[gnome-panel/wip/muktupavels/floating-panels: 3/4] toplevel: make sure panels move only along monitor edges

[Alberts Muktupāvels <muktupavels src gnome org>]

commit ef4fc407379c4caa03c8381a1cc9d85e5ef55f0e
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Apr 22 00:18:27 2021 +0300

    toplevel: make sure panels move only along monitor edges

 gnome-panel/panel-toplevel.c | 130 +++++++++++++++++++++++++------------------
 1 file changed, 76 insertions(+), 54 deletions(-)
---
diff --git a/gnome-panel/panel-toplevel.c b/gnome-panel/panel-toplevel.c
index b9065b492..1d04b2c66 100644
--- a/gnome-panel/panel-toplevel.c
+++ b/gnome-panel/panel-toplevel.c
@@ -826,85 +826,107 @@ panel_toplevel_move_to (PanelToplevel *toplevel,
        GdkScreen        *screen;
        PanelOrientation  new_orientation;
        gboolean          x_centered, y_centered;
-       int               screen_width, screen_height;
+       int               monitor_x, monitor_y;
        int               monitor_width, monitor_height;
        int               width, height;
        int               new_monitor;
        int               x, y, x_right, y_bottom;
        int               snap_tolerance;
 
-       screen = panel_toplevel_get_screen_geometry (
-                       toplevel, &screen_width, &screen_height);
+       screen = gtk_window_get_screen (GTK_WINDOW (toplevel));
+       new_monitor = panel_multiscreen_get_monitor_at_point (new_x, new_y);
+
+       monitor_x = panel_multiscreen_x (screen, new_monitor);
+       monitor_y = panel_multiscreen_y (screen, new_monitor);
+       monitor_width = panel_multiscreen_width (screen, new_monitor);
+       monitor_height = panel_multiscreen_height (screen, new_monitor);
 
        width  = toplevel->priv->geometry.width;
        height = toplevel->priv->geometry.height;
 
        snap_tolerance = toplevel->priv->snap_tolerance;
 
-       new_x = CLAMP (new_x, 0, screen_width  - width);
-       new_y = CLAMP (new_y, 0, screen_height - height);
+       new_x = CLAMP (new_x, 0, monitor_x + monitor_width - width);
+       new_y = CLAMP (new_y, 0, monitor_y + monitor_height - height);
 
-       new_orientation = toplevel->priv->orientation;
-
-       if (new_x <= snap_tolerance &&
-           toplevel->priv->orientation & PANEL_VERTICAL_MASK)
-               new_orientation = PANEL_ORIENTATION_LEFT;
+       x = new_x - monitor_x;
+       y = new_y - monitor_y;
 
-       else if ((new_x + width) >= (screen_width - snap_tolerance) &&
-                toplevel->priv->orientation & PANEL_VERTICAL_MASK)
-               new_orientation = PANEL_ORIENTATION_RIGHT;
-
-       if (new_y <= snap_tolerance &&
-           toplevel->priv->orientation & PANEL_HORIZONTAL_MASK)
-               new_orientation = PANEL_ORIENTATION_TOP;
-
-       else if ((new_y + height) >= (screen_height - snap_tolerance) &&
-                toplevel->priv->orientation & PANEL_HORIZONTAL_MASK)
-               new_orientation = PANEL_ORIENTATION_BOTTOM;
+       new_orientation = toplevel->priv->orientation;
 
-       new_monitor = panel_multiscreen_get_monitor_at_point (new_x, new_y);
+       if (toplevel->priv->orientation & PANEL_HORIZONTAL_MASK) {
+               if (x <= snap_tolerance &&
+                   y > snap_tolerance &&
+                   y < monitor_height - snap_tolerance) {
+                       new_orientation = PANEL_ORIENTATION_LEFT;
+               } else if (x + width >= monitor_width - snap_tolerance &&
+                          y > snap_tolerance &&
+                          y < monitor_height - snap_tolerance) {
+                       new_orientation = PANEL_ORIENTATION_RIGHT;
+               } else if (y <= monitor_height / 2) {
+                       new_orientation = PANEL_ORIENTATION_TOP;
+               } else {
+                       new_orientation = PANEL_ORIENTATION_BOTTOM;
+               }
+       } else {
+               if (y <= snap_tolerance &&
+                   x > snap_tolerance &&
+                   x < monitor_width - snap_tolerance) {
+                       new_orientation = PANEL_ORIENTATION_TOP;
+               } else if (y + height >= monitor_height - snap_tolerance &&
+                          x > snap_tolerance &&
+                          x < monitor_width - snap_tolerance) {
+                       new_orientation = PANEL_ORIENTATION_BOTTOM;
+               } else if (x <= monitor_width / 2) {
+                       new_orientation = PANEL_ORIENTATION_LEFT;
+               } else {
+                       new_orientation = PANEL_ORIENTATION_RIGHT;
+               }
+       }
 
-       panel_toplevel_get_monitor_geometry (
-                       toplevel, NULL, NULL, &monitor_width, &monitor_height);
+       x_right = toplevel->priv->x_right;
+       y_bottom = toplevel->priv->y_bottom;
 
        x_centered = toplevel->priv->x_centered;
        y_centered = toplevel->priv->y_centered;
 
-       x = new_x - panel_multiscreen_x (screen, new_monitor);
-       y = new_y - panel_multiscreen_y (screen, new_monitor);
-
-       if (toplevel->priv->orientation & PANEL_HORIZONTAL_MASK) {
+       if (new_orientation & PANEL_HORIZONTAL_MASK) {
+               x_centered = abs (x - ((monitor_width - width) / 2)) <= snap_tolerance;
                y_centered = FALSE;
-               if (new_y <= snap_tolerance ||
-                   new_y + height >= screen_height - snap_tolerance)
-                       x_centered = abs (x - ((monitor_width - width) / 2))
-                                                               <= snap_tolerance;
-               else
-                       x_centered = FALSE;
+
+               if (x_centered) {
+                       x = (monitor_width - width) / 2;
+               } else if ((x + width / 2) > monitor_width / 2) {
+                       x_right = monitor_width - (x + width);
+               } else {
+                       x_right = -1;
+               }
+
+               if ((y + height / 2) > monitor_height / 2) {
+                       y_bottom = 0;
+               } else {
+                       y_bottom = -1;
+                       y = 0;
+               }
        } else {
                x_centered = FALSE;
-               if (new_x <= snap_tolerance ||
-                   new_x + width >= screen_width - snap_tolerance)
-                       y_centered = abs (y - ((monitor_height - height) / 2))
-                                                               <= snap_tolerance;
-               else
-                       y_centered = FALSE;
-       }
-
-       if (x_centered)
-               x = (monitor_width  - width) / 2;
-       if (y_centered)
-               y = (monitor_height - height) / 2;
+               y_centered = abs (y - ((monitor_height - height) / 2)) <= snap_tolerance;
 
-       if (!x_centered && (x + width / 2) > monitor_width / 2)
-               x_right = monitor_width - (x + width);
-       else
-               x_right = -1;
+               if ((x + width / 2) > monitor_width / 2) {
+                       x_right = 0;
+               } else {
+                       x_right = -1;
+                       x = 0;
+               }
 
-       if (!y_centered && (y + height / 2) > monitor_height / 2)
-               y_bottom = monitor_height - (y + height);
-       else
-               y_bottom = -1;
+               if (y_centered) {
+                       y = (monitor_height - height) / 2;
+               } else if ((y + height / 2) > monitor_height / 2) {
+                       y_bottom = monitor_height - (y + height);
+               } else {
+                       y_bottom = -1;
+               }
+       }
 
        panel_toplevel_set_monitor (toplevel, new_monitor);
        panel_toplevel_set_orientation (toplevel, new_orientation);