Kotlin:FlowLayout横向流式自定义布局
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2022-09-05 11:20:12
package com.chenxh.flowlayoutimport android.content.Contextimport android.content.res.Resourcesimport android.graphics.Canvasimport android.icu.util.Measureimport android.util.AttributeSetimport android.util.Logimport android.util.TypedValueimport...
package com.chenxh.flowlayout
import android.content.Context
import android.content.res.Resources
import android.graphics.Canvas
import android.icu.util.Measure
import android.util.AttributeSet
import android.util.Log
import android.util.TypedValue
import android.view.View
import android.view.View.MeasureSpec.EXACTLY
import android.view.ViewGroup
/**
* @description:
*
* @Date: 2021/1/13
*/
class FlowLayout1 : ViewGroup {
/**
* 每行的View集合
*/
private var mLinesView: MutableList<MutableList<View>> = mutableListOf()
/**
* 行高
*/
private var mLineHeight: MutableList<Int> = mutableListOf()
/**
* 水平、垂直间距
*/
private val mHorizontalSpacing = dp2px(20) //每个item横向间距
private val mVerticalSpacing = dp2px(8) //每个item横向间距
constructor(context: Context) : super(context) {
}
constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {
}
constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(
context,
attrs,
defStyleAttr
) {
}
fun clearData() {
mLinesView.clear()
mLineHeight.clear()
}
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
clearData()
//孩子个数
val childCount = childCount
ll("childCount = $childCount")
//解析 MeasureSpec
val selfWidth = MeasureSpec.getSize(widthMeasureSpec)
val selfWidthMode = MeasureSpec.getMode(widthMeasureSpec)
val selfHeight = MeasureSpec.getSize(widthMeasureSpec)
val selfHeightMode = MeasureSpec.getMode(widthMeasureSpec)
//当前行 使用宽度
var lineUseWidth = 0
//一行记录
var lineViews = mutableListOf<View>()
//行高
var lineHeight = 0
//该View 所需宽度 高度
var parentNeedHeight = 0
var parentNeedWidth = 0
//遍历子View
for (i in 0 until childCount) {
val childView = getChildAt(i)
val childLP = childView.layoutParams
val childWidthMeasureSpec = getChildMeasureSpec(
widthMeasureSpec,
paddingLeft + paddingRight,
childLP.width)
val childHeightMeasureSpec = getChildMeasureSpec(
heightMeasureSpec,
paddingTop + paddingBottom,
childLP.height
)
childView.measure(childWidthMeasureSpec, childHeightMeasureSpec)
//子View 宽高
val childMeasureWidth = childView.measuredWidth
val childMeasureHeight = childView.measuredHeight
ll("onMeasure childMeasureWidth = $childMeasureWidth")
ll("onMeasure childMeasureHeight = $childMeasureHeight")
if (childMeasureWidth + mHorizontalSpacing + lineUseWidth > selfWidth) {
mLinesView.add(lineViews)
mLineHeight.add(lineHeight)
//存入
parentNeedHeight += lineHeight + mVerticalSpacing
parentNeedWidth = Integer.max(parentNeedWidth, lineUseWidth + mHorizontalSpacing)
//重置换行
lineViews = ArrayList()
lineHeight = 0
lineUseWidth = 0
}
lineViews.add(childView)
lineUseWidth += childMeasureWidth + mHorizontalSpacing
lineHeight = Integer.max(lineHeight, childMeasureHeight)
if (i == childCount - 1) {
mLinesView.add(lineViews)
mLineHeight.add(lineHeight)
parentNeedHeight += lineHeight + mVerticalSpacing
parentNeedWidth = Integer.max(parentNeedWidth, lineUseWidth + mHorizontalSpacing)
}
}
val realWidth = if (selfWidthMode == EXACTLY) selfWidth else parentNeedWidth
val realHeight = if (selfHeightMode == EXACTLY) selfHeight else parentNeedHeight
setMeasuredDimension(realWidth, realHeight)
}
override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {
var curL: Int = paddingLeft
var curT: Int = paddingTop
for (i in 0 until mLinesView.size) {
ll("onLayout line = $i")
val curList: MutableList<View> = mLinesView[i]
val lineHeight: Int = mLineHeight[i]
curList.forEach {
val left = curL
val top = curT
val right = left + it.measuredWidth
val bottom = top + it.measuredHeight
it.layout(left, top, right, bottom)
curL = right + mHorizontalSpacing
}
curL = paddingLeft
curT += lineHeight + mVerticalSpacing
}
}
override fun onDraw(canvas: Canvas?) {
super.onDraw(canvas)
}
fun dp2px(dp: Int): Int {
return TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_DIP,
dp.toFloat(),
Resources.getSystem().displayMetrics
).toInt()
}
fun ll(msg: String) {
Log.e("chenxh1", msg)
}
}
本文地址:https://blog.csdn.net/Mr_ChenXu/article/details/112557919
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