UI: Drag and Drop Modifiers, Layout Updates

This patch implements the list panel system D7490 for modifiers.
It also moves modifier drawing to a callback in ModifierTypeInfo
in line with the extensible architecture refactoring goal T75724.

This adds a PanelRegister callback and utilities for registering
panels and subpanels. It also adds the callbacks for expansion saving
and drag and drop reordering described in D7490.

These utilities, callbacks, and other common UI elements shared
between modifiers live in MOD_ui_common.c.

Because modifier buttons are now in panels, we can make use of
subpanels for organization. The UI layouts also use the single
column layout style consistently used elsewhere in Blender.
Additionally, the mode-setting buttons are aligned and ordered
consistently with the outliner.

However, the large number of UI changes in this patch may mean
that additional polishing is required in master.

Thanks to William Reynish (@billreynish) who did a fair amount of the
layout work and to Julian Eisel (@Severin) for consistent help.

Differential Revision: https://developer.blender.org/D7498

1 files changed, 70 insertions, 0 deletions

diff --git a/source/blender/modifiers/intern/MOD_ui_common.h b/source/blender/modifiers/intern/MOD_ui_common.h
new file mode 100644
index 00000000000..59c0fe1c413
--- /dev/null
+++ b/source/blender/modifiers/intern/MOD_ui_common.h
@@ -0,0 +1,70 @@
+/*
+ * 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 2
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/** \file
+ * \ingroup modifiers
+ */
+
+#ifndef __MOD_UI_COMMON_H__
+#define __MOD_UI_COMMON_H__
+
+/* so modifier types match their defines */
+#include "MOD_modifiertypes.h"
+
+#include "DEG_depsgraph_build.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ARegionType;
+struct bContext;
+struct PanelType;
+struct uiLayout;
+typedef void (*PanelDrawFn)(const bContext *, struct Panel *);
+
+void modifier_panel_buttons(const struct bContext *C, struct Panel *panel);
+
+void modifier_vgroup_ui(struct uiLayout *layout,
+                        struct PointerRNA *ptr,
+                        struct PointerRNA *ob_ptr,
+                        const char *vgroup_prop,
+                        const char *invert_vgroup_prop,
+                        const char *text);
+
+void modifier_panel_end(struct uiLayout *layout, PointerRNA *ptr);
+
+void modifier_panel_get_property_pointers(const bContext *C,
+                                          struct Panel *panel,
+                                          struct PointerRNA *r_ob_ptr,
+                                          struct PointerRNA *r_ptr);
+
+struct PanelType *modifier_panel_register(struct ARegionType *region_type,
+                                          ModifierType type,
+                                          PanelDrawFn draw);
+
+struct PanelType *modifier_subpanel_register(struct ARegionType *region_type,
+                                             const char *name,
+                                             const char *label,
+                                             PanelDrawFn draw_header,
+                                             PanelDrawFn draw,
+                                             struct PanelType *parent);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __MOD_UI_COMMON_H__ */