Explain platform clipboard external dependencies in OptionsView

src/common/clipboard/Clipboard.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <memory>
+#include <optional>
 #include "common/String.h"
 
 class GameSave;
@@ -13,4 +14,5 @@ namespace Clipboard
 	bool GetEnabled();
 	void SetEnabled(bool newEnabled);
 	void RecreateWindow();
+	std::optional<String> Explanation();
 }

src/common/clipboard/Cocoa.mm

@@ -62,6 +62,11 @@ namespace Clipboard
 			}
 			return gdc;
 		}
+
+		std::optional<String> Explanation() final override
+		{
+			return std::nullopt;
+		}
 	};
 
 	std::unique_ptr<ClipboardImpl> CocoaClipboardFactory()

src/common/clipboard/Dynamic.cpp

@@ -24,7 +24,7 @@ namespace Clipboard
 	};
 
 	std::unique_ptr<GameSave> clipboardData;
-	std::unique_ptr<ClipboardImpl> clipboard;
+	static std::unique_ptr<ClipboardImpl> clipboard;
 
 	void InvokeClipboardSetClipboardData()
 	{
@@ -94,7 +94,7 @@ namespace Clipboard
 	static bool enabled = false;
 	void Init()
 	{
-		enabled = GlobalPrefs::Ref().Get<bool>("NativeClipboard.Enabled", true);
+		enabled = GlobalPrefs::Ref().Get("NativeClipboard.Enabled", false);
 	}
 
 	bool GetEnabled()
@@ -131,4 +131,9 @@ namespace Clipboard
 		}
 		InvokeClipboardSetClipboardData();
 	}
+
+	std::optional<String> Explanation()
+	{
+		return clipboard ? clipboard->Explanation() : std::nullopt;
+	}
 }

src/common/clipboard/Dynamic.h

@@ -3,6 +3,7 @@
 #include <vector>
 #include <variant>
 #include <memory>
+#include <optional>
 
 class GameSave;
 
@@ -35,6 +36,8 @@ namespace Clipboard
 			GetClipboardDataUnknown
 		>;
 		virtual GetClipboardDataResult GetClipboardData() = 0;
+
+		virtual std::optional<String> Explanation() = 0;
 	};
 
 	extern std::unique_ptr<GameSave> clipboardData;

src/common/clipboard/External.cpp

@@ -18,6 +18,7 @@ namespace Clipboard
 		ByteString inCommand;
 		ByteString formatsCommand;
 		ByteString outCommand;
+		std::optional<String> explanation;
 		std::optional<int> defaultForSubsystem;
 	};
 	std::map<ByteString, Preset> builtInPresets = {
@@ -25,12 +26,14 @@ namespace Clipboard
 			"xclip -selection clipboard -target %s",
 			"xclip -out -selection clipboard -target TARGETS",
 			"xclip -out -selection clipboard -target %s",
+			"Requires the xclip utility to be installed",
 			SDL_SYSWM_X11,
 		} },
 		{ "wl-clipboard", {
 			"wl-copy --type %s",
 			"wl-paste --list-types",
 			"wl-paste --type %s",
+			"Requires the wl-clipboard utility to be installed",
 			SDL_SYSWM_WAYLAND,
 		} },
 	};
@@ -98,6 +101,7 @@ namespace Clipboard
 			SubstFormat(it->second.inCommand),
 			SubstFormat(it->second.formatsCommand),
 			SubstFormat(it->second.outCommand),
+			it->second.explanation,
 		};
 	}
 
@@ -240,6 +244,12 @@ namespace Clipboard
 			}
 			return GetClipboardDataChanged{ std::move(*saveDataOpt) };
 		}
+
+		std::optional<String> Explanation() final override
+		{
+			auto preset = GetPreset();
+			return preset ? preset->explanation : std::nullopt;
+		}
 	};
 
 	std::unique_ptr<ClipboardImpl> ExternalClipboardFactory()

src/common/clipboard/Null.cpp

@@ -28,4 +28,9 @@ namespace Clipboard
 	void RecreateWindow()
 	{
 	}
+
+	std::optional<String> Explanation()
+	{
+		return std::nullopt;
+	}
 }

src/common/clipboard/Windows.cpp

@@ -217,6 +217,11 @@ namespace Clipboard
 			auto base = reinterpret_cast<const char *>(data.get());
 			return GetClipboardDataChanged{ std::vector<char>(base, base + size) };
 		}
+
+		std::optional<String> Explanation() final override
+		{
+			return std::nullopt;
+		}
 	};
 
 	std::unique_ptr<ClipboardImpl> WindowsClipboardFactory()

src/gui/options/OptionsView.cpp

@@ -2,6 +2,7 @@
 #include "Format.h"
 #include "OptionsController.h"
 #include "OptionsModel.h"
+#include "common/clipboard/Clipboard.h"
 #include "common/platform/Platform.h"
 #include "graphics/Graphics.h"
 #include "graphics/Renderer.h"
@@ -59,7 +60,18 @@ OptionsView::OptionsView() : ui::Window(ui::Point(-1, -1), ui::Point(320, 340))
 	AddComponent(scrollPanel);
 
 	int currentY = 8;
-	auto addCheckbox = [this, &currentY, &autoWidth](int indent, String text, String info, std::function<void ()> action) {
+	auto addLabel = [this, &currentY, &autoWidth](int indent, String text) {
+		auto *label = new ui::Label(ui::Point(22 + indent * 15, currentY), ui::Point(1, 16), "");
+		autoWidth(label, 0);
+		label->Appearance.HorizontalAlign = ui::Appearance::AlignLeft;
+		label->Appearance.VerticalAlign = ui::Appearance::AlignMiddle;
+		label->SetMultiline(true);
+		label->SetText("\bg" + text); // stupid hack because autoWidth just changes Size.X and that doesn't update the text wrapper
+		label->AutoHeight();
+		scrollPanel->AddChild(label);
+		currentY += label->Size.Y - 1;
+	};
+	auto addCheckbox = [this, &currentY, &autoWidth, &addLabel](int indent, String text, String info, std::function<void ()> action) {
 		auto *checkbox = new ui::Checkbox(ui::Point(8 + indent * 15, currentY), ui::Point(1, 16), text, "");
 		autoWidth(checkbox, 0);
 		checkbox->SetActionCallback({ action });
@@ -67,12 +79,7 @@ OptionsView::OptionsView() : ui::Window(ui::Point(-1, -1), ui::Point(320, 340))
 		currentY += 14;
 		if (info.size())
 		{
-			auto *label = new ui::Label(ui::Point(22 + indent * 15, currentY), ui::Point(1, 16), "\bg" + info);
-			autoWidth(label, 0);
-			label->Appearance.HorizontalAlign = ui::Appearance::AlignLeft;
-			label->Appearance.VerticalAlign = ui::Appearance::AlignMiddle;
-			scrollPanel->AddChild(label);
-			currentY += 14;
+			addLabel(indent, info);
 		}
 		currentY += 4;
 		return checkbox;
@@ -298,9 +305,16 @@ OptionsView::OptionsView() : ui::Window(ui::Point(-1, -1), ui::Point(320, 340))
 	});
 	if constexpr (PLATFORM_CLIPBOARD)
 	{
-		nativeClipoard = addCheckbox(0, "Use platform clipboard", "Allows copying and pasting across TPT instances", [this] {
+		auto indent = 0;
+		nativeClipoard = addCheckbox(indent, "Use platform clipboard", "Allows copying and pasting across TPT instances", [this] {
 			c->SetNativeClipoard(nativeClipoard->GetChecked());
 		});
+		currentY -= 4; // temporarily undo the currentY += 4 at the end of addCheckbox
+		if (auto extra = Clipboard::Explanation())
+		{
+			addLabel(indent, "\bg" + *extra);
+		}
+		currentY += 4; // and then undo the undo
 	}
 	decoSpace = addDropDown("Colour space used by decoration tools", {
 		{ "sRGB", 0 },