Windows XP, Vista styles: Share dynamically resolved theme functions.

Extract a struct containing the function pointers and derive
QWindowsXPStylePrivate from it, so that both styles can use them.
Remove duplicated variables.

Task-number: QTBUG-38858
Change-Id: I7c2c665b5930c56ffdf33c5185720f71517d146c
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>

1 files changed, 59 insertions, 1 deletions

diff --git a/src/widgets/styles/qwindowsxpstyle_p_p.h b/src/widgets/styles/qwindowsxpstyle_p_p.h
index 7327fa5581..190055b24b 100644
--- a/src/widgets/styles/qwindowsxpstyle_p_p.h
+++ b/src/widgets/styles/qwindowsxpstyle_p_p.h
@@ -282,7 +282,65 @@ struct ThemeMapData {
                      hasAlphaChannel(false), wasAlphaSwapped(false), hadInvalidAlpha(false) {}
 };
 
-class QWindowsXPStylePrivate : public QWindowsStylePrivate
+struct QWindowsUxThemeLib {
+    typedef bool (WINAPI *PtrIsAppThemed)();
+    typedef bool (WINAPI *PtrIsThemeActive)();
+    typedef HTHEME (WINAPI *PtrOpenThemeData)(HWND hwnd, LPCWSTR pszClassList);
+    typedef HRESULT (WINAPI *PtrCloseThemeData)(HTHEME hTheme);
+    typedef HRESULT (WINAPI *PtrDrawThemeBackground)(HTHEME hTheme, HDC hdc, int iPartId, int iStateId, const RECT *pRect, OPTIONAL const RECT *pClipRect);
+    typedef HRESULT (WINAPI *PtrDrawThemeBackgroundEx)(HTHEME hTheme, HDC hdc, int iPartId, int iStateId, const RECT *pRect, OPTIONAL const DTBGOPTS *pOptions);
+    typedef HRESULT (WINAPI *PtrGetCurrentThemeName)(OUT LPWSTR pszThemeFileName, int cchMaxNameChars, OUT OPTIONAL LPWSTR pszColorBuff, int cchMaxColorChars, OUT OPTIONAL LPWSTR pszSizeBuff, int cchMaxSizeChars);
+    typedef HRESULT (WINAPI *PtrGetThemeDocumentationProperty)(LPCWSTR pszThemeName, LPCWSTR pszPropertyName, OUT LPWSTR pszValueBuff, int cchMaxValChars);
+    typedef HRESULT (WINAPI *PtrGetThemeBool)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT BOOL *pfVal);
+    typedef HRESULT (WINAPI *PtrGetThemeColor)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT COLORREF *pColor);
+    typedef HRESULT (WINAPI *PtrGetThemeEnumValue)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT int *piVal);
+    typedef HRESULT (WINAPI *PtrGetThemeFilename)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT LPWSTR pszThemeFileName, int cchMaxBuffChars);
+    typedef HRESULT (WINAPI *PtrGetThemeFont)(HTHEME hTheme, OPTIONAL HDC hdc, int iPartId, int iStateId, int iPropId, OUT LOGFONT *pFont);
+    typedef HRESULT (WINAPI *PtrGetThemeInt)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT int *piVal);
+    typedef HRESULT (WINAPI *PtrGetThemeIntList)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT INTLIST *pIntList);
+    typedef HRESULT (WINAPI *PtrGetThemeMargins)(HTHEME hTheme, OPTIONAL HDC hdc, int iPartId, int iStateId, int iPropId, OPTIONAL RECT *prc, OUT MARGINS *pMargins);
+    typedef HRESULT (WINAPI *PtrGetThemeMetric)(HTHEME hTheme, OPTIONAL HDC hdc, int iPartId, int iStateId, int iPropId, OUT int *piVal);
+    typedef HRESULT (WINAPI *PtrGetThemePartSize)(HTHEME hTheme, HDC hdc, int iPartId, int iStateId, OPTIONAL RECT *prc, enum THEMESIZE eSize, OUT SIZE *psz);
+    typedef HRESULT (WINAPI *PtrGetThemePosition)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT POINT *pPoint);
+    typedef HRESULT (WINAPI *PtrGetThemePropertyOrigin)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT enum PROPERTYORIGIN *pOrigin);
+    typedef HRESULT (WINAPI *PtrGetThemeRect)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT RECT *pRect);
+    typedef HRESULT (WINAPI *PtrGetThemeString)(HTHEME hTheme, int iPartId, int iStateId, int iPropId, OUT LPWSTR pszBuff, int cchMaxBuffChars);
+    typedef HRESULT (WINAPI *PtrGetThemeBackgroundRegion)(HTHEME hTheme, OPTIONAL HDC hdc, int iPartId, int iStateId, const RECT *pRect, OUT HRGN *pRegion);
+    typedef BOOL (WINAPI *PtrIsThemeBackgroundPartiallyTransparent)(HTHEME hTheme, int iPartId, int iStateId);
+    typedef HRESULT (WINAPI *PtrSetWindowTheme)(HWND hwnd, LPCWSTR pszSubAppName, LPCWSTR pszSubIdList);
+    typedef HRESULT (WINAPI *PtrGetThemeTransitionDuration)(HTHEME hTheme, int iPartId, int iStateFromId, int iStateToId, int iPropId, int *pDuration);
+
+    static bool resolveSymbols();
+
+    static PtrIsAppThemed pIsAppThemed;
+    static PtrIsThemeActive pIsThemeActive;
+    static PtrOpenThemeData pOpenThemeData;
+    static PtrCloseThemeData pCloseThemeData;
+    static PtrDrawThemeBackground pDrawThemeBackground;
+    static PtrDrawThemeBackgroundEx pDrawThemeBackgroundEx;
+    static PtrGetCurrentThemeName pGetCurrentThemeName;
+    static PtrGetThemeBool pGetThemeBool;
+    static PtrGetThemeColor pGetThemeColor;
+    static PtrGetThemeEnumValue pGetThemeEnumValue;
+    static PtrGetThemeFilename pGetThemeFilename;
+    static PtrGetThemeFont pGetThemeFont;
+    static PtrGetThemeInt pGetThemeInt;
+    static PtrGetThemeIntList pGetThemeIntList;
+    static PtrGetThemeMargins pGetThemeMargins;
+    static PtrGetThemeMetric pGetThemeMetric;
+    static PtrGetThemePartSize pGetThemePartSize;
+    static PtrGetThemePosition pGetThemePosition;
+    static PtrGetThemePropertyOrigin pGetThemePropertyOrigin;
+    static PtrGetThemeRect pGetThemeRect;
+    static PtrGetThemeString pGetThemeString;
+    static PtrGetThemeBackgroundRegion pGetThemeBackgroundRegion;
+    static PtrGetThemeDocumentationProperty pGetThemeDocumentationProperty;
+    static PtrIsThemeBackgroundPartiallyTransparent pIsThemeBackgroundPartiallyTransparent;
+    static PtrSetWindowTheme pSetWindowTheme;
+    static PtrGetThemeTransitionDuration pGetThemeTransitionDuration; // Windows Vista onwards.
+};
+
+class QWindowsXPStylePrivate : public QWindowsStylePrivate, public QWindowsUxThemeLib
 {
     Q_DECLARE_PUBLIC(QWindowsXPStyle)
 public: