Add window swallow plugin

metadata/meson.build

@@ -13,6 +13,7 @@ install_data('mag.xml', install_dir: wayfire.get_variable(pkgconfig: 'metadatadi
 install_data('showrepaint.xml', install_dir: wayfire.get_variable(pkgconfig: 'metadatadir'))
 install_data('view-shot.xml', install_dir: wayfire.get_variable(pkgconfig: 'metadatadir'))
 install_data('water.xml', install_dir: wayfire.get_variable(pkgconfig: 'metadatadir'))
+install_data('window-swallow.xml', install_dir: wayfire.get_variable(pkgconfig: 'metadatadir'))
 install_data('window-zoom.xml', install_dir: wayfire.get_variable(pkgconfig: 'metadatadir'))
 install_data('workspace-names.xml', install_dir: wayfire.get_variable(pkgconfig: 'metadatadir'))
 install_data('hinge.xml', install_dir: wayfire.get_variable(pkgconfig: 'metadatadir'))

metadata/window-swallow.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<wayfire>
+	<plugin name="window-swallow">
+		<_short>Window Swallow</_short>
+		<category>Window Management</category>
+		<option name="swallower_views" type="string">
+			<_short>Swallower Views</_short>
+			<_long>Views matching this criteria will swallow other mapped views when focused.</_long>
+			<default>app_id is "foot"</default>
+		</option>
+	</plugin>
+</wayfire>

src/meson.build

@@ -66,6 +66,10 @@ water = shared_module('water', 'water.cpp',
     dependencies: [wayfire],
     install: true, install_dir: join_paths(get_option('libdir'), 'wayfire'))
 
+window_swallow = shared_module('window-swallow', 'window-swallow.cpp',
+    dependencies: [wayfire],
+    install: true, install_dir: join_paths(get_option('libdir'), 'wayfire'))
+
 window_zoom = shared_module('winzoom', 'window-zoom.cpp',
     dependencies: [wayfire],
     install: true, install_dir: join_paths(get_option('libdir'), 'wayfire'))

src/window-swallow.cpp

@@ -0,0 +1,289 @@
+/*
+ * Copyright © 2023 Scott Moreau
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <wayfire/per-output-plugin.hpp>
+#include <wayfire/workspace-manager.hpp>
+#include <wayfire/matcher.hpp>
+
+
+namespace wayfire_window_swallow
+{
+std::map<wayfire_view, std::vector<std::pair<wayfire_view, wf::geometry_t>>> swallowed_views;
+std::map<wayfire_view, wf::geometry_t> swallowed_geometries;
+wayfire_view last_focus_view    = nullptr;
+wayfire_view current_focus_view = nullptr;
+
+/* Hack: When we swallow a view, we want the size to match the swallower size,
+ * so we call set_seometry() to set it. However, the geometry might be changed
+ * if the swallowed view has server side decorations, because adding decoration
+ * triggers a set_geometry() call as well. However it sets it to the size of
+ * the current geometry and not the geometry of what we intended. So to work
+ * around this problem, we set a bool to true on mapped and set it to false
+ * a short time later. Then if the geometry was changed right after we set it,
+ * change it back to the geometry we intended. */
+wf::wl_idle_call idle_set_geometry;
+wf::wl_timer no_longer_newly_mapped;
+bool newly_mapped = false;
+
+wf::view_matcher_t swallower_views{"window-swallow/swallower_views"};
+
+class window_swallow : public wf::per_output_plugin_instance_t
+{
+  private:
+
+    wf::signal::connection_t<wf::focus_view_signal> view_focused = [=] (wf::focus_view_signal *ev)
+    {
+        if (!ev->view)
+        {
+            return;
+        }
+
+        if (swallower_views.matches(ev->view))
+        {
+            if (current_focus_view && swallower_views.matches(current_focus_view))
+            {
+                last_focus_view = current_focus_view;
+            }
+
+            current_focus_view = ev->view;
+        }
+    };
+
+    void hide_view(wayfire_view hiding, wayfire_view swallowed)
+    {
+        if (!hiding || !swallowed)
+        {
+            return;
+        }
+
+        output->workspace->remove_view(hiding);
+        std::vector<std::pair<wayfire_view, wf::geometry_t>> v;
+        try {
+            v = swallowed_views.at(hiding);
+        } catch (const std::out_of_range&)
+        {}
+
+        std::pair<wayfire_view, wf::geometry_t> p(hiding, hiding->get_wm_geometry());
+        v.push_back(p);
+        swallowed_views[swallowed] = v;
+        swallowed->connect(&view_geometry_changed);
+        hiding->set_output(nullptr);
+    }
+
+    wf::signal::connection_t<wf::view_geometry_changed_signal> view_geometry_changed{[this] (wf::
+                                                                                             view_geometry_changed_signal
+                                                                                             *ev)
+        {
+            auto view = ev->view;
+            wf::geometry_t g;
+            try {
+                g = swallowed_geometries.at(view);
+            } catch (const std::out_of_range&)
+            {
+                return;
+            }
+
+            if (newly_mapped)
+            {
+                idle_set_geometry.run_once([=] ()
+                {
+                    view->disconnect(&view_geometry_changed);
+                    view->set_geometry(g);
+                    view->connect(&view_geometry_changed);
+                });
+            } else
+            {
+                swallowed_geometries[view] = view->get_wm_geometry();
+            }
+        }
+    };
+
+    wf::signal::connection_t<wf::view_mapped_signal> view_mapped{[this] (wf::view_mapped_signal *ev)
+        {
+            auto view = ev->view;
+
+            if (last_focus_view)
+            {
+                current_focus_view = last_focus_view;
+                last_focus_view    = nullptr;
+            }
+
+            if ((view == current_focus_view) || !view || (view->role != wf::VIEW_ROLE_TOPLEVEL) ||
+                !swallower_views.matches(current_focus_view))
+            {
+                return;
+            }
+
+            /* swallow */
+            if (current_focus_view->get_decoration())
+            {
+                auto g1 = current_focus_view->get_wm_geometry();
+                auto g2 = current_focus_view->get_decoration()->expand_wm_geometry(
+                    current_focus_view->get_wm_geometry());
+
+                view->set_geometry({g2.x - (g2.x - g1.x), g2.y - (g2.y - g1.y), g1.width, g1.height});
+                swallowed_geometries[view] =
+                {g2.x - (g2.x - g1.x), g2.y - (g2.y - g1.y), g1.width, g1.height};
+            } else
+            {
+                view->set_geometry(current_focus_view->get_wm_geometry());
+                swallowed_geometries[view] = current_focus_view->get_wm_geometry();
+            }
+
+            ev->is_positioned = true;
+            hide_view(current_focus_view, view);
+            current_focus_view = view;
+            newly_mapped = true;
+            no_longer_newly_mapped.disconnect();
+            no_longer_newly_mapped.set_timeout(250, [=] ()
+            {
+                newly_mapped = false;
+                return false; // disconnect
+            });
+        }
+    };
+
+    wayfire_view unhide_view(std::vector<std::pair<wayfire_view, wf::geometry_t>> & v, wayfire_view swallowed)
+    {
+        auto p = v.back();
+        auto unhiding = p.first;
+        unhiding->set_output(output);
+        wf::get_core().move_view_to_output(unhiding, output, true);
+        output->workspace->add_view(unhiding, wf::LAYER_WORKSPACE);
+        auto g = p.second;
+        auto saved_geometry = g;
+        try {
+            saved_geometry = swallowed_geometries.at(swallowed);
+            swallowed_geometries.erase(swallowed_geometries.find(swallowed));
+        } catch (const std::out_of_range&)
+        {}
+
+        g.x = saved_geometry.x;
+        g.y = saved_geometry.y;
+        if (g.width != saved_geometry.width)
+        {
+            g.x += (saved_geometry.width - g.width) / 2;
+        }
+
+        if (g.height != saved_geometry.height)
+        {
+            g.y += (saved_geometry.height - g.height) / 2;
+        }
+
+        unhiding->set_geometry(g);
+        current_focus_view = unhiding;
+        v.erase(std::remove(v.begin(), v.end(), p), v.end());
+        if (!v.empty())
+        {
+            swallowed_views[unhiding] = v;
+        }
+
+        return unhiding;
+    }
+
+    void prune()
+    {
+        auto all_views = wf::get_core().get_all_views();
+        for (auto & [swallowed, v] : swallowed_views)
+        {
+            for (auto & p : v)
+            {
+                if (std::find(all_views.begin(), all_views.end(), p.first) == all_views.end())
+                {
+                    /* Prune view in swallowed_views but not in all_views */
+                    v.erase(std::remove(v.begin(), v.end(), p), v.end());
+                }
+            }
+        }
+    }
+
+    wf::signal::connection_t<wf::view_unmapped_signal> view_unmapped{[this] (wf::view_unmapped_signal *ev)
+        {
+            auto view = ev->view;
+
+            if (view == current_focus_view)
+            {
+                current_focus_view = nullptr;
+            }
+
+            if (view == last_focus_view)
+            {
+                last_focus_view = nullptr;
+            }
+
+            if (!view)
+            {
+                return;
+            }
+
+            prune();
+
+            std::vector<std::pair<wayfire_view, wf::geometry_t>> v;
+            try {
+                v = swallowed_views.at(view);
+            } catch (const std::out_of_range&)
+            {
+                return;
+            }
+
+            if (v.empty())
+            {
+                swallowed_views.erase(swallowed_views.find(view));
+                return;
+            }
+
+            /* unswallow */
+            unhide_view(v, view);
+            swallowed_views.erase(swallowed_views.find(view));
+        }
+    };
+
+  public:
+    void init() override
+    {
+        output->connect(&view_mapped);
+        output->connect(&view_focused);
+        output->connect(&view_unmapped);
+    }
+
+    void fini() override
+    {
+        for (auto & [s, hidden_views] : swallowed_views)
+        {
+            auto swallowed = s;
+            while (!hidden_views.empty())
+            {
+                swallowed = unhide_view(hidden_views, swallowed);
+            }
+        }
+
+        swallowed_views.clear();
+
+        view_mapped.disconnect();
+        view_focused.disconnect();
+        view_unmapped.disconnect();
+        view_geometry_changed.disconnect();
+    }
+};
+
+DECLARE_WAYFIRE_PLUGIN(wf::per_output_plugin_t<window_swallow>);
+}