ui/gtk3: Erase Emojier preedit/lookup popup between applications

It would be better to erase Emojier popup window when users change
the input focus between applications. But it hasn't been implemented
because the focus-out/in events also happen when the Emojier popup window
is launching or rebuilding to the category list in GNOME Wayland.
The focus-out/in events do not happen in Xorg desktops with the rebuilding
GUI because GTK popup window causes focus-in/out evnets in Wayland.

Now I'm convinced with several issues and added a little complicated logic
to erase Emojier popup window with the focus changes between input contexts
to handle focus-in/out events in Wayland.

BUG=rhbz#1942970

3 files changed, 94 insertions, 8 deletions

diff --git a/ui/gtk3/emojier.vala b/ui/gtk3/emojier.vala
index 9e6e9263..69fb8abe 100644
--- a/ui/gtk3/emojier.vala
+++ b/ui/gtk3/emojier.vala
@@ -2,7 +2,7 @@
  *
  * ibus - The Input Bus
  *
- * Copyright (c) 2017-2019 Takao Fujiwara <takao.fujiwara1@gmail.com>
+ * Copyright (c) 2017-2021 Takao Fujiwara <takao.fujiwara1@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -227,6 +227,8 @@ public class IBusEmojier : Gtk.ApplicationWindow {
         BACKWARD,
     }
 
+    public bool is_wayland { get; set; }
+
     public const uint BUTTON_CLOSE_BUTTON = 1000;
 
     private const uint EMOJI_GRID_PAGE = 10;
@@ -317,15 +319,18 @@ public class IBusEmojier : Gtk.ApplicationWindow {
     private Gdk.Rectangle m_cursor_location;
     private bool m_is_up_side_down = false;
     private uint m_redraw_window_id;
+    private bool m_rebuilding_gui = false;
+    private uint m_rebuilding_gui_timeout_id;
 
     public signal void candidate_clicked(uint index, uint button, uint state);
     public signal void commit_text(string text);
     public signal void cancel();
 
-    public IBusEmojier() {
+    public IBusEmojier(bool is_wayland) {
         GLib.Object(
             type : Gtk.WindowType.POPUP
         );
+        this.is_wayland = is_wayland;
 
         // GLib.ActionEntry accepts const variables only.
         var action = new GLib.SimpleAction.stateful(
@@ -1002,6 +1007,7 @@ public class IBusEmojier : Gtk.ApplicationWindow {
         button.button_press_event.connect((w, e) => {
             m_category_active_index = -1;
             m_show_unicode = false;
+            start_rebuild_gui(false);
             hide_candidate_panel();
             show_all();
             return true;
@@ -1458,6 +1464,7 @@ public class IBusEmojier : Gtk.ApplicationWindow {
                     show_emoji_for_category(m_backward);
                     show_candidate_panel();
                 } else {
+                    start_rebuild_gui(false);
                     hide_candidate_panel();
                     show_all();
                 }
@@ -1778,6 +1785,34 @@ public class IBusEmojier : Gtk.ApplicationWindow {
     }
 
 
+    private void start_rebuild_gui(bool initial_launching) {
+        if (!this.is_wayland)
+            return;
+        if (!initial_launching && !base.get_visible())
+            return;
+        if (initial_launching && base.get_visible())
+            return;
+        if (m_rebuilding_gui_timeout_id != 0) {
+            GLib.Source.remove(m_rebuilding_gui_timeout_id);
+            m_rebuilding_gui_timeout_id = 0;
+        }
+
+        m_rebuilding_gui = true;
+        m_rebuilding_gui_timeout_id =
+                GLib.Timeout.add_seconds(10, () => {
+                    if (!m_rebuilding_gui) {
+                        m_rebuilding_gui_timeout_id = 0;
+                        return false;
+                    }
+                    warning("Rebuilding GUI is time out.");
+                    m_rebuilding_gui = false;
+                    m_rebuilding_gui_timeout_id = 0;
+                    return false;
+                },
+                GLib.Priority.DEFAULT_IDLE);
+    }
+
+
     public bool has_variants(uint index,
                              bool need_commit_signal) {
         if (index >= m_lookup_table.get_number_of_candidates())
@@ -1880,12 +1915,17 @@ public class IBusEmojier : Gtk.ApplicationWindow {
                 m_show_unicode = false;
                 m_category_active_index = -1;
             }
+            start_rebuild_gui(false);
             hide_candidate_panel();
             return true;
         } else if (m_backward_index >= 0 && m_backward != null) {
+            // Escape on Emoji variants window does not call focus-out events
+            // because hide() is not called here so start_rebuild_gui()
+            // is not called.
             show_emoji_for_category(m_backward);
             return true;
         } else if (m_candidate_panel_is_visible && m_backward != null) {
+            start_rebuild_gui(false);
             hide_candidate_panel();
             return true;
         }
@@ -2218,7 +2258,7 @@ public class IBusEmojier : Gtk.ApplicationWindow {
 
         /* Some window managers, e.g. MATE, GNOME, Plasma desktops,
          * does not give the keyboard focus when Emojier is lauched
-         * twice with Ctrl-Shift-e via XIEvent, if present_with_time()
+         * twice with Ctrl-period via XIEvent, if present_with_time()
          * is not applied.
          * But XFCE4 desktop does not effect this bug.
          * Seems this is caused by the window manager's focus stealing
@@ -2265,8 +2305,10 @@ public class IBusEmojier : Gtk.ApplicationWindow {
 #endif
 
 
-    /* override virtual functions */
+    // override virtual functions
     public override void show_all() {
+        // Ctrl-period, space keys causes focus-out/in events in GNOME Wayland.
+        start_rebuild_gui(true);
         base.show_all();
         if (m_candidate_panel_mode)
             show_candidate_panel();
@@ -2416,6 +2458,17 @@ public class IBusEmojier : Gtk.ApplicationWindow {
     }
 
 
+    public override bool focus_in_event(Gdk.EventFocus event) {
+        m_rebuilding_gui = false;
+        return base.focus_in_event(event);
+    }
+
+
+    public override bool focus_out_event(Gdk.EventFocus event) {
+        return base.focus_out_event(event);
+    }
+
+
     public bool is_running() {
         return m_is_running;
     }
@@ -2511,6 +2564,14 @@ public class IBusEmojier : Gtk.ApplicationWindow {
     }
 
 
+    public bool is_rebuilding_gui() {
+        /* The candidate window and preedit text should not be closed
+         * when the GUI is rebuilding.
+         */
+        return m_rebuilding_gui;
+    }
+
+
     public static bool has_loaded_emoji_dict() {
         if (m_emoji_to_data_dict == null)
             return false;
diff --git a/ui/gtk3/emojierapp.vala b/ui/gtk3/emojierapp.vala
index 783c611c..812356f0 100644
--- a/ui/gtk3/emojierapp.vala
+++ b/ui/gtk3/emojierapp.vala
@@ -3,7 +3,7 @@
  * ibus - The Input Bus
  *
  * Copyright (c) 2017 Peng Wu <alexepico@gmail.com>
- * Copyright (c) 2017-2019 Takao Fujiwara <takao.fujiwara1@gmail.com>
+ * Copyright (c) 2017-2021 Takao Fujiwara <takao.fujiwara1@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -208,7 +208,15 @@ public class EmojiApplication : Gtk.Application {
         IBusEmojier.load_unicode_dict();
 
         if (m_emojier == null) {
-            m_emojier = new IBusEmojier();
+            bool is_wayland = false;
+#if USE_GDK_WAYLAND
+            Type instance_type = Gdk.Display.get_default().get_type();
+            Type wayland_type = typeof(GdkWayland.Display);
+            is_wayland = instance_type.is_a(wayland_type);
+#else
+            warning("Checking Wayland is disabled");
+#endif
+            m_emojier = new IBusEmojier(is_wayland);
             // For title handling in gnome-shell
             add_window(m_emojier);
             m_emojier.candidate_clicked.connect((i, b, s) => {
diff --git a/ui/gtk3/panelbinding.vala b/ui/gtk3/panelbinding.vala
index 861255b1..e63d93f2 100644
--- a/ui/gtk3/panelbinding.vala
+++ b/ui/gtk3/panelbinding.vala
@@ -3,7 +3,7 @@
  * ibus - The Input Bus
  *
  * Copyright(c) 2018 Peng Huang <shawn.p.huang@gmail.com>
- * Copyright(c) 2018-2020 Takao Fujwiara <takao.fujiwara1@gmail.com>
+ * Copyright(c) 2018-2021 Takao Fujwiara <takao.fujiwara1@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -799,6 +799,23 @@ class PanelBinding : IBus.PanelService {
 
     public override void focus_out(string input_context_path) {
         m_current_context_path = "";
+        /* Close emoji typing when the focus out happens but it's not a
+         * rebuilding GUI.
+         * Emojier rebuilding GUI happens when Escape key is pressed on
+         * Emojier candidate list and the rebuilding also causes focus-out/in
+         * events in GNOME Wayland but not Xorg desktops.
+         * The rebuilding GUI can be checked with m_emojier.is_rebuilding_gui()
+         * in Wayland.
+         * m_emojier.is_rebuilding_gui() always returns false in Xorg desktops
+         * since focus-out/in events does not happen.
+         */
+        if (m_emojier != null && !m_emojier.is_rebuilding_gui()) {
+            m_preedit.reset();
+            m_emojier.set_annotation("");
+            if (m_wayland_lookup_table_is_visible)
+                hide_wayland_lookup_table();
+            key_press_escape();
+        }
     }
 
 
@@ -822,7 +839,7 @@ class PanelBinding : IBus.PanelService {
             m_loaded_unicode = true;
         }
         if (m_emojier == null) {
-            m_emojier = new IBusEmojier();
+            m_emojier = new IBusEmojier(m_is_wayland);
             // For title handling in gnome-shell
             m_application.add_window(m_emojier);
             m_emojier.candidate_clicked.connect((i, b, s) => {