Update POS WebView

WebView Introduction

WebView is a crucial system component in Android that allows embedding and displaying HTML content within applications. It utilizes the Blink engine from Chrome, offering a seamless integration of web content in native apps.

Main Functions

• Content Display: Loads and shows HTML, CSS, and JavaScript content.

• Web Elements Support: Handles images, videos, audio, tables, forms, and more.

• Interactivity: Offers APIs for JavaScript and Java interaction.

• Caching: Improves speed and user experience by caching content and data.

Importance in Android Apps

• Used extensively in e-commerce, social networking, and news apps.

• Enhances user experience by providing a unified interface.

• Simplifies updates and maintenance through server-side changes.

• Allows reuse of existing web technology stacks.

Common Usage Scenarios

• In-app Browsing: Offers in-app website content display.

• Hybrid Apps: Combines native functionality with web content.

• Single-Page Applications (SPA): Enables fast-loading, interactive SPAs within WebView.

• Widgets: Displays dynamic content in home screen widgets.

Conclusion

WebView is a flexible and powerful tool in Android development, suitable for a variety of use cases and enhancing the capabilities of mobile applications.

Creating and Displaying a WebView

1. WebView Object Creation:

   • Instantiate a new WebView object and set its layout parameters to fill the screen.

2. Loading a URL:

   • Use the 'loadUrl()' method to load a specified URL into the WebView.

3. Adding to Layout:

   • Add the WebView object to your application's layout.

// Create a new WebView object
WebView webView = new WebView(this);

// Set the layout parameters for the WebView
webView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
        ViewGroup.LayoutParams.MATCH_PARENT));

// Load the specified URL into the WebView
webView.loadUrl("https://www.example.com");

// Add the WebView to the layout
((ViewGroup) findViewById(R.id.activity_main)).addView(webView);

Handling JavaScript Events

1. Setting a WebViewClient:

   • Assign a new WebViewClient instance to the WebView.

   • Override 'shouldOverrideUrlLoading()' to manage URL navigation events.

2. Setting a WebChromeClient:

   • Assign a new WebChromeClient instance for additional interactive events, like handling JavaScript dialog boxes within the webpage.

webView.setWebViewClient(new WebViewClient() {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        // Handle URL navigation events here
        return super.shouldOverrideUrlLoading(view, url);
    }
});

webView.setWebChromeClient(new WebChromeClient());

Additional Considerations

• Advanced Functionality: Depending on project needs, you might implement features to handle network errors, caching, and more complex web content interactions.

Upgrading System WebView

1. System Signature Requirement:

   • Upgrading to a higher version of WebView requires the installation of a WebView version signed by the system.

2. Customer Preferences:

   • Customers can provide their preferred WebView versions for review and signing. These versions can be downloaded from the Google Developer website.

   • Alternatively, customers can select from several signed versions offered by the provider for installation.

3. Considerations and Risks

   • System Modification: Updating the system WebView involves altering the device's operating system, which carries risks and may void warranties.

   • Compatibility with Android OS: The version of the system WebView depends on the Android OS version on the POS. Older devices might not support the latest WebView versions.

4. Alternative Approach: Third-Party WebView Libraries

   • Using Libraries like Crosswalk: These libraries come with their own WebView component, offering more control over the WebView version in your app.

   • Advantages: Bypasses system WebView limitations.

   • Trade-offs: May increase app size and introduce potential stability issues.

WebView Version Compatibility Across Different Models

Model	Default version
Q2 Android 6	74.0.3729.186
Q2 Android 7	74.0.3729.186
Q2 Android 12	95.0.4638.74
Q3 Android 7	74.0.3729.186

Available WebView Versions

Download URL	Version	Android requirement
WebView version 106 download	106.0.5249.126	Android version >=6
WebView version 119 download	119.0.6045.134	Android version >= 7