Enable swiping on favorites

Author: joshliebe

saved-sites/saved-sites-impl/src/main/java/com/duckduckgo/savedsites/impl/newtab/FavouritesNewTabSectionView.kt

@@ -24,6 +24,7 @@ import android.util.AttributeSet
 import android.view.LayoutInflater
 import android.view.MotionEvent
 import android.view.View
+import android.view.ViewConfiguration
 import android.widget.LinearLayout
 import android.widget.PopupWindow
 import androidx.core.text.HtmlCompat
@@ -77,6 +78,7 @@ import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionViewModel.Co
 import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionViewModel.Command.DeleteSavedSiteConfirmation
 import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionViewModel.Command.ShowEditSavedSiteDialog
 import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionViewModel.SavedSiteChangedViewState
+import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionViewModel.SwipeDecision
 import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionViewModel.ViewState
 import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionsAdapter.Companion.QUICK_ACCESS_GRID_MAX_COLUMNS
 import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionsAdapter.Companion.QUICK_ACCESS_ITEM_MAX_SIZE_DP
@@ -134,6 +136,14 @@ class FavouritesNewTabSectionView @JvmOverloads constructor(
     private val conflatedStateJob = ConflatedJob()
     private val conflatedCommandJob = ConflatedJob()
 
+    private val touchSlop: Int by lazy { ViewConfiguration.get(context).scaledTouchSlop }
+    private val longPressTimeoutMs: Long by lazy { ViewConfiguration.getLongPressTimeout().toLong() }
+
+    private val longPressRunnable = Runnable {
+        viewModel.onLongPressTriggered()
+        parent?.requestDisallowInterceptTouchEvent(true)
+    }
+
     init {
         context.obtainStyledAttributes(
             attrs,
@@ -186,8 +196,35 @@ class FavouritesNewTabSectionView @JvmOverloads constructor(
     }
 
     override fun dispatchTouchEvent(ev: MotionEvent?): Boolean {
-        if (swipingTabsFeature.isEnabled) {
-            parent.requestDisallowInterceptTouchEvent(true)
+        if (!swipingTabsFeature.isEnabled) return super.dispatchTouchEvent(ev)
+
+        when (ev?.actionMasked) {
+            MotionEvent.ACTION_DOWN -> {
+                viewModel.onTouchDown(ev.x, ev.y)
+                removeCallbacks(longPressRunnable)
+                postDelayed(longPressRunnable, longPressTimeoutMs)
+                parent?.requestDisallowInterceptTouchEvent(false)
+            }
+
+            MotionEvent.ACTION_MOVE -> {
+                if (viewModel.isLongPressActive()) {
+                    parent?.requestDisallowInterceptTouchEvent(true)
+                } else {
+                    viewModel.onTouchMove(ev.x, ev.y, touchSlop)?.let { decision ->
+                        when (decision) {
+                            SwipeDecision.CANCEL_LONG_PRESS -> removeCallbacks(longPressRunnable)
+                            SwipeDecision.HORIZONTAL -> parent?.requestDisallowInterceptTouchEvent(false)
+                            SwipeDecision.VERTICAL -> parent?.requestDisallowInterceptTouchEvent(true)
+                        }
+                    }
+                }
+            }
+
+            MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> {
+                removeCallbacks(longPressRunnable)
+                viewModel.onTouchUp()
+                parent?.requestDisallowInterceptTouchEvent(false)
+            }
         }
         return super.dispatchTouchEvent(ev)
     }

saved-sites/saved-sites-impl/src/main/java/com/duckduckgo/savedsites/impl/newtab/FavouritesNewTabSectionViewModel.kt

@@ -41,6 +41,7 @@ import com.duckduckgo.savedsites.impl.newtab.FavouritesNewTabSectionViewModel.Co
 import com.duckduckgo.sync.api.engine.SyncEngine
 import com.duckduckgo.sync.api.engine.SyncEngine.SyncTrigger.FEATURE_READ
 import javax.inject.Inject
+import kotlin.math.abs
 import kotlinx.coroutines.channels.BufferOverflow
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
@@ -89,6 +90,12 @@ class FavouritesNewTabSectionViewModel @Inject constructor(
     private val command = Channel<Command>(1, BufferOverflow.DROP_OLDEST)
     internal fun commands(): Flow<Command> = command.receiveAsFlow()
 
+    enum class SwipeDecision { HORIZONTAL, VERTICAL, CANCEL_LONG_PRESS }
+
+    private var initialTouchX = 0f
+    private var initialTouchY = 0f
+    private var longPressActivated = false
+
     override fun onResume(owner: LifecycleOwner) {
         super.onResume(owner)
 
@@ -287,4 +294,32 @@ class FavouritesNewTabSectionViewModel @Inject constructor(
     ): String {
         return pixelName.pixelName + "_" + placement.name.lowercase()
     }
+
+    fun onTouchDown(x: Float, y: Float) {
+        initialTouchX = x
+        initialTouchY = y
+        longPressActivated = false
+    }
+
+    fun onTouchUp() {
+        longPressActivated = false
+    }
+
+    fun onTouchMove(x: Float, y: Float, touchSlop: Int): SwipeDecision? {
+        val dx = abs(x - initialTouchX)
+        val dy = abs(y - initialTouchY)
+
+        return when {
+            dx > dy && dx > touchSlop -> SwipeDecision.HORIZONTAL
+            dy > dx && dy > touchSlop -> SwipeDecision.VERTICAL
+            dx > touchSlop || dy > touchSlop -> SwipeDecision.CANCEL_LONG_PRESS
+            else -> null
+        }
+    }
+
+    fun onLongPressTriggered() {
+        longPressActivated = true
+    }
+
+    fun isLongPressActive(): Boolean = longPressActivated
 }