Migrate to Viewpager2 (#387)

* Migrate ReaderActivity to ViewPager2

* Use tint on icons in place of filters

* Prevent crash when opening the first article

* Add the correct background color to the article reader

* Use consistent colors in the article reader

* Migrate ImageActivity to ViewPager2

app/build.gradle

@@ -155,6 +155,7 @@ dependencies {
 
     // Pager
     implementation 'me.relex:circleindicator:2.1.6'
+    implementation "androidx.viewpager2:viewpager2:1.1.0-beta01"
 
     //PhotoView
     implementation 'com.github.chrisbanes:PhotoView:2.3.0'

app/src/main/java/apps/amine/bou/readerforselfoss/ImageActivity.kt

@@ -3,8 +3,9 @@ package apps.amine.bou.readerforselfoss
 import android.os.Bundle
 import android.view.MenuItem
 import androidx.appcompat.app.AppCompatActivity
-import androidx.fragment.app.FragmentManager
+import androidx.fragment.app.Fragment
-import androidx.fragment.app.FragmentStatePagerAdapter
+import androidx.fragment.app.FragmentActivity
+import androidx.viewpager2.adapter.FragmentStateAdapter
 import apps.amine.bou.readerforselfoss.databinding.ActivityImageBinding
 import apps.amine.bou.readerforselfoss.fragments.ImageFragment
 
@@ -28,8 +29,8 @@ class ImageActivity : AppCompatActivity() {
         allImages = intent.getStringArrayListExtra("allImages") as ArrayList<String>
         position = intent.getIntExtra("position", 0)
 
-        binding.pager.adapter = ScreenSlidePagerAdapter(supportFragmentManager)
+        binding.pager.adapter = ScreenSlidePagerAdapter(this)
-        binding.pager.currentItem = position
+        binding.pager.setCurrentItem(position, false)
     }
 
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
@@ -43,14 +44,10 @@ class ImageActivity : AppCompatActivity() {
         return super.onOptionsItemSelected(item)
     }
 
-    private inner class ScreenSlidePagerAdapter(fm: FragmentManager) : FragmentStatePagerAdapter(fm, FragmentStatePagerAdapter.BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
+    private inner class ScreenSlidePagerAdapter(fa: FragmentActivity) : FragmentStateAdapter(fa) {
 
-        override fun getCount(): Int {
+        override fun getItemCount(): Int = allImages.size
-            return allImages.size
-        }
 
-        override fun getItem(position: Int): ImageFragment {
+        override fun createFragment(position: Int): Fragment = ImageFragment.newInstance(allImages[position])
-            return ImageFragment.newInstance(allImages[position])
-        }
     }
 }

app/src/main/java/apps/amine/bou/readerforselfoss/ReaderActivity.kt

@@ -3,21 +3,16 @@ package apps.amine.bou.readerforselfoss
 import android.content.Context
 import android.content.SharedPreferences
 import android.graphics.Color
-import android.graphics.PorterDuff
-import android.graphics.PorterDuffColorFilter
-import android.graphics.drawable.ColorDrawable
-import android.os.Build
 import android.os.Bundle
 import androidx.preference.PreferenceManager
-import androidx.fragment.app.FragmentManager
-import androidx.fragment.app.FragmentStatePagerAdapter
-import androidx.core.content.ContextCompat
-import androidx.viewpager.widget.ViewPager
 import androidx.appcompat.app.AppCompatActivity
 import android.view.Menu
 import android.view.MenuItem
-import android.view.ViewGroup
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentActivity
 import androidx.room.Room
+import androidx.viewpager2.adapter.FragmentStateAdapter
+import androidx.viewpager2.widget.ViewPager2
 import apps.amine.bou.readerforselfoss.api.selfoss.Item
 import apps.amine.bou.readerforselfoss.api.selfoss.SelfossApi
 import apps.amine.bou.readerforselfoss.databinding.ActivityReaderBinding
@@ -26,14 +21,11 @@ import apps.amine.bou.readerforselfoss.persistence.database.AppDatabase
 import apps.amine.bou.readerforselfoss.persistence.migrations.MIGRATION_1_2
 import apps.amine.bou.readerforselfoss.persistence.migrations.MIGRATION_2_3
 import apps.amine.bou.readerforselfoss.persistence.migrations.MIGRATION_3_4
-import apps.amine.bou.readerforselfoss.themes.AppColors
 import apps.amine.bou.readerforselfoss.themes.Toppings
-import apps.amine.bou.readerforselfoss.transformers.DepthPageTransformer
 import apps.amine.bou.readerforselfoss.utils.Config
 import apps.amine.bou.readerforselfoss.utils.SharedItems
 import apps.amine.bou.readerforselfoss.utils.toggleStar
 import com.ftinc.scoop.Scoop
-import me.relex.circleindicator.CircleIndicator
 
 class ReaderActivity : AppCompatActivity() {
 
@@ -50,14 +42,14 @@ class ReaderActivity : AppCompatActivity() {
     private lateinit var binding: ActivityReaderBinding
 
     private var activeAlignment: Int = 1
-    val JUSTIFY = 1
+    private val JUSTIFY = 1
-    val ALIGN_LEFT = 2
+    private val ALIGN_LEFT = 2
 
     private fun showMenuItem(willAddToFavorite: Boolean) {
         if (willAddToFavorite) {
-            toolbarMenu.findItem(R.id.star).icon.colorFilter = PorterDuffColorFilter(Color.WHITE, PorterDuff.Mode.SRC_ATOP)
+            toolbarMenu.findItem(R.id.star).icon.setTint(Color.WHITE)
         } else {
-            toolbarMenu.findItem(R.id.star).icon.colorFilter = PorterDuffColorFilter(Color.RED, PorterDuff.Mode.SRC_ATOP)
+            toolbarMenu.findItem(R.id.star).icon.setTint(Color.RED)
         }
     }
 
@@ -116,33 +108,14 @@ class ReaderActivity : AppCompatActivity() {
 
         readItem(allItems[currentItem])
 
-        binding.pager.adapter =
+        binding.pager.adapter = ScreenSlidePagerAdapter(this)
-                ScreenSlidePagerAdapter(supportFragmentManager, AppColors(this@ReaderActivity))
+        binding.pager.setCurrentItem(currentItem, false)
-        binding.pager.currentItem = currentItem
     }
 
     override fun onResume() {
         super.onResume()
 
-        notifyAdapter()
-
-        binding.pager.setPageTransformer(true, DepthPageTransformer())
         binding.indicator.setViewPager(binding.pager)
-
-        binding.pager.addOnPageChangeListener(
-            object : ViewPager.SimpleOnPageChangeListener() {
-
-                override fun onPageSelected(position: Int) {
-
-                    if (allItems[position].starred) {
-                        canRemoveFromFavorite()
-                    } else {
-                        canFavorite()
-                    }
-                    readItem(allItems[position])
-                }
-            }
-        )
     }
 
     private fun readItem(item: Item) {
@@ -151,46 +124,22 @@ class ReaderActivity : AppCompatActivity() {
             }
     }
 
-    private fun notifyAdapter() {
-        (binding.pager.adapter as ScreenSlidePagerAdapter).notifyDataSetChanged()
-    }
-
-    override fun onPause() {
-        super.onPause()
-        if (markOnScroll) {
-            binding.pager.clearOnPageChangeListeners()
-        }
-    }
-
     override fun onSaveInstanceState(oldInstanceState: Bundle) {
         super.onSaveInstanceState(oldInstanceState)
         oldInstanceState.clear()
     }
 
-    private inner class ScreenSlidePagerAdapter(fm: FragmentManager, val appColors: AppColors) :
+    private inner class ScreenSlidePagerAdapter(fa: FragmentActivity) :
-        FragmentStatePagerAdapter(fm) {
+        FragmentStateAdapter(fa) {
 
-        override fun getCount(): Int {
-            return allItems.size
-        }
 
-        override fun getItem(position: Int): ArticleFragment {
+        override fun getItemCount(): Int = allItems.size
-            return ArticleFragment.newInstance(position, allItems)
-        }
 
-        override fun startUpdate(container: ViewGroup) {
+        override fun createFragment(position: Int): Fragment = ArticleFragment.newInstance(position, allItems)
-            super.startUpdate(container)
 
-            container.background = ColorDrawable(
-                ContextCompat.getColor(
-                    this@ReaderActivity,
-                    appColors.colorBackground
-                )
-            )
-        }
     }
 
-    fun alignmentMenu(showJustify: Boolean) {
+    private fun alignmentMenu(showJustify: Boolean) {
         toolbarMenu.findItem(R.id.align_left).isVisible = !showJustify
         toolbarMenu.findItem(R.id.align_justify).isVisible = showJustify
     }
@@ -200,7 +149,7 @@ class ReaderActivity : AppCompatActivity() {
         inflater.inflate(R.menu.reader_menu, menu)
         toolbarMenu = menu
 
-        if (!allItems.isEmpty() && allItems[currentItem].starred) {
+        if (allItems.isNotEmpty() && allItems[currentItem].starred) {
             canRemoveFromFavorite()
         } else {
             canFavorite()
@@ -211,6 +160,22 @@ class ReaderActivity : AppCompatActivity() {
             alignmentMenu(true)
         }
 
+        binding.pager.registerOnPageChangeCallback(
+                object : ViewPager2.OnPageChangeCallback() {
+
+                    override fun onPageSelected(position: Int) {
+                        super.onPageSelected(position)
+
+                        if (allItems[position].starred) {
+                            canRemoveFromFavorite()
+                        } else {
+                            canFavorite()
+                        }
+                        readItem(allItems[position])
+                    }
+                }
+        )
+
         return true
     }
 
@@ -218,13 +183,11 @@ class ReaderActivity : AppCompatActivity() {
         fun afterSave() {
             allItems[binding.pager.currentItem] =
                     allItems[binding.pager.currentItem].toggleStar()
-            notifyAdapter()
             canRemoveFromFavorite()
         }
 
         fun afterUnsave() {
             allItems[binding.pager.currentItem] = allItems[binding.pager.currentItem].toggleStar()
-            notifyAdapter()
             canFavorite()
         }
 

app/src/main/java/apps/amine/bou/readerforselfoss/fragments/ArticleFragment.kt

@@ -17,7 +17,6 @@ import android.widget.Toast
 import androidx.browser.customtabs.CustomTabsIntent
 import com.google.android.material.floatingactionbutton.FloatingActionButton
 import androidx.fragment.app.Fragment
-import androidx.core.content.ContextCompat
 import androidx.core.widget.NestedScrollView
 import androidx.appcompat.app.AlertDialog
 import androidx.core.content.res.ResourcesCompat
@@ -93,6 +92,7 @@ class ArticleFragment : Fragment() {
         super.onCreate(savedInstanceState)
 
         pageNumber = requireArguments().getInt(ARG_POSITION)
+        // TODO: The full list of items is not required, only the item used should be passed
         allItems = requireArguments().getParcelableArrayList<Item>(ARG_ITEMS) as ArrayList<Item>
 
         db = Room.databaseBuilder(
@@ -391,30 +391,12 @@ class ArticleFragment : Fragment() {
 
         binding.webcontent.settings.standardFontFamily = a.getString(0)
         binding.webcontent.visibility = View.VISIBLE
-        val (textColor, backgroundColor) = if (appColors.isDarkTheme) {
-            if (context != null) {
-                Pair(ContextCompat.getColor(requireContext(), R.color.dark_webview_text), ContextCompat.getColor(requireContext(), R.color.dark_webview))
-            } else {
-                Pair(null, null)
-            }
-        } else {
-            if (context != null) {
-                Pair(ContextCompat.getColor(requireContext(), R.color.light_webview_text), ContextCompat.getColor(requireContext(), R.color.light_webview))
-            } else {
-                Pair(null, null)
-            }
-        }
 
-        val stringTextColor: String = if (textColor != null) {
+        // TODO: Set the color strings programmatically
-            String.format("#%06X", 0xFFFFFF and textColor)
+        val (stringTextColor, stringBackgroundColor) = if (appColors.isDarkTheme) {
+            Pair("#FFFFFF", "#303030")
         } else {
-            "#000000"
+            Pair("#212121", "#FAFAFA")
-        }
-
-        val stringBackgroundColor = if (backgroundColor != null) {
-            String.format("#%06X", 0xFFFFFF and backgroundColor)
-        } else {
-            "#FFFFFF"
         }
 
         binding.webcontent.settings.useWideViewPort = true

app/src/main/java/apps/amine/bou/readerforselfoss/themes/AppColors.kt

@@ -49,7 +49,7 @@ class AppColors(a: Activity) {
             R.color.darkBackground
         } else {
             a.setTheme(R.style.NoBar)
-            android.R.color.background_light
+            R.color.grey_50
         }
 
         textColor = if (isDarkTheme) {

app/src/main/java/apps/amine/bou/readerforselfoss/transformers/DepthPageTransformer.kt

@@ -1,43 +0,0 @@
-package apps.amine.bou.readerforselfoss.transformers
-
-import androidx.viewpager.widget.ViewPager
-import android.view.View
-
-class DepthPageTransformer : ViewPager.PageTransformer {
-
-    override fun transformPage(view: View, position: Float) {
-        val pageWidth = view.width
-
-        when {
-            position < -1 -> // [-Infinity,-1)
-                // This page is way off-screen to the left.
-                view.alpha = 0F
-            position <= 0 -> { // [-1,0]
-                // Use the default slide transition when moving to the left page
-                view.alpha = 1F
-                view.translationX = 0F
-                view.scaleX = 1F
-                view.scaleY = 1F
-            }
-            position <= 1 -> { // (0,1]
-                // Fade the page out.
-                view.alpha = 1 - position
-
-                // Counteract the default slide transition
-                view.translationX = pageWidth * -position
-
-                // Scale the page down (between MIN_SCALE and 1)
-                val scaleFactor = MIN_SCALE + (1 - MIN_SCALE) * (1 - Math.abs(position))
-                view.scaleX = scaleFactor
-                view.scaleY = scaleFactor
-            }
-            else -> // (1,+Infinity]
-                // This page is way off-screen to the right.
-                view.alpha = 0F
-        }
-    }
-
-    companion object {
-        private val MIN_SCALE = 0.75f
-    }
-}

app/src/main/res/layout/activity_image.xml

@@ -21,7 +21,7 @@
 
     </com.google.android.material.appbar.AppBarLayout>
 
-    <androidx.viewpager.widget.ViewPager
+    <androidx.viewpager2.widget.ViewPager2
         android:id="@+id/pager"
         android:layout_width="match_parent"
         android:layout_height="0dp"

app/src/main/res/layout/activity_reader.xml

@@ -22,7 +22,7 @@
 
     </com.google.android.material.appbar.AppBarLayout>
 
-    <androidx.viewpager.widget.ViewPager
+    <androidx.viewpager2.widget.ViewPager2
         android:id="@+id/pager"
         android:layout_width="match_parent"
         android:layout_height="0dp"
@@ -33,7 +33,7 @@
         app:layout_constraintTop_toBottomOf="@+id/appBarLayout" />
 
 
-    <me.relex.circleindicator.CircleIndicator
+    <me.relex.circleindicator.CircleIndicator3
         android:id="@+id/indicator"
         android:layout_width="match_parent"
         android:layout_height="20dp"

app/src/main/res/layout/fragment_article.xml

@@ -4,6 +4,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:background="?android:colorBackground"
     android:descendantFocusability="blocksDescendants">
 
     <androidx.core.widget.NestedScrollView

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

@@ -5,7 +5,7 @@
     <color name="colorAccent">#FFff5722</color>
     <color name="colorAccentDark">#FFbf360c</color>
     <color name="pink">#FFe91e63</color>
-    <color name="white">#FFFFFFFF</color>
+    <color name="white">#FFFFFF</color>
     <color name="black">#FF000000</color>
     <color name="red">#FF0000</color>
     <color name="refresh_progress_1">@color/colorAccentDark</color>
@@ -20,5 +20,5 @@
 
     <color name="cardBackgroundColor">#FFFFFFFF</color>
     <color name="materialDrawerHeaderSelectionText">#212121</color>
-    <color name="darkBackground">#FF303030</color>
+    <color name="darkBackground">#303030</color>
 </resources>