fix, change_display_resolution, add comments

Signed-off-by: dignow <linlong1265@gmail.com>

flutter/lib/models/model.dart

@@ -430,14 +430,12 @@ class FfiModel with ChangeNotifier {
       Map<String, dynamic> evt, SessionID sessionId, String peerId) {
     final curDisplay = int.parse(evt['display']);
 
-    // The message should be handled by the another UI session.
-    if (isChooseDisplayToOpenInNewWindow(_pi, sessionId)) {
+    if (_pi.currentDisplay != kAllDisplayValue) {
+      if (bind.peerGetDefaultSessionsCount(id: peerId) > 1) {
         if (curDisplay != _pi.currentDisplay) {
           return;
         }
       }
-
-    if (_pi.currentDisplay != kAllDisplayValue) {
       _pi.currentDisplay = curDisplay;
     }
 
@@ -825,6 +823,7 @@ class FfiModel with ChangeNotifier {
       }
       _pi.displays = newDisplays;
       _pi.displaysCount.value = _pi.displays.length;
+
       if (_pi.currentDisplay == kAllDisplayValue) {
         updateCurDisplay(sessionId);
         // to-do: What if the displays are changed?

src/server/display_service.rs

@@ -59,7 +59,10 @@ impl SyncDisplaysInfo {
     }
 }
 
+// This function is really useful, though a duplicate check if display changed.
+// Because the video server will send the supported resolutions of the {idx} display to the subscribers.
 pub(super) fn check_display_changed(
+    ndisplay: usize,
     idx: usize,
     (x, y, w, h): (i32, i32, usize, usize),
 ) -> Option<DisplayInfo> {
@@ -72,7 +75,14 @@ pub(super) fn check_display_changed(
     }
 
     let lock = SYNC_DISPLAYS.lock().unwrap();
+    // If plugging out a monitor && lock.displays.get(idx) is None.
+    //  1. The client version < 1.2.4. The client side has to reconnect.
+    //  2. The client version > 1.2.4, The client side can handle the case becuase sync peer info message will be sent.
+    // But it is acceptable to for the user to reconnect manually, becuase the monitor is unplugged.
     let d = lock.displays.get(idx)?;
+    if ndisplay != lock.displays.len() {
+        return Some(d.clone());
+    }
     if !(d.x == x && d.y == y && d.width == w as i32 && d.height == h as i32) {
         Some(d.clone())
     } else {
@@ -144,6 +154,8 @@ fn displays_to_msg(displays: Vec<DisplayInfo>) -> Message {
         ..Default::default()
     };
     pi.displays = displays.clone();
+    // current_display should not be used in server.
+    // It is set to 0 for compatibility with old clients.
     pi.current_display = 0;
     let mut msg_out = Message::new();
     msg_out.set_peer_info(pi);

src/server/video_service.rs

@@ -297,6 +297,7 @@ pub(super) struct CapturerInfo {
     pub origin: (i32, i32),
     pub width: usize,
     pub height: usize,
+    pub ndisplay: usize,
     pub current: usize,
     pub privacy_mode_id: i32,
     pub _capturer_privacy_mode_id: i32,
@@ -388,6 +389,7 @@ fn get_capturer(
         origin,
         width,
         height,
+        ndisplay,
         current,
         privacy_mode_id,
         _capturer_privacy_mode_id: capturer_privacy_mode_id,
@@ -503,9 +505,11 @@ fn run(vs: VideoService) -> ResultType<()> {
         let now = time::Instant::now();
         if last_check_displays.elapsed().as_millis() > 1000 {
             last_check_displays = now;
-            if let Some(display) =
-                check_display_changed(c.current, (c.origin.0, c.origin.1, c.width, c.height))
-            {
+            if let Some(display) = check_display_changed(
+                c.ndisplay,
+                c.current,
+                (c.origin.0, c.origin.1, c.width, c.height),
+            ) {
                 log::info!("Display {} changed", display);
                 broadcast_display_changed(display_idx, &sp, &c.name, display);
                 bail!("SWITCH");
@@ -586,6 +590,16 @@ fn run(vs: VideoService) -> ResultType<()> {
                 }
             }
             Err(err) => {
+                if let Some(display) = check_display_changed(
+                    c.ndisplay,
+                    c.current,
+                    (c.origin.0, c.origin.1, c.width, c.height),
+                ) {
+                    log::info!("Display {} changed", display);
+                    broadcast_display_changed(display_idx, &sp, &c.name, display);
+                    bail!("SWITCH");
+                }
+
                 #[cfg(windows)]
                 if !c.is_gdi() {
                     c.set_gdi();
@@ -850,20 +864,6 @@ fn broadcast_display_changed(
     }
 }
 
-fn get_display_info_simple_meta(display_idx: usize) -> Option<(String, (i32, i32), usize, usize)> {
-    let displays = display_service::try_get_displays().ok()?;
-    if let Some(display) = displays.get(display_idx) {
-        Some((
-            display.name(),
-            display.origin(),
-            display.width(),
-            display.height(),
-        ))
-    } else {
-        None
-    }
-}
-
 fn make_display_changed_msg(
     display_idx: usize,
     name: &str,

src/server/wayland.rs

@@ -84,6 +84,7 @@ impl TraitCapturer for CapturerPtr {
 struct CapDisplayInfo {
     rects: Vec<((i32, i32), usize, usize)>,
     displays: Vec<DisplayInfo>,
+    num: usize,
     primary: usize,
     current: usize,
     capturer: CapturerPtr,
@@ -194,6 +195,7 @@ pub(super) async fn check_init() -> ResultType<()> {
                 let cap_display_info = Box::into_raw(Box::new(CapDisplayInfo {
                     rects,
                     displays,
+                    num,
                     primary,
                     current,
                     capturer,
@@ -275,6 +277,7 @@ pub(super) fn get_capturer() -> ResultType<super::video_service::CapturerInfo> {
                 origin: rect.0,
                 width: rect.1,
                 height: rect.2,
+                ndisplay: cap_display_info.num,
                 current: cap_display_info.current,
                 privacy_mode_id: 0,
                 _capturer_privacy_mode_id: 0,