Added WM_PAINT handling for scroll bar controls

Now size box rendering works correctly, so no need for that workaround in
CompatGdiScrollBar.
There seems to be a bug with subclassing scroll bars though, as the cursor
will no longer change to a sizing arrow when it's over a size box control.
At least there is a simple workaround for that via WM_SETCURSOR.

DDrawCompat/CompatGdiPaintHandlers.cpp

@@ -18,6 +18,7 @@ namespace
 
 	WNDPROC g_origEditWndProc = nullptr;
 	WNDPROC g_origListBoxWndProc = nullptr;
+	WNDPROC g_origScrollBarWndProc = nullptr;
 
 	LRESULT WINAPI defDlgProcA(HWND hdlg, UINT msg, WPARAM wParam, LPARAM lParam)
 	{
@@ -156,6 +157,33 @@ namespace
 		return 0;
 	}
 
+	LRESULT onPaint(HWND hwnd, WNDPROC origWndProc)
+	{
+		if (!hwnd || !CompatGdi::beginGdiRendering())
+		{
+			return origWndProc(hwnd, WM_PAINT, 0, 0);
+		}
+
+		PAINTSTRUCT paint = {};
+		HDC dc = BeginPaint(hwnd, &paint);
+		HDC compatDc = CompatGdiDc::getDc(dc);
+
+		if (compatDc)
+		{
+			origWndProc(hwnd, WM_PRINTCLIENT, reinterpret_cast<WPARAM>(compatDc), PRF_CLIENT);
+			CompatGdiDc::releaseDc(dc);
+		}
+		else
+		{
+			origWndProc(hwnd, WM_PRINTCLIENT, reinterpret_cast<WPARAM>(dc), PRF_CLIENT);
+		}
+
+		EndPaint(hwnd, &paint);
+
+		CompatGdi::endGdiRendering();
+		return 0;
+	}
+
 	LRESULT onPrint(HWND hwnd, UINT msg, HDC dc, LONG flags, WNDPROC origWndProc)
 	{
 		if (!CompatGdi::beginGdiRendering())
@@ -178,6 +206,34 @@ namespace
 		CompatGdi::endGdiRendering();
 		return result;
 	}
+
+	LRESULT WINAPI scrollBarWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+	{
+		Compat::LogEnter("scrollBarWndProc", hwnd, msg, wParam, lParam);
+		LRESULT result = 0;
+
+		switch (msg)
+		{
+		case WM_PAINT:
+			result = onPaint(hwnd, g_origScrollBarWndProc);
+			break;
+
+		case WM_SETCURSOR:
+			if (GetWindowLong(hwnd, GWL_STYLE) & (SBS_SIZEBOX | SBS_SIZEGRIP))
+			{
+				SetCursor(LoadCursor(nullptr, IDC_SIZENWSE));
+			}
+			result = TRUE;
+			break;
+
+		default:
+			result = g_origScrollBarWndProc(hwnd, msg, wParam, lParam);
+			break;
+		}
+
+		Compat::LogLeave("scrollBarWndProc", hwnd, msg, wParam, lParam) << result;
+		return result;
+	}
 }
 
 namespace CompatGdiPaintHandlers
@@ -186,6 +242,7 @@ namespace CompatGdiPaintHandlers
 	{
 		CompatGdi::hookWndProc("Edit", g_origEditWndProc, &editWndProc);
 		CompatGdi::hookWndProc("ListBox", g_origListBoxWndProc, &listBoxWndProc);
+		CompatGdi::hookWndProc("ScrollBar", g_origScrollBarWndProc, &scrollBarWndProc);
 
 		DetourTransactionBegin();
 		HOOK_GDI_FUNCTION(user32, DefWindowProcA, defWindowProcA);

DDrawCompat/CompatGdiScrollBar.cpp

@@ -19,14 +19,12 @@ namespace CompatGdi
 	ScrollBar::ScrollBar(HWND hwnd, HDC compatDc) :
 		m_hwnd(hwnd), m_compatDc(compatDc), m_windowRect(),
 		m_isLeftMouseButtonDown(false), m_cursorPos(),
-		m_horizontalSbi(), m_verticalSbi(),
+		m_horizontalSbi(), m_verticalSbi()
-		m_hasSizeBox(false), m_sizeBoxRect()
 	{
 		const LONG windowStyle = GetWindowLongPtr(hwnd, GWL_STYLE);
 
 		m_horizontalSbi.isVisible = 0 != (windowStyle & WS_HSCROLL);
 		m_verticalSbi.isVisible = 0 != (windowStyle & WS_VSCROLL);
-		m_hasSizeBox = 0 != (windowStyle & WS_SIZEBOX);
 
 		GetWindowRect(hwnd, &m_windowRect);
 
@@ -53,18 +51,12 @@ namespace CompatGdi
 				m_verticalSbi = getScrollBarInfo(OBJID_VSCROLL);
 			}
 		}
-
-		if (m_hasSizeBox)
-		{
-			m_sizeBoxRect = getSizeBoxRect();
-		}
 	}
 
 	void ScrollBar::drawAll() const
 	{
 		drawHorizArrows();
 		drawVertArrows();
-		drawSizeBox();
 	}
 
 	void ScrollBar::drawArrow(const ScrollBarChildInfo& sbci, UINT dfcState) const
@@ -92,15 +84,6 @@ namespace CompatGdi
 		}
 	}
 
-	void ScrollBar::drawSizeBox() const
-	{
-		if (m_hasSizeBox)
-		{
-			RECT rect = m_sizeBoxRect;
-			CALL_ORIG_GDI(DrawFrameControl)(m_compatDc, &rect, DFC_SCROLL, DFCS_SCROLLSIZEGRIP);
-		}
-	}
-
 	void ScrollBar::drawVertArrows() const
 	{
 		if (m_verticalSbi.isVisible)
@@ -128,11 +111,6 @@ namespace CompatGdi
 	{
 		excludeFromClipRegion(m_horizontalSbi);
 		excludeFromClipRegion(m_verticalSbi);
-
-		if (m_hasSizeBox)
-		{
-			excludeFromClipRegion(m_sizeBoxRect);
-		}
 	}
 
 	ScrollBar::ScrollBarInfo ScrollBar::getScrollBarInfo(LONG objId) const
@@ -183,36 +161,6 @@ namespace CompatGdi
 		return scrollBarInfo;
 	}
 
-	RECT ScrollBar::getSizeBoxRect() const
-	{
-		RECT clientRect = {};
-		GetClientRect(m_hwnd, &clientRect);
-		POINT clientOrigin = {};
-		ClientToScreen(m_hwnd, &clientOrigin);
-		OffsetRect(&clientRect, clientOrigin.x - m_windowRect.left, clientOrigin.y - m_windowRect.top);
-
-		const int width = GetSystemMetrics(SM_CXVSCROLL);
-		const int height = GetSystemMetrics(SM_CYHSCROLL);
-
-		RECT sizeBoxRect = {};
-
-		if (m_horizontalSbi.isVisible && m_verticalSbi.isVisible)
-		{
-			sizeBoxRect.left = clientRect.right;
-			sizeBoxRect.top = clientRect.bottom;
-		}
-		else
-		{
-			sizeBoxRect.left = clientRect.right - width;
-			sizeBoxRect.top = clientRect.bottom - height;
-		}
-
-		sizeBoxRect.right = sizeBoxRect.left + width;
-		sizeBoxRect.bottom = sizeBoxRect.top + height;
-
-		return sizeBoxRect;
-	}
-
 	void ScrollBar::setPressedState(ScrollBarChildInfo& sbci) const
 	{
 		if (!(sbci.state & STATE_SYSTEM_UNAVAILABLE) && PtInRect(&sbci.rect, m_cursorPos))

DDrawCompat/CompatGdiScrollBar.h

@@ -13,7 +13,6 @@ namespace CompatGdi
 
 		void drawAll() const;
 		void drawHorizArrows() const;
-		void drawSizeBox() const;
 		void drawVertArrows() const;
 		void excludeFromClipRegion() const;
 
@@ -35,7 +34,6 @@ namespace CompatGdi
 		void excludeFromClipRegion(const RECT& rect) const;
 		void excludeFromClipRegion(const ScrollBarInfo& sbi) const;
 		ScrollBarInfo getScrollBarInfo(LONG objId) const;
-		RECT getSizeBoxRect() const;
 		void setPressedState(ScrollBarChildInfo& sbci) const;
 
 		HWND m_hwnd;
@@ -45,7 +43,5 @@ namespace CompatGdi
 		POINT m_cursorPos;
 		ScrollBarInfo m_horizontalSbi;
 		ScrollBarInfo m_verticalSbi;
-		bool m_hasSizeBox;
-		RECT m_sizeBoxRect;
 	};
 }