From c02a905d33f18ad68bee6a1c122462585ebf4147 Mon Sep 17 00:00:00 2001
From: Takao Fujiwara <tfujiwar@redhat.com>
Date: Fri, 20 May 2022 20:34:29 +0900
Subject: [PATCH] ibusCandidatePopup: Put popup window with screen

ibusCandidatePopup can be placed off the screen easily in GNOME Xorg
because GTK4 no longer provide the focused widget position and IBus
GTK4 module get the window position instead with X APIs and the
cursor position is the window position.
This makes the popup position with the workarea.

Fixes #5510
---
 js/ui/ibusCandidatePopup.js | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/js/ui/ibusCandidatePopup.js b/js/ui/ibusCandidatePopup.js
index c57e289cb..953b45423 100644
--- a/js/ui/ibusCandidatePopup.js
+++ b/js/ui/ibusCandidatePopup.js
@@ -303,6 +303,31 @@ class IbusCandidatePopup extends BoxPointer.BoxPointer {
     }
 
     _setDummyCursorGeometry(x, y, w, h) {
+        // GTK4 IMContext does not provide the absolute position of the focused
+        // widgets and IM clients get the current window position instead
+        // using X APIs in Xorg and this cursor position is the window position.
+        // The IbusCandidatePopup could be placed off the screen easily and
+        // the cursor position is adjusted within the workarea here.
+        if (global.display.focus_window != null) {
+            let [, , natWidth, natHeight] = this.get_preferred_size();
+            let window = global.display.focus_window.get_compositor_private();
+            let monitorIndex = Main.layoutManager.findIndexForActor(this._dummyCursor);
+            let workArea = Main.layoutManager.getWorkAreaForMonitor(monitorIndex);
+            if (x + natWidth > workArea.width)
+                x = x - natWidth;
+            if (x < workArea.x)
+                x = workArea.x;
+            if (y + h + natHeight > workArea.height)
+                y = y - h - natHeight;
+            if (y + h < window.y && y + h + natHeight > window.y)
+                y = window.y - h - natHeight;
+            if (y < workArea.y) {
+                y = workArea.y;
+                // h would be the window height in GTK4 Xorg
+                if (h > 50)
+                    h = 5;
+            }
+        }
         this._dummyCursor.set_position(Math.round(x), Math.round(y));
         this._dummyCursor.set_size(Math.round(w), Math.round(h));