android - EditText with SpannableStringBuilder and ImageSpan doesn't works fine

Question

I'm trying to put emoticons inside a EditText. I've managed to do it and it works fine but I have a problem when I try to delete these emoticons from the EditText using the soft keyboard. I can't do this action with a single delete button's click. When I insert a new ImageSpan I replace an imageId for it but when I try to delete de icon I have to delete all the imageId characters before delete the image.

String fileName = "emoticon1.png";
Drawable d = new BitmapDrawable(getResources(), fileName);
String imageId = "[" + fileName + "]";
int cursorPosition = content.getSelectionStart();
int end = cursorPosition + imageId.length();
content.getText().insert(cursorPosition, imageId);

SpannableStringBuilder ss = new SpannableStringBuilder(content.getText());
d.setBounds(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight());
ImageSpan span = new ImageSpan(d, ImageSpan.ALIGN_BASELINE);
ss.setSpan(span, cursorPosition, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
content.setText(ss, TextView.BufferType.SPANNABLE);
content.setSelection(end);

I need to remove the emoticons with a single delete button's click. Could you help me, please?

Thanks!

Answer 1

This is the implementation to handle emoticons inside a EditText. This implementation uses the TextWatcher to monitor the EditText changes and detect if some emoticon was removed when some text is deleted.

Note that this implementation also verifies if a text selection was deleted (not only the delete key).

To avoid issues with text prediction when typing a text, it is recommended to surround the emoticon text with spaces (the text prediction can join the emoticon text with the adjacent text).

package com.takamori.testapp;

import java.util.ArrayList;

import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.text.Editable;
import android.text.Spanned;
import android.text.TextWatcher;
import android.text.style.ImageSpan;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.EditText;

public class MainActivity extends Activity {

    private EmoticonHandler mEmoticonHandler;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        EditText editor = (EditText) findViewById(R.id.messageEditor);
        // Create the emoticon handler.
        mEmoticonHandler = new EmoticonHandler(editor);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_insert_emoticon:
                // WARNING: The emoticon text shall be surrounded by spaces
                // to avoid issues with text prediction.
                mEmoticonHandler.insert(" :-) ", R.drawable.smile);
                return true;

            default:
                return super.onOptionsItemSelected(item);
        }
    }

    private static class EmoticonHandler implements TextWatcher {

        private final EditText mEditor;
        private final ArrayList<ImageSpan> mEmoticonsToRemove = new ArrayList<ImageSpan>();

        public EmoticonHandler(EditText editor) {
            // Attach the handler to listen for text changes.
            mEditor = editor;
            mEditor.addTextChangedListener(this);
        }

        public void insert(String emoticon, int resource) {
            // Create the ImageSpan
            Drawable drawable = mEditor.getResources().getDrawable(resource);
            drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
            ImageSpan span = new ImageSpan(drawable, ImageSpan.ALIGN_BASELINE);

            // Get the selected text.
            int start = mEditor.getSelectionStart();
            int end = mEditor.getSelectionEnd();
            Editable message = mEditor.getEditableText();

            // Insert the emoticon.
            message.replace(start, end, emoticon);
            message.setSpan(span, start, start + emoticon.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        }

        @Override
        public void beforeTextChanged(CharSequence text, int start, int count, int after) {
            // Check if some text will be removed.
            if (count > 0) {
                int end = start + count;
                Editable message = mEditor.getEditableText();
                ImageSpan[] list = message.getSpans(start, end, ImageSpan.class);

                for (ImageSpan span : list) {
                    // Get only the emoticons that are inside of the changed
                    // region.
                    int spanStart = message.getSpanStart(span);
                    int spanEnd = message.getSpanEnd(span);
                    if ((spanStart < end) && (spanEnd > start)) {
                        // Add to remove list
                        mEmoticonsToRemove.add(span);
                    }
                }
            }
        }

        @Override
        public void afterTextChanged(Editable text) {
            Editable message = mEditor.getEditableText();

            // Commit the emoticons to be removed.
            for (ImageSpan span : mEmoticonsToRemove) {
                int start = message.getSpanStart(span);
                int end = message.getSpanEnd(span);

                // Remove the span
                message.removeSpan(span);

                // Remove the remaining emoticon text.
                if (start != end) {
                    message.delete(start, end);
                }
            }
            mEmoticonsToRemove.clear();
        }

        @Override
        public void onTextChanged(CharSequence text, int start, int before, int count) {
        }

    }
}