[gnome-todo/gbsneto/animations: 3/6] Introduce GtdBinLayout

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

commit 1a5037b919333cc672141871774e70c3abac9ef4
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Thu Aug 6 20:33:21 2020 -0300

    Introduce GtdBinLayout
    
    GtdBinLayout is a copy of GtkBinLayout that knows how to deal
    with the linear transformation of child GtdWidgets.

 src/gnome-todo.h         |   1 +
 src/gtd-utils.c          |   2 +
 src/gui/gtd-bin-layout.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++
 src/gui/gtd-bin-layout.h |  32 +++++++++++++
 src/meson.build          |   4 ++
 5 files changed, 158 insertions(+)
---
diff --git a/src/gnome-todo.h b/src/gnome-todo.h
index 507c6cd..de306c4 100644
--- a/src/gnome-todo.h
+++ b/src/gnome-todo.h
@@ -22,6 +22,7 @@
 #include <libpeas/peas.h>
 
 #include "gtd-activatable.h"
+#include "gtd-bin-layout.h"
 #include "gtd-list-model-filter.h"
 #include "gtd-list-model-sort.h"
 #include "gtd-list-store.h"
diff --git a/src/gtd-utils.c b/src/gtd-utils.c
index 9a04c7e..c6f1559 100644
--- a/src/gtd-utils.c
+++ b/src/gtd-utils.c
@@ -18,6 +18,7 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
+#include "gtd-bin-layout.h"
 #include "gtd-max-size-layout.h"
 #include "gtd-task.h"
 #include "gtd-utils.h"
@@ -235,6 +236,7 @@ gtd_collate_compare_strings (const gchar *string_a,
 void
 gtd_ensure_types (void)
 {
+  g_type_ensure (GTD_TYPE_BIN_LAYOUT);
   g_type_ensure (GTD_TYPE_MAX_SIZE_LAYOUT);
   g_type_ensure (GTD_TYPE_WIDGET);
 }
diff --git a/src/gui/gtd-bin-layout.c b/src/gui/gtd-bin-layout.c
new file mode 100644
index 0000000..0534639
--- /dev/null
+++ b/src/gui/gtd-bin-layout.c
@@ -0,0 +1,119 @@
+/* gtd-bin-layout.c
+ *
+ * Copyright 2020 Georges Basile Stavracas Neto <georges stavracas gmail 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
+ */
+
+#include "gtd-bin-layout.h"
+#include "gtd-widget-private.h"
+
+struct _GtdBinLayout
+{
+  GtkLayoutManager    parent_instance;
+};
+
+G_DEFINE_TYPE (GtdBinLayout, gtd_bin_layout, GTK_TYPE_LAYOUT_MANAGER)
+
+static void
+gtd_bin_layout_measure (GtkLayoutManager *layout_manager,
+                        GtkWidget        *widget,
+                        GtkOrientation    orientation,
+                        int               for_size,
+                        int              *minimum,
+                        int              *natural,
+                        int              *minimum_baseline,
+                        int              *natural_baseline)
+{
+  GtkWidget *child;
+
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    {
+      if (gtk_widget_should_layout (child))
+        {
+          int child_min = 0;
+          int child_nat = 0;
+          int child_min_baseline = -1;
+          int child_nat_baseline = -1;
+
+          gtk_widget_measure (child, orientation, for_size,
+                              &child_min, &child_nat,
+                              &child_min_baseline, &child_nat_baseline);
+
+          *minimum = MAX (*minimum, child_min);
+          *natural = MAX (*natural, child_nat);
+
+          if (child_min_baseline > -1)
+            *minimum_baseline = MAX (*minimum_baseline, child_min_baseline);
+          if (child_nat_baseline > -1)
+            *natural_baseline = MAX (*natural_baseline, child_nat_baseline);
+        }
+    }
+}
+
+static void
+gtd_bin_layout_allocate (GtkLayoutManager *layout_manager,
+                         GtkWidget        *widget,
+                         int               width,
+                         int               height,
+                         int               baseline)
+{
+  GtkWidget *child;
+
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    {
+      if (child && gtk_widget_should_layout (child))
+        {
+          GskTransform *transform = NULL;
+
+          if (GTD_IS_WIDGET (child))
+            {
+              GtkAllocation adjusted;
+
+              gtk_widget_get_adjusted_allocation (child, width, height, &adjusted);
+              gtd_widget_update_pivot_for_geometry (GTD_WIDGET (child), &adjusted);
+
+              transform = gtd_widget_apply_transform (GTD_WIDGET (child), NULL);
+            }
+
+          gtk_widget_allocate (child, width, height, baseline, transform);
+        }
+    }
+}
+
+static void
+gtd_bin_layout_class_init (GtdBinLayoutClass *klass)
+{
+  GtkLayoutManagerClass *layout_manager_class = GTK_LAYOUT_MANAGER_CLASS (klass);
+
+  layout_manager_class->measure = gtd_bin_layout_measure;
+  layout_manager_class->allocate = gtd_bin_layout_allocate;
+}
+
+static void
+gtd_bin_layout_init (GtdBinLayout *self)
+{
+}
+
+GtkLayoutManager*
+gtd_bin_layout_new (void)
+{
+  return g_object_new (GTD_TYPE_BIN_LAYOUT, NULL);
+}
diff --git a/src/gui/gtd-bin-layout.h b/src/gui/gtd-bin-layout.h
new file mode 100644
index 0000000..fe40a44
--- /dev/null
+++ b/src/gui/gtd-bin-layout.h
@@ -0,0 +1,32 @@
+/* gtd-bin-layout.h
+ *
+ * Copyright 2020 Georges Basile Stavracas Neto <georges stavracas gmail 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 "gnome-todo.h"
+
+G_BEGIN_DECLS
+
+#define GTD_TYPE_BIN_LAYOUT (gtd_bin_layout_get_type())
+G_DECLARE_FINAL_TYPE (GtdBinLayout, gtd_bin_layout, GTD, BIN_LAYOUT, GtkLayoutManager)
+
+GtkLayoutManager*    gtd_bin_layout_new                          (void);
+
+G_END_DECLS
diff --git a/src/meson.build b/src/meson.build
index 44bfa8f..309f471 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -56,6 +56,7 @@ headers = files(
   'core/gtd-provider.h',
   'core/gtd-task.h',
   'core/gtd-task-list.h',
+  'gui/gtd-bin-layout.h',
   'gui/gtd-max-size-layout.h',
   'gui/gtd-menu-button.h',
   'gui/gtd-omni-area.h',
@@ -92,6 +93,7 @@ sources += files(
   'core/gtd-provider.c',
   'core/gtd-task.c',
   'core/gtd-task-list.c',
+  'gui/gtd-bin-layout.c',
   'gui/gtd-panel.c',
   'gui/gtd-workspace.c',
   'gui/gtd-notification-widget.c',
@@ -249,6 +251,8 @@ if get_option('introspection')
     'core/gtd-task.h',
     'core/gtd-task-list.c',
     'core/gtd-task-list.h',
+    'gui/gtd-bin-layout.c',
+    'gui/gtd-bin-layout.h',
     'gui/gtd-max-size-layout.c',
     'gui/gtd-max-size-layout.h',
     'gui/gtd-menu-button.c',