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
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
/*
* This file is part of GNU Taler
* (C) 2020 Taler Systems S.A.
*
* GNU Taler is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation; either version 3, or (at your option) any later version.
*
* GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with
* GNU Taler; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
package net.taler.merchantpos.order
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.fragment.app.activityViewModels
import androidx.recyclerview.selection.SelectionPredicates
import androidx.recyclerview.selection.SelectionTracker
import androidx.recyclerview.selection.StorageStrategy
import androidx.recyclerview.widget.LinearLayoutManager
import net.taler.common.Amount
import net.taler.common.fadeIn
import net.taler.common.fadeOut
import net.taler.merchantpos.MainViewModel
import net.taler.merchantpos.R
import net.taler.merchantpos.databinding.FragmentOrderStateBinding
import net.taler.merchantpos.order.OrderAdapter.OrderLineLookup
class OrderStateFragment : Fragment() {
private val viewModel: MainViewModel by activityViewModels()
private val orderManager by lazy { viewModel.orderManager }
private val liveOrder by lazy { orderManager.getOrder(orderManager.currentOrderId.value!!) }
private lateinit var ui: FragmentOrderStateBinding
private val adapter = OrderAdapter()
private var tracker: SelectionTracker<String>? = null
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
ui = FragmentOrderStateBinding.inflate(inflater, container, false)
return ui.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
ui.orderList.apply {
adapter = this@OrderStateFragment.adapter
layoutManager = LinearLayoutManager(requireContext())
}
val detailsLookup = OrderLineLookup(ui.orderList)
val tracker = SelectionTracker.Builder(
"order-selection-id",
ui.orderList,
adapter.keyProvider,
detailsLookup,
StorageStrategy.createStringStorage()
).withSelectionPredicate(
SelectionPredicates.createSelectSingleAnything()
).build()
savedInstanceState?.let { tracker.onRestoreInstanceState(it) }
adapter.tracker = tracker
this.tracker = tracker
if (savedInstanceState == null) {
// select last selected order line when re-creating this fragment
// do it before attaching the tracker observer
liveOrder.selectedProductKey?.let { tracker.select(it) }
}
tracker.addObserver(object : SelectionTracker.SelectionObserver<String>() {
override fun onItemStateChanged(key: String, selected: Boolean) {
super.onItemStateChanged(key, selected)
val item = if (selected) adapter.getItemByKey(key) else null
liveOrder.selectOrderLine(item)
}
})
liveOrder.order.observe(viewLifecycleOwner) { order ->
if (order == null) return@observe
onOrderChanged(order, tracker)
}
liveOrder.orderTotal.observe(viewLifecycleOwner) { orderTotal: Amount ->
if (orderTotal.isZero()) {
ui.totalView.fadeOut()
ui.totalView.text = null
} else {
ui.totalView.text = getString(R.string.order_total, orderTotal)
ui.totalView.fadeIn()
}
}
}
override fun onSaveInstanceState(outState: Bundle) {
super.onSaveInstanceState(outState)
tracker?.onSaveInstanceState(outState)
}
private fun onOrderChanged(order: Order, tracker: SelectionTracker<String>) {
adapter.setItems(order.products) {
liveOrder.lastAddedProduct?.let {
val position = adapter.findPosition(it)
if (position >= 0) {
ui.orderList.scrollToPosition(position)
ui.orderList.post { this.tracker?.select(it.id) }
}
}
// workaround for bug: SelectionObserver doesn't update when removing selected item
if (tracker.hasSelection()) {
val key = tracker.selection.first()
val product = order.products.find { it.id == key }
if (product == null) tracker.clearSelection()
}
}
}
}
|
