TagsSelector undo feature

app/src/main/java/space/taran/arknavigator/mvp/presenter/ResourcesPresenter.kt

@@ -9,12 +9,11 @@ import space.taran.arknavigator.mvp.model.UserPreferences
 import space.taran.arknavigator.mvp.model.dao.ResourceId
 import space.taran.arknavigator.mvp.model.repo.*
 import space.taran.arknavigator.mvp.presenter.adapter.ResourcesGridPresenter
-import space.taran.arknavigator.mvp.presenter.adapter.TagsSelectorPresenter
+import space.taran.arknavigator.mvp.presenter.adapter.tagsselector.TagsSelectorPresenter
 import space.taran.arknavigator.mvp.view.ResourcesView
 import space.taran.arknavigator.ui.App
 import space.taran.arknavigator.ui.fragments.utils.Notifications
 import space.taran.arknavigator.utils.RESOURCES_SCREEN
-import space.taran.arknavigator.utils.Tags
 import java.nio.file.Path
 import javax.inject.Inject
 
@@ -133,6 +132,12 @@ class ResourcesPresenter(
         viewState.closeSortDialog()
     }
 
+    fun onBackClick(): Boolean {
+        if (!tagsSelectorPresenter.onBackClick())
+            router.exit()
+        return true
+    }
+
     private fun onSelectionChange(selection: Set<ResourceId>) {
         viewState.notifyUser("${selection.size} resources selected")
         gridPresenter.updateResources(selection.toList())

app/src/main/java/space/taran/arknavigator/mvp/presenter/adapter/tagsselector/TagsSelectorActions.kt

@@ -0,0 +1,12 @@
+package space.taran.arknavigator.mvp.presenter.adapter.tagsselector
+
+import space.taran.arknavigator.utils.Tag
+
+sealed class TagsSelectorAction(val tag: Tag?)
+
+class Include(tag: Tag): TagsSelectorAction(tag)
+class Exclude(tag: Tag): TagsSelectorAction(tag)
+class UncheckIncluded(tag: Tag): TagsSelectorAction(tag)
+class UncheckExcluded(tag: Tag): TagsSelectorAction(tag)
+class UncheckAndExclude(tag: Tag): TagsSelectorAction(tag)
+class Clear(val included: Set<Tag>, val excluded: Set<Tag>): TagsSelectorAction(null)

app/src/main/java/space/taran/arknavigator/mvp/presenter/adapter/TagsSelectorPresenter.kt → app/src/main/java/space/taran/arknavigator/mvp/presenter/adapter/tagsselector/TagsSelectorPresenter.kt

@@ -1,4 +1,4 @@
-package space.taran.arknavigator.mvp.presenter.adapter
+package space.taran.arknavigator.mvp.presenter.adapter.tagsselector
 
 import android.util.Log
 import space.taran.arknavigator.mvp.model.dao.ResourceId
@@ -18,6 +18,7 @@ class TagsSelectorPresenter(
 ) {
     private var index: ResourcesIndex? = null
     private var storage: TagsStorage? = null
+    private val actions = ArrayDeque<TagsSelectorAction>()
 
     var included = mutableSetOf<Tag>()
         private set
@@ -59,7 +60,8 @@ class TagsSelectorPresenter(
     }
 
     fun onClearClick() {
-        (included + excluded).forEach { uncheckTag(it, needToCalculate = false) }
+        actions.addLast(Clear(included.toSet(), excluded.toSet()))
+        (included + excluded).forEach { uncheckTag(it, fromClearClick = true) }
         calculateTagsAndSelection()
     }
 
@@ -116,11 +118,66 @@ class TagsSelectorPresenter(
         viewState.drawTags()
     }
 
+    fun onBackClick(): Boolean {
+        verifyActions()
+
+        if (actions.isEmpty())
+            return false
+
+        when(val action = actions.last()) {
+            is Include -> {
+                included.remove(action.tag!!)
+            }
+            is Exclude -> {
+                excluded.remove(action.tag!!)
+            }
+            is UncheckIncluded -> {
+                included.add(action.tag!!)
+            }
+            is UncheckExcluded -> {
+                excluded.add(action.tag!!)
+            }
+            is UncheckAndExclude -> {
+                included.remove(action.tag!!)
+                excluded.add(action.tag)
+            }
+            is Clear -> {
+                included = action.included.toMutableSet()
+                excluded = action.excluded.toMutableSet()
+            }
+        }
+
+        actions.removeLast()
+
+        calculateTagsAndSelection()
+
+        return true
+    }
+
+    private fun verifyActions() {
+        if (storage == null || index == null)
+            return
+
+        val allTags = storage!!.getTags(index!!.listIds(prefix))
+        actions.toList().forEach { action ->
+            action.tag?.let { tag ->
+                if (!allTags.contains(tag))
+                    actions.remove(action)
+            } ?: let {
+                action as Clear
+                if (action.excluded.intersect(allTags).isEmpty() &&
+                    action.included.intersect(allTags).isEmpty())
+                        actions.remove(action)
+            }
+        }
+    }
+
     private fun includeTag(tag: Tag) {
         Log.d(TAGS_SELECTOR, "including tag $tag")
 
         included.add(tag)
         excluded.remove(tag)
+        actions.addLast(Include(tag))
 
         calculateTagsAndSelection()
     }
@@ -130,11 +187,12 @@ class TagsSelectorPresenter(
 
         excluded.add(tag)
         included.remove(tag)
+        actions.addLast(Exclude(tag))
 
         calculateTagsAndSelection()
     }
 
-    private fun uncheckTag(tag: Tag, needToCalculate: Boolean = true) {
+    private fun uncheckTag(tag: Tag, fromClearClick: Boolean = false) {
         Log.d(TAGS_SELECTOR, "un-checking tag $tag")
 
         if (included.contains(tag) && excluded.contains(tag)) {
@@ -146,9 +204,12 @@ class TagsSelectorPresenter(
 
         if (!included.remove(tag)) {
             excluded.remove(tag)
+            if (!fromClearClick) actions.addLast(UncheckExcluded(tag))
+        } else {
+            if (!fromClearClick) actions.addLast(UncheckIncluded(tag))
         }
 
-        if (needToCalculate)
+        if (!fromClearClick)
             calculateTagsAndSelection()
     }
 }

app/src/main/java/space/taran/arknavigator/ui/adapter/TagsSelectorAdapter.kt

@@ -6,7 +6,7 @@ import androidx.core.content.ContextCompat
 import com.google.android.material.chip.Chip
 import com.google.android.material.chip.ChipGroup
 import space.taran.arknavigator.R
-import space.taran.arknavigator.mvp.presenter.adapter.TagsSelectorPresenter
+import space.taran.arknavigator.mvp.presenter.adapter.tagsselector.TagsSelectorPresenter
 import space.taran.arknavigator.utils.Tag
 
 class TagsSelectorAdapter(val chipGroup: ChipGroup, val presenter: TagsSelectorPresenter) {

app/src/main/java/space/taran/arknavigator/ui/fragments/ResourcesFragment.kt

@@ -35,7 +35,7 @@ import kotlin.math.abs
 //`path` is used for filtering resources' paths
 //       if it is `null`, then no filtering is performed
 //       (recommended instead of passing same value for `path` and `root)
-class ResourcesFragment(val root: Path?, val path: Path?): MvpAppCompatFragment(), ResourcesView {
+class ResourcesFragment(val root: Path?, val path: Path?): MvpAppCompatFragment(), ResourcesView, BackButtonListener {
 
     private val presenter by moxyPresenter {
         ResourcesPresenter(root, path).apply {
@@ -172,6 +172,10 @@ class ResourcesFragment(val root: Path?, val path: Path?): MvpAppCompatFragment(
         sortByDialog?.dismiss()
     }
 
+    override fun backClicked(): Boolean {
+        return presenter.onBackClick()
+    }
+
     private fun showSortByDialog(sorting: Sorting, ascending: Boolean) {
         Log.d(RESOURCES_SCREEN, "showing sort-by dialog in ResourcesFragment")
         val dialogBinding = DialogSortBinding.inflate(LayoutInflater.from(requireContext()))