android - How to get the selected text of webview in ActionMode override

Question

I am adding some custom menu items in the Contextual Action Menu. I need to give a web search feature with the words selected in the WebView.

I override the ActionMode using this code.

@Override
    public void onActionModeStarted(ActionMode mode) {
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            if (mActionMode == null) {
                mActionMode = mode;
            Menu menu = mode.getMenu();

            mode.getMenuInflater().inflate(R.menu.menu_search, menu);
        }
    }
    super.onActionModeStarted(mode);
}


public void onContextualMenuItemClicked(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.menu_search:
            //HERE I WANT TO GET THE TEXT: HOW CAN I?
            break;
    }

    if (mActionMode != null) {
        mActionMode.finish();
    }
}

I want to search my site using the word selected by the user in the webview, but I couln't get the way to get the selected text. How could i get that, any one please help.

Thanks in advance.

Answer 1

The only way to get text selection from a WebView is based on javascript. This is not specific to the action mode, this is how WebView text selection is supposed to be retrieved according to WebView developers' point of view. They deliberately decided to not provide an API to access text selection from Java.

The solution comprise 2 approaches.

With Android API >= 19 you can use evaluateJavascript:

webview.evaluateJavascript("(function(){return window.getSelection().toString()})()",
new ValueCallback<String>()
{
    @Override
    public void onReceiveValue(String value)
    {
        Log.v(TAG, "SELECTION:" + value);
    }
});

On older builds your only resort is a custom javascript interface with a single method accepting String, which you should call via webview.loadUrl passing the same thing:

webview.loadUrl("javascript:js.callback(window.getSelection().toString())");

where js is the attached javascript interface:

webview.getSettings().setJavaScriptEnabled(true);
webview.addJavascriptInterface(new WebAppInterface(), "js");

and

public class WebAppInterface
{
    @JavascriptInterface
    public void callback(String value)
    {
        Log.v(TAG, "SELECTION:" + value);
    }
}