ui/text/RoundedBackground-Kotlin/lib/src/main/java/com/android/example/text/styling/roundedbg/RoundedBgTextView.kt

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * 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 com.android.example.text.styling.roundedbg

import android.content.Context
import android.graphics.Canvas
import android.text.Spanned
import android.util.AttributeSet
import androidx.appcompat.widget.AppCompatTextView
import androidx.core.graphics.withTranslation

/**
 * A TextView that can draw rounded background to the portions of the text. See
 * [TextRoundedBgHelper] for more information.
 *
 * See [TextRoundedBgAttributeReader] for supported attributes.
 */
class RoundedBgTextView : AppCompatTextView {

    private val textRoundedBgHelper: TextRoundedBgHelper

    @JvmOverloads
    constructor(
        context: Context,
        attrs: AttributeSet? = null,
        defStyleAttr: Int = android.R.attr.textViewStyle
    ) : super(context, attrs, defStyleAttr) {
        val attributeReader = TextRoundedBgAttributeReader(context, attrs)
        textRoundedBgHelper = TextRoundedBgHelper(
            horizontalPadding = attributeReader.horizontalPadding,
            verticalPadding = attributeReader.verticalPadding,
            drawable = attributeReader.drawable,
            drawableLeft = attributeReader.drawableLeft,
            drawableMid = attributeReader.drawableMid,
            drawableRight = attributeReader.drawableRight
        )
    }

    override fun onDraw(canvas: Canvas) {
        // need to draw bg first so that text can be on top during super.onDraw()
        if (text is Spanned && layout != null) {
            canvas.withTranslation(totalPaddingLeft.toFloat(), totalPaddingTop.toFloat()) {
                textRoundedBgHelper.draw(canvas, text as Spanned, layout)
            }
        }
        super.onDraw(canvas)
    }
}