Android: Backspace in Webview/Baseinputconnection

Android: Backspace in WebView/BaseInputConnection

Ok, finally figured this out.

In Android 4.2 (maybe in earlier versions as well) the backspace is not sent as a sendKeyEvent(..., KeyEvent.KEYCODE_DEL) by the standard soft keyboard. Instead, it is sent as deleteSurroundingText(1, 0).

So the solution in my case is to make a custom InputConnection with the following:

@Override
public boolean deleteSurroundingText(int beforeLength, int afterLength) {       
    // magic: in latest Android, deleteSurroundingText(1, 0) will be called for backspace
    if (beforeLength == 1 && afterLength == 0) {
        // backspace
        return super.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DEL))
            && super.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_DEL));
    }

    return super.deleteSurroundingText(beforeLength, afterLength);
}

Note: Please let me know if I am doing something stupid here, as it is my 3rd day writing for Android.

Can't get backspace to work in codemirror, under Phonegap on Android 4.x?

Override init Activity method :

public class ProjectName extends DroidGap
{
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        init(); // Don't forget this, you'll get runtime error otherwise!

        // The following does the trick:
        super.appView.getSettings().setUseWideViewPort(true);
        super.appView.getSettings().setLoadWithOverviewMode(true);

        // Set by <content src="index.html" /> in config.xml
        super.loadUrl(Config.getStartUrl());
        //super.loadUrl("file:///android_asset/www/index.html")
        super.setIntegerProperty("loadUrlTimeoutValue", 10000); 
    }

    /**
     * Create and initialize web container with default web view objects.
     */
    @Override
    public void init() {
        CordovaWebView webView = new CustomWebView(ProjectName.this);
        CordovaWebViewClient webViewClient;
        if(android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.HONEYCOMB)
        {
            webViewClient = new CordovaWebViewClient(this, webView);
        }
        else
        {
            webViewClient = new IceCreamCordovaWebViewClient(this, webView);
        }
        this.init(webView, webViewClient, new CordovaChromeClient(this, webView));
    }

}

Create on CustomWebView which extends CordovaWebView

public class CustomWebView extends CordovaWebView{

    public CustomWebView(Context context) {
        super(context);
    }

    @Override
    public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
        MyCustomInputConnection connection = new MyCustomInputConnection(this, false);

        return connection;
    }

}

Create your custom InputConnection :

public class MyCustomInputConnection extends BaseInputConnection{

    public MyCustomInputConnection(View targetView, boolean fullEditor) {
        super(targetView, fullEditor);
    }

    @Override
    public boolean deleteSurroundingText(int beforeLength, int afterLength) {       
        // magic: in latest Android, deleteSurroundingText(1, 0) will be called for backspace
        if (beforeLength == 1 && afterLength == 0) {
            // backspace
            return super.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DEL))
                && super.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_DEL));
        }

        return super.deleteSurroundingText(beforeLength, afterLength);
    }
}

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