Differential D12573 Diff 42327 source/blender/editors/interface/interface_view.cc

Changeset View

Standalone View

source/blender/editors/interface/interface_view.cc

This file was added.

				/*
				* 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 edinterface
				*
				* This part of the UI-View API is mostly needed to support persistent state of items within the
				* view. Views are stored in #uiBlock's, and kept alive with it until after the next redraw. So we
				* can compare the old view items with the new view items and keep state persistent for matching
				* ones.
				*/

				#include <memory>
				#include <variant>

				#include "BLI_listbase.h"

				#include "interface_intern.h"

				#include "UI_interface.hh"
				#include "UI_tree_view.hh"

				using namespace blender;
				using namespace blender::ui;

				/**
				* Wrapper to store views in a #ListBase. There's no `uiView` base class, we just store views as a
				* #std::variant.
				*/
				struct ViewLink : public Link {
				using TreeViewPtr = std::unique_ptr<AbstractTreeView>;

				std::string idname;
				/* Note: Can't use std::get() on this until minimum macOS deployment target is 10.14. */
				std::variant<TreeViewPtr> view;
				};

				template<class T> T *get_view_from_link(ViewLink &link)
				{
				auto *t_uptr = std::get_if<std::unique_ptr<T>>(&link.view);
				return t_uptr ? t_uptr->get() : nullptr;
				}

				/**
				* Override this for all available tree types.
				*/
				AbstractTreeView *UI_block_add_view(uiBlock &block,
				StringRef idname,
				std::unique_ptr<AbstractTreeView> tree_view)
				{
				ViewLink *view_link = OBJECT_GUARDED_NEW(ViewLink);
				BLI_addtail(&block.views, view_link);

				view_link->view = std::move(tree_view);
				view_link->idname = idname;

				return get_view_from_link<AbstractTreeView>(*view_link);
				}

				void ui_block_free_views(uiBlock *block)
				{
				LISTBASE_FOREACH_MUTABLE (ViewLink *, link, &block->views) {
				OBJECT_GUARDED_DELETE(link, ViewLink);
				}
				}

				static StringRef ui_block_view_find_idname(const uiBlock &block, const AbstractTreeView &view)
				{
				/* First get the idname the of the view we're looking for. */
				LISTBASE_FOREACH (ViewLink *, view_link, &block.views) {
				if (get_view_from_link<AbstractTreeView>(*view_link) == &view) {
				return view_link->idname;
				}
				}

				return {};
				}

				uiTreeViewHandle ui_block_view_find_matching_in_old_block(const uiBlock new_block,
				const uiTreeViewHandle *new_view_handle)
				{
				const AbstractTreeView &needle_view = reinterpret_cast<const AbstractTreeView &>(
				*new_view_handle);

				uiBlock *old_block = new_block->oldblock;
				if (!old_block) {
				return nullptr;
				}

				StringRef idname = ui_block_view_find_idname(*new_block, needle_view);
				if (idname.is_empty()) {
				return nullptr;
				}

				LISTBASE_FOREACH (ViewLink *, old_view_link, &old_block->views) {
				if (old_view_link->idname == idname) {
				return reinterpret_cast<uiTreeViewHandle *>(
				get_view_from_link<AbstractTreeView>(*old_view_link));
				}
				}

				return nullptr;
				}