[gnome-builder/wip/gtk4-port] libide/tree: add interface for popup positioning

[Christian Hergert <chergert src gnome org>]

commit 06c2c17a1fdf6d30895b58d739a93817899d651d
Author: Christian Hergert <chergert redhat com>
Date:   Wed Apr 27 16:28:48 2022 -0700

    libide/tree: add interface for popup positioning
    
    We can implement this in the workspace so we can position dynamic popovers
    from things like treeviews.

 src/libide/tree/ide-popover-positioner.c | 56 ++++++++++++++++++++++++++++++++
 src/libide/tree/ide-popover-positioner.h | 50 ++++++++++++++++++++++++++++
 src/libide/tree/ide-tree.h               |  1 +
 src/libide/tree/libide-tree.h            | 11 +++----
 src/libide/tree/meson.build              |  2 ++
 5 files changed, 114 insertions(+), 6 deletions(-)
---
diff --git a/src/libide/tree/ide-popover-positioner.c b/src/libide/tree/ide-popover-positioner.c
new file mode 100644
index 000000000..637061f5c
--- /dev/null
+++ b/src/libide/tree/ide-popover-positioner.c
@@ -0,0 +1,56 @@
+/* ide-popover-positioner.c
+ *
+ * Copyright 2022 Christian Hergert <chergert redhat com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#define G_LOG_DOMAIN "ide-popover-positioner"
+
+#include "config.h"
+
+#include "ide-popover-positioner.h"
+
+G_DEFINE_INTERFACE (IdePopoverPositioner, ide_popover_positioner, GTK_TYPE_WIDGET)
+
+static void
+ide_popover_positioner_default_init (IdePopoverPositionerInterface *iface)
+{
+}
+
+void
+ide_popover_positioner_present (IdePopoverPositioner *self,
+                                GtkPopover           *popover,
+                                GtkWidget            *relative_to,
+                                const GdkRectangle   *pointing_at)
+{
+  GdkRectangle empty;
+
+  g_return_if_fail (IDE_IS_POPOVER_POSITIONER (self));
+  g_return_if_fail (GTK_IS_POPOVER (popover));
+  g_return_if_fail (GTK_IS_WIDGET (relative_to));
+
+  if (pointing_at == NULL)
+    {
+      empty.x = 0;
+      empty.y = 0;
+      empty.width = gtk_widget_get_width (relative_to);
+      empty.height = gtk_widget_get_height (relative_to);
+      pointing_at = &empty;
+    }
+
+  IDE_POPOVER_POSITIONER_GET_IFACE (self)->present (self, popover, relative_to, pointing_at);
+}
diff --git a/src/libide/tree/ide-popover-positioner.h b/src/libide/tree/ide-popover-positioner.h
new file mode 100644
index 000000000..ac76e4a4e
--- /dev/null
+++ b/src/libide/tree/ide-popover-positioner.h
@@ -0,0 +1,50 @@
+/* ide-popover-positioner.h
+ *
+ * Copyright 2022 Christian Hergert <chergert redhat com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+#include <libide-core.h>
+
+G_BEGIN_DECLS
+
+#define IDE_TYPE_POPOVER_POSITIONER (ide_popover_positioner_get_type())
+
+IDE_AVAILABLE_IN_ALL
+G_DECLARE_INTERFACE (IdePopoverPositioner, ide_popover_positioner, IDE, POPOVER_POSITIONER, GtkWidget)
+
+struct _IdePopoverPositionerInterface
+{
+  GTypeInterface parent_iface;
+
+  void (*present) (IdePopoverPositioner *self,
+                   GtkPopover           *popover,
+                   GtkWidget            *relative_to,
+                   const GdkRectangle   *pointing_to);
+};
+
+IDE_AVAILABLE_IN_ALL
+void ide_popover_positioner_present (IdePopoverPositioner *self,
+                                     GtkPopover           *popover,
+                                     GtkWidget            *relative_to,
+                                     const GdkRectangle   *pointing_to);
+
+G_END_DECLS
diff --git a/src/libide/tree/ide-tree.h b/src/libide/tree/ide-tree.h
index ef4f045e4..c9e3d8a51 100644
--- a/src/libide/tree/ide-tree.h
+++ b/src/libide/tree/ide-tree.h
@@ -21,6 +21,7 @@
 #pragma once
 
 #include <gtk/gtk.h>
+
 #include <libide-core.h>
 
 #include "ide-tree-node.h"
diff --git a/src/libide/tree/libide-tree.h b/src/libide/tree/libide-tree.h
index 515828d11..be4915a14 100644
--- a/src/libide/tree/libide-tree.h
+++ b/src/libide/tree/libide-tree.h
@@ -25,12 +25,11 @@
 G_BEGIN_DECLS
 
 #define IDE_TREE_INSIDE
-
-#include "ide-tree.h"
-#include "ide-tree-addin.h"
-#include "ide-tree-model.h"
-#include "ide-tree-node.h"
-
+# include "ide-popover-positioner.h"
+# include "ide-tree.h"
+# include "ide-tree-addin.h"
+# include "ide-tree-model.h"
+# include "ide-tree-node.h"
 #undef IDE_TREE_INSIDE
 
 G_END_DECLS
diff --git a/src/libide/tree/meson.build b/src/libide/tree/meson.build
index 5a591106c..d0a99b73d 100644
--- a/src/libide/tree/meson.build
+++ b/src/libide/tree/meson.build
@@ -6,6 +6,7 @@ libide_include_directories += include_directories('.')
 #
 
 libide_tree_public_headers = [
+  'ide-popover-positioner.h',
   'ide-tree.h',
   'ide-tree-addin.h',
   'ide-tree-model.h',
@@ -20,6 +21,7 @@ install_headers(libide_tree_public_headers, subdir: libide_tree_header_subdir)
 #
 
 libide_tree_public_sources = [
+  'ide-popover-positioner.c',
   'ide-tree.c',
   'ide-tree-addin.c',
   'ide-tree-model.c',