ----- | --------------------------------------------------- | --------------------------------------------------------------- |
| 0     | BABYLON.Container3D.UNSET_ORIENTATION               | Control rotation will remain unchanged                          |
| 1     | BABYLON.Container3D.FACEORIGIN_ORIENTATION          | Control will rotate to make it look at sphere central axis      |
| 2     | BABYLON.Container3D.FACEORIGINREVERSED_ORIENTATION  | Control will rotate to make it look back at sphere central axis |
| 3     | BABYLON.Container3D.FACEFORWARD_ORIENTATION         | Control will rotate to look at z axis (0, 0, 1)                 |
| 4     | BABYLON.Container3D.FACEFORWARDREVERSED_ORIENTATION | Control will rotate to look at negative z axis (0, 0, -1)       |

#### SpherePanel

The `SpherePanel` container can be used to dispatch items on the surface of a sphere:

```javascript
var panel = new BABYLON.GUI.SpherePanel();
panel.radius = 5;
```

The radius property is used to define the radius of the hosting sphere.

See it in action here: <Playground id="#HB4C01#9" title="3D GUI SpherePanel" description="Simple example showing how to add a 3D GUI SpherePanel to your scene." image="/img/playgroundsAndNMEs/divingDeeperBabylon3DGUI2.jpg"/>

![SpherePanel](/img/how_to/gui/SpherePanel.jpg)

#### CylinderPanel

The `CylinderPanel` container can be used to dispatch item on the surface of a cylinder:

```javascript
var panel = new BABYLON.GUI.CylinderPanel();
panel.radius = 5;
```

The radius property is used to define the radius of the hosting cylinder.

See it in action here: <Playground id="#HB4C01#8" title="3D GUI CylinderPanel" description="Simple example showing how to add a 3D GUI CylinderPanel to your scene." image="/img/playgroundsAndNMEs/divingDeeperBabylon3DGUI3.jpg"/>

![CylinderPanel](/img/how_to/gui/CylinderPanel.jpg)

#### PlanePanel

The `PlanePanel` container can be used to dispatch item on the surface of a plane:

```javascript
var panel = new BABYLON.GUI.PlanePanel();
```

See it in action here: <Playground id="#HB4C01#7" title="3D GUI PlanePanel" description="Simple example showing how to add a 3D GUI PlanePanel to your scene." image="/img/playgroundsAndNMEs/divingDeeperBabylon3DGUI4.jpg"/>

![PlanePanel](/img/how_to/gui/PlanePanel.jpg)

#### ScatterPanel

The `ScatterPanel` container can be used to dispatch items using a randomized planar mapping:

```javascript
var panel = new BABYLON.GUI.ScatterPanel();
panel.iterations = 100;
```

The iterations property is used to define the number of iteration to use to scatter the controls (100 by default)

![ScatterPanel](/img/how_to/gui/ScatterPanel.jpg)

See it in action here: <Playground id="#HB4C01#6" title="3D GUI ScatterPanel" description="Simple example showing how to add a 3D GUI ScatterPanel to your scene." image="/img/playgroundsAndNMEs/divingDeeperBabylon3DGUI5.jpg"/>

## Controls

All controls inherit from the `Control3D` class which provides a set of basic features:

- `position`: Gets or sets the control position in world space
- `scaling`: Gets or sets the control scaling in world space
- `parent`: Gets or sets the parent container
- `isVisible`: Gets or sets a boolean indicating if the control is visible
- `node`: Gets the transform node used by this control
- `mesh`: Gets the mesh used to render this control

You can attach a control to a mesh or tranform node from your scene with:

```javascript
control.linkToTransformNode(anchor);
```

This way the control will always follow the linked node or mesh. Please note that in this case, the `position` and `scaling` properties are considered local to the new parent node or mesh.
When linking a control to a transform node, please make sure that the control was first added to a container or to the root manager.

Some observables are also available to help tracking control state:

- `onPointerEnterObservable`: An event triggered when pointer enters the control
- `onPointerOutObservable`: An event triggered when the pointer move out of the control
- `onPointerDownObservable`: An event triggered when the pointer taps the control
- `onPointerUpObservable`: An event triggered when pointer is up
- `onPointerClickObservable`: An event triggered when a control is clicked on (with a mouse)
- `onPointerMoveObservable`: An event triggered when the pointer move over the control

All controls can also be the target of [behaviors](/divingDeeper/behaviors) so they expose the associated properties and functions:

- `behaviors`: Gets the list of attached behaviors
- `addBehavior()`: Attach a behavior to the control
- `removeBehavior()`: Remove an attached behavior
- `getBehaviorByName()`: Gets an attached behavior by name

All controls can also define a callback when specific event is happening. These callbacks will be called to let the user defines an animation for the control. Here is the list of available callbakcs:

- `pointerEnterAnimation`: Callback used to start pointer enter animation
- `pointerOutAnimation`: Callback used to start pointer out animation
- `pointerDownAnimation`: Callback used to start pointer down animation
- `pointerUpAnimation`: Callback used to start pointer up animation

All these callbacks are empty by default and will be implemented by specialized controls.

### Button3D

`Button3D` is a class used to create 3D buttons.

A button is a control with default animations for enter/out/down and up events.
It is based on a 2D GUI content.

You can specify the content through the `content` property and set it to any regular [2D GUI content](/divingDeeper/gui):

```javascript
var button = new BABYLON.GUI.Button3D("reset");

var text = new BABYLON.GUI.TextBlock();
text.text = "reset";
text.color = "white";
text.fontSize = 24;
button.content = text;
```

By default the `Button3D` control uses a 512x512 AdvancedDynamicTexture to render its content.
You can use the following properties to change the texture resolution:

- `contentResolution`: Gets or sets the texture resolution used to render content (512 by default)
- `contentScaleRatio`: Gets or sets the texture scale ratio used to render content (2 by default)

See it in action here: <Playground id="#2YZFA0#0" title="3D GUI Button3D Control" description="Simple example showing how to add a 3D GUI Button3D to your scene." image="/img/playgroundsAndNMEs/divingDeeperBabylon3DGUI6.jpg"/>

### HolographicButton

The `HolographicButton` is a specialized button that mimics the Mixed Reality Toolkit holographic button.

An `HolographicButton` can be defined with two properties:

- `text`: Gets or sets text for the button
- `imageUrl`: Gets or sets the image url for the button

![Babylon.GUI](/img/how_to/gui/MRTK_HolographicButton.jpg)

See it in action here: <Playground id="#2YZFA0#2" title="3D GUI HolographicButton Control" description="Simple example showing how to add a 3D GUI HolographicButton to your scene." image="/img/playgroundsAndNMEs/divingDeeperBabylon3DGUI7.jpg"/>

Please note that you can overwrite the default content but you need to do it after the call to addControl:

```javascript
var button = new BABYLON.GUI.HolographicButton("reset");
panel.addControl(button);

// Must be done AFTER addControl in order to overwrite the default content
var text1 = new BABYLON.GUI.TextBlock();
text1.text = "Reset";
text1.color = "Red";
text1.fontSize = 48;
button.content = text1;
```

### MeshButton3D

This class is used to to create an interactable object which will use a mesh coming from the current scene to render.

```javascript
var pushButton = new BABYLON.GUI.MeshButton3D(mesh, "pushButton");
```

Once created, you can use the new MeshButton3D to add animations:

```javascript
pushButton.pointerEnterAnimation = () => {
  mesh.material.albedoColor = hoverColor;
};
pushButton.pointerOutAnimation = () => {
  mesh.material.albedoColor = new BABYLON.Color3(0.5, 0.19, 0);
};
```

See a complete GUI3D Demo here: <Playground id="#8Y780Y#20" title="Full GUI3D Demo" description="Full demo of the Babylon 3D GUI system." image="/img/playgroundsAndNMEs/divingDeeperBabylon3DGUI8.jpg"/>

### Custom controls

You can create your own custom control by inheriting from the `Control3D` class and implementing the following functions:

- `_createNode()`: Called on controls to create a transform node or a mesh to represent the control
- `_affectMaterial()`: Called on controls to prepare and affect a material if a mesh is used to represent the control

Input

Coming next

Gamepads

Learn about gamepad input support in Babylon.js.

Virtual Joysticks

Learn about virtual gamepad input support in Babylon.js.

Device Source Manager

Learn about managing input devices with the Device Source Manager.