GifSpanChangeWatcher.java

package net.coding.program.common.enter;

import android.graphics.drawable.Drawable;
import android.text.Editable;
import android.text.SpanWatcher;
import android.text.Spannable;
import android.text.Spanned;
import android.text.TextWatcher;

/**
 * Created by chenchao on 15/9/15.
 */
public class GifSpanChangeWatcher implements SpanWatcher, TextWatcher {

    private Drawable.Callback mCallback;

    public GifSpanChangeWatcher(Drawable.Callback callback) {
        mCallback = callback;
    }

    public void onSpanChanged(Spannable buf, Object what, int s, int e, int st, int en) {
        //do nothing
    }

    public void onSpanAdded(Spannable buf, Object what, int s, int e) {
        //设置callback
        if (what instanceof GifImageSpan) {
            ((GifImageSpan) what).getDrawable().setCallback(mCallback);
        }
    }

    public void onSpanRemoved(Spannable buf, Object what, int s, int e) {
        //清空callback
        if (what instanceof GifImageSpan) {
            ((GifImageSpan) what).getDrawable().setCallback(null);
        }
    }

    @Override
    public void afterTextChanged(Editable s) {
        if (s != null) {
            s.setSpan(this, 0, s.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE | (100 << Spanned.SPAN_PRIORITY_SHIFT));
        }
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }

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

}