feat(audio): add native audio processing and Google Cast support

app/src/main/java/com/michatec/radio/EqualizerFragment.kt

@@ -0,0 +1,74 @@
+package com.michatec.radio
+
+import android.os.Bundle
+import android.view.View
+import androidx.appcompat.app.AppCompatActivity
+import androidx.preference.Preference
+import androidx.preference.PreferenceFragmentCompat
+import androidx.preference.SeekBarPreference
+import com.michatec.radio.helpers.PreferencesHelper
+
+/*
+ * EqualizerFragment class: Handles audio frequency settings
+ */
+class EqualizerFragment : PreferenceFragmentCompat() {
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+        (activity as AppCompatActivity).supportActionBar?.title = getString(R.string.pref_equalizer_title)
+    }
+
+    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
+        val context = preferenceManager.context
+        val screen = preferenceManager.createPreferenceScreen(context)
+
+        // Reset Button
+        val resetPreference = Preference(context)
+        resetPreference.title = getString(R.string.pref_equalizer_reset_title)
+        resetPreference.setIcon(R.drawable.ic_refresh_24dp)
+        resetPreference.setOnPreferenceClickListener {
+            PreferencesHelper.resetEqualizer()
+            // Manually update SeekBars to 0
+            findPreference<SeekBarPreference>(Keys.PREF_EQ_LOW)?.value = 0
+            findPreference<SeekBarPreference>(Keys.PREF_EQ_MID)?.value = 0
+            findPreference<SeekBarPreference>(Keys.PREF_EQ_HIGH)?.value = 0
+            return@setOnPreferenceClickListener true
+        }
+        screen.addPreference(resetPreference)
+
+        // EQ Low
+        val eqLow = SeekBarPreference(context)
+        eqLow.title = getString(R.string.pref_eq_low_title)
+        eqLow.key = Keys.PREF_EQ_LOW
+        eqLow.setIcon(R.drawable.ic_music_note_24dp)
+        eqLow.min = -12
+        eqLow.max = 12
+        eqLow.showSeekBarValue = true
+        eqLow.setDefaultValue(0)
+        screen.addPreference(eqLow)
+
+        // EQ Mid
+        val eqMid = SeekBarPreference(context)
+        eqMid.title = getString(R.string.pref_eq_mid_title)
+        eqMid.key = Keys.PREF_EQ_MID
+        eqMid.setIcon(R.drawable.ic_music_note_24dp)
+        eqMid.min = -12
+        eqMid.max = 12
+        eqMid.showSeekBarValue = true
+        eqMid.setDefaultValue(0)
+        screen.addPreference(eqMid)
+
+        // EQ High
+        val eqHigh = SeekBarPreference(context)
+        eqHigh.title = getString(R.string.pref_eq_high_title)
+        eqHigh.key = Keys.PREF_EQ_HIGH
+        eqHigh.setIcon(R.drawable.ic_music_note_24dp)
+        eqHigh.min = -12
+        eqHigh.max = 12
+        eqHigh.showSeekBarValue = true
+        eqHigh.setDefaultValue(0)
+        screen.addPreference(eqHigh)
+
+        preferenceScreen = screen
+    }
+}

app/src/main/java/com/michatec/radio/SettingsFragment.kt

@@ -210,6 +210,16 @@ class SettingsFragment : PreferenceFragmentCompat(), YesNoDialog.YesNoDialogList
         preferenceDrc.summary = getString(R.string.pref_drc_summary)
         preferenceDrc.setDefaultValue(true)
 
+        // set up "Equalizer" preference entry
+        val preferenceEqualizer = Preference(context)
+        preferenceEqualizer.title = getString(R.string.pref_equalizer_title)
+        preferenceEqualizer.setIcon(R.drawable.ic_music_note_24dp)
+        preferenceEqualizer.summary = getString(R.string.pref_equalizer_summary)
+        preferenceEqualizer.setOnPreferenceClickListener {
+            findNavController().navigate(R.id.action_settings_to_equalizer)
+            return@setOnPreferenceClickListener true
+        }
+
         // set up "App Version" preference
         val preferenceAppVersion = Preference(context)
         preferenceAppVersion.title = getString(R.string.pref_app_version_title)
@@ -287,6 +297,7 @@ class SettingsFragment : PreferenceFragmentCompat(), YesNoDialog.YesNoDialogList
         preferenceCategoryAudioEffects.addPreference(preferenceBassBoost)
         preferenceCategoryAudioEffects.addPreference(preferenceReverb)
         preferenceCategoryAudioEffects.addPreference(preferenceDrc)
+        preferenceCategoryAudioEffects.addPreference(preferenceEqualizer)
 
         screen.addPreference(preferenceCategoryMaintenance)
         preferenceCategoryMaintenance.addPreference(preferenceUpdateStationImages)

app/src/main/java/com/michatec/radio/helpers/PreferencesHelper.kt

@@ -277,4 +277,13 @@ object PreferencesHelper {
     fun loadEqMid(): Float = sharedPreferences.getInt(Keys.PREF_EQ_MID, 0).toFloat()
     fun loadEqHigh(): Float = sharedPreferences.getInt(Keys.PREF_EQ_HIGH, 0).toFloat()
 
+    /* Resets Equalizer settings to default */
+    fun resetEqualizer() {
+        sharedPreferences.edit {
+            putInt(Keys.PREF_EQ_LOW, 0)
+            putInt(Keys.PREF_EQ_MID, 0)
+            putInt(Keys.PREF_EQ_HIGH, 0)
+        }
+    }
+
 }