在自定义ViewGroup中裁剪ImageViews

Question

我正在实现自定义ViewGroup，它具有重叠的ImageViews。 我使用GlideApp加载图像。问题是某些图像被裁剪了一些（在左侧可见），我无法防止这种情况。被裁剪的可绘制对象是Vector可绘制对象，它们的mDrawableWidth和mDrawableHeight大于ViewGroup的高度。我认为可以缩放图像以适合视图尺寸（mScaleType = FIT_CENTER）。

class OverlappingImageViewGroup : ViewGroup {

constructor(context: Context) : this(context, null)
constructor(context: Context, attrs: AttributeSet?) : this(context, attrs, 0)
constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr) {}

override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
    val widthSize: Int = getDefaultSize(0, widthMeasureSpec)
    val heightSize: Int = getDefaultSize(0, heightMeasureSpec)

    val majorDimension = Math.min(widthSize, heightSize)
    //Measure all child views
    val childSpec = MeasureSpec.makeMeasureSpec(majorDimension, MeasureSpec.EXACTLY)
    measureChildren(childSpec, childSpec)

    //MUST call this to save our own dimensions
    setMeasuredDimension(majorDimension, majorDimension)
}

override fun onLayout(changed: Boolean,
                      leftRelativeToParent: Int,
                      topRelativeToParent: Int,
                      rightRelativeToParent: Int,
                      bottomRelativeToParent: Int) {

    val percentOverlap = 0.8f

    if (childCount > 0) {
        for (i in 0 until childCount) {
            val child = getChildAt(i)
            val childWidth = child.measuredWidth

            val topBound = 0 /* there is just one row */

            if (i == 0) {
                child.layout(0, topBound, childWidth, childWidth)
            } else {
                val leftBound = i * percentOverlap * childWidth
                child.layout(
                        leftBound.toInt(),
                        topBound,
                        leftBound.toInt() + childWidth,
                        topBound + childWidth)
            }
        }
    }
}

}

以编程方式创建ImageView：

val context = holder.rootView.context
            val imageView: ImageView = ImageView(context)
            GlideApp.with(context)
                    .load(imageUrl)
                    .placeholder(userPlaceholder)
                    .fallback(userPlaceholder)
                    .error(userPlaceholder)
                    .transform(CircleWithBorderTransform())
                    .into(imageView)
            holder.membersIcons.addView(imageView)

滑行变换

override fun transform(pool: BitmapPool, source: Bitmap, outWidth: Int, outHeight: Int): Bitmap {

    val width = source.width
    val height = source.height

    val canvasBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
    val shader = BitmapShader(source, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP)
    val paint = Paint()
    paint.isAntiAlias = true
    paint.shader = shader

    val canvas = Canvas(canvasBitmap)
    val radius = if (width > height) height.toFloat() / 2f else width.toFloat() / 2f
    canvas.drawCircle((width / 2).toFloat(), (height / 2).toFloat(), radius, paint)

    //border around the image
    paint.shader = null
    paint.style = Paint.Style.STROKE
    paint.strokeWidth = 2f
    paint.color = Color.WHITE
    canvas.drawCircle((width / 2).toFloat(), (height / 2).toFloat(), radius, paint)

    return canvasBitmap
}