android – Use a custom contextual action bar for WebView text selection-ThrowExceptions

Exception or error:

I have used this guide from Google and this tutorial to produce my own contextual action bar.

private ActionMode.Callback mActionModeCallback = new ActionMode.Callback() {

    // Called when the action mode is created; startActionMode() was called
    @Override
    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
        // Inflate a menu resource providing context menu items
        MenuInflater inflater = mode.getMenuInflater();
        inflater.inflate(R.menu.annotation_menu, menu);
        return true;
    }

    // Called each time the action mode is shown.
    // Always called after onCreateActionMode, but
    // may be called multiple times if the mode is invalidated.
    @Override
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
        return false; // Return false if nothing is done
    }

    // Called when the user selects a contextual menu item
    @Override
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
        switch (item.getItemId()) {
            case R.id.custom_button:
                // do some stuff
                break;
            case R.id.custom_button2:
                // do some other stuff
                break;
            default:
                // This essentially acts as a catch statement
                // If none of the other cases are true, return false
                // because the action was not handled
                return false;
        }
        finish(); // An action was handled, so close the CAB
        return true;
    }

    // Called when the user exits the action mode
    @Override
    public void onDestroyActionMode(ActionMode mode) {
        mActionMode = null;
    }
};

This menu is designed to appear when the user selects text, so it overrides the native copy/paste menu. Now I get to my issue.

Because I am overriding functions for text selection, I also added a LongClickListener to a WebView and implemented the onLongClick(View v) method so I can detect when users make the selection.

    myWebView.setOnLongClickListener(new View.OnLongClickListener() {

        @Override
        public boolean onLongClick(View v) {
            if (mActionMode != null) {
                return false;
            }

            mActionMode = startActionMode(mActionModeCallback);
            v.setSelected(true);
            return true;
        }
    });

When I long click, I see my custom menu appear, but no text is highlighted.
I need to have the text selection functionality; without it, my menu is pointless.

How do I override onLongClick(View v), but maintain the text selection provided by Android?
If that is not possible, can I make the call to startActionMode(mActionModeCallback) somewhere else so that text will be selected as normal, but my custom menu will also appear?
If neither of those are possible… help.

How to solve:

THERE IS AN EASIER WAY! See update below 😀


For the sake of completeness, here is how I fixed the problem:

I followed the suggestion according to this answer, with a little more tweaking to more closely match the overridden code:

public class MyWebView extends WebView {

    private ActionMode mActionMode;
    private mActionMode.Callback mActionModeCallback;

    @Override
    public ActionMode startActionMode(Callback callback) {
        ViewParent parent = getParent();
        if (parent == null) {
            return null;
        }
        mActionModeCallback = new CustomActionModeCallback();
        return parent.startActionModeForChild(this, mActionModeCallback);
    }
}

Essentially, this forces your customized CAB to appear instead of the Android CAB. Now you have to modify your callback so that the text highlight will go away along with the CAB:

public class MyWebView extends WebView {
    ...
    private class CustomActionModeCallback implements ActionMode.Callback {
        ...
        // Everything up to this point is the same as in the question

        // Called when the user exits the action mode
        @Override
        public void onDestroyActionMode(ActionMode mode) {
            clearFocus(); // This is the new code to remove the text highlight
             mActionMode = null;
        }
    }
}

That’s all there is to it. Be aware that as long as you are using MyWebView with the overridden startActionMode there is NO WAY to get the native CAB (the copy/paste menu, in the case of a WebView). It may be possible to implement that sort of behavior, but that is not the way this code works.


UPDATE: There is a much easier way to do this! The above solution works well, but here is an alternative, easier way.

This solution provides less control over the ActionMode, but it requires far less code than the above solution.

public class MyActivity extends Activity {

    private ActionMode mActionMode = null;

    @Override
    public void onActionModeStarted(ActionMode mode) {
        if (mActionMode == null) {
            mActionMode = mode;
            Menu menu = mode.getMenu();
            // Remove the default menu items (select all, copy, paste, search)
            menu.clear();

            // If you want to keep any of the defaults,
            // remove the items you don't want individually:
            // menu.removeItem(android.R.id.[id_of_item_to_remove])

            // Inflate your own menu items
            mode.getMenuInflater().inflate(R.menu.my_custom_menu, menu);
        }

        super.onActionModeStarted(mode);
    }

    // This method is what you should set as your item's onClick
    // <item android:onClick="onContextualMenuItemClicked" />
    public void onContextualMenuItemClicked(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.example_item_1:
                // do some stuff
                break;
            case R.id.example_item_2:
                // do some different stuff
                break;
            default:
                // ...
                break;
        }

        // This will likely always be true, but check it anyway, just in case
        if (mActionMode != null) {
            mActionMode.finish();
        }
    }

    @Override
    public void onActionModeFinished(ActionMode mode) {
        mActionMode = null;
        super.onActionModeFinished(mode);
    }
}

Here is an example Menu to get you started:

<!-- my_custom_menu.xml -->
<?xml version="1.0" encoding="utf-8"?>

<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@+id/example_item_1"
        android:icon="@drawable/ic_menu_example_1"
        android:showAsAction="always"
        android:onClick="onContextualMenuItemClicked"
        android:title="@string/example_1">
    </item>

    <item
        android:id="@+id/example_item_2"
        android:icon="@drawable/ic_menu_example_2"
        android:showAsAction="ifRoom"
        android:onClick="onContextualMenuItemClicked"
        android:title="@string/example_2">
    </item>

</menu>

That’s it! You’re done! Now your custom menu will show up, you don’t have to worry about the selection, and you barely have to concern yourself with the ActionMode lifecycle.

This works nearly flawlessly with a WebView that occupies its entire parent Activity. I am not sure how well it will work if there are multiple Views within your Activity at one time. It will likely require some tweaking in that case.

###

The way I did something similar was to only override the onTouchListener and to invoke a GestureDetector to detect when the WebView was long-pressed and do what I wanted from there. Here’s some sample code that allows you to catch long-press events without sacrificing text-selection in the WebView. Hopefully this helps.

@Override
protected void onCreate(Bundle savedInstanceState) {
    WebView mWebView = (WebView) findViewById(R.id.myWebView);
    GestureDetector mGestureDetector = new GestureDetector(this, new CustomGestureListener());
    mWebView.setOnTouchListener(new OnTouchListener(){
        @Override
        public boolean onTouch(View view, MotionEvent arg1) {

            //Suggestion #1 - this just lets the touch to be handled by the system but allows you to detect long presses
            mGestureDetector.onTouchEvent(arg1);
            return false;

            //Suggestion #2 - this code will only let the touch be handled by the system if you don't detect a long press
            return mGestureDetector.onTouchEvent(arg1);
        }
    });
}

private class CustomGestureListener extends SimpleOnGestureListener {

    @Override
    public void onLongPress(MotionEvent e) {
        //do stuff
    }

}

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