feature: Allow changing deck name in statistics screen

AnkiDroid/src/main/AndroidManifest.xml

@@ -431,6 +431,9 @@
             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.PreviewerActivity"
             android:exported="false"

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

@@ -83,6 +83,17 @@ class DeckSpinnerSelection(
         setSpinnerListener()
     }
 
+    @MainThread // spinner.adapter
+    suspend fun initializeStatsBarDeckSpinner(actionBar: ActionBar) {
+        actionBar.setDisplayShowTitleEnabled(false)
+
+        // Add drop-down menu to select deck to action bar.
+        dropDownDecks = computeDropDownDecks(includeFiltered = showFilteredDecks).toMutableList()
+        deckDropDownAdapter = DeckDropDownAdapter(context, dropDownDecks)
+        spinner.adapter = deckDropDownAdapter
+        setSpinnerListener()
+    }
+
     @MainThread // spinner.adapter
     fun initializeNoteEditorDeckSpinner(col: Collection) {
         dropDownDecks = computeDropDownDecks(col, includeFiltered = false).toMutableList()

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

@@ -0,0 +1,113 @@
+/*
+ *  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.content.Context
+import android.content.Intent
+import android.os.Bundle
+import android.view.Menu
+import android.widget.Spinner
+import androidx.activity.viewModels
+import androidx.appcompat.app.ActionBar
+import androidx.fragment.app.Fragment
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.lifecycleScope
+import com.ichi2.anki.dialogs.DeckSelectionDialog
+import com.ichi2.anki.widgets.DeckDropDownAdapter
+import com.ichi2.libanki.DeckId
+import kotlinx.coroutines.launch
+import kotlin.reflect.KClass
+import kotlin.reflect.jvm.jvmName
+
+/**
+ * Handles changing of deck in Statistics webview
+ *
+ * Based in [SingleFragmentActivity], but with `configChanges="orientation|screenSize"`
+ * to avoid unwanted activity recreations
+ */
+class StatisticsActivity :
+    SingleFragmentActivity(),
+    DeckSelectionDialog.DeckSelectionListener,
+    DeckDropDownAdapter.SubtitleListener {
+
+    override val subtitleText: String
+        get() = resources.getString(R.string.statistics)
+
+    private val statisticsViewModel: StatisticsViewModel by viewModels()
+
+    private var deckSpinnerSelection: DeckSpinnerSelection? = null
+    var deckId: DeckId = 0
+
+    // menu wouldn't be visible in fragment's toolbar unless we override here
+    override fun onCreateOptionsMenu(menu: Menu?): Boolean {
+        menuInflater.inflate(R.menu.statistics, menu)
+        return super.onCreateOptionsMenu(menu)
+    }
+
+    fun setupDeckSelector(spinner: Spinner, supportActionBar: ActionBar) {
+        startLoadingCollection()
+        deckSpinnerSelection = DeckSpinnerSelection(
+            this,
+            spinner,
+            showAllDecks = true,
+            alwaysShowDefault = false,
+            showFilteredDecks = false
+        ).apply {
+            lifecycleScope.launch {
+                initializeStatsBarDeckSpinner(supportActionBar)
+            }
+            launchCatchingTask {
+                selectDeckById(deckId, true)
+            }
+        }
+    }
+
+    override fun onDeckSelected(deck: DeckSelectionDialog.SelectableDeck?) {
+        if (deck == null) {
+            return
+        }
+        statisticsViewModel.setDeckName(deck.name)
+        deckId = deck.deckId
+        launchCatchingTask {
+            deckSpinnerSelection!!.selectDeckById(deckId, true)
+        }
+    }
+
+    companion object {
+
+        fun getIntent(context: Context, fragmentClass: KClass<out Fragment>, arguments: Bundle? = null): Intent {
+            return Intent(context, StatisticsActivity::class.java).apply {
+                putExtra(FRAGMENT_NAME_EXTRA, fragmentClass.jvmName)
+                putExtra(FRAGMENT_ARGS_EXTRA, arguments)
+            }
+        }
+    }
+}
+
+/**
+ * ViewModel for the StatisticsActivity, storing and managing the current deck name.
+ */
+class StatisticsViewModel : ViewModel() {
+    private val _deckName = MutableLiveData<String>()
+    val deckName: LiveData<String> = _deckName
+
+    fun setDeckName(value: String) {
+        _deckName.value = value
+    }
+}

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

@@ -32,7 +32,7 @@ import timber.log.Timber
  */
 @Suppress("LeakingThis")
 abstract class PageFragment : Fragment(R.layout.page_fragment), PostRequestHandler {
-    abstract val title: String
+    abstract val title: String?
     abstract val pageName: String
 
     lateinit var webView: WebView

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

@@ -21,32 +21,75 @@ import android.os.Bundle
 import android.print.PrintAttributes
 import android.print.PrintManager
 import android.view.View
+import android.widget.Spinner
+import androidx.appcompat.app.AppCompatActivity
 import androidx.core.content.ContextCompat.getSystemService
+import androidx.core.view.isVisible
+import androidx.fragment.app.activityViewModels
+import androidx.lifecycle.Observer
 import com.google.android.material.appbar.MaterialToolbar
 import com.ichi2.anki.CollectionManager
 import com.ichi2.anki.R
-import com.ichi2.anki.SingleFragmentActivity
+import com.ichi2.anki.StatisticsActivity
+import com.ichi2.anki.StatisticsViewModel
 import com.ichi2.anki.utils.getTimestamp
 import com.ichi2.libanki.utils.TimeManager
+import timber.log.Timber
 
 class Statistics : PageFragment() {
-    override val title: String
-        get() = resources.getString(R.string.statistics)
+    override val title: String?
+        get() = null
 
     override val pageName = "graphs"
 
+    private val statisticsViewModel: StatisticsViewModel by activityViewModels()
+
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
-        view.findViewById<MaterialToolbar>(R.id.toolbar)?.apply {
+
+        val toolbar = view.findViewById<MaterialToolbar>(R.id.toolbar)
+        (activity as? AppCompatActivity)?.setSupportActionBar(toolbar)
+
+        toolbar.apply {
             inflateMenu(R.menu.statistics)
             menu.findItem(R.id.action_export_stats).title = CollectionManager.TR.statisticsSavePdf()
+
             setOnMenuItemClickListener { item ->
                 if (item.itemId == R.id.action_export_stats) {
                     exportWebViewContentAsPDF()
                 }
                 true
             }
+            val toolbarSpinner = findViewById<Spinner>(R.id.stats_toolbar_spinner)
+            toolbarSpinner.isVisible = true
+            val supportActionBar = (activity as? StatisticsActivity)?.supportActionBar
+
+            if (supportActionBar != null) {
+                (activity as? StatisticsActivity)?.setupDeckSelector(toolbarSpinner, supportActionBar)
+            } else {
+                Timber.w("SupportActionBar is null")
+            }
         }
+        statisticsViewModel.deckName.observe(
+            viewLifecycleOwner,
+            Observer { deck ->
+                changeDeck(deck)
+            }
+        )
+    }
+
+    /**
+     * This method is a workaround to change the deck in the webview by finding the text box and
+     * replacing the deck name with the selected deck name from the dialog and updating the stats
+     **/
+    private fun changeDeck(selectedDeck: String) {
+        val javascriptCode = """
+        var textBox = [].slice.call(document.getElementsByTagName('input'), 0).filter(x => x.type == "text")[0];
+        textBox.value = "deck:$selectedDeck";
+        textBox.dispatchEvent(new Event("input", { bubbles: true }));
+        textBox.dispatchEvent(new Event("change"));
+        """.trimIndent()
+        webView.evaluateJavascript(javascriptCode, null)
     }
 
     /**Prepares and initiates a printing task for the content(stats) displayed in the WebView.
@@ -66,7 +109,7 @@ class Statistics : PageFragment() {
 
     companion object {
         fun getIntent(context: Context): Intent {
-            return SingleFragmentActivity.getIntent(context, Statistics::class)
+            return StatisticsActivity.getIntent(context, Statistics::class)
         }
     }
 }

AnkiDroid/src/main/java/com/ichi2/anki/widgets/DeckDropDownAdapter.kt

@@ -22,8 +22,12 @@ import android.view.View
 import android.view.ViewGroup
 import android.widget.BaseAdapter
 import android.widget.TextView
+import androidx.core.content.ContextCompat
 import com.ichi2.anki.R
+import com.ichi2.anki.StatisticsActivity
 import com.ichi2.libanki.DeckNameId
+import com.ichi2.themes.Theme
+import com.ichi2.themes.Themes
 
 class DeckDropDownAdapter(private val context: Context, decks: List<DeckNameId>) : BaseAdapter() {
     private val deckList = decks.toMutableList()
@@ -69,6 +73,14 @@ class DeckDropDownAdapter(private val context: Context, decks: List<DeckNameId>)
             convertView = LayoutInflater.from(context).inflate(R.layout.dropdown_deck_selected_item, parent, false)
             deckNameView = convertView.findViewById(R.id.dropdown_deck_name)
             deckCountsView = convertView.findViewById(R.id.dropdown_deck_counts)
+            // Spinner has white text color in light theme, we change it only for StatisticsActivity
+            if (context is StatisticsActivity && (Themes.currentTheme.id == Theme.LIGHT.id)) {
+                deckNameView?.setTextColor(ContextCompat.getColor(context, android.R.color.black))
+                val drawableEnd = ContextCompat.getDrawable(context, R.drawable.ic_spinner_triangle)
+                drawableEnd?.setTint(ContextCompat.getColor(context, android.R.color.black))
+                deckNameView?.setCompoundDrawablesRelativeWithIntrinsicBounds(null, null, drawableEnd, null)
+                deckCountsView?.setTextColor(ContextCompat.getColor(context, android.R.color.black))
+            }
             viewHolder = DeckDropDownViewHolder()
             viewHolder.deckNameView = deckNameView
             viewHolder.deckCountsView = deckCountsView

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

@@ -12,13 +12,23 @@
         android:layout_height="wrap_content"
         app:layout_constraintTop_toTopOf="parent"
         app:navigationContentDescription="@string/abc_action_bar_up_description"
-        app:navigationIcon="?attr/homeAsUpIndicator"
-        />
+        app:navigationIcon="?attr/homeAsUpIndicator">
+
+        <Spinner
+            android:id="@+id/stats_toolbar_spinner"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:visibility="gone"
+            android:background="?attr/selectableItemBackground"
+            app:popupTheme="@style/ActionBar.Popup" />
+
+    </com.google.android.material.appbar.MaterialToolbar>
 
     <WebView
         android:id="@+id/webview"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1"
         android:visibility="invisible"/>
 
 </LinearLayout>

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

@@ -76,6 +76,7 @@ object ActivityList {
             get(PermissionsActivity::class.java),
             get(SingleFragmentActivity::class.java),
             get(ImageOcclusionActivity::class.java),
+            get(StatisticsActivity::class.java),
             get(PreviewerActivity::class.java)
         )
     }