Add custom widget theme with color picker

This commit introduces a new "Custom" theme option for the widget,
allowing users to select a custom background color.

Changes include:
- Added "Custom" theme to widget_themes array in arrays.xml.
- Introduced new string resources for custom theme color in strings.xml.
- Modified preferences_widget.xml to include a color picker preference
for the custom theme.
- Updated WidgetSettings.kt to manage the visibility and functionality
of the custom color picker based on theme selection.
- Extended WidgetPreferences.kt to store and retrieve the custom theme
color, and to apply it to the widget's background.
- Implemented a isLight utility function in Theme.kt to determine text
color based on the custom background color.

app/src/main/java/org/tasks/preferences/fragments/WidgetSettings.kt

@@ -44,6 +44,7 @@ class WidgetSettings : InjectingPreferenceFragment() {
     companion object {
         private const val REQUEST_THEME_SELECTION = 1006
         private const val REQUEST_COLOR_SELECTION = 1007
+        private const val REQUEST_CUSTOM_THEME_COLOR_SELECTION = 1009
         private const val REQUEST_SORT = 1008
 
         const val EXTRA_WIDGET_ID = "extra_widget_id"
@@ -163,6 +164,13 @@ class WidgetSettings : InjectingPreferenceFragment() {
         updateFilter()
         updateTheme()
         updateColor()
+
+        val customThemeColor = findPreference(R.string.p_widget_custom_theme_color)
+        customThemeColor.onPreferenceClickListener = Preference.OnPreferenceClickListener {
+            newColorPalette(this, REQUEST_CUSTOM_THEME_COLOR_SELECTION, widgetPreferences.customThemeColor, Palette.WIDGET)
+                .show(parentFragmentManager, FRAG_TAG_COLOR_PICKER)
+            false
+        }
     }
 
     override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
@@ -182,6 +190,12 @@ class WidgetSettings : InjectingPreferenceFragment() {
                 )
                 updateColor()
             }
+            REQUEST_CUSTOM_THEME_COLOR_SELECTION -> if (resultCode == Activity.RESULT_OK) {
+                widgetPreferences.setCustomThemeColor(
+                    data!!.getIntExtra(ColorWheelPicker.EXTRA_SELECTED, 0)
+                )
+                updateCustomThemeColor()
+            }
             REQUEST_SORT -> if (resultCode == Activity.RESULT_OK) updateSort()
             else -> super.onActivityResult(requestCode, resultCode, data)
         }
@@ -198,12 +212,17 @@ class WidgetSettings : InjectingPreferenceFragment() {
         val widgetNames = resources.getStringArray(R.array.widget_themes)
         findPreference(R.string.p_widget_theme).summary = widgetNames[index]
         findPreference(R.string.p_widget_color_v2).isVisible = index != 4
+        findPreference(R.string.p_widget_custom_theme_color).isVisible = index == 5
     }
 
     private fun updateColor() {
         tintColorPreference(R.string.p_widget_color_v2, widgetPreferences.color)
     }
 
+    private fun updateCustomThemeColor() {
+        tintColorPreference(R.string.p_widget_custom_theme_color, widgetPreferences.customThemeColor)
+    }
+
     private fun updateFilter() = lifecycleScope.launch {
         findPreference(R.string.p_widget_filter).summary = getFilter().title
         updateSort()

app/src/main/java/org/tasks/themes/Theme.kt

@@ -1,6 +1,7 @@
 package org.tasks.themes
 
 import android.app.Activity
+import androidx.core.graphics.ColorUtils
 import javax.inject.Inject
 
 class Theme @Inject constructor(
@@ -15,4 +16,10 @@ class Theme @Inject constructor(
     fun applyTheme(activity: Activity) {
         themeBase.set(activity)
     }
+
+    companion object {
+        fun isLight(color: Int): Boolean {
+            return ColorUtils.calculateLuminance(color) > 0.5
+        }
+    }
 }

app/src/main/java/org/tasks/widget/WidgetPreferences.kt

@@ -13,6 +13,8 @@ import org.tasks.preferences.QueryPreferences
 import org.tasks.tasklist.SectionedDataSource.Companion.HEADER_COMPLETED
 import timber.log.Timber
 
+import org.tasks.themes.Theme
+
 class WidgetPreferences(
     private val context: Context,
     private val preferences: Preferences,
@@ -92,18 +94,18 @@ class WidgetPreferences(
         get() = when (themeIndex) {
             0 -> false
             3, 4 -> context.isNightMode
+            5 -> !Theme.isLight(backgroundColor)
             else -> true
         }
 
     private val backgroundColor: Int
-        get() = context.getColor(
-            when (themeIndex) {
-                1 -> android.R.color.black
-                2 -> R.color.md_background_dark
-                3, 4 -> R.color.widget_background_follow_system
-                else -> android.R.color.white
-            }
-        )
+        get() = when (themeIndex) {
+            1 -> context.getColor(android.R.color.black)
+            2 -> context.getColor(R.color.md_background_dark)
+            3, 4 -> context.getColor(R.color.widget_background_follow_system)
+            5 -> customThemeColor
+            else -> context.getColor(android.R.color.white)
+        }
 
     var collapsed: Set<Long>
         get() {
@@ -160,6 +162,13 @@ class WidgetPreferences(
     fun setColor(color: Int) {
         setInt(R.string.p_widget_color_v2, color)
     }
+
+    val customThemeColor: Int
+        get() = getInt(R.string.p_widget_custom_theme_color, 0)
+
+    fun setCustomThemeColor(color: Int) {
+        setInt(R.string.p_widget_custom_theme_color, color)
+    }
     val footerOpacity: Int
         get() = getAlphaValue(R.string.p_widget_footer_opacity)
     val rowOpacity: Int

app/src/main/res/values/arrays.xml

@@ -35,7 +35,8 @@
     <item>@string/theme_black</item>
     <item>@string/theme_dark</item>
     <item>@string/theme_system_default</item>
-    <item>@string/theme_dynamic</item>
+        <item>@string/theme_dynamic</item>
+    <item>@string/theme_custom</item>
   </string-array>
 
   <string-array name="EPr_default_urgency">

app/src/main/res/values/strings.xml

@@ -386,11 +386,14 @@ File %1$s contained %2$s.\n\n
   <string name="launcher_icon">Launcher icon</string>
   <string name="theme_black">Black</string>
   <string name="theme_light">Light</string>
+  <string name="theme_custom">Custom</string>
   <string name="theme_dark">Dark</string>
   <string name="theme_wallpaper">Wallpaper</string>
   <string name="theme_day_night">Day/Night</string>
   <string name="theme_system_default">System default</string>
   <string name="theme_dynamic">Dynamic</string>
+  <string name="p_widget_custom_theme_color" translatable="false">p_widget_custom_theme_color</string>
+  <string name="custom_theme_color">Custom theme color</string>
   <string name="language">Language</string>
   <string name="restart_required">Restart Tasks for this change to take effect</string>
   <string name="restart_now">Restart now</string>

app/src/main/res/xml/preferences_widget.xml

@@ -10,6 +10,10 @@
     android:key="@string/p_widget_theme"
     android:title="@string/theme" />
 
+  <Preference
+    android:key="@string/p_widget_custom_theme_color"
+    android:title="@string/custom_theme_color" />
+
   <Preference
     android:key="@string/p_widget_sort"
     android:title="@string/TLA_menu_sort" />