-
Notifications
You must be signed in to change notification settings - Fork 2
/
InfiniteBannerActivity.kt
91 lines (76 loc) · 3.24 KB
/
InfiniteBannerActivity.kt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
@SuppressLint("Registered")
class InfiniteScrollActivity : AppCompatActivity() {
private val handler = Handler()
lateinit var changeItemRunnable: Runnable
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val resList =
mutableListOf<Int>(R.drawable.ic_launcher_background, R.drawable.ic_launcher_foreground)
val manager = LinearLayoutManager(this, RecyclerView.HORIZONTAL, false)
val adapter = InfiniteScrollAdapter(this, resList)
val snapHelper = PagerSnapHelper()
// 配置列表
recycler_view_main.apply {
layoutManager = manager
this.adapter = adapter
addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
super.onScrollStateChanged(recyclerView, newState)
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
changeBanner()
snapHelper.findSnapView(manager)?.apply {
// 指示器
([email protected]_group_main[recycler_view_main.getChildAdapterPosition(
this
) % resList.size] as RadioButton).isChecked = true
}
} else stopBanner()
}
})
}
changeItemRunnable = Runnable {
val pos = recycler_view_main.getChildAdapterPosition(snapHelper.findSnapView(manager)!!)
recycler_view_main.smoothScrollToPosition(pos + 1)
}
handler.post {
// 无限滚动可以左滑
recycler_view_main.scrollToPosition(Int.MAX_VALUE.shr(1))
// 初始化指示器
recycler_view_main.smoothScrollToPosition(Int.MAX_VALUE.shr(1) + 1)
}
}
fun changeBanner() {
stopBanner()
handler.postDelayed(changeItemRunnable, 5000)
}
fun stopBanner(): Unit = handler.removeCallbacks(changeItemRunnable)
override fun onResume() {
super.onResume()
// 滚动
changeBanner()
}
override fun onPause() {
super.onPause()
// 防止资源消耗
stopBanner()
}
class InfiniteScrollAdapter(
val context: Context,
private val drawableResList: MutableList<Int>
) :
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
return object : RecyclerView.ViewHolder(ImageView(context).apply {
layoutParams = ViewGroup.LayoutParams(MATCH_PARENT, WRAP_CONTENT)
}) {}
}
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
val nowData = drawableResList[position % drawableResList.size]
(holder.itemView as ImageView).setImageResource(nowData)
}
override fun getItemCount(): Int = Int.MAX_VALUE
override fun getItemId(position: Int): Long =
super.getItemId(position % drawableResList.size)
}
}