From a22aafaf96460bb8984fbd0bef34544077667150 Mon Sep 17 00:00:00 2001
From: Gary Talent <gary@drinkingtea.net>
Date: Sun, 26 Jan 2025 22:12:57 -0600
Subject: [PATCH] [nostalgia/gfx/studio/palette] Add ability to reorder Palette
 pages

---
 .../src/studio/paletteeditor/CMakeLists.txt   |  1 +
 .../paletteeditor/commands/commands.hpp       |  1 +
 .../commands/movepagecommand.cpp              | 40 +++++++++++++++++++
 .../commands/movepagecommand.hpp              | 35 ++++++++++++++++
 .../paletteeditor/paletteeditor-imgui.cpp     | 22 ++++++++++
 5 files changed, 99 insertions(+)
 create mode 100644 src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.cpp
 create mode 100644 src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.hpp

diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/CMakeLists.txt b/src/nostalgia/modules/gfx/src/studio/paletteeditor/CMakeLists.txt
index cdaf9d3e..9ec397bf 100644
--- a/src/nostalgia/modules/gfx/src/studio/paletteeditor/CMakeLists.txt
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/CMakeLists.txt
@@ -5,6 +5,7 @@ target_sources(
 		commands/applycolorallpagescommand.cpp
 		commands/duplicatepagecommand.cpp
 		commands/movecolorcommand.cpp
+		commands/movepagecommand.cpp
 		commands/removecolorcommand.cpp
 		commands/removepagecommand.cpp
 		commands/renamepagecommand.cpp
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/commands.hpp b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/commands.hpp
index 7ca6ee69..666a0f20 100644
--- a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/commands.hpp
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/commands.hpp
@@ -12,6 +12,7 @@ enum class PaletteEditorCommandId {
 	AddPage,
 	DuplicatePage,
 	RemovePage,
+	MovePage,
 	AddColor,
 	RemoveColor,
 	UpdateColorInfo,
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.cpp b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.cpp
new file mode 100644
index 00000000..86a9c80d
--- /dev/null
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.cpp
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2016 - 2025 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#include "commands.hpp"
+
+#include "movepagecommand.hpp"
+
+namespace nostalgia::gfx {
+
+MovePageCommand::MovePageCommand(
+		Palette &pal,
+		size_t const srcIdx,
+		size_t const dstIdx) noexcept:
+	m_pal(pal),
+	m_srcIdx(srcIdx),
+	m_dstIdx(dstIdx) {}
+
+int MovePageCommand::commandId() const noexcept {
+	return static_cast<int>(PaletteEditorCommandId::MovePage);
+}
+
+ox::Error MovePageCommand::redo() noexcept {
+	movePage(m_srcIdx, m_dstIdx);
+	return {};
+}
+
+ox::Error MovePageCommand::undo() noexcept {
+	movePage(m_dstIdx, m_srcIdx);
+	return {};
+}
+
+void MovePageCommand::movePage(
+		size_t const srcIdx, size_t const dstIdx) noexcept {
+	auto page = std::move(m_pal.pages[srcIdx]);
+	std::ignore = m_pal.pages.erase(srcIdx);
+	m_pal.pages.emplace(dstIdx, std::move(page));
+}
+
+}
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.hpp b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.hpp
new file mode 100644
index 00000000..0b42161d
--- /dev/null
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.hpp
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2016 - 2025 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#pragma once
+
+#include <studio/studio.hpp>
+
+#include <nostalgia/gfx/palette.hpp>
+
+namespace nostalgia::gfx {
+
+class MovePageCommand: public studio::UndoCommand {
+	private:
+		Palette &m_pal;
+		std::size_t const m_srcIdx = 0;
+		std::size_t const m_dstIdx = 0;
+
+	public:
+		MovePageCommand(Palette &pal, size_t srcIdx, size_t dstIdx) noexcept;
+
+		~MovePageCommand() noexcept override = default;
+
+		[[nodiscard]]
+		int commandId() const noexcept override;
+
+		ox::Error redo() noexcept override;
+
+		ox::Error undo() noexcept override;
+
+	private:
+		void movePage(size_t srcIdx, size_t dstIdx) noexcept;
+};
+
+}
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/paletteeditor-imgui.cpp b/src/nostalgia/modules/gfx/src/studio/paletteeditor/paletteeditor-imgui.cpp
index 28d1275a..8a433078 100644
--- a/src/nostalgia/modules/gfx/src/studio/paletteeditor/paletteeditor-imgui.cpp
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/paletteeditor-imgui.cpp
@@ -11,6 +11,7 @@
 #include "commands/applycolorallpagescommand.hpp"
 #include "commands/duplicatepagecommand.hpp"
 #include "commands/movecolorcommand.hpp"
+#include "commands/movepagecommand.hpp"
 #include "commands/removecolorcommand.hpp"
 #include "commands/removepagecommand.hpp"
 #include "commands/renamepagecommand.hpp"
@@ -19,6 +20,7 @@
 
 #include "paletteeditor-imgui.hpp"
 
+
 namespace nostalgia::gfx {
 
 namespace ig = studio::ig;
@@ -33,6 +35,16 @@ OX_MODEL_BEGIN(ColorDragDrop)
 	OX_MODEL_FIELD(i)
 OX_MODEL_END()
 
+struct PageDragDrop {
+	static constexpr auto TypeName = "nostalgia.gfx.PageDragDrop";
+	static constexpr auto TypeVersion = 1;
+	uint32_t page{};
+};
+
+OX_MODEL_BEGIN(PageDragDrop)
+	OX_MODEL_FIELD(page)
+OX_MODEL_END()
+
 void PaletteEditorImGui::PageRenameDialog::draw(turbine::Context &tctx) noexcept {
 	if (!m_show) {
 		return;
@@ -235,6 +247,16 @@ void PaletteEditorImGui::drawPagesEditor() noexcept {
 			if (ImGui::Selectable("##PageRow", i == m_page, ImGuiSelectableFlags_SpanAllColumns)) {
 				m_page = i;
 			}
+			std::ignore = ig::dragDropSource([this, i] {
+				ImGui::Text("%s", m_pal.pages[i].name.c_str());
+				return ig::setDragDropPayload(PageDragDrop{i});
+			}, ImGuiDragDropFlags_SourceAllowNullID);
+			if (ig::DragDropTarget const d; d) {
+				auto const [src, err] = ig::getDragDropPayload<PageDragDrop>();
+				if (!err) {
+					std::ignore = pushCommand<MovePageCommand>(m_pal, src.page, i);
+				}
+			}
 		}
 	}
 	ImGui::EndTable();