Host Callback

On the PC platform, host callbacks are implemented using the JavaScript callback function (Callback) pattern.

1 SDK Initialization Callback

Callback function when SDK initialization is completed.

Function Signature

(hostHandle, error) => void

Parameter Description

parameter	Data Type	Description
hostHandle	TJHostHandle	Host handle returned when initialization succeeds, null when it fails
error	HostRuntimeError	Error object when initialization fails, null when successful

Usage Example

TJHostHandle.initialize('sdk-key', 'sdk-secret', (hostHandle, error) => {
  if (error) {
    console.error('Initialization failed:', error);
    return;
  }
  
  console.log('Initialization successful');
  // Use hostHandle...
});

2 First Frame Rendering Callback

Callback function when the first frame of the game is rendered.

Function Signature

() => void

Usage Example

gameHandle.setOnFirstFrameRenderedListener(() => {
  console.log('First frame rendered');
  // Hide loading screen, etc.
});

3 Game Package Download Callback

A collection of callback functions during the game package download process.

3.1 onStart - Start Download

Function Signature

() => void

3.2 onProgress - Download Progress

Function Signature

(progress, totalBytesWritten, totalBytesExpected) => void

Parameter Description

parameter	Data Type	Description
progress	Number	Download Progress (0-1)
totalBytesWritten	Number	Downloaded ByteDance Count
totalBytesExpected	Number	Total ByteDance

3.3 onSuccess - Download successful

Function Signature

() => void

3.4 onFailure - Download Failed

Function Signature

(error) => void

Parameter Description

parameter	Data Type	Description
error	Error	Error Object

Usage Example

gameHandle.setOnGamePackageDownloadListener({
  onStart: () => {
    console.log('Download started');
  },
  
  onProgress: (progress, totalBytesWritten, totalBytesExpected) => {
    const percent = (progress * 100).toFixed(2);
    console.log(`Download progress: ${percent}%`);
  },
  
  onSuccess: () => {
    console.log('Download completed');
  },
  
  onFailure: (error) => {
    console.error('Download failed:', error);
  }
});

4 Game Failure Callback

Callback function when the game fails to run.

Function Signature

(error) => void

Parameter Description

parameter	Data Type	Description
error	HostRuntimeError	Error Object

Usage Example

gameHandle.setOnHostFailureListener((error) => {
  console.error('Game host failure:', error.code, error.message);
  // Handle failure: show error UI, restart game, etc.
});

5 Menu Button Click Callback

Callback function when the top-right menu button is clicked.

Function Signature

() => void

Usage Example

gameHandle.setOnTJMenuListener(() => {
  console.log('Menu button clicked');
  // Show menu UI
});

6 Close button click callback

Callback function when the close button in the upper right corner is clicked.

Function Signature

() => void

Usage Example

gameHandle.setOnTJCloseListener(() => {
  console.log('Close button clicked');
  // Show confirmation dialog, close game, etc.
});

7 Custom Command Callback

Callback function for handling custom commands in the game.

Function Signature

(request, handle) => void

Parameter Description

parameter	Data Type	Description
request	Object	Request Parameter Object
handle	Object	Command handling handle, containing success() and fail()

handle object method

• handle.success(result) - returns a successful result

• handle.fail(errorCode, errorMsg) - returns a failure result

Usage Example

gameHandle.setCustomCommandListener('login', (request, handle) => {
  // Validate parameters
  if (!request.username) {
    handle.fail(20001, 'Username is required');
    return;
  }

  // Process login
  performLogin(request.username, request.password)
    .then(result => {
      handle.success({
        userId: result.userId,
        token: result.token
      });
    })
    .catch(error => {
      handle.fail(20002, error.message);
    });
});

8 Custom Script Execution Callback

Callback function after executing a custom script.

Function Signature

(result, error) => void

Parameter Description

parameter	Data Type	Description
result	Any	Script execution result, null when failed
error	Error	Error object when execution fails, null when successful

Usage Example

const script = `
  console.log('Custom script running');
  return { success: true, data: 'Hello' };
`;

gameHandle.runCustomScript(script, (result, error) => {
  if (error) {
    console.error('Script execution failed:', error);
    return;
  }
  
  console.log('Script result:', result);
});

9 Privacy Permission Check Callback

Callback function when checking system permissions.

Function Signature

(methodName, callback) => void

Parameter Description

parameter	Data Type	Description
methodName	String	Method name that requires permission check
callback	Function	Permission check result callback(result) => {}

result object

{
  passed: Boolean,      // if passed
  errorNo: Number,      // error Number
  errorMessage: String  // error Message
}

Usage Example

const privacyChecker = {
  requirePrivacy: (methodName, callback) => {
    console.log(`Checking privacy for: ${methodName}`);
    
    // Perform permission check
    checkSystemPermission(methodName)
      .then(() => {
        callback({
          passed: true,
          errorNo: 0,
          errorMessage: ''
        });
      })
      .catch(error => {
        callback({
          passed: false,
          errorNo: 1,
          errorMessage: error.message
        });
      });
  }
};

gameHandle.setPrivacyChecker(privacyChecker);

10 Complete Callback Example

const { TJHostHandle } = require('webglhost-runtime-pc');

class GameCallbackManager {
  constructor() {
    this.gameHandle = null;
  }

  setupAllCallbacks(gameHandle) {
    this.gameHandle = gameHandle;

    // First frame rendered
    gameHandle.setOnFirstFrameRenderedListener(() => {
      this.onFirstFrameRendered();
    });

    // Download callbacks
    gameHandle.setOnGamePackageDownloadListener({
      onStart: () => this.onDownloadStart(),
      onProgress: (p, w, t) => this.onDownloadProgress(p, w, t),
      onSuccess: () => this.onDownloadSuccess(),
      onFailure: (e) => this.onDownloadFailure(e)
    });

    // Game failure
    gameHandle.setOnHostFailureListener((error) => {
      this.onGameFailure(error);
    });

    // UI callbacks
    gameHandle.setOnTJMenuListener(() => {
      this.onMenuClicked();
    });

    gameHandle.setOnTJCloseListener(() => {
      this.onCloseClicked();
    });

    // Custom command
    gameHandle.setCustomCommandListener('myCommand', (request, handle) => {
      this.handleCustomCommand(request, handle);
    });

    // Privacy checker
    gameHandle.setPrivacyChecker({
      requirePrivacy: (methodName, callback) => {
        this.checkPrivacy(methodName, callback);
      }
    });
  }

  onFirstFrameRendered() {
    console.log('First frame rendered');
  }

  onDownloadStart() {
    console.log('Download started');
  }

  onDownloadProgress(progress, written, total) {
    console.log(`Progress: ${(progress * 100).toFixed(2)}%`);
  }

  onDownloadSuccess() {
    console.log('Download completed');
  }

  onDownloadFailure(error) {
    console.error('Download failed:', error);
  }

  onGameFailure(error) {
    console.error('Game failure:', error);
  }

  onMenuClicked() {
    console.log('Menu clicked');
  }

  onCloseClicked() {
    console.log('Close clicked');
  }

  handleCustomCommand(request, handle) {
    // Process command
    handle.success({ result: 'ok' });
  }

  checkPrivacy(methodName, callback) {
    // Check permission
    callback({ passed: true, errorNo: 0, errorMessage: '' });
  }
}

// Usage
const callbackManager = new GameCallbackManager();
callbackManager.setupAllCallbacks(gameHandle);