[gedit] app: remove some deprecated gdk_screen_* methods

[Sébastien Lafargue <slafargue src gnome org>]

commit 801848243ff89fde2171faa1ffc7c7e9fe79a8ec
Author: Sebastien Lafargue <slafargue gnome org>
Date:   Wed Nov 28 22:48:37 2018 +0100

    app: remove some deprecated gdk_screen_* methods
    
    This code impact the tab vs new window opening policy,
    some cleanup is done but it's still not working under Wayland
    as Gdk is returning (0,0) for the window position.
    
    Under X11, the same policy on x coordinates
    (in the viewport if 25% of the window is in it)
    is used for the Y coordinates.

 gedit/gedit-app.c | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)
---
diff --git a/gedit/gedit-app.c b/gedit/gedit-app.c
index 4e186aa0a..24693e585 100644
--- a/gedit/gedit-app.c
+++ b/gedit/gedit-app.c
@@ -307,33 +307,30 @@ is_in_viewport (GtkWindow    *window,
 {
        GdkScreen *s;
        GdkDisplay *display;
+       GdkMonitor *monitor;
        GdkWindow *gdkwindow;
+       GdkRectangle geometry;
        const gchar *cur_name;
        const gchar *name;
-       gint cur_n;
-       gint n;
        gint ws;
-       gint sc_width, sc_height;
        gint x, y, width, height;
-       gint vp_x, vp_y;
 
        /* Check for screen and display match */
        display = gdk_screen_get_display (screen);
        cur_name = gdk_display_get_name (display);
-       cur_n = gdk_screen_get_number (screen);
 
        s = gtk_window_get_screen (window);
        display = gdk_screen_get_display (s);
        name = gdk_display_get_name (display);
-       n = gdk_screen_get_number (s);
 
-       if (strcmp (cur_name, name) != 0 || cur_n != n)
+       if (strcmp (cur_name, name) != 0)
        {
                return FALSE;
        }
 
        /* Check for workspace match */
        ws = gedit_utils_get_window_workspace (window);
+
        if (ws != workspace && ws != GEDIT_ALL_WORKSPACES)
        {
                return FALSE;
@@ -344,17 +341,17 @@ is_in_viewport (GtkWindow    *window,
        gdk_window_get_position (gdkwindow, &x, &y);
        width = gdk_window_get_width (gdkwindow);
        height = gdk_window_get_height (gdkwindow);
-       gedit_utils_get_current_viewport (screen, &vp_x, &vp_y);
-       x += vp_x;
-       y += vp_y;
 
-       sc_width = gdk_screen_get_width (screen);
-       sc_height = gdk_screen_get_height (screen);
+       x += viewport_x;
+       y += viewport_y;
+
+       monitor = gdk_display_get_monitor_at_window(display, gdkwindow);
+       gdk_monitor_get_geometry(monitor, &geometry);
 
-       return x + width * .25 >= viewport_x &&
-              x + width * .75 <= viewport_x + sc_width &&
-              y >= viewport_y &&
-              y + height <= viewport_y + sc_height;
+       return x + width * .75 >= geometry.x &&
+              x + width * .25 <= geometry.x + geometry.width &&
+              y + height * .75 >= geometry.y &&
+              y + height * .25 <= geometry.y + geometry.height;
 }
 
 static GeditWindow *