From 79518f880bd04258706ca562ce268e451a1063b7 Mon Sep 17 00:00:00 2001
From: Jeff Boek <jeff@jeffboek.com>
Date: Wed, 10 Apr 2019 16:35:30 -0700
Subject: [PATCH] [fenix] for
 https://github.com/mozilla-mobile/fenix/issues/1430 - Copy
 BottomToolbarBehavior to customize snackbar position

---
 .../mozilla/fenix/browser/BrowserFragment.kt  |   1 -
 .../browser/BrowserToolbarBottomBehavior.kt   | 123 ++++++++++++++++++
 2 files changed, 123 insertions(+), 1 deletion(-)
 create mode 100644 app/src/main/java/org/mozilla/fenix/browser/BrowserToolbarBottomBehavior.kt

diff --git a/app/src/main/java/org/mozilla/fenix/browser/BrowserFragment.kt b/app/src/main/java/org/mozilla/fenix/browser/BrowserFragment.kt
index accba6ae7..6e59a893d 100644
--- a/app/src/main/java/org/mozilla/fenix/browser/BrowserFragment.kt
+++ b/app/src/main/java/org/mozilla/fenix/browser/BrowserFragment.kt
@@ -32,7 +32,6 @@ import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
 import mozilla.appservices.places.BookmarkRoot
 import mozilla.components.browser.session.Session
-import mozilla.components.browser.toolbar.behavior.BrowserToolbarBottomBehavior
 import mozilla.components.feature.contextmenu.ContextMenuCandidate
 import mozilla.components.feature.contextmenu.ContextMenuFeature
 import mozilla.components.feature.downloads.DownloadsFeature
diff --git a/app/src/main/java/org/mozilla/fenix/browser/BrowserToolbarBottomBehavior.kt b/app/src/main/java/org/mozilla/fenix/browser/BrowserToolbarBottomBehavior.kt
new file mode 100644
index 000000000..a76e3d56c
--- /dev/null
+++ b/app/src/main/java/org/mozilla/fenix/browser/BrowserToolbarBottomBehavior.kt
@@ -0,0 +1,123 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.browser
+
+import android.animation.ValueAnimator
+import android.content.Context
+import android.util.AttributeSet
+import android.view.Gravity
+import android.view.View
+import android.view.View.SCROLL_AXIS_VERTICAL
+import android.view.animation.DecelerateInterpolator
+import androidx.coordinatorlayout.widget.CoordinatorLayout
+import androidx.core.view.ViewCompat.TYPE_NON_TOUCH
+import androidx.core.view.ViewCompat.TYPE_TOUCH
+import com.google.android.material.snackbar.Snackbar
+import mozilla.components.browser.toolbar.BrowserToolbar
+import org.mozilla.fenix.R
+import kotlin.math.max
+import kotlin.math.min
+
+private const val SNAP_ANIMATION_DURATION = 150L
+
+/**
+ * A [CoordinatorLayout.Behavior] implementation to be used when placing [BrowserToolbar] at the bottom of the screen.
+ *
+ * This implementation will:
+ * - Show/Hide the [BrowserToolbar] automatically when scrolling vertically.
+ * - On showing a [Snackbar] position it above the [BrowserToolbar].
+ * - Snap the [BrowserToolbar] to be hidden or visible when the user stops scrolling.
+ */
+class BrowserToolbarBottomBehavior(
+    context: Context?,
+    attrs: AttributeSet?
+) : CoordinatorLayout.Behavior<BrowserToolbar>(context, attrs) {
+    // This implementation is heavily based on this blog article:
+    // https://android.jlelse.eu/scroll-your-bottom-navigation-view-away-with-10-lines-of-code-346f1ed40e9e
+
+    internal var shouldSnapAfterScroll: Boolean = false
+
+    internal var snapAnimator: ValueAnimator = ValueAnimator().apply {
+        interpolator = DecelerateInterpolator()
+        duration = SNAP_ANIMATION_DURATION
+    }
+
+    override fun onStartNestedScroll(
+        coordinatorLayout: CoordinatorLayout,
+        child: BrowserToolbar,
+        directTargetChild: View,
+        target: View,
+        axes: Int,
+        type: Int
+    ): Boolean {
+        return if (axes == SCROLL_AXIS_VERTICAL) {
+            shouldSnapAfterScroll = type == TYPE_TOUCH
+            snapAnimator.cancel()
+            true
+        } else {
+            false
+        }
+    }
+
+    @Suppress("MagicNumber")
+    override fun onStopNestedScroll(
+        coordinatorLayout: CoordinatorLayout,
+        child: BrowserToolbar,
+        target: View,
+        type: Int
+    ) {
+        if (shouldSnapAfterScroll || type == TYPE_NON_TOUCH) {
+            if (child.translationY >= (child.height * 0.5f)) {
+                animateSnap(child, SnapDirection.DOWN)
+            } else {
+                animateSnap(child, SnapDirection.UP)
+            }
+        }
+    }
+
+    override fun onNestedPreScroll(
+        coordinatorLayout: CoordinatorLayout,
+        child: BrowserToolbar,
+        target: View,
+        dx: Int,
+        dy: Int,
+        consumed: IntArray,
+        type: Int
+    ) {
+        super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type)
+        child.translationY = max(0f, min(child.height.toFloat(), child.translationY + dy))
+    }
+
+    override fun layoutDependsOn(parent: CoordinatorLayout, child: BrowserToolbar, dependency: View): Boolean {
+        if (dependency is Snackbar.SnackbarLayout) {
+            positionSnackbar(child, dependency)
+        }
+
+        return super.layoutDependsOn(parent, child, dependency)
+    }
+
+    private fun animateSnap(child: View, direction: SnapDirection) = with(snapAnimator) {
+        addUpdateListener { child.translationY = it.animatedValue as Float }
+        setFloatValues(child.translationY, if (direction == SnapDirection.UP) 0f else child.height.toFloat())
+        start()
+    }
+
+    @Suppress("MagicNumber")
+    private fun positionSnackbar(child: View, view: View) {
+        val params = view.layoutParams as CoordinatorLayout.LayoutParams
+
+        // Position the snackbar above the toolbar so that it doesn't overlay the toolbar.
+        params.anchorId = R.id.quick_action_sheet
+        params.anchorGravity = Gravity.TOP or Gravity.CENTER_HORIZONTAL
+        params.gravity = Gravity.TOP or Gravity.CENTER_HORIZONTAL
+
+        view.layoutParams = params
+    }
+}
+
+private enum class SnapDirection {
+    UP,
+    DOWN
+}