Java tutorial
/* * Copyright (c) 2015 Ha Duy Trung * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package io.github.hidroh.materialistic.widget; import android.content.Context; import android.graphics.Canvas; import android.graphics.Paint; import android.support.annotation.NonNull; import android.support.v4.content.ContextCompat; import android.text.style.ReplacementSpan; import io.github.hidroh.materialistic.AppUtils; import io.github.hidroh.materialistic.R; public class AsteriskSpan extends ReplacementSpan { private final int mBackgroundColor; private final int mTextColor; private final float mPadding; public AsteriskSpan(Context context) { super(); mBackgroundColor = ContextCompat.getColor(context, AppUtils.getThemedResId(context, R.attr.colorAccent)); mTextColor = ContextCompat.getColor(context, android.R.color.transparent); mPadding = context.getResources().getDimension(R.dimen.padding_asterisk); } @Override public int getSize(@NonNull Paint paint, CharSequence text, int start, int end, Paint.FontMetricsInt fm) { return Math.round(mPadding * 4); // padding let + radius * 2 + padding right } @Override public void draw(@NonNull Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, @NonNull Paint paint) { float radius = mPadding; float centerX = x + radius + mPadding; float centerY = top + radius + mPadding; paint.setColor(mBackgroundColor); canvas.drawCircle(centerX, centerY, radius, paint); paint.setColor(mTextColor); canvas.drawText(text, start, end, x + mPadding * 2, y, paint); } }