# pymmcore\_plus.core.events

Signals emitted by `CMMCorePlus.events`.

See `PCoreSignaler` for the list of signals.

**Classes**

| Name | Description |
| --- | --- |
| `QCoreSignaler` | Signals that will be emitted from CMMCorePlus objects (Qt backend). |

## Classes

### QCoreSignaler

```python
QCoreSignaler()
```

Bases: `QObject`

Signals that will be emitted from CMMCorePlus objects (Qt backend).

See `PCoreSignaler` for what each signal emits.

#### propertiesChanged

```python
propertiesChanged = Signal()
```

#### propertyChanged

```python
propertyChanged = Signal(str, str, object)
```

#### channelGroupChanged

```python
channelGroupChanged = Signal(str)
```

#### configGroupChanged

```python
configGroupChanged = Signal(str, str)
```

#### configSet

```python
configSet = Signal(str, str)
```

#### systemConfigurationLoaded

```python
systemConfigurationLoaded = Signal()
```

#### pixelSizeChanged

```python
pixelSizeChanged = Signal(float)
```

#### pixelSizeAffineChanged

```python
pixelSizeAffineChanged = Signal(float, float, float, float, float, float)
```

#### stagePositionChanged

```python
stagePositionChanged = Signal(str, float)
```

#### XYStagePositionChanged

```python
XYStagePositionChanged = Signal(str, float, float)
```

#### xYStagePositionChanged

```python
xYStagePositionChanged = XYStagePositionChanged
```

#### exposureChanged

```python
exposureChanged = Signal(str, float)
```

#### SLMExposureChanged

```python
SLMExposureChanged = Signal(str, float)
```

#### sLMExposureChanged

```python
sLMExposureChanged = SLMExposureChanged
```

#### shutterOpenChanged

```python
shutterOpenChanged = Signal(str, bool)
```

#### imageSnapped

```python
imageSnapped = Signal(str)
```

#### sequenceAcquisitionStopped

```python
sequenceAcquisitionStopped = Signal(str)
```

#### sequenceAcquisitionStarted

```python
sequenceAcquisitionStarted
```

#### mdaEngineRegistered

```python
mdaEngineRegistered = Signal(object, object)
```

#### continuousSequenceAcquisitionStarting

```python
continuousSequenceAcquisitionStarting = Signal()
```

#### continuousSequenceAcquisitionStarted

```python
continuousSequenceAcquisitionStarted = Signal()
```

#### sequenceAcquisitionStarting

```python
sequenceAcquisitionStarting
```

#### autoShutterSet

```python
autoShutterSet = Signal(bool)
```

#### configGroupDeleted

```python
configGroupDeleted = Signal(str)
```

#### configDeleted

```python
configDeleted = Signal(str, str)
```

#### configDefined

```python
configDefined = Signal(str, str, str, str, str)
```

#### roiSet

```python
roiSet = Signal(str, int, int, int, int)
```

#### property\_callbacks

```python
property_callbacks: PropKeyDict = {}
```

#### devicePropertyChanged

```python
devicePropertyChanged(
    device: str, property: str | None = None
) -> _PropertySignal
```

Return object to connect/disconnect to device/property-specific changes.

Note that the callback provided to `.connect()` must take *two* parameters (property\_name, new\_value) if only `device` is provided, and *one* parameter (new\_value) of both `device` and `property` are provided.

Parameters:

| Name | Type | Description | Default |
| --- | --- | --- | --- |
| `device` | `str` | A device label | *required* |
| `property` | `Optional[str]` | Optional property label. If not provided, all property changes on `device` will trigger an event emission. by default None | `None` |

Returns:

| Type | Description |
| --- | --- |
| `_PropertySignal` | Object with `connect` and `disconnect` methods that attach a callback to the change event of a specific property or device. |

Examples:

```pycon
>>> core.events.devicePropertyChanged("Camera", "Gain").connect(callback)
>>> core.events.devicePropertyChanged("Camera").connect(callback)
```

## Re-exports

These can also be imported from this module, but each is documented under its shortest import path (linked below).

| Name | Description |
| --- | --- |
| `CMMCoreSignaler` | Signals that will be emitted from CMMCorePlus objects (psygnal backend). |
| `PCoreSignaler` | Declares the protocol for all signals that will be emitted from CMMCorePlus. |