fix: allow swipe-to-close when drawer is open on pager screens

Keep drawer gestures enabled when the drawer is open so users can
swipe left to close it. Only disable gestures when the drawer is
closed (to let the pager and ZonedSwipeModifier handle gestures).

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/components/ZonedSwipeModifier.kt

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.components
+
+import androidx.compose.foundation.gestures.awaitEachGesture
+import androidx.compose.foundation.gestures.awaitFirstDown
+import androidx.compose.foundation.pager.PagerState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.composed
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
+import androidx.compose.ui.input.nestedscroll.NestedScrollSource
+import androidx.compose.ui.input.nestedscroll.nestedScroll
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.unit.dp
+
+private val EDGE_ZONE_WIDTH = 48.dp
+
+fun Modifier.zonedDrawerSwipe(
+    pagerState: PagerState,
+    openDrawer: () -> Unit,
+): Modifier =
+    composed {
+        val edgeZonePx = with(LocalDensity.current) { EDGE_ZONE_WIDTH.toPx() }
+
+        var gestureStartX by remember { mutableFloatStateOf(0f) }
+        var gestureStartPage by remember { mutableIntStateOf(0) }
+        var drawerOpened by remember { mutableStateOf(false) }
+
+        val connection =
+            remember {
+                object : NestedScrollConnection {
+                    override fun onPreScroll(
+                        available: Offset,
+                        source: NestedScrollSource,
+                    ): Offset {
+                        if (source != NestedScrollSource.UserInput) return Offset.Zero
+                        if (drawerOpened) return Offset(available.x, 0f)
+
+                        // available.x > 0 means user is swiping right
+                        if (available.x > 0f) {
+                            val wasOnFirstPage = gestureStartPage == 0
+                            val isInEdgeZone = gestureStartX < edgeZonePx
+
+                            if (wasOnFirstPage || !isInEdgeZone) {
+                                drawerOpened = true
+                                openDrawer()
+                                return Offset(available.x, 0f)
+                            }
+                        }
+                        return Offset.Zero
+                    }
+                }
+            }
+
+        this
+            .pointerInput(Unit) {
+                awaitEachGesture {
+                    val down = awaitFirstDown(requireUnconsumed = false)
+                    gestureStartX = down.position.x
+                    gestureStartPage = pagerState.currentPage
+                    drawerOpened = false
+                }
+            }.nestedScroll(connection)
+    }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/AppNavigation.kt

@@ -37,8 +37,10 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.platform.LocalContext
 import androidx.core.net.toUri
 import androidx.core.util.Consumer
+import androidx.navigation.NavDestination.Companion.hasRoute
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
+import androidx.navigation.compose.currentBackStackEntryAsState
 import com.vitorpamplona.amethyst.Amethyst
 import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.service.crashreports.DisplayCrashMessages
@@ -142,7 +144,14 @@ fun AppNavigation(
 ) {
     val nav = rememberNav()
 
-    AccountSwitcherAndLeftDrawerLayout(accountViewModel, accountSessionManager, nav) {
+    val navBackStackEntry by nav.controller.currentBackStackEntryAsState()
+    val isTabPagerRoute =
+        navBackStackEntry?.destination?.let { dest ->
+            dest.hasRoute<Route.Home>() || dest.hasRoute<Route.Message>()
+        } ?: false
+    val drawerGesturesEnabled = !isTabPagerRoute || nav.drawerState.isOpen
+
+    AccountSwitcherAndLeftDrawerLayout(accountViewModel, accountSessionManager, nav, drawerGesturesEnabled) {
         NavHost(
             navController = nav.controller,
             startDestination = Route.Home,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountSwitcherAndLeftDrawerLayout.kt

@@ -49,6 +49,7 @@ fun AccountSwitcherAndLeftDrawerLayout(
     accountViewModel: AccountViewModel,
     accountSessionManager: AccountSessionManager,
     nav: INav,
+    gesturesEnabled: Boolean = true,
     content: @Composable () -> Unit,
 ) {
     val scope = rememberCoroutineScope()
@@ -83,6 +84,7 @@ fun AccountSwitcherAndLeftDrawerLayout(
 
     ModalNavigationDrawer(
         drawerState = nav.drawerState,
+        gesturesEnabled = gesturesEnabled,
         drawerContent = {
             DrawerContent(nav, openSheetFunction, accountViewModel)
             BackHandler(enabled = nav.drawerState.isOpen, nav::closeDrawer)

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/rooms/feed/ChatroomListTabs.kt

@@ -48,6 +48,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.commons.ui.feeds.FeedContentState
+import com.vitorpamplona.amethyst.ui.components.zonedDrawerSwipe
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.stringRes
@@ -124,7 +125,12 @@ fun MessagesPager(
     HorizontalPager(
         contentPadding = paddingValues,
         state = pagerState,
-        userScrollEnabled = false,
+        userScrollEnabled = true,
+        modifier =
+            Modifier.zonedDrawerSwipe(
+                pagerState = pagerState,
+                openDrawer = nav::openDrawer,
+            ),
     ) { page ->
         ChatroomListFeedView(
             feedContentState = tabs[page].feedContentState,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/HomeScreen.kt

@@ -63,6 +63,7 @@ import com.vitorpamplona.amethyst.model.TopFilter
 import com.vitorpamplona.amethyst.service.OnlineChecker
 import com.vitorpamplona.amethyst.service.location.LocationState
 import com.vitorpamplona.amethyst.ui.actions.CrossfadeIfEnabled
+import com.vitorpamplona.amethyst.ui.components.zonedDrawerSwipe
 import com.vitorpamplona.amethyst.ui.feeds.ChannelFeedContentState
 import com.vitorpamplona.amethyst.ui.feeds.ChannelFeedState
 import com.vitorpamplona.amethyst.ui.feeds.PagerStateKeys
@@ -211,7 +212,12 @@ private fun HomePages(
         HorizontalPager(
             contentPadding = it,
             state = pagerState,
-            userScrollEnabled = false,
+            userScrollEnabled = true,
+            modifier =
+                Modifier.zonedDrawerSwipe(
+                    pagerState = pagerState,
+                    openDrawer = nav::openDrawer,
+                ),
         ) { page ->
             HomeFeeds(
                 feedState = tabs[page].feedState,