Closes #2916: Improve BrowserMenu popup orientation.

components/browser/menu/src/main/java/mozilla/components/browser/menu/BrowserMenu.kt

@@ -6,15 +6,20 @@ package mozilla.components.browser.menu
 
 import android.annotation.SuppressLint
 import android.graphics.Color
+import android.graphics.Rect
 import android.graphics.drawable.ColorDrawable
 import android.view.Gravity
 import android.view.LayoutInflater
 import android.view.View
 import android.view.WindowManager
 import android.widget.PopupWindow
+import androidx.annotation.VisibleForTesting
 import androidx.coordinatorlayout.widget.CoordinatorLayout
+import androidx.core.widget.PopupWindowCompat
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
+import mozilla.components.browser.menu.BrowserMenu.Orientation.DOWN
+import mozilla.components.browser.menu.BrowserMenu.Orientation.UP
 import mozilla.components.support.ktx.android.content.res.pxToDp
 import mozilla.components.support.ktx.android.view.isRTL
 
@@ -28,7 +33,7 @@ class BrowserMenu internal constructor(
     private var menuList: RecyclerView? = null
 
     @SuppressLint("InflateParams")
-    fun show(anchor: View, orientation: Orientation = Orientation.DOWN): PopupWindow {
+    fun show(anchor: View, orientation: Orientation = DOWN): PopupWindow {
         val view = LayoutInflater.from(anchor.context).inflate(R.layout.mozac_browser_menu, null)
 
         adapter.menu = this
@@ -39,15 +44,11 @@ class BrowserMenu internal constructor(
         }
 
         return PopupWindow(
-                view,
-                WindowManager.LayoutParams.WRAP_CONTENT,
-                WindowManager.LayoutParams.WRAP_CONTENT
+            view,
+            WindowManager.LayoutParams.WRAP_CONTENT,
+            WindowManager.LayoutParams.WRAP_CONTENT
         ).apply {
             setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
-            animationStyle = when (orientation) {
-                Orientation.DOWN -> R.style.Mozac_Browser_Menu_Animation_OverflowMenuTop
-                Orientation.UP -> R.style.Mozac_Browser_Menu_Animation_OverflowMenuBottom
-            }
             isFocusable = true
             elevation = view.resources.pxToDp(MENU_ELEVATION_DP).toFloat()
 
@@ -56,9 +57,7 @@ class BrowserMenu internal constructor(
                 currentPopup = null
             }
 
-            val xOffset = if (anchor.isRTL) -anchor.width else 0
-            val yOffset = determineVerticalOffset(orientation, view, anchor)
-            showAsDropDown(anchor, xOffset, yOffset)
+            displayPopup(view, anchor, orientation)
         }.also {
             currentPopup = it
         }
@@ -82,12 +81,12 @@ class BrowserMenu internal constructor(
             val params = parent.layoutParams
             return if (params is CoordinatorLayout.LayoutParams) {
                 if ((params.gravity and Gravity.BOTTOM) == Gravity.BOTTOM) {
-                    Orientation.UP
+                    UP
                 } else {
-                    Orientation.DOWN
+                    DOWN
                 }
             } else {
-                Orientation.DOWN
+                DOWN
             }
         }
     }
@@ -98,14 +97,101 @@ class BrowserMenu internal constructor(
     }
 }
 
-private fun determineVerticalOffset(orientation: BrowserMenu.Orientation, view: View, anchor: View): Int {
-    return if (orientation == BrowserMenu.Orientation.DOWN) {
-        // Menu should overlay anchor.
-        -anchor.height
+@VisibleForTesting
+internal fun PopupWindow.displayPopup(
+    containerView: View,
+    anchor: View,
+    preferredOrientation: BrowserMenu.Orientation
+) {
+    // Measure menu
+    val spec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED)
+    containerView.measure(spec, spec)
+
+    val topAndBottomPair = getMaxAvailableHeightToTopAndBottom(anchor)
+    val availableHeightToTop = topAndBottomPair.first
+    val availableHeightToBottom = topAndBottomPair.second
+    val containerHeight = containerView.measuredHeight
+
+    val fitsUp = availableHeightToTop >= containerHeight
+    val fitsDown = availableHeightToBottom >= containerHeight
+
+    // Try to use the preferred orientation, if doesn't fit fallback to the best fit.
+    when {
+        preferredOrientation == DOWN && fitsDown -> {
+            showPopupWithDownOrientation(anchor)
+        }
+        preferredOrientation == UP && fitsUp -> {
+            showPopupWithUpOrientation(anchor, availableHeightToBottom, containerHeight)
+        }
+        else -> {
+            showPopupWhereBestFits(anchor, fitsUp, fitsDown, availableHeightToBottom, containerHeight)
+        }
+    }
+}
+
+private fun PopupWindow.showPopupWhereBestFits(
+    anchor: View,
+    fitsUp: Boolean,
+    fitsDown: Boolean,
+    availableHeightToBottom: Int,
+    containerHeight: Int
+) {
+    // We don't have enough space to show the menu UP neither DOWN.
+    // Let's just show the popup at the location of the anchor.
+    if (!fitsUp && !fitsDown) {
+        showAtAnchorLocation(anchor)
     } else {
-        // Measure menu and then position menu above (and overlapping) anchor
-        val spec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED)
-        view.measure(spec, spec)
-        -view.measuredHeight
+        if (fitsDown) {
+            showPopupWithDownOrientation(anchor)
+        } else {
+            showPopupWithUpOrientation(anchor, availableHeightToBottom, containerHeight)
+        }
     }
 }
+
+private fun PopupWindow.showPopupWithUpOrientation(anchor: View, availableHeightToBottom: Int, containerHeight: Int) {
+    val xOffset = if (anchor.isRTL) -anchor.width else 0
+    animationStyle = R.style.Mozac_Browser_Menu_Animation_OverflowMenuBottom
+
+    // Positioning the menu above and overlapping the anchor.
+    val yOffset = if (availableHeightToBottom < 0) {
+        // The anchor is partially below of the bottom of the screen, let's make the menu completely visible.
+        availableHeightToBottom - containerHeight
+    } else {
+        -containerHeight
+    }
+    showAsDropDown(anchor, xOffset, yOffset)
+}
+
+private fun PopupWindow.showPopupWithDownOrientation(anchor: View) {
+    val xOffset = if (anchor.isRTL) -anchor.width else 0
+    animationStyle = R.style.Mozac_Browser_Menu_Animation_OverflowMenuTop
+    // Menu should overlay the anchor.
+    showAsDropDown(anchor, xOffset, -anchor.height)
+}
+
+private fun PopupWindow.showAtAnchorLocation(anchor: View) {
+    val anchorPosition = IntArray(2)
+    anchor.getLocationOnScreen(anchorPosition)
+    val x = anchorPosition[0]
+    val y = anchorPosition[1]
+    PopupWindowCompat.setOverlapAnchor(this, true)
+    showAtLocation(anchor, Gravity.START or Gravity.TOP, x, y)
+}
+
+private fun getMaxAvailableHeightToTopAndBottom(anchor: View): Pair<Int, Int> {
+    val anchorPosition = IntArray(2)
+    val displayFrame = Rect()
+
+    val appView = anchor.rootView
+    appView.getWindowVisibleDisplayFrame(displayFrame)
+
+    anchor.getLocationOnScreen(anchorPosition)
+
+    val bottomEdge = displayFrame.bottom
+
+    val distanceToBottom = bottomEdge - (anchorPosition[1] + anchor.height)
+    val distanceToTop = anchorPosition[1] - displayFrame.top
+
+    return distanceToTop to distanceToBottom
+}

components/browser/menu/src/test/java/mozilla/components/browser/menu/BrowserMenuTest.kt

@@ -8,10 +8,12 @@ import android.content.Context
 import android.view.Gravity
 import android.view.View
 import android.widget.Button
+import android.widget.PopupWindow
 import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.recyclerview.widget.RecyclerView
 import androidx.test.core.app.ApplicationProvider
 import mozilla.components.browser.menu.item.SimpleBrowserMenuItem
+import mozilla.components.support.test.any
 import mozilla.components.support.test.mock
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertFalse
@@ -20,8 +22,13 @@ import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.mockito.Mockito
+import org.mockito.Mockito.doAnswer
+import org.mockito.Mockito.doReturn
 import org.mockito.Mockito.spy
+import org.mockito.Mockito.verify
 import org.robolectric.RobolectricTestRunner
+import org.robolectric.Shadows
+import org.robolectric.shadows.ShadowDisplay
 
 @RunWith(RobolectricTestRunner::class)
 class BrowserMenuTest {
@@ -165,4 +172,130 @@ class BrowserMenuTest {
             BrowserMenu.determineMenuOrientation(view)
         )
     }
+
+    @Test
+    fun `displayPopup that fitsDown with preferredOrientation DOWN`() {
+        val menuContentView = createMockViewWith(y = 0)
+        val anchor = createMockViewWith(y = 10)
+        val popupWindow = spy(PopupWindow())
+
+        // Makes the availableHeightToBottom bigger than the menuContentView
+        setScreenHeight(200)
+        doReturn(11).`when`(menuContentView).measuredHeight
+        doReturn(-10).`when`(anchor).height
+
+        popupWindow.displayPopup(menuContentView, anchor, BrowserMenu.Orientation.DOWN)
+
+        assertEquals(popupWindow.animationStyle, R.style.Mozac_Browser_Menu_Animation_OverflowMenuTop)
+        verify(popupWindow).showAsDropDown(anchor, 0, 10)
+    }
+
+    @Test
+    fun `displayPopup that fitsDown with preferredOrientation UP`() {
+        val menuContentView = createMockViewWith(y = 0)
+        val anchor = createMockViewWith(y = 10)
+        val popupWindow = spy(PopupWindow())
+
+        // Makes the availableHeightToBottom bigger than the menuContentView
+        setScreenHeight(200)
+        doReturn(11).`when`(menuContentView).measuredHeight
+        doReturn(-10).`when`(anchor).height
+
+        popupWindow.displayPopup(menuContentView, anchor, BrowserMenu.Orientation.UP)
+
+        assertEquals(popupWindow.animationStyle, R.style.Mozac_Browser_Menu_Animation_OverflowMenuTop)
+        verify(popupWindow).showAsDropDown(anchor, 0, 10)
+    }
+
+    @Test
+    fun `displayPopup that fitsUp with preferredOrientation UP`() {
+        val containerView = createMockViewWith(y = 0)
+        // Makes the availableHeightToTop 10
+        val anchor = createMockViewWith(y = 10)
+        val popupWindow = spy(PopupWindow())
+
+        // Makes the availableHeightToBottom smaller than the availableHeightToTop
+        setScreenHeight(0)
+        doReturn(-10).`when`(anchor).height
+
+        // Makes the content of the menu smaller than the availableHeightToTop
+        doReturn(9).`when`(containerView).measuredHeight
+
+        popupWindow.displayPopup(containerView, anchor, BrowserMenu.Orientation.UP)
+
+        assertEquals(popupWindow.animationStyle, R.style.Mozac_Browser_Menu_Animation_OverflowMenuBottom)
+        verify(popupWindow).showAsDropDown(anchor, 0, -9)
+    }
+
+    @Test
+    fun `displayPopup that fitsUp with preferredOrientation DOWN`() {
+        val containerView = createMockViewWith(y = 0)
+        // Makes the availableHeightToTop 10
+        val anchor = createMockViewWith(y = 10)
+        val popupWindow = spy(PopupWindow())
+        val contentHeight = 9
+
+        // Makes the availableHeightToBottom smaller than the availableHeightToTop
+        setScreenHeight(0)
+        doReturn(-10).`when`(anchor).height
+
+        // Makes the content of the menu smaller than the availableHeightToTop
+        doReturn(contentHeight).`when`(containerView).measuredHeight
+
+        popupWindow.displayPopup(containerView, anchor, BrowserMenu.Orientation.DOWN)
+
+        assertEquals(popupWindow.animationStyle, R.style.Mozac_Browser_Menu_Animation_OverflowMenuBottom)
+        verify(popupWindow).showAsDropDown(anchor, 0, -contentHeight)
+    }
+
+    @Test
+    fun `displayPopup that fitsUp when anchor is partially below of the bottom of the screen`() {
+        val containerView = createMockViewWith(y = 0)
+        // Makes the availableHeightToTop 10
+        val anchor = createMockViewWith(y = 10)
+        val popupWindow = spy(PopupWindow())
+        val screenHeight = -1
+        val contentHeight = -9
+
+        // Makes the availableHeightToBottom smaller than the availableHeightToTop
+        setScreenHeight(screenHeight)
+        doReturn(-10).`when`(anchor).height
+
+        // Makes the content of the menu smaller than the availableHeightToTop
+        doReturn(contentHeight).`when`(containerView).measuredHeight
+
+        popupWindow.displayPopup(containerView, anchor, BrowserMenu.Orientation.UP)
+
+        assertEquals(popupWindow.animationStyle, R.style.Mozac_Browser_Menu_Animation_OverflowMenuBottom)
+        verify(popupWindow).showAsDropDown(anchor, 0, screenHeight - contentHeight)
+    }
+
+    @Test
+    fun `displayPopup that don't fitUp neither fitDown`() {
+        val containerView = createMockViewWith(y = 0)
+        val anchor = createMockViewWith(y = 0)
+        val popupWindow = spy(PopupWindow())
+        doReturn(Int.MAX_VALUE).`when`(containerView).measuredHeight
+
+        popupWindow.displayPopup(containerView, anchor, BrowserMenu.Orientation.DOWN)
+        assertEquals(popupWindow.animationStyle, -1)
+        verify(popupWindow).showAtLocation(anchor, Gravity.START or Gravity.TOP, 0, 0)
+    }
+
+    private fun createMockViewWith(y: Int): View {
+        val view = spy(View(context))
+        doAnswer { invocation ->
+            val locationInWindow = (invocation.getArgument(0) as IntArray)
+            locationInWindow[0] = 0
+            locationInWindow[1] = y
+            locationInWindow
+        }.`when`(view).getLocationInWindow(any())
+        return view
+    }
+
+    private fun setScreenHeight(value: Int) {
+        val display = ShadowDisplay.getDefaultDisplay()
+        val shadow = Shadows.shadowOf(display)
+        shadow.setHeight(value)
+    }
 }