SubwayTooter-Android-App/colorpicker/src/main/java/com/jrummyapps/android/colorpicker/TilePatternDrawable.kt

67 lines
2.4 KiB
Kotlin

/*
* Copyright (C) 2017 JRummy Apps Inc.
*
* 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.jrummyapps.android.colorpicker
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.ColorFilter
import android.graphics.Paint
import android.graphics.PixelFormat
import android.graphics.Rect
import android.graphics.drawable.Drawable
import kotlin.math.min
/**
* This drawable will draw a simple white and gray chessboard pattern.
* It's the pattern you will often see as a background behind a partly transparent image in many applications.
*/
internal class TilePatternDrawable(
private val rectangleSize: Int,
) : Drawable() {
private val rect = Rect()
private val paintWhite = Paint().apply { color = Color.WHITE }
private val paintGray = Paint().apply { color = -0x343434 }
override fun draw(canvas: Canvas) {
val xEnd = bounds.right
val yEnd = bounds.bottom
var verticalStartWhite = true
for (y in bounds.top until yEnd step rectangleSize) {
rect.top = y
rect.bottom = min(yEnd, y + rectangleSize)
var isWhite = verticalStartWhite
for (x in bounds.left until xEnd step rectangleSize) {
rect.left = x
rect.right = min(xEnd, x + rectangleSize)
canvas.drawRect(rect, if (isWhite) paintWhite else paintGray)
isWhite = !isWhite
}
verticalStartWhite = !verticalStartWhite
}
}
@Suppress("OVERRIDE_DEPRECATION")
override fun getOpacity() = PixelFormat.OPAQUE
override fun setAlpha(alpha: Int) {
throw UnsupportedOperationException("Alpha is not supported by this drawable.")
}
override fun setColorFilter(cf: ColorFilter?) {
throw UnsupportedOperationException("ColorFilter is not supported by this drawable.")
}
}