# Xử lý các sự kiện

## Notification callback

### Call notification:

#### 1. To listen event of Call we setting notification:

```
   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(callStateChanged:) name:OMICallStateChangedNotification object:nil];
```

Declare function Listen event Call State to know when call confirm or invite state: Notification key: OMICallStateChangedNotification Example

```
- (void)callStateChanged: (NSNotification *)notification {
   
   __weak typeof(self)weakSelf = self;
   dispatch_async(dispatch_get_main_queue(), ^{
       __weak  OMICall *call = [[notification userInfo] objectForKey:OMINotificationUserInfoCallKey];
       switch(call.callState)
       {
           case OMICallStateEarly:
               OMILogDebug(@"callStateChanged OMICallStateEarly : %@",call.uuid.UUIDString);
               break;
           case OMICallStateCalling:
               OMILogDebug(@"callStateChanged OMICallStateCalling : %@",call.uuid.UUIDString);
               break;
           case OMICallStateIncoming:{
               OMILogDebug(@"callStateChanged OMICallStateIncoming : %@",call.uuid.UUIDString);
               break;
           }
           case OMICallStateConnecting:
               OMILogDebug(@"callStateChanged OMICallStateConnecting : %@",call.uuid.UUIDString);
               break;
           case OMICallStateConfirmed:{
               OMILogDebug(@"callStateChanged OMICallStateConfirmed : %@",call.uuid.UUIDString);
              
               break;
           }
           case OMICallStateDisconnected:
               OMILogDebug(@"callStateChanged OMICallStateDisconnected : %@",call.uuid.UUIDString);
               break;
       }
   });
}
```

#### 2. Listen event Media event:

Notification key: OMICallMediaStateChangedNotification Example:

```
- (void)callMediaStateChanged: (NSNotification *)notification {
    
    __weak typeof(self)weakSelf = self;
    dispatch_async(dispatch_get_main_queue(), ^{
        OMICallMediaState mediaState = (OMICallMediaState)[[notification userInfo] objectForKey:OMINotificationUserInfoCallMediaStateKey];
        switch(mediaState)
        {
            case OMICallStateMuted:
                OMILogDebug(@"OMICallMediaState OMICallStateMuted");
                break;
            case OMICallStateToggleSpeaker:
                OMILogDebug(@"OMICallMediaState OMICallStateToggleSpeaker");
                break;
            case OMICallStatePermissionCameraDenied:
                OMILogDebug(@"OMICallMediaState OMICallStateToggleSpeaker");
                break;
            case OMICallStatePermissionMicrophoneDenied:
                OMILogDebug(@"OMICallMediaState OMICallStateToggleSpeaker");
                break;
            
        }
    });
}
```

#### 3. Listen event call misscall:

```
[Omiclient setMissedCallBlock:^(OMICall * _Nonnull __weak call) {
        <#code#>
}];
```

#### 4. Listen the Video call state

when event come we need to re-render video screen Detail sample project can view here: <https://github.com/VIHATTeam/IOS-Objective-VideoCall-Example>

```
### Listen: 
```

````
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(videoNotification:) name:OMICallVideoInfoNotification object:nil];
    ```
    ### Process: 
```ruby
    -(void) videoNotification:(NSNotification *) noti {
        NSDictionary *dic = [noti userInfo];
        NSNumber * state = [dic valueForKey:OMIVideoInfoState];
        switch([state intValue]){
            case OMIVideoRemoteReady:{
                [self startPreview];
                break;
            }
        }
    }
````

```
### Show Video Preview:
```

```
    - (void)startPreview {
        __weak typeof(self) weakSelf = self;
        if(!_remoteVideoRenderView || !_localVideoRenderView) return;
        
            dispatch_async(dispatch_get_main_queue(), ^{
                weakSelf.remoteVideoRenderView.contentMode = UIViewContentModeScaleAspectFill;
                [weakSelf.remoteVideoRenderView setView:[self.videoManager createViewForVideoRemote:weakSelf.remoteVideoRenderView.frame]];
                weakSelf.localVideoRenderView.contentMode = UIViewContentModeScaleAspectFill;
                [weakSelf.localVideoRenderView setView:[self.videoManager createViewForVideoLocal:weakSelf.localVideoRenderView.frame]];
            });
    }
```

#### 5. Listen the network health for update UI instruction for user

The information we calculator on MOS score and device 3 level bellow

```
    Listen: 
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateNetworkHealth:) name:OMICallNetworkQualityNotification object:nil];
    
    Process: 
    
    -(void) updateNetworkHealth:(NSNotification *) noti {
        NSDictionary *dic = [noti userInfo];
        NSNumber * state = [dic valueForKey:OMINotificationNetworkStatusKey];
        switch([state intValue]){
            case OMINetworkGood:{
                [self.networkStatus setImage: [UIImage imageNamed: @"network_best"]];
                break;
            }
            case OMINetworkMedium:{
                [self.networkStatus setImage: [UIImage imageNamed: @"network_medium"]];
                break;
            }
            case OMINetworkBad:{
                [self.networkStatus setImage: [UIImage imageNamed: @"network_bad"]];
                break;
            }
        }
    }
```

<br>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://api.omicall.com/sdk/mobile-sdk/ios-sdk/xu-ly-cac-su-kien.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.