package com.dnaer.android.telephone.widgets;

import android.content.Context;
import android.os.Build;
import android.support.annotation.RequiresApi;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;

import com.anbetter.log.MLog;

public class MultiVideoChatLayout extends ViewGroup implements CommLayoutAdapter.OnDataChangedListener {

 private CommLayoutAdapter mCommLayoutAdapter;

 private int mScreenWidth;

 //人數為2,3,4狀態下的寬高度
 private int mSizeModel1;

 //人數為5,6,7,8，9狀態下的寬高度
 private int mSizeModel2;

 public MultiVideoChatLayout(Context context) {
 this(context, null);
 }

 public MultiVideoChatLayout(Context context, AttributeSet attrs) {
 this(context, attrs, 0);
 }

 public MultiVideoChatLayout(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 initialize(context);
 }

 @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
 public MultiVideoChatLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
 super(context, attrs, defStyleAttr, defStyleRes);
 initialize(context);
 }

 private void initialize(Context context) {
 WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
 DisplayMetrics metrics = new DisplayMetrics();
 wm.getDefaultDisplay().getMetrics(metrics);
 mScreenWidth = metrics.widthPixels;

 mSizeModel1 = mScreenWidth / 2;
 mSizeModel2 = mScreenWidth / 3;
 }

 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 //寬度默認給屏幕的寬度，高度直接取寬度，形成一個正方形
 final int width = MeasureSpec.makeMeasureSpec(mScreenWidth, MeasureSpec.EXACTLY);
 final int height = MeasureSpec.makeMeasureSpec(mScreenWidth, MeasureSpec.EXACTLY);
 setMeasuredDimension(width, height);

 MLog.d("width: " + width + ", height:" + height);

 final int childWidth = MeasureSpec.makeMeasureSpec(mScreenWidth / 3, MeasureSpec.EXACTLY);
 final int childHeight = MeasureSpec.makeMeasureSpec(mScreenWidth / 3, MeasureSpec.EXACTLY);

 final int childWidth3 = MeasureSpec.makeMeasureSpec(mScreenWidth / 2, MeasureSpec.EXACTLY);
 final int childHeight2 = MeasureSpec.makeMeasureSpec(mScreenWidth / 2, MeasureSpec.EXACTLY);

 if (getChildCount() > 4) {
 for (int i = 0; i < getChildCount(); i++) {
 View child = getChildAt(i);
 child.measure(childWidth, childHeight);
 }
 } else {
 for (int i = 0; i < getChildCount(); i++) {
 View child = getChildAt(i);
 child.measure(childWidth3, childHeight2);
 }
 }
 }

 @Override
 protected void onLayout(boolean changed, int l, int t, int r, int b) {
 if (getChildCount() <= 4) {
 layoutModel1();
 } else {
 layoutModel2();
 }
 }

 private void layoutModel2() {
 int currentWidth = 0;
 for (int i = 0; i < getChildCount(); i++) {
 View item = getChildAt(i);
 if (i % 3 == 0) {
 currentWidth = 0;
 item.layout(0, i / 3 * mSizeModel2, mSizeModel2, i / 3 * mSizeModel2 + mSizeModel2);
 } else {
 item.layout(currentWidth + mSizeModel2, i / 3 * mSizeModel2, currentWidth + 2 * mSizeModel2, i / 3 * mSizeModel2 + mSizeModel2);
 currentWidth = currentWidth + mSizeModel2;
 }
 }
 }

 private void layoutModel1() {
 if (getChildCount() == 3) {
 for (int i = 0; i < getChildCount(); i++) {
 View item = getChildAt(i);
 MLog.d("width: " + item.getMeasuredWidth() + ", height: " + item.getMeasuredHeight() + ", mSizeModel1: " + mSizeModel1);
 if (i == 0) {
 item.layout(0, 0, mSizeModel1, mSizeModel1);
 } else if (i == 1) {
 item.layout(mSizeModel1, 0, mSizeModel1 * 2, mSizeModel1);
 } else if (i == 2) {
 item.layout(mSizeModel1 / 2, mSizeModel1, mSizeModel1 + mSizeModel1 / 2, mSizeModel1 * 2);
 }
 }
 } else {
 for (int i = 0; i < getChildCount(); i++) {
 View item = getChildAt(i);
 if (i % 2 == 0) {
 item.layout(0, i / 2 * mSizeModel1, mSizeModel1, i / 2 * mSizeModel1 + mSizeModel1);
 } else {
 item.layout(mSizeModel1, i / 2 * mSizeModel1, 2 * mSizeModel1, i / 2 * mSizeModel1 + mSizeModel1);
 }
 }
 }
 }

 public void setAdapter(CommLayoutAdapter adapter) {
 mCommLayoutAdapter = adapter;
 mCommLayoutAdapter.setOnDataChangedListener(this);
 changedAdapter();
 }

 @Override
 public void onChanged() {
 changedAdapter();
 }

 private void changedAdapter() {
 removeAllViews();
 CommLayoutAdapter layoutAdapter = mCommLayoutAdapter;
 for (int i = 0; i < layoutAdapter.getCount(); i++) {
 View view = layoutAdapter.getView(this, i, layoutAdapter.getItem(i));
 view.setDuplicateParentStateEnabled(true);
 addView(view);
 }
 }
}

package org.fireking.customgridlayoutmanager

import android.content.res.Resources
import android.support.v7.widget.RecyclerView
import java.lang.IllegalArgumentException

class MultiChatLayoutManager : RecyclerView.LayoutManager() {

 private var leftMargin = 0
 private var rightMargin = 0
 private var mScreenWidth = 0

 override fun generateDefaultLayoutParams(): RecyclerView.LayoutParams {
 return RecyclerView.LayoutParams(RecyclerView.LayoutParams.WRAP_CONTENT, RecyclerView.LayoutParams.WRAP_CONTENT)
 }

 override fun onLayoutChildren(recycler: RecyclerView.Recycler?, state: RecyclerView.State?) {
 super.onLayoutChildren(recycler, state)
 if (itemCount == 0) {
 detachAndScrapAttachedViews(recycler!!)
 return
 }
 if (childCount == 0 && state!!.isPreLayout) {
 return
 }
 val params = recycler!!.getViewForPosition(0).layoutParams as RecyclerView.LayoutParams
 leftMargin = params.leftMargin
 rightMargin = params.rightMargin
 detachAndScrapAttachedViews(recycler)
 layoutItem(recycler)
 }

 private fun layoutItem(recycler: RecyclerView.Recycler) {

 if (itemCount > 9) {
 throw IllegalArgumentException("${javaClass.simpleName}最多支持9個item布局， 請檢查你的item個數是否正確")
 }

 mScreenWidth = Resources.getSystem().displayMetrics.widthPixels

 val itemSize = if (itemCount > 4) {
 mScreenWidth / 3
 } else {
 mScreenWidth / 2
 }

 if (itemCount <= 4) {
 if (itemCount == 3) {
 for (i in 0 until itemCount) {
 val view = recycler.getViewForPosition(i)
 addView(view) // 因為detach過所以重新添加
 measureChildWithMargins(view, 0, 0)
 when (i) {
 0 -> layoutDecoratedWithMargins(view, 0, 0, itemSize, itemSize)
 1 -> layoutDecoratedWithMargins(view, itemSize, 0, itemSize * 2, itemSize)
 else -> layoutDecoratedWithMargins(
 view,
 itemSize / 2,
 itemSize,
 itemSize + itemSize / 2,
 itemSize * 2
 )
 }
 }
 } else {
 for (i in 0 until itemCount) {
 val view = recycler.getViewForPosition(i)
 addView(view) // 因為detach過所以重新添加
 measureChildWithMargins(view, 0, 0)
 if (i % 2 == 0) {
 layoutDecoratedWithMargins(view, 0, i / 2 * itemSize, itemSize, i / 2 * itemSize + itemSize)
 } else {
 layoutDecoratedWithMargins(
 view,
 itemSize,
 i / 2 * itemSize,
 2 * itemSize,
 i / 2 * itemSize + itemSize
 )
 }
 }
 }
 } else {
 var currentWidth = 0
 for (i in 0 until itemCount) {
 val view = recycler.getViewForPosition(i)
 addView(view) // 因為detach過所以重新添加
 measureChildWithMargins(view, 0, 0)
 if (i % 3 == 0) {
 currentWidth = 0
 layoutDecoratedWithMargins(view, 0, i / 3 * itemSize, itemSize, i / 3 * itemSize + itemSize)
 } else {
 layoutDecoratedWithMargins(
 view,
 currentWidth + itemSize,
 i / 3 * itemSize,
 currentWidth + 2 * itemSize,
 i / 3 * itemSize + itemSize
 )
 currentWidth += itemSize
 }
 }
 }
 }

 //因為這個布局不需要有滾動，所以直接將橫豎兩個方向的滾動全部取消了
 override fun canScrollHorizontally(): Boolean {
 return false
 }

 override fun canScrollVertically(): Boolean {
 return false
 }
}