feat: Show keyboard shortcuts preference

it shows up the system dialog with the available shortcuts if the user has a physical keyboard attached. It helps the discoverability of keyboard shortcuts along the app.

After the user knows that the app has keyboard shortcuts, they can use the system shortcut (which can be seen in the dialog itself) in any other screen to see the available shortcuts there

Author: BrayanDSO

AnkiDroid/src/main/java/com/ichi2/anki/preferences/ControlsSettingsFragment.kt

@@ -15,7 +15,9 @@
  */
 package com.ichi2.anki.preferences
 
+import android.content.res.Configuration
 import androidx.annotation.StringRes
+import androidx.preference.Preference
 import com.ichi2.anki.CollectionManager.TR
 import com.ichi2.anki.R
 import com.ichi2.anki.cardviewer.ViewerCommand
@@ -41,6 +43,16 @@ class ControlsSettingsFragment : SettingsFragment() {
             .forEach { pref -> pref.value = commands[pref.key]?.defaultValue?.toPreferenceString() }
 
         setDynamicTitle()
+
+        // TODO replace the preference with something dismissible. This is meant only to improve
+        //  the discoverability of the system shortcut for the shortcuts dialog.
+        requirePreference<Preference>(R.string.pref_keyboard_shortcuts_key).apply {
+            isVisible = resources.configuration.keyboard == Configuration.KEYBOARD_QWERTY
+            setOnPreferenceClickListener {
+                requireActivity().requestShowKeyboardShortcuts()
+                true
+            }
+        }
     }
 
     private fun setDynamicTitle() {

AnkiDroid/src/main/res/drawable/ic_keyboard.xml

@@ -0,0 +1,5 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android" android:height="24dp" android:tint="?attr/colorControlNormal" android:viewportHeight="24" android:viewportWidth="24" android:width="24dp">
+      
+    <path android:fillColor="@android:color/white" android:pathData="M20,5L4,5c-1.1,0 -1.99,0.9 -1.99,2L2,17c0,1.1 0.9,2 2,2h16c1.1,0 2,-0.9 2,-2L22,7c0,-1.1 -0.9,-2 -2,-2zM11,8h2v2h-2L11,8zM11,11h2v2h-2v-2zM8,8h2v2L8,10L8,8zM8,11h2v2L8,13v-2zM7,13L5,13v-2h2v2zM7,10L5,10L5,8h2v2zM16,17L8,17v-2h8v2zM16,13h-2v-2h2v2zM16,10h-2L14,8h2v2zM19,13h-2v-2h2v2zM19,10h-2L17,8h2v2z"/>
+    
+</vector>

AnkiDroid/src/main/res/values/10-preferences.xml

@@ -74,6 +74,7 @@
     <string name="gestures_summ">Assign gestures to actions such as answering and editing cards.</string>
     <string name="gestures_corner_touch" maxLength="41">9-point touch</string>
     <string name="gestures_corner_touch_summary">Allow touch gestures in screen corners</string>
+    <string name="show_keyboard_shortcuts" maxLength="41">Show keyboard shortcuts</string>
     <string name="gestures_full_screen_nav_drawer" maxLength="41">Full screen navigation drawer</string>
     <string name="gestures_fullscreen_nav_drawer_summary">Open navigation drawer when swiped right from anywhere on the screen</string>
     <string name="gestures_none" maxLength="41" comment="No gestures">None</string>

AnkiDroid/src/main/res/values/preferences.xml

@@ -84,6 +84,7 @@
     <string name="gestures_preference">gestures</string>
     <string name="gestures_corner_touch_preference">gestureCornerTouch</string>
     <string name="nav_drawer_gesture_key">gestureFullScreenNavigationDrawer</string>
+    <string name="pref_keyboard_shortcuts_key">showKeyboardShortcuts</string>
     <string name="pref_swipe_sensitivity_key">swipeSensitivity</string>
     <string name="show_answer_command_key">binding_SHOW_ANSWER</string>
     <string name="answer_again_command_key">binding_FLIP_OR_ANSWER_EASE1</string>

AnkiDroid/src/main/res/xml/preferences_controls.xml

@@ -20,7 +20,8 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:title="@string/pref_cat_controls"
-    android:key="@string/pref_controls_screen_key">
+    android:key="@string/pref_controls_screen_key"
+    tools:context=".preferences.ControlsSettingsFragment">
 
     <SwitchPreferenceCompat
         android:defaultValue="false"
@@ -48,7 +49,13 @@
         android:defaultValue="100"
         android:valueFrom="20"
         android:valueTo="180"
-        app:displayValue="true"/>
+        app:displayValue="true" />
+
+    <Preference
+        android:key="@string/pref_keyboard_shortcuts_key"
+        android:title="@string/show_keyboard_shortcuts"
+        android:icon="@drawable/ic_keyboard"
+        />
 
     <PreferenceCategory android:title="@string/answer_buttons">
         <com.ichi2.preferences.ControlPreference

AnkiDroid/src/test/java/com/ichi2/anki/analytics/PreferencesAnalyticsTest.kt

@@ -66,6 +66,7 @@ class PreferencesAnalyticsTest : RobolectricTest() {
             // Preferences that only click: don't have a value
             R.string.tts_key, // tts
             R.string.pref_reset_languages_key, // resetLanguages
+            R.string.pref_keyboard_shortcuts_key, // showKeyboardShortcuts
             // Opens App Bar buttons fragment
             R.string.custom_buttons_link_preference, // custom_buttons_link
             // Opens Custom sync server fragment