Added a Direct2D scratch control that will be used by the font and color dialogs we will implement.

windows/GNUfiles.mk

@@ -14,6 +14,7 @@ CFILES += \
 	windows/combobox.c \
 	windows/container.c \
 	windows/control.c \
+	windows/d2dscratch.c \
 	windows/datetimepicker.c \
 	windows/debug.c \
 	windows/draw.c \

windows/d2dscratch.c

@@ -0,0 +1,124 @@
+// 17 april 2016
+#include "uipriv_windows.h"
+
+// The Direct2D scratch window is a utility for libui internal use to do quick things with Direct2D.
+// To use, call newD2DScratch() passing in a subclass procedure. This subclass procedure should handle the msgD2DScratchPaint message, which has the following usage:
+// - wParam - 0
+// - lParam - ID2D1RenderTarget *
+// - lResult - 0
+// Other messages can also be handled here.
+
+// TODO allow resize
+
+#define d2dScratchClass L"libui_d2dScratchClass"
+
+// TODO clip rect
+static HRESULT d2dScratchDoPaint(HWND hwnd, ID2D1RenderTarget *rt)
+{
+	COLORREF bgcolorref;
+	D2D1_COLOR_F bgcolor;
+
+	ID2D1RenderTarget_BeginDraw(rt);
+
+	// TODO only clear the clip area
+	// TODO clear with actual background brush
+	bgcolorref = GetSysColor(COLOR_BTNFACE);
+	bgcolor.r = ((float) GetRValue(bgcolorref)) / 255.0;
+	// due to utter apathy on Microsoft's part, GetGValue() does not work with MSVC's Run-Time Error Checks
+	// it has not worked since 2008 and they have *never* fixed it
+	bgcolor.g = ((float) ((BYTE) ((bgcolorref & 0xFF00) >> 8))) / 255.0;
+	bgcolor.b = ((float) GetBValue(bgcolorref)) / 255.0;
+	bgcolor.a = 1.0;
+	ID2D1RenderTarget_Clear(rt, &bgcolor);
+
+	SendMessageW(hwnd, msgD2DScratchPaint, 0, (LPARAM) rt);
+
+	return ID2D1RenderTarget_EndDraw(rt, NULL, NULL);
+}
+
+static LRESULT CALLBACK d2dScratchWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+	LONG_PTR init;
+	ID2D1HwndRenderTarget *rt;
+	HRESULT hr;
+
+	init = GetWindowLongPtrW(hwnd, 0);
+	if (!init) {
+		if (uMsg == WM_CREATE)
+			SetWindowLongPtrW(hwnd, 0, (LONG_PTR) TRUE);
+		return DefWindowProcW(hwnd, uMsg, wParam, lParam);
+	}
+
+	rt = (ID2D1HwndRenderTarget *) GetWindowLongPtrW(hwnd, GWLP_USERDATA);
+	if (rt == NULL) {
+		rt = makeHWNDRenderTarget(hwnd);
+		SetWindowLongPtrW(hwnd, GWLP_USERDATA, (LONG_PTR) rt);
+	}
+
+	switch (uMsg) {
+	case WM_DESTROY:
+		ID2D1HwndRenderTarget_Release(rt);
+		SetWindowLongPtrW(hwnd, 0, (LONG_PTR) FALSE);
+		break;
+	case WM_PAINT:
+		hr = d2dScratchDoPaint(hwnd, (ID2D1RenderTarget *) rt);
+		switch (hr) {
+		case S_OK:
+			if (ValidateRect(hwnd, NULL) == 0)
+				logLastError("error validating D2D scratch control rect in d2dScratchWndProc()");
+			break;
+		case D2DERR_RECREATE_TARGET:
+			// DON'T validate the rect
+			// instead, simply drop the render target
+			// we'll get another WM_PAINT and make the render target again
+			// TODO would this require us to invalidate the entire client area?
+			ID2D1HwndRenderTarget_Release(rt);
+			SetWindowLongPtrW(hwnd, GWLP_USERDATA, (LONG_PTR) NULL);
+			break;
+		default:
+			logHRESULT("error drawing D2D scratch window in d2dScratchWndProc()", hr);
+		}
+		return 0;
+	case WM_PRINTCLIENT:
+		// TODO
+		break;
+	}
+	return DefWindowProcW(hwnd, uMsg, wParam, lParam);
+}
+
+ATOM registerD2DScratchClass(HICON hDefaultIcon, HCURSOR hDefaultCursor)
+{
+	WNDCLASSW wc;
+
+	ZeroMemory(&wc, sizeof (WNDCLASSW));
+	wc.lpszClassName = d2dScratchClass;
+	wc.lpfnWndProc = d2dScratchWndProc;
+	wc.hInstance = hInstance;
+	wc.hIcon = hDefaultIcon;
+	wc.hCursor = hDefaultCursor;
+	wc.hbrBackground = (HBRUSH) (COLOR_BTNFACE + 1);
+	return RegisterClassW(&wc);
+}
+
+void unregisterD2DScratchClass(void)
+{
+	if (UnregisterClassW(d2dScratchClass, hInstance) == 0)
+		logLastError("error unregistering D2D scratch window class in unregisterD2DScratchClass()");
+}
+
+HWND newD2DScratch(HWND parent, RECT *rect, HMENU controlID, SUBCLASSPROC subclass, DWORD_PTR subclassData)
+{
+	HWND hwnd;
+
+	hwnd = CreateWindowExW(0,
+		d2dScratchClass, L"",
+		WS_CHILD | WS_VISIBLE,
+		rect->left, rect->top,
+		rect->right - rect->left, rect->bottom - rect->top,
+		parent, controlID, hInstance, NULL);
+	if (hwnd == NULL)
+		logLastError("error creating D2D scratch window in newD2DScratch()");
+	if (SetWindowSubclass(hwnd, subclass, 0, subclassData) == FALSE)
+		logLastError("error subclassing D2D scratch window in newD2DScratch()");
+	return hwnd;
+}

windows/init.c

@@ -130,6 +130,7 @@ const char *uiInit(uiInitOptions *o)
 	if (hMessageFont == NULL)
 		return loadLastError("loading default messagebox font; this is the default UI font");
 
+	// TODO rewrite this error message
 	if (initContainer(hDefaultIcon, hDefaultCursor) == 0)
 		return loadLastError("initializing uiMakeContainer() window class");
 
@@ -165,12 +166,16 @@ const char *uiInit(uiInitOptions *o)
 	if (registerAreaFilter() == 0)
 		return loadLastError("registering uiArea message filter");
 
+	if (registerD2DScratchClass(hDefaultIcon, hDefaultCursor) == 0)
+		return loadLastError("initializing D2D scratch window class");
+
 	return NULL;
 }
 
 void uiUninit(void)
 {
 	uninitMenus();
+	unregisterD2DScratchClass();
 	unregisterArea();
 	uninitDrawText();
 	uninitDraw();

windows/uipriv_windows.h

@@ -18,6 +18,7 @@ enum {
 	msgHSCROLL,
 	msgConsoleEndSession,
 	msgQueued,
+	msgD2DScratchPaint,
 };
 
 // init.c
@@ -159,6 +160,11 @@ extern void doDrawText(ID2D1RenderTarget *rt, ID2D1Brush *black, double x, doubl
 // fontdialog.cpp
 extern void showFontDialog(HWND parent);
 
+// d2dscratch.c
+extern ATOM registerD2DScratchClass(HICON, HCURSOR);
+extern void unregisterD2DScratchClass(void);
+extern HWND newD2DScratch(HWND parent, RECT *rect, HMENU controlID, SUBCLASSPROC subclass, DWORD_PTR subclassData);
+
 #ifdef __cplusplus
 }
 #endif