core: transfer views to same workspace as on destroyed output

Currently, when an output is destroyed, views are transferred to
the new output in roughly the same position as they were on the
old output, but they are all transferred to the first workspace.

This is annoying: if they were not on the first workspace, then
the user must have moved them, and after they're transferred, the
user will have to move them agein.

Instead, move each view to the same workspace it was on before,
or, if the new workspace set has a smaller grid, to the edge.

Author: lcolitti

src/api/wayfire/core.hpp

@@ -387,7 +387,12 @@ enum
      * Adjust the view geometry for the new output and clamp it to the output geometry so it is
      * at an expected size and position.
      */
-    VIEW_TO_OUTPUT_FLAG_RECONFIGURE = 1 << 0,
+    VIEW_TO_OUTPUT_FLAG_RECONFIGURE    = 1 << 0,
+    /**
+     * When reconfiguring, also move the view to the same workspace as it is currently on. Only
+     * meaningful if VIEW_TO_OUTPUT_FLAG_RECONFIGURE is also set.
+     */
+    VIEW_TO_OUTPUT_FLAG_SAME_WORKSPACE = 1 << 1,
 };
 
 /**

src/core/core.cpp

@@ -626,10 +626,13 @@ void wf::move_view_to_output(wayfire_toplevel_view v, wf::output_t *new_output,
 
     auto old_output = v->get_output();
     auto old_wset   = v->get_wset();
+    auto old_ws     = old_wset->get_view_main_workspace(v);
+    auto new_wset   = new_output->wset();
 
     uint32_t edges;
     bool fullscreen;
-    bool reconfigure = flags & VIEW_TO_OUTPUT_FLAG_RECONFIGURE;
+    bool reconfigure    = flags & VIEW_TO_OUTPUT_FLAG_RECONFIGURE;
+    bool same_workspace = flags & VIEW_TO_OUTPUT_FLAG_SAME_WORKSPACE;
     wf::geometry_t view_g;
     wf::geometry_t old_output_g;
     wf::geometry_t new_output_g;
@@ -655,24 +658,39 @@ void wf::move_view_to_output(wayfire_toplevel_view v, wf::output_t *new_output,
 
     assert(new_output);
 
-    start_move_view_to_wset(v, new_output->wset());
+    start_move_view_to_wset(v, new_wset);
     if (new_output == wf::get_core().seat->get_active_output())
     {
         wf::get_core().seat->focus_view(v);
     }
 
     if (reconfigure)
     {
+        std::optional<wf::point_t> new_ws;
+
+        if (same_workspace)
+        {
+            auto new_grid_size = new_wset->get_workspace_grid_size();
+            new_ws = {
+                std::min(old_ws.x, new_grid_size.width),
+                std::min(old_ws.y, new_grid_size.height)
+            };
+        }
+
         if (fullscreen)
         {
-            wf::get_core().default_wm->fullscreen_request(v, new_output, true);
+            wf::get_core().default_wm->fullscreen_request(v, new_output, true, new_ws);
         } else if (edges)
         {
-            wf::get_core().default_wm->tile_request(v, edges);
+            wf::get_core().default_wm->tile_request(v, edges, new_ws);
         } else
         {
             auto new_g = wf::clamp(view_g, new_output->workarea->get_workarea());
             v->set_geometry(new_g);
+            if (new_ws.has_value())
+            {
+                v->get_wset()->move_to_workspace(v, new_ws.value());
+            }
         }
 
         for (auto& dialog : v->enumerate_views())

src/core/output-layout.cpp

@@ -263,7 +263,8 @@ void transfer_views(wf::output_t *from, wf::output_t *to)
         auto views = from->wset()->get_views(WSET_SORT_STACKING);
         for (auto& view : views)
         {
-            move_view_to_output(view, to, true);
+            unsigned flags = VIEW_TO_OUTPUT_FLAG_RECONFIGURE | VIEW_TO_OUTPUT_FLAG_SAME_WORKSPACE;
+            move_view_to_output(view, to, flags);
         }
     }