[mutter/wip/gbsneto/edge-constraints: 1/3] wayland: Send edge constraints

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit e4bd3863f10f325f2e773437ea0b55f26b60479a
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Thu Aug 17 00:49:36 2017 -0300

    wayland: Send edge constraints
    
    Following up the previous patch, this patch makes the
    Wayland backend send the edge constraints through a
    custom protocol extension internal to GTK.
    
    As it mature, we can think of upstreaming the protocol
    to Wayland itself.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=751857

 src/wayland/meta-wayland-gtk-shell.c |   82 ++++++++++++++++++++++++++++++++++
 src/wayland/protocol/gtk-shell.xml   |   19 +++++++-
 2 files changed, 99 insertions(+), 2 deletions(-)
---
diff --git a/src/wayland/meta-wayland-gtk-shell.c b/src/wayland/meta-wayland-gtk-shell.c
index d6e249f..ec79886 100644
--- a/src/wayland/meta-wayland-gtk-shell.c
+++ b/src/wayland/meta-wayland-gtk-shell.c
@@ -40,6 +40,7 @@ typedef struct _MetaWaylandGtkSurface
   struct wl_resource *resource;
   MetaWaylandSurface *surface;
   gboolean is_modal;
+  gulong configure_edges_handler_id;
   gulong configure_handler_id;
 } MetaWaylandGtkSurface;
 
@@ -54,6 +55,8 @@ gtk_surface_destructor (struct wl_resource *resource)
                             quark_gtk_surface_data);
       g_signal_handler_disconnect (gtk_surface->surface,
                                    gtk_surface->configure_handler_id);
+      g_signal_handler_disconnect (gtk_surface->surface,
+                                   gtk_surface->configure_edges_handler_id);
     }
 
   g_free (gtk_surface);
@@ -148,6 +151,56 @@ gtk_surface_surface_destroyed (MetaWaylandGtkSurface *gtk_surface)
 }
 
 static void
+fill_edge_states (struct wl_array *states,
+                  MetaWindow      *window)
+{
+  uint32_t *s;
+
+  /* Top */
+  if (window->edge_constraints[0] != META_EDGE_CONSTRAINT_MONITOR)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_EDGE_CONSTRAINT_RESIZABLE_TOP;
+    }
+
+  /* Right */
+  if (window->edge_constraints[1] != META_EDGE_CONSTRAINT_MONITOR)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_EDGE_CONSTRAINT_RESIZABLE_RIGHT;
+    }
+
+  /* Bottom */
+  if (window->edge_constraints[2] != META_EDGE_CONSTRAINT_MONITOR)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_EDGE_CONSTRAINT_RESIZABLE_BOTTOM;
+    }
+
+  /* Left */
+  if (window->edge_constraints[3] != META_EDGE_CONSTRAINT_MONITOR)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_EDGE_CONSTRAINT_RESIZABLE_LEFT;
+    }
+}
+
+static void
+on_configure_edges (MetaWaylandSurface    *surface,
+                    MetaWaylandGtkSurface *gtk_surface)
+{
+  struct wl_array states;
+
+  wl_array_init (&states);
+  fill_edge_states (&states, surface->window);
+
+  gtk_surface1_send_configure_edges (gtk_surface->resource, &states);
+
+  wl_array_release (&states);
+}
+
+
+static void
 fill_states (struct wl_array *states,
              MetaWindow      *window)
 {
@@ -159,6 +212,30 @@ fill_states (struct wl_array *states,
       s = wl_array_add (states, sizeof *s);
       *s = GTK_SURFACE1_STATE_TILED;
     }
+
+  if (window->edge_constraints[0] != META_EDGE_CONSTRAINT_NONE)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_STATE_TILED_TOP;
+    }
+
+  if (window->edge_constraints[1] != META_EDGE_CONSTRAINT_NONE)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_STATE_TILED_RIGHT;
+    }
+
+  if (window->edge_constraints[2] != META_EDGE_CONSTRAINT_NONE)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_STATE_TILED_BOTTOM;
+    }
+
+  if (window->edge_constraints[3] != META_EDGE_CONSTRAINT_NONE)
+    {
+      s = wl_array_add (states, sizeof *s);
+      *s = GTK_SURFACE1_STATE_TILED_LEFT;
+    }
 }
 
 static void
@@ -208,6 +285,11 @@ gtk_shell_get_gtk_surface (struct wl_client   *client,
                                                         G_CALLBACK (on_configure),
                                                         gtk_surface);
 
+  gtk_surface->configure_edges_handler_id = g_signal_connect (surface,
+                                                              "configure_edges",
+                                                              G_CALLBACK (on_configure_edges),
+                                                              gtk_surface);
+
   g_object_set_qdata_full (G_OBJECT (surface),
                            quark_gtk_surface_data,
                            gtk_surface,
diff --git a/src/wayland/protocol/gtk-shell.xml b/src/wayland/protocol/gtk-shell.xml
index 5cfdd42..0dd44d9 100644
--- a/src/wayland/protocol/gtk-shell.xml
+++ b/src/wayland/protocol/gtk-shell.xml
@@ -1,6 +1,6 @@
 <protocol name="gtk">
 
-  <interface name="gtk_shell1" version="1">
+  <interface name="gtk_shell1" version="2">
     <description summary="gtk specific extensions">
       gtk_shell is a protocol extension providing additional features for
       clients implementing it.
@@ -30,7 +30,7 @@
     </request>
   </interface>
 
-  <interface name="gtk_surface1" version="1">
+  <interface name="gtk_surface1" version="2">
     <request name="set_dbus_properties">
       <arg name="application_id" type="string" allow-null="true"/>
       <arg name="app_menu_path" type="string" allow-null="true"/>
@@ -51,11 +51,26 @@
 
     <enum name="state">
       <entry name="tiled" value="1"/>
+      <entry name="tiled_top" value="2"/>
+      <entry name="tiled_right" value="3"/>
+      <entry name="tiled_bottom" value="4"/>
+      <entry name="tiled_left" value="5"/>
+    </enum>
+
+    <enum name="edge_constraint">
+      <entry name="resizable_top" value="1"/>
+      <entry name="resizable_right" value="2"/>
+      <entry name="resizable_bottom" value="3"/>
+      <entry name="resizable_left" value="4"/>
     </enum>
 
     <event name="configure">
       <arg name="states" type="array"/>
     </event>
+
+    <event name="configure_edges">
+      <arg name="constraints" type="array"/>
+    </event>
   </interface>
 
 </protocol>