Initial release

engine/vendor/vst3sdk/vstgui4/vstgui/contrib/externalview_hwnd.h

@@ -0,0 +1,223 @@
+// This file is part of VSTGUI. It is subject to the license terms
+// in the LICENSE file found in the top-level directory of this
+// distribution and at http://github.com/steinbergmedia/vstgui/LICENSE
+
+#pragma once
+
+#include "../lib/vstguibase.h"
+#include "../lib/iexternalview.h"
+
+#include <windows.h>
+#include <cassert>
+#include <functional>
+#include <cstdint>
+#include <string>
+
+//------------------------------------------------------------------------
+namespace VSTGUI {
+namespace ExternalView {
+
+//------------------------------------------------------------------------
+inline void setWindowSize (HWND window, IntRect r)
+{
+	SetWindowPos (window, HWND_TOP, static_cast<int> (r.origin.x), static_cast<int> (r.origin.y),
+				  static_cast<int> (r.size.width), static_cast<int> (r.size.height),
+				  SWP_NOZORDER | SWP_NOCOPYBITS | SWP_NOREDRAW | SWP_DEFERERASE);
+}
+
+//------------------------------------------------------------------------
+struct HWNDWindow final
+{
+	using WindowProcFunc =
+		std::function<LONG_PTR (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)>;
+
+	HWNDWindow (HINSTANCE instance) : instance (instance) {}
+
+	~HWNDWindow () noexcept
+	{
+		if (window)
+		{
+			SetWindowLongPtr (window, GWLP_USERDATA, (__int3264)(LONG_PTR) nullptr);
+			DestroyWindow (window);
+		}
+		destroyWindowClass ();
+	}
+
+	bool create (const TCHAR* title, const IntRect& frame, HWND parent, DWORD exStyle = 0,
+				 DWORD style = WS_CHILD)
+	{
+		if (!initWindowClass ())
+			return false;
+		window = CreateWindowEx (
+			exStyle, MAKEINTATOM (windowClassAtom), title, style, static_cast<int> (frame.origin.x),
+			static_cast<int> (frame.origin.y), static_cast<int> (frame.size.width),
+			static_cast<int> (frame.size.height), parent, nullptr, instance, nullptr);
+		if (!window)
+			return false;
+		SetWindowLongPtr (window, GWLP_USERDATA, (__int3264)(LONG_PTR)this);
+		return true;
+	}
+
+	void setWindowProc (WindowProcFunc&& func) { windowProc = std::move (func); }
+
+	void setSize (const IntRect& r)
+	{
+		if (!window)
+			return;
+		setWindowSize (window, r);
+	}
+
+	void show (bool state) { ShowWindow (window, state ? SW_SHOW : SW_HIDE); }
+	void setEnabled (bool state) { EnableWindow (window, state); }
+
+	HWND getHWND () const { return window; }
+	HINSTANCE getInstance () const { return instance; }
+
+private:
+	bool initWindowClass ()
+	{
+		assert (instance != nullptr);
+
+		if (windowClassAtom != 0)
+			return true;
+
+		std::wstring windowClassName;
+		windowClassName = TEXT ("VSTGUI ExternalView Container ");
+		windowClassName += std::to_wstring (reinterpret_cast<uint64_t> (this));
+
+		WNDCLASS windowClass;
+		windowClass.style = CS_GLOBALCLASS;
+
+		windowClass.lpfnWndProc = WindowProc;
+		windowClass.cbClsExtra = 0;
+		windowClass.cbWndExtra = 0;
+		windowClass.hInstance = instance;
+		windowClass.hIcon = 0;
+
+		windowClass.hCursor = LoadCursor (NULL, IDC_ARROW);
+		windowClass.hbrBackground = 0;
+
+		windowClass.lpszMenuName = 0;
+		windowClass.lpszClassName = windowClassName.data ();
+		windowClassAtom = RegisterClass (&windowClass);
+		return windowClassAtom != 0;
+	}
+
+	void destroyWindowClass ()
+	{
+		if (windowClassAtom == 0)
+			return;
+		UnregisterClass (MAKEINTATOM (windowClassAtom), instance);
+		windowClassAtom = 0;
+	}
+
+	static LONG_PTR WINAPI WindowProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
+	{
+		if (message == WM_ERASEBKGND)
+			return 1;
+		auto instance = reinterpret_cast<HWNDWindow*> (GetWindowLongPtr (hwnd, GWLP_USERDATA));
+		if (instance && instance->windowProc)
+			return instance->windowProc (hwnd, message, wParam, lParam);
+		return DefWindowProc (hwnd, message, wParam, lParam);
+	}
+
+	WindowProcFunc windowProc;
+	HWND window {nullptr};
+	HINSTANCE instance {nullptr};
+	ATOM windowClassAtom {0};
+};
+
+//------------------------------------------------------------------------
+struct NonClientMetrics
+{
+	static const NONCLIENTMETRICS& get ()
+	{
+		static NonClientMetrics gInstance;
+		return gInstance.nonClientMetrics;
+	}
+
+private:
+	NonClientMetrics ()
+	{
+		nonClientMetrics.cbSize = sizeof (nonClientMetrics);
+		SystemParametersInfoForDpi (SPI_GETNONCLIENTMETRICS, nonClientMetrics.cbSize,
+									&nonClientMetrics, 0, 96);
+	}
+
+	NONCLIENTMETRICS nonClientMetrics {};
+};
+
+//------------------------------------------------------------------------
+struct ExternalHWNDBase : ViewAdapter
+{
+	using Base = ExternalHWNDBase;
+	using PlatformViewType = ExternalView::PlatformViewType;
+	using IntRect = ExternalView::IntRect;
+
+	HWNDWindow container;
+	HWND child {nullptr};
+
+	ExternalHWNDBase (HINSTANCE hInst) : container (hInst)
+	{
+		container.create (nullptr, {{0, 0}, {1, 1}}, HWND_MESSAGE,
+						  WS_EX_NOPARENTNOTIFY | WS_EX_COMPOSITED, WS_CHILD | WS_VISIBLE);
+	}
+
+	virtual ~ExternalHWNDBase () noexcept
+	{
+		if (child)
+			DestroyWindow (child);
+	}
+
+	bool platformViewTypeSupported (PlatformViewType type) override
+	{
+		return type == PlatformViewType::HWND;
+	}
+
+	bool attach (void* parent, PlatformViewType parentViewType) override
+	{
+		assert (container.getHWND ());
+		if (parent == nullptr || parentViewType != PlatformViewType::HWND)
+			return false;
+		auto parentHWND = reinterpret_cast<HWND> (parent);
+		SetParent (container.getHWND (), parentHWND);
+		return true;
+	}
+
+	bool remove () override
+	{
+		assert (container.getHWND ());
+		SetParent (container.getHWND (), HWND_MESSAGE);
+		return true;
+	}
+
+	void setViewSize (IntRect frame, IntRect visible) override
+	{
+		assert (container.getHWND ());
+		container.setSize (visible);
+		if (child)
+		{
+			frame.origin.x -= visible.origin.x;
+			frame.origin.y -= visible.origin.y;
+			setWindowSize (child, frame);
+		}
+	}
+
+	void setContentScaleFactor (double scaleFactor) override {}
+
+	void setMouseEnabled (bool state) override { EnableWindow (container.getHWND (), state); }
+
+	void takeFocus () override { SetFocus (child); }
+
+	void looseFocus () override
+	{
+		if (GetFocus () == child)
+		{
+			SetFocus (GetParent (container.getHWND ()));
+		}
+	}
+};
+
+//------------------------------------------------------------------------
+} // ExternalView
+} // VSTGUI