feat: Allow deck selection in statistics screen

A Spinner was introduced in the statistics screen which can be used by
the user to change the current selected deck and also trigger a reload
of the statistics UI.

AnkiDroid/src/main/AndroidManifest.xml

@@ -424,6 +424,9 @@
             android:exported="false"
             android:configChanges="orientation|screenSize"
             />
+        <activity android:name="com.ichi2.anki.StatisticsActivity"
+            android:exported="false"
+            android:configChanges="orientation|screenSize" />
         <activity
             android:name="com.ichi2.anki.previewer.CardViewerActivity"
             android:exported="false"

AnkiDroid/src/main/java/com/ichi2/anki/DeckSpinnerSelection.kt

@@ -84,6 +84,26 @@ class DeckSpinnerSelection(
         setSpinnerListener()
     }
 
+    @MainThread // spinner.adapter
+    fun initializeStatsBarDeckSpinner(col: Collection) {
+        // compute decks doesn't handle Default deck
+        dropDownDecks = col.decks.allNamesAndIds(includeFiltered = showFilteredDecks, skipEmptyDefault = true)
+            .toMutableList()
+        // custom implementation as DeckDropDownAdapter automatically includes a ALL_DECKS entry
+        spinner.adapter = object : ArrayAdapter<DeckNameId>(
+            context,
+            android.R.layout.simple_spinner_item,
+            dropDownDecks
+        ) {
+            override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+                val rowView = super.getView(position, convertView, parent) as TextView
+                rowView.text = getItem(position)!!.name
+                return rowView
+            }
+        }.apply { setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item) }
+        setSpinnerListener()
+    }
+
     @MainThread // spinner.adapter
     fun initializeNoteEditorDeckSpinner(col: Collection, @LayoutRes layoutResource: Int = R.layout.multiline_spinner_item) {
         dropDownDecks = computeDropDownDecks(col, includeFiltered = false).toMutableList()

AnkiDroid/src/main/java/com/ichi2/anki/NavigationDrawerActivity.kt

@@ -314,7 +314,7 @@ abstract class NavigationDrawerActivity :
 
                 R.id.nav_stats -> {
                     Timber.i("Navigating to stats")
-                    val intent = com.ichi2.anki.pages.Statistics.getIntent(this)
+                    val intent = Intent(this, StatisticsActivity::class.java)
                     startActivity(intent)
                 }
 

AnkiDroid/src/main/java/com/ichi2/anki/StatisticsActivity.kt

@@ -0,0 +1,83 @@
+/*
+ *  Copyright (c) 2024 Ashish Yadav <mailtoashish693@gmail.com>
+ *
+ *  This program 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 of the License, or (at your option) any later
+ *  version.
+ *
+ *  This program 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
+ *  this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.ichi2.anki
+
+import android.os.Bundle
+import androidx.fragment.app.commit
+import com.ichi2.anki.dialogs.DeckSelectionDialog
+import com.ichi2.anki.pages.Statistics
+import com.ichi2.libanki.Collection
+
+/**
+ * Shows the statistics for the current selected deck and offers the possibility of changing the deck.
+ *
+ * Note: uses `configChanges="orientation|screenSize"` to avoid activity recreations as it doesn't
+ * play well with the embedded WebView.
+ *
+ * @see Statistics
+ */
+class StatisticsActivity :
+    AnkiActivity(),
+    DeckSelectionDialog.DeckSelectionListener {
+
+    private lateinit var deckSpinnerSelection: DeckSpinnerSelection
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        if (showedActivityFailedScreen(savedInstanceState)) {
+            return
+        }
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_statistics)
+        if (savedInstanceState == null) {
+            supportFragmentManager.commit {
+                replace(
+                    R.id.fragment_container,
+                    Statistics.newInstance(path = "graphs", title = getString(R.string.statistics)),
+                    STATS_FRAGMENT_TAG
+                )
+            }
+        }
+        startLoadingCollection()
+    }
+
+    override fun onCollectionLoaded(col: Collection) {
+        super.onCollectionLoaded(col)
+        deckSpinnerSelection = DeckSpinnerSelection(
+            this,
+            findViewById(R.id.deck_selector),
+            showAllDecks = false,
+            alwaysShowDefault = false,
+            showFilteredDecks = false
+        )
+        deckSpinnerSelection.initializeStatsBarDeckSpinner(col)
+        launchCatchingTask {
+            deckSpinnerSelection.selectDeckById(col.decks.selected(), true)
+        }
+    }
+
+    override fun onDeckSelected(deck: DeckSelectionDialog.SelectableDeck?) {
+        if (deck == null) return
+        (supportFragmentManager.findFragmentByTag(STATS_FRAGMENT_TAG) as? Statistics)?.webView?.reload()
+        launchCatchingTask {
+            deckSpinnerSelection.selectDeckById(deck.deckId, true)
+        }
+    }
+
+    companion object {
+        private const val STATS_FRAGMENT_TAG = "stats_fragment_tag"
+    }
+}

AnkiDroid/src/main/java/com/ichi2/anki/pages/Statistics.kt

@@ -22,6 +22,7 @@ import android.print.PrintAttributes
 import android.print.PrintManager
 import android.view.View
 import androidx.core.content.ContextCompat.getSystemService
+import androidx.core.os.bundleOf
 import com.google.android.material.appbar.AppBarLayout
 import com.google.android.material.appbar.MaterialToolbar
 import com.ichi2.anki.CollectionManager
@@ -69,5 +70,12 @@ class Statistics : PageFragment(R.layout.statistics) {
         fun getIntent(context: Context): Intent {
             return getIntent(context, "graphs", context.getString(R.string.statistics), Statistics::class)
         }
+
+        fun newInstance(path: String, title: String) = Statistics().apply {
+            arguments = bundleOf(
+                PATH_ARG_KEY to path,
+                TITLE_ARG_KEY to title
+            )
+        }
     }
 }

AnkiDroid/src/main/res/layout/activity_statistics.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".StatisticsActivity">
+
+    <FrameLayout
+        android:id="@+id/deck_selector_layout"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:minHeight="?attr/listPreferredItemHeightSmall"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        android:paddingHorizontal="8dp"
+        android:background="?attr/currentDeckBackground"
+        android:paddingTop="8dp"
+        app:layout_constraintStart_toStartOf="parent">
+
+        <Spinner
+            android:id="@+id/deck_selector"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"/>
+    </FrameLayout>
+
+    <androidx.fragment.app.FragmentContainerView
+        android:id="@+id/fragment_container"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toTopOf="@id/deck_selector_layout"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+</androidx.constraintlayout.widget.ConstraintLayout>

AnkiDroid/src/test/java/com/ichi2/testutils/ActivityList.kt

@@ -75,7 +75,8 @@ object ActivityList {
             get(PermissionsActivity::class.java),
             get(SingleFragmentActivity::class.java),
             get(CardViewerActivity::class.java),
-            get(InstantNoteEditorActivity::class.java)
+            get(InstantNoteEditorActivity::class.java),
+            get(StatisticsActivity::class.java)
         )
     }