room-details: Ask to confirm some changes in PermissionsMemberRow

When muting, promoting to the same level as our own user, or demoting
oneself like on the UserPage.

src/components/dialogs/message_dialogs.rs

@@ -7,7 +7,7 @@ use crate::{
     i18n::gettext_f,
     ngettext_f,
     prelude::*,
-    session::model::{Member, Membership, Room, RoomCategory},
+    session::model::{Member, Membership, Room, RoomCategory, User},
 };
 
 /// Show a dialog to confirm leaving a room.
@@ -358,7 +358,7 @@ pub(crate) struct ConfirmRoomMemberDestructiveActionResponse {
 
 /// Show a dialog to confirm muting one or several room members.
 pub(crate) async fn confirm_mute_room_member_dialog(
-    members: &[Member],
+    members: &[impl IsA<User>],
     parent: &impl IsA<gtk::Widget>,
 ) -> bool {
     if members.is_empty() {
@@ -367,7 +367,8 @@ pub(crate) async fn confirm_mute_room_member_dialog(
 
     let first_member = members
         .first()
-        .expect("there should be at least one member");
+        .expect("there should be at least one member")
+        .upcast_ref();
     let count = members.len() as u32;
 
     let heading = ngettext_f(
@@ -406,7 +407,7 @@ pub(crate) async fn confirm_mute_room_member_dialog(
 /// Show a dialog to confirm setting the power level of one or several room
 /// members with the same value as our own.
 pub(crate) async fn confirm_set_room_member_power_level_same_as_own_dialog(
-    members: &[Member],
+    members: &[impl IsA<User>],
     parent: &impl IsA<gtk::Widget>,
 ) -> bool {
     if members.is_empty() {
@@ -415,7 +416,8 @@ pub(crate) async fn confirm_set_room_member_power_level_same_as_own_dialog(
 
     let first_member = members
         .first()
-        .expect("there should be at least one member");
+        .expect("there should be at least one member")
+        .upcast_ref();
     let count = members.len() as u32;
 
     let heading = ngettext_f(

src/session/model/room/permissions.rs

@@ -500,6 +500,11 @@ impl Permissions {
         self.imp().power_levels.borrow().clone()
     }
 
+    /// The power level for the user with the given ID.
+    pub(crate) fn user_power_level(&self, user_id: &UserId) -> PowerLevel {
+        self.imp().power_levels.borrow().for_user(user_id).into()
+    }
+
     /// The current [`MemberRole`] for the given power level.
     pub(crate) fn role(&self, power_level: PowerLevel) -> MemberRole {
         if power_level >= POWER_LEVEL_ADMIN {

src/session/view/content/room_details/permissions/member_power_level.rs

@@ -77,10 +77,7 @@ mod imp {
                 return;
             };
 
-            let power_levels = permissions.power_levels();
-            let power_level = power_levels.for_user(user.user_id());
-
-            self.set_power_level(power_level.into());
+            self.set_power_level(permissions.user_power_level(user.user_id()));
         }
 
         /// Set the wanted power level of the member.

src/session/view/content/room_details/permissions/member_row.rs

@@ -1,8 +1,14 @@
+use std::slice;
+
 use gtk::{CompositeTemplate, glib, glib::clone, prelude::*, subclass::prelude::*};
 
 use super::MemberPowerLevel;
 use crate::{
-    components::{Avatar, PowerLevelSelectionPopover, RoleBadge},
+    components::{
+        Avatar, PowerLevelSelectionPopover, RoleBadge, confirm_mute_room_member_dialog,
+        confirm_own_demotion_dialog, confirm_set_room_member_power_level_same_as_own_dialog,
+    },
+    prelude::*,
     session::model::Permissions,
     utils::{BoundObject, key_bindings},
 };
@@ -82,7 +88,9 @@ mod imp {
     impl PermissionsMemberRow {
         /// Set the permissions of the room.
         fn set_permissions(&self, permissions: Permissions) {
-            self.permissions.set(permissions.clone()).unwrap();
+            self.permissions
+                .set(permissions.clone())
+                .expect("permissions should be uninitialized");
             self.popover.set_permissions(Some(permissions));
         }
 
@@ -174,13 +182,69 @@ mod imp {
 
         /// The popover's selected power level changed.
         #[template_callback]
-        fn power_level_changed(&self) {
+        async fn power_level_changed(&self) {
             let Some(member) = self.member.obj() else {
                 return;
             };
 
-            let pl = self.popover.selected_power_level();
-            member.set_power_level(pl);
+            let power_level = self.popover.selected_power_level();
+            let old_power_level = member.power_level();
+
+            if power_level == old_power_level {
+                // Nothing changed.
+                return;
+            }
+
+            let permissions = self
+                .permissions
+                .get()
+                .expect("permissions should be initialized");
+            let user = member.user();
+            let room_power_level = permissions.user_power_level(user.user_id());
+
+            if room_power_level == power_level {
+                // The power level was reset to the one in the room, nothing to check.
+                member.set_power_level(power_level);
+                return;
+            }
+
+            let obj = self.obj();
+
+            if user.is_own_user() {
+                // Warn that demoting oneself is irreversible.
+                if !confirm_own_demotion_dialog(&*obj).await {
+                    // Reset the value in the popover.
+                    self.popover.set_selected_power_level(old_power_level);
+                    return;
+                }
+            } else {
+                // Warn if user is muted but was not before.
+                let mute_power_level = permissions.mute_power_level();
+                let is_muted =
+                    power_level <= mute_power_level && old_power_level > mute_power_level;
+                if is_muted && !confirm_mute_room_member_dialog(slice::from_ref(&user), &*obj).await
+                {
+                    // Reset the value in the popover.
+                    self.popover.set_selected_power_level(old_power_level);
+                    return;
+                }
+
+                // Warn if power level is set at same level as own power level.
+                let is_own_power_level = power_level == permissions.own_power_level();
+                if is_own_power_level
+                    && !confirm_set_room_member_power_level_same_as_own_dialog(
+                        slice::from_ref(&user),
+                        &*obj,
+                    )
+                    .await
+                {
+                    // Reset the value in the popover.
+                    self.popover.set_selected_power_level(old_power_level);
+                    return;
+                }
+            }
+
+            member.set_power_level(power_level);
         }
     }
 }