NEW:added dark mode

Change-Id: I3f61f1d93020e0a9dfba2c7d6cf6bf5194effcfa

src/slic3r/GUI/dark_mode/UAHMenuBar.hpp

@@ -0,0 +1,74 @@
+#pragma once
+
+// MIT license, see LICENSE
+// Copyright(c) 2021 adzm / Adam D. Walling
+
+// processes messages related to UAH / custom menubar drawing.
+// return true if handled, false to continue with normal processing in your wndproc
+bool UAHDarkModeWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam, LRESULT* lr);
+
+// window messages related to menu bar drawing
+#define WM_UAHDESTROYWINDOW    0x0090	// handled by DefWindowProc
+#define WM_UAHDRAWMENU         0x0091	// lParam is UAHMENU
+#define WM_UAHDRAWMENUITEM     0x0092	// lParam is UAHDRAWMENUITEM
+#define WM_UAHINITMENU         0x0093	// handled by DefWindowProc
+#define WM_UAHMEASUREMENUITEM  0x0094	// lParam is UAHMEASUREMENUITEM
+#define WM_UAHNCPAINTMENUPOPUP 0x0095	// handled by DefWindowProc
+
+// describes the sizes of the menu bar or menu item
+typedef union tagUAHMENUITEMMETRICS
+{
+	// cx appears to be 14 / 0xE less than rcItem's width!
+	// cy 0x14 seems stable, i wonder if it is 4 less than rcItem's height which is always 24 atm
+	struct {
+		DWORD cx;
+		DWORD cy;
+	} rgsizeBar[2];
+	struct {
+		DWORD cx;
+		DWORD cy;
+	} rgsizePopup[4];
+} UAHMENUITEMMETRICS;
+
+// not really used in our case but part of the other structures
+typedef struct tagUAHMENUPOPUPMETRICS
+{
+	DWORD rgcx[4];
+	DWORD fUpdateMaxWidths : 2; // from kernel symbols, padded to full dword
+} UAHMENUPOPUPMETRICS;
+
+// hmenu is the main window menu; hdc is the context to draw in
+typedef struct tagUAHMENU
+{
+	HMENU hmenu;
+	HDC hdc;
+	DWORD dwFlags; // no idea what these mean, in my testing it's either 0x00000a00 or sometimes 0x00000a10
+} UAHMENU;
+
+// menu items are always referred to by iPosition here
+typedef struct tagUAHMENUITEM
+{
+	int iPosition; // 0-based position of menu item in menubar
+	UAHMENUITEMMETRICS umim;
+	UAHMENUPOPUPMETRICS umpm;
+} UAHMENUITEM;
+
+// the DRAWITEMSTRUCT contains the states of the menu items, as well as
+// the position index of the item in the menu, which is duplicated in
+// the UAHMENUITEM's iPosition as well
+typedef struct UAHDRAWMENUITEM
+{
+	DRAWITEMSTRUCT dis; // itemID looks uninitialized
+	UAHMENU um;
+	UAHMENUITEM umi;
+} UAHDRAWMENUITEM;
+
+// the MEASUREITEMSTRUCT is intended to be filled with the size of the item
+// height appears to be ignored, but width can be modified
+typedef struct tagUAHMEASUREMENUITEM
+{
+	MEASUREITEMSTRUCT mis;
+	UAHMENU um;
+	UAHMENUITEM umi;
+} UAHMEASUREMENUITEM;
+