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/*
* Copyright 2015 Google 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 ca.allanwang.kau.views
import android.content.Context
import android.graphics.*
import android.text.TextPaint
import android.util.AttributeSet
import android.util.DisplayMetrics
import android.util.TypedValue
import android.view.View
import ca.allanwang.kau.R
import ca.allanwang.kau.logging.KL
import ca.allanwang.kau.utils.dimenPixelSize
import ca.allanwang.kau.utils.getFont
import ca.allanwang.kau.utils.parentVisibleHeight
/**
* A view which punches out some text from an opaque color block, allowing you to see through it.
*/
class KauCutoutTextView @JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {
private val textPaint: TextPaint = TextPaint(Paint.ANTI_ALIAS_FLAG)
private var cutout: Bitmap? = null
var foregroundColor = Color.MAGENTA
var text: String? = "Text"
var overlayType: Int = 0 //todo add vector overlay options
private var textSize: Float = 0f
private var textY: Float = 0f
private var textX: Float = 0f
private var heightPercentage: Float = 0f
private var minHeight: Float = 0f
private val maxTextSize: Float
init {
if (attrs != null) {
val a = context.obtainStyledAttributes(attrs, R.styleable.KauCutoutTextView, 0, 0)
if (a.hasValue(R.styleable.KauCutoutTextView_kau_font))
textPaint.typeface = context.getFont(a.getString(R.styleable.KauCutoutTextView_kau_font))
foregroundColor = a.getColor(R.styleable.KauCutoutTextView_kau_foregroundColor, foregroundColor)
text = a.getString(R.styleable.KauCutoutTextView_android_text) ?: text
minHeight = a.getDimension(R.styleable.KauCutoutTextView_android_minHeight, minHeight)
heightPercentage = a.getFloat(R.styleable.KauCutoutTextView_kau_heightPercentageToScreen, heightPercentage)
a.recycle()
}
maxTextSize = context.dimenPixelSize(R.dimen.kau_display_4_text_size).toFloat()
}
override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
super.onSizeChanged(w, h, oldw, oldh)
calculateTextPosition()
createBitmap()
KL.d("Size changed")
}
private fun calculateTextPosition() {
val targetWidth = width / PHI
textSize = getSingleLineTextSize(text!!, textPaint, targetWidth, 0f, maxTextSize,
0.5f, resources.displayMetrics)
textPaint.textSize = textSize
// measuring text is fun :] see: https://chris.banes.me/2014/03/27/measuring-text/
textX = (width - textPaint.measureText(text)) / 2
val textBounds = Rect()
textPaint.getTextBounds(text, 0, text!!.length, textBounds)
val textHeight = textBounds.height().toFloat()
textY = (height + textHeight) / 2
}
/**
* If height percent is specified, ensure it is met
*/
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
val minHeight = Math.max(minHeight, heightPercentage * parentVisibleHeight)
val trueHeightMeasureSpec = if (minHeight > 0)
MeasureSpec.makeMeasureSpec(Math.max(minHeight.toInt(), measuredHeight), MeasureSpec.EXACTLY)
else heightMeasureSpec
super.onMeasure(widthMeasureSpec, trueHeightMeasureSpec)
}
/**
* Recursive binary search to find the best size for the text.
* Adapted from https://github.com/grantland/android-autofittextview
*/
fun getSingleLineTextSize(text: String,
paint: TextPaint,
targetWidth: Float,
low: Float,
high: Float,
precision: Float,
metrics: DisplayMetrics): Float {
val mid = (low + high) / 2.0f
paint.textSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, mid, metrics)
val maxLineWidth = paint.measureText(text)
if (high - low < precision) {
return low
} else if (maxLineWidth > targetWidth) {
return getSingleLineTextSize(text, paint, targetWidth, low, mid, precision, metrics)
} else if (maxLineWidth < targetWidth) {
return getSingleLineTextSize(text, paint, targetWidth, mid, high, precision, metrics)
} else {
return mid
}
}
private fun createBitmap() {
if (!(cutout?.isRecycled ?: true))
cutout?.recycle()
if (width == 0 || height == 0) return
cutout = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
cutout!!.setHasAlpha(true)
val cutoutCanvas = Canvas(cutout!!)
cutoutCanvas.drawColor(foregroundColor)
// this is the magic – Clear mode punches out the bitmap
textPaint.xfermode = PorterDuffXfermode(PorterDuff.Mode.CLEAR)
cutoutCanvas.drawText(text, textX, textY, textPaint)
}
override fun onDraw(canvas: Canvas) {
canvas.drawBitmap(cutout!!, 0f, 0f, null)
}
override fun hasOverlappingRendering(): Boolean = true
companion object {
val PHI = 1.6182f
}
}
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