Add interface to get/set dark background state in WinIMergeLib

Author: sdottaka

src/WinIMergeLib/ImgMergeWindow.hpp

@@ -74,6 +74,7 @@ class CImgMergeWindow : public IImgMergeWindow
 		, m_gdiplusToken(0)
 		, m_timerPrev()
 		, m_timerNext()
+		, m_bDarkBackgroundEnabled(false)
 	{
 		for (int i = 0; i < 3; ++i)
 			m_ChildWndProc[i] = NULL;
@@ -867,6 +868,7 @@ class CImgMergeWindow : public IImgMergeWindow
 					m_imgWindow[i].SetScrollBar(m_bHorizontalSplit ? SB_VERT : SB_HORZ);
 				m_imgWindow[i].SetWindowRect(rects[i]);
 				m_imgWindow[i].SetImage(m_buffer.GetImage(i)->getFipImage());
+				m_imgWindow[i].SetDarkBackgroundEnabled(m_bDarkBackgroundEnabled);
 			}
 
 			Event evt;
@@ -899,6 +901,7 @@ class CImgMergeWindow : public IImgMergeWindow
 					m_imgWindow[i].SetScrollBar(m_bHorizontalSplit ? SB_VERT : SB_HORZ);
 				m_imgWindow[i].SetWindowRect(rects[i]);
 				m_imgWindow[i].SetImage(m_buffer.GetImage(i)->getFipImage());
+				m_imgWindow[i].SetDarkBackgroundEnabled(m_bDarkBackgroundEnabled);
 			}
 
 			Event evt;
@@ -1206,6 +1209,25 @@ class CImgMergeWindow : public IImgMergeWindow
 		m_buffer.SetOverlayAnimationInterval(interval);
 	}
 
+	bool IsDarkBackgroundEnabled() const
+	{
+		return m_bDarkBackgroundEnabled;
+	}
+
+	void SetDarkBackgroundEnabled(bool enabled)
+	{
+		m_bDarkBackgroundEnabled = enabled;
+		if (m_hWnd)
+		{
+			for (int pane = 0; pane < m_nImages; ++pane)
+				m_imgWindow[pane].SetDarkBackgroundEnabled(m_bDarkBackgroundEnabled);
+			DeleteObject(s_hbrBackground	);
+			s_hbrBackground = CreateSolidBrush(m_bDarkBackgroundEnabled ? RGB(0, 0, 0) : GetSysColor(COLOR_3DFACE));
+			SetClassLongPtr(m_hWnd, GCLP_HBRBACKGROUND, (LONG_PTR)s_hbrBackground);
+			InvalidateRect(m_hWnd, NULL, TRUE);
+		}
+	}
+
 private:
 
 	ATOM MyRegisterClass(HINSTANCE hInstance)
@@ -1218,7 +1240,7 @@ class CImgMergeWindow : public IImgMergeWindow
 		wcex.cbWndExtra		= 0;
 		wcex.hInstance		= hInstance;
 		wcex.hCursor        = LoadCursor (NULL, IDC_ARROW);
-		wcex.hbrBackground  = (HBRUSH)(COLOR_3DFACE+1);
+		wcex.hbrBackground = s_hbrBackground;
 		wcex.lpszClassName	= L"WinImgMergeWindowClass";
 		return RegisterClassExW(&wcex);
 	}
@@ -1978,6 +2000,7 @@ class CImgMergeWindow : public IImgMergeWindow
 	int m_nImages;
 	HWND m_hWnd;
 	HINSTANCE m_hInstance;
+	inline static HBRUSH s_hbrBackground = CreateSolidBrush(GetSysColor(COLOR_3DFACE));
 	CImgWindow m_imgWindow[3];
 	WNDPROC m_ChildWndProc[3];
 	std::vector<EventListenerInfo> m_listener;
@@ -1995,4 +2018,5 @@ class CImgMergeWindow : public IImgMergeWindow
 	std::unique_ptr<ocr::COcr> m_pOcr;
 	std::chrono::milliseconds m_timerPrev;
 	std::chrono::milliseconds m_timerNext;
+	bool m_bDarkBackgroundEnabled;
 };

src/WinIMergeLib/ImgToolWindow.hpp

@@ -351,7 +351,12 @@ class CImgToolWindow : public IImgToolWindow
 		RECT rc;
 		GetClientRect(pDrawItem->hwndItem, &rc);
 		Image *pImage = static_cast<CImgMergeWindow *>(m_pImgMergeWindow)->GetDiffMapImage(rc.right - rc.left, rc.bottom - rc.top);
-		RGBQUAD bkColor = { 0xff, 0xff, 0xff, 0xff };
+		RGBQUAD bkColor;
+		const bool dark = m_pImgMergeWindow->IsDarkBackgroundEnabled();
+		if (!dark)
+			bkColor = { 0xff, 0xff, 0xff, 0xff };
+		else
+			bkColor = { 0x00, 0x00, 0x00, 0xff };
 		pImage->getFipImage()->drawEx(pDrawItem->hDC, rc, false, &bkColor);
 		HWND hwndLeftPane = m_pImgMergeWindow->GetPaneHWND(0);
 
@@ -367,7 +372,7 @@ class CImgToolWindow : public IImgToolWindow
 			rcFrame.right = rcFrame.left + (rc.right - rc.left) * sih.nPage / sih.nMax;
 			rcFrame.top = rc.top + (rc.bottom - rc.top) * siv.nPos / siv.nMax;
 			rcFrame.bottom = rcFrame.top + (rc.bottom - rc.top) * siv.nPage / siv.nMax;
-			FrameRect(pDrawItem->hDC, &rcFrame, reinterpret_cast<HBRUSH>(GetStockObject(BLACK_BRUSH)));
+			FrameRect(pDrawItem->hDC, &rcFrame, reinterpret_cast<HBRUSH>(GetStockObject(dark ? BLACK_BRUSH : WHITE_BRUSH)));
 		}
 	}
 

src/WinIMergeLib/ImgWindow.hpp

@@ -38,6 +38,7 @@ class CImgWindow
 		, m_ptOverlappedImage{}
 		, m_ptOverlappedImageCursor{}
 		, m_wBar{SB_BOTH}
+		, m_bDarkBackgroundEnabled(false)
 	{
 		memset(&m_backColor, 0xff, sizeof(m_backColor));
 	}
@@ -445,6 +446,18 @@ class CImgWindow
 		m_wBar = wBar;
 	}
 
+	bool IsDarkBackgroundEnabled() const
+	{
+		return m_bDarkBackgroundEnabled;
+	}
+
+	void SetDarkBackgroundEnabled(bool enabled)
+	{
+		m_bDarkBackgroundEnabled = enabled;
+		if (m_fip)
+			InvalidateRect(m_hWnd, NULL, TRUE);
+	}
+
 private:
 
 	ATOM MyRegisterClass(HINSTANCE hInstance)
@@ -476,7 +489,8 @@ class CImgWindow
 			HDC hdcMem = CreateCompatibleDC(hdc);
 			HBITMAP hbmMem = CreateCompatibleBitmap(hdc, rc.right - rc.left, rc.bottom - rc.top);
 			HDC hOld = static_cast<HDC>(SelectObject(hdcMem, hbmMem));
-			HBRUSH hOldBrush = static_cast<HBRUSH>(SelectObject(hdcMem, static_cast<HGDIOBJ>(CreateSolidBrush(RGB(206, 215, 230)))));
+			HBRUSH hOldBrush = static_cast<HBRUSH>(SelectObject(hdcMem, static_cast<HGDIOBJ>(CreateSolidBrush(
+				m_bDarkBackgroundEnabled ? RGB(40, 40, 60) : RGB(206, 215, 230)))));
 
 			PatBlt(hdcMem, 0, 0, rc.right - rc.left, rc.bottom - rc.top, PATCOPY);
 
@@ -782,4 +796,5 @@ class CImgWindow
 	POINT m_ptSelectionEnd;
 	HCURSOR m_hCursor;
 	int m_wBar;
+	bool m_bDarkBackgroundEnabled;
 };

src/WinIMergeLib/WinIMergeLib.h

@@ -187,6 +187,8 @@ struct IImgMergeWindow
 	virtual void SetBlinkInterval(int interval) = 0;
 	virtual int GetOverlayAnimationInterval() const = 0;
 	virtual void SetOverlayAnimationInterval(int interval) = 0;
+	virtual bool IsDarkBackgroundEnabled() const = 0;
+	virtual void SetDarkBackgroundEnabled(bool enabled) = 0;
 };
 
 struct IImgToolWindow