Edge-to-edge manga details view (#5613)

* Prepare for edge-to-edge MangaController

* Fix derpy liftToScroll with our own implementation

* Edge-to-edge MangaController

Except when legacy blue theme is used.

* Save app bar lift state for controller backstack

* Fix expanded cover position after the view recycled

* Handle overlap changes when incognito mode disabled

* Tablet fixes

* Revert "Handle overlap changes when incognito mode disabled"

This reverts commit 1f492449

Breaks on rotation changes.

* Fix MangaController's swipe refresh position

* All controllers are now doing lift app bar on scroll by default

They are already doing that before so this pretty much just a cleanups.

* TachiyomiCoordinatorLayout: Support ViewPager for app bar lift state check

I'm willing to revert this if this minute detail solution is deemed too hacky xD

* Fix app bar not lifted when scrolled without fling

* Save app bar lift state across configuration changes

* Fix MangaController's swipe refresh position after configuration change

* TachiyomiCoordinatorLayout: Update ViewPager reference when controller is changed

app/src/main/java/eu/kanade/tachiyomi/widget/ElevationAppBarLayout.kt

@@ -1,47 +1,87 @@
 package eu.kanade.tachiyomi.widget
 
-import android.animation.ObjectAnimator
-import android.animation.StateListAnimator
+import android.animation.ValueAnimator
 import android.content.Context
 import android.util.AttributeSet
-import com.google.android.material.R
+import com.google.android.material.animation.AnimationUtils
 import com.google.android.material.appbar.AppBarLayout
+import com.google.android.material.appbar.MaterialToolbar
+import eu.kanade.tachiyomi.R
 
 class ElevationAppBarLayout @JvmOverloads constructor(
     context: Context,
     attrs: AttributeSet? = null
 ) : AppBarLayout(context, attrs) {
 
-    private var origStateAnimator: StateListAnimator? = null
+    private var lifted = true
+    private var transparent = false
 
-    init {
-        origStateAnimator = stateListAnimator
+    private val toolbar by lazy { findViewById<MaterialToolbar>(R.id.toolbar) }
+
+    private var elevationAnimator: ValueAnimator? = null
+    private var backgroundAlphaAnimator: ValueAnimator? = null
+
+    var isTransparentWhenNotLifted = false
+        set(value) {
+            if (field != value) {
+                field = value
+                updateBackgroundAlpha()
+            }
+        }
+
+    /**
+     * Disabled. Lift on scroll is handled manually with [TachiyomiCoordinatorLayout]
+     */
+    override fun isLiftOnScroll(): Boolean = false
+
+    override fun isLifted(): Boolean = lifted
+
+    override fun setLifted(lifted: Boolean): Boolean {
+        return if (this.lifted != lifted) {
+            this.lifted = lifted
+            val from = elevation
+            val to = if (lifted) {
+                resources.getDimension(R.dimen.design_appbar_elevation)
+            } else {
+                0F
+            }
+
+            elevationAnimator?.cancel()
+            elevationAnimator = ValueAnimator.ofFloat(from, to).apply {
+                duration = resources.getInteger(R.integer.app_bar_elevation_anim_duration).toLong()
+                interpolator = AnimationUtils.LINEAR_INTERPOLATOR
+                addUpdateListener {
+                    elevation = it.animatedValue as Float
+                }
+                start()
+            }
+
+            updateBackgroundAlpha()
+            true
+        } else {
+            false
+        }
     }
 
-    fun enableElevation(liftOnScroll: Boolean) {
-        setElevation(liftOnScroll)
-    }
+    private fun updateBackgroundAlpha() {
+        val newTransparent = if (lifted) false else isTransparentWhenNotLifted
+        if (transparent != newTransparent) {
+            transparent = newTransparent
+            val fromAlpha = if (transparent) 255 else 0
+            val toAlpha = if (transparent) 0 else 255
 
-    private fun setElevation(liftOnScroll: Boolean) {
-        stateListAnimator = origStateAnimator
-        isLiftOnScroll = liftOnScroll
-    }
-
-    fun disableElevation() {
-        stateListAnimator = StateListAnimator().apply {
-            val objAnimator = ObjectAnimator.ofFloat(this, "elevation", 0f)
-
-            // Enabled and collapsible, but not collapsed means not elevated
-            addState(
-                intArrayOf(android.R.attr.enabled, R.attr.state_collapsible, -R.attr.state_collapsed),
-                objAnimator
-            )
-
-            // Default enabled state
-            addState(intArrayOf(android.R.attr.enabled), objAnimator)
-
-            // Disabled state
-            addState(IntArray(0), objAnimator)
+            backgroundAlphaAnimator?.cancel()
+            backgroundAlphaAnimator = ValueAnimator.ofInt(fromAlpha, toAlpha).apply {
+                duration = resources.getInteger(R.integer.app_bar_elevation_anim_duration).toLong()
+                interpolator = AnimationUtils.LINEAR_INTERPOLATOR
+                addUpdateListener {
+                    val alpha = it.animatedValue as Int
+                    background.alpha = alpha
+                    toolbar?.background?.alpha = alpha
+                    statusBarForeground?.alpha = alpha
+                }
+                start()
+            }
         }
     }
 }

app/src/main/java/eu/kanade/tachiyomi/widget/RecyclerViewPagerAdapter.kt

@@ -2,6 +2,7 @@ package eu.kanade.tachiyomi.widget
 
 import android.view.View
 import android.view.ViewGroup
+import androidx.viewpager.widget.ViewPager
 import com.nightlynexus.viewstatepageradapter.ViewStatePagerAdapter
 import java.util.Stack
 
@@ -22,7 +23,11 @@ abstract class RecyclerViewPagerAdapter : ViewStatePagerAdapter() {
     protected open fun recycleView(view: View, position: Int) {}
 
     override fun createView(container: ViewGroup, position: Int): View {
-        val view = if (pool.isNotEmpty()) pool.pop() else createView(container)
+        val view = if (pool.isNotEmpty()) {
+            pool.pop().setViewPagerPositionParam(position)
+        } else {
+            createView(container)
+        }
         bindView(view, position)
         return view
     }
@@ -31,4 +36,25 @@ abstract class RecyclerViewPagerAdapter : ViewStatePagerAdapter() {
         recycleView(view, position)
         if (recycle) pool.push(view)
     }
+
+    /**
+     * Making sure that this ViewPager child view has the correct "position" layout param
+     * after being recycled.
+     */
+    private fun View.setViewPagerPositionParam(position: Int): View {
+        val params = layoutParams
+        if (params is ViewPager.LayoutParams) {
+            if (!params.isDecor) {
+                try {
+                    val positionField = ViewPager.LayoutParams::class.java.getDeclaredField("position")
+                    positionField.isAccessible = true
+                    positionField.setInt(params, position)
+                    layoutParams = params
+                } catch (e: NoSuchFieldException) {
+                } catch (e: IllegalAccessException) {
+                }
+            }
+        }
+        return this
+    }
 }

app/src/main/java/eu/kanade/tachiyomi/widget/TachiyomiChangeHandlerFrameLayout.kt

@@ -0,0 +1,38 @@
+package eu.kanade.tachiyomi.widget
+
+import android.content.Context
+import android.util.AttributeSet
+import androidx.coordinatorlayout.widget.CoordinatorLayout
+import com.bluelinelabs.conductor.ChangeHandlerFrameLayout
+
+/**
+ * [ChangeHandlerFrameLayout] with the ability to draw behind the header sibling in [CoordinatorLayout].
+ * The layout behavior of this view is set to [TachiyomiScrollingViewBehavior] and should not be changed.
+ */
+class TachiyomiChangeHandlerFrameLayout(
+    context: Context,
+    attrs: AttributeSet
+) : ChangeHandlerFrameLayout(context, attrs), CoordinatorLayout.AttachedBehavior {
+
+    /**
+     * If true, this view will draw behind the header sibling.
+     *
+     * @see TachiyomiScrollingViewBehavior.shouldHeaderOverlap
+     */
+    var overlapHeader = false
+        set(value) {
+            if (field != value) {
+                field = value
+                (layoutParams as? CoordinatorLayout.LayoutParams)?.behavior = behavior.apply {
+                    shouldHeaderOverlap = value
+                }
+                if (!value) {
+                    // The behavior doesn't reset translationY when shouldHeaderOverlap is false
+                    translationY = 0F
+                }
+                forceLayout()
+            }
+        }
+
+    override fun getBehavior() = TachiyomiScrollingViewBehavior()
+}

app/src/main/java/eu/kanade/tachiyomi/widget/TachiyomiCoordinatorLayout.kt

@@ -0,0 +1,177 @@
+package eu.kanade.tachiyomi.widget
+
+import android.content.Context
+import android.os.Parcel
+import android.os.Parcelable
+import android.util.AttributeSet
+import android.view.View
+import android.view.ViewGroup
+import androidx.coordinatorlayout.R
+import androidx.coordinatorlayout.widget.CoordinatorLayout
+import androidx.core.view.doOnLayout
+import androidx.customview.view.AbsSavedState
+import androidx.lifecycle.coroutineScope
+import androidx.lifecycle.findViewTreeLifecycleOwner
+import androidx.recyclerview.widget.RecyclerView
+import androidx.viewpager.widget.ViewPager
+import com.bluelinelabs.conductor.ChangeHandlerFrameLayout
+import com.google.android.material.appbar.AppBarLayout
+import eu.kanade.tachiyomi.util.system.isTablet
+import eu.kanade.tachiyomi.util.view.findChild
+import eu.kanade.tachiyomi.util.view.findDescendant
+import eu.kanade.tachiyomi.util.view.getActivePageView
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+import reactivecircus.flowbinding.android.view.HierarchyChangeEvent
+import reactivecircus.flowbinding.android.view.hierarchyChangeEvents
+
+/**
+ * [CoordinatorLayout] with its own app bar lift state handler.
+ * This parent view checks for the app bar lift state from the following:
+ *
+ * 1. When nested scroll detected, lift state will be decided from the nested
+ * scroll target. (See [onNestedScroll])
+ *
+ * 2. When a descendant ViewPager active page is changed and the page contains RecyclerView,
+ * lift state will be decided from the said RecyclerView. (See [pageChangeListener])
+ *
+ *
+ * With those conditions, this view expects the following direct child:
+ *
+ * 1. An [AppBarLayout].
+ *
+ * 2. A [ChangeHandlerFrameLayout] that contains an optional [ViewPager].
+ */
+class TachiyomiCoordinatorLayout @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null,
+    defStyleAttr: Int = R.attr.coordinatorLayoutStyle
+) : CoordinatorLayout(context, attrs, defStyleAttr) {
+
+    /**
+     * Keep lifted state and do nothing on tablet UI
+     */
+    private val isTablet = context.isTablet()
+
+    private var appBarLayout: AppBarLayout? = null
+    private var viewPager: ViewPager? = null
+        set(value) {
+            field?.removeOnPageChangeListener(pageChangeListener)
+            field = value
+            field?.addOnPageChangeListener(pageChangeListener)
+        }
+
+    private val pageChangeListener = object : ViewPager.SimpleOnPageChangeListener() {
+        override fun onPageScrollStateChanged(state: Int) {
+            // Wait until idle to make sure all the views laid out properly before checked
+            if (canLiftAppBarOnScroll && state == ViewPager.SCROLL_STATE_IDLE) {
+                appBarLayout?.isLifted = (viewPager?.getActivePageView() as? ViewGroup)
+                    ?.findDescendant<RecyclerView>()
+                    ?.canScrollVertically(-1) ?: false
+            }
+        }
+    }
+
+    /**
+     * If true, [AppBarLayout] child will be lifted on nested scroll.
+     */
+    var isLiftAppBarOnScroll = true
+
+    /**
+     * Internal check
+     */
+    private val canLiftAppBarOnScroll
+        get() = !isTablet && isLiftAppBarOnScroll
+
+    override fun onNestedScroll(
+        target: View,
+        dxConsumed: Int,
+        dyConsumed: Int,
+        dxUnconsumed: Int,
+        dyUnconsumed: Int,
+        type: Int,
+        consumed: IntArray
+    ) {
+        super.onNestedScroll(target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type, consumed)
+        if (canLiftAppBarOnScroll) {
+            appBarLayout?.isLifted = dyConsumed != 0 || dyUnconsumed >= 0
+        }
+    }
+
+    override fun onAttachedToWindow() {
+        super.onAttachedToWindow()
+        appBarLayout = findChild()
+        viewPager = findChild<ChangeHandlerFrameLayout>()?.findDescendant()
+
+        // Updates ViewPager reference when controller is changed
+        findViewTreeLifecycleOwner()?.lifecycle?.coroutineScope?.let { scope ->
+            findChild<ChangeHandlerFrameLayout>()?.hierarchyChangeEvents()
+                ?.onEach {
+                    if (it is HierarchyChangeEvent.ChildRemoved) {
+                        viewPager = (it.parent as? ViewGroup)?.findDescendant()
+                    }
+                }
+                ?.launchIn(scope)
+        }
+    }
+
+    override fun onDetachedFromWindow() {
+        super.onDetachedFromWindow()
+        appBarLayout = null
+        viewPager = null
+    }
+
+    override fun onSaveInstanceState(): Parcelable? {
+        val superState = super.onSaveInstanceState()
+        return if (superState != null) {
+            SavedState(superState).also {
+                it.appBarLifted = appBarLayout?.isLifted ?: false
+            }
+        } else {
+            superState
+        }
+    }
+
+    override fun onRestoreInstanceState(state: Parcelable?) {
+        if (state is SavedState) {
+            super.onRestoreInstanceState(state.superState)
+            doOnLayout {
+                appBarLayout?.isLifted = state.appBarLifted
+            }
+        } else {
+            super.onRestoreInstanceState(state)
+        }
+    }
+
+    internal class SavedState : AbsSavedState {
+        var appBarLifted = false
+
+        constructor(superState: Parcelable) : super(superState)
+
+        constructor(source: Parcel, loader: ClassLoader?) : super(source, loader) {
+            appBarLifted = source.readByte().toInt() == 1
+        }
+
+        override fun writeToParcel(out: Parcel, flags: Int) {
+            super.writeToParcel(out, flags)
+            out.writeByte((if (appBarLifted) 1 else 0).toByte())
+        }
+
+        companion object {
+            @JvmField
+            val CREATOR: Parcelable.ClassLoaderCreator<SavedState> = object : Parcelable.ClassLoaderCreator<SavedState> {
+                override fun createFromParcel(source: Parcel, loader: ClassLoader): SavedState {
+                    return SavedState(source, loader)
+                }
+
+                override fun createFromParcel(source: Parcel): SavedState {
+                    return SavedState(source, null)
+                }
+
+                override fun newArray(size: Int): Array<SavedState> {
+                    return newArray(size)
+                }
+            }
+        }
+    }
+}

app/src/main/java/eu/kanade/tachiyomi/widget/TachiyomiScrollingViewBehavior.kt

@@ -0,0 +1,15 @@
+package eu.kanade.tachiyomi.widget
+
+import com.google.android.material.appbar.AppBarLayout
+
+/**
+ * [AppBarLayout.ScrollingViewBehavior] that lets the app bar overlaps the scrolling child.
+ */
+class TachiyomiScrollingViewBehavior : AppBarLayout.ScrollingViewBehavior() {
+
+    var shouldHeaderOverlap = false
+
+    override fun shouldHeaderOverlapScrollingChild(): Boolean {
+        return shouldHeaderOverlap
+    }
+}