notebook: uxtheme drawing and more fixes

still missing mouseover effect and some fine tuning

1 files changed, 313 insertions, 96 deletions

diff --git a/alf/alfnotebook.cpp b/alf/alfnotebook.cpp
index 96e188f..dcb0a89 100644
--- a/alf/alfnotebook.cpp
+++ b/alf/alfnotebook.cpp
@@ -1,8 +1,19 @@
 #include "alfpriv.h"
 #include "alfcompat.h"
 
+#define TABP_TOPTABITEM 5
+#define TABP_TOPTABITEMLEFTEDGE 6
+#define TABP_TOPTABITEMRIGHTEDGE 7
+#define TABP_TOPTABITEMBOTHEDGE 8
+#define TABP_PANE 9
 #define TABP_BODY 10
 
+#define TIS_NORMAL 1
+#define TIS_HOT 2
+#define TIS_SELECTED 3
+#define TIS_DISABLED 4
+#define TIS_FOCUSED 5
+
 #define ALF_NB_FLAG_TAB_RECTS_INVALID   1
 #define ALF_NB_FLAG_SWITCHER_FOCUSED    2
 #define ALF_NB_FLAG_SWITCHER_HIDEFOCUS  4
@@ -20,6 +31,8 @@ typedef struct {
     HWND                hwndContainer;
     HWND                hwndSwitcher;
     HTHEME              hTheme;
+    HBRUSH              tabPaneBgBrush;
+    HBITMAP             tabPaneBgBrushBitmap;
     ALFColor            tabPaneBgColor;
     DWORD               flags;
     int                 dpi;
@@ -48,7 +61,7 @@ ALF_Notebook_CreatePriv(void)
 static int
 ALF_Notebook_SwitcherHeight(ALFNotebookPriv *priv)
 {
-    return priv->fontHeight + 8;
+    return priv->fontHeight + 9;
 }
 
 static void
@@ -56,10 +69,10 @@ ALF_Notebook_PanelRect(ALFNotebookPriv *priv, RECT *rc)
 {
     GetClientRect(priv->hwndContainer, rc);
 
-    rc->left   += 4;
-    rc->right  -= 4;
-    rc->top    += ALF_Notebook_SwitcherHeight(priv) + 1;
-    rc->bottom -= 4;
+    rc->right  = rc->right - rc->left - 4;
+    rc->bottom = rc->bottom - rc->top - 4;
+    rc->left   = 4;
+    rc->top    = ALF_Notebook_SwitcherHeight(priv);
 }
 
 static void
@@ -67,7 +80,7 @@ ALF_Notebook_PanelToContainerRect(ALFNotebookPriv *priv, RECT *rc)
 {
     rc->left   -= 4;
     rc->right  += 4;
-    rc->top    -= ALF_Notebook_SwitcherHeight(priv) + 1;
+    rc->top    -= ALF_Notebook_SwitcherHeight(priv);
     rc->bottom += 4;
 }
 
@@ -88,7 +101,8 @@ ALF_Notebook_FreePriv(ALFNotebookPriv *priv)
     }
 
     ALF_Compat_CloseThemeData(priv->hTheme);
-    priv->hTheme = NULL;
+    DeleteBrush(priv->tabPaneBgBrush);
+    DeleteBitmap(priv->tabPaneBgBrushBitmap);
     ALF_Free(priv);
 }
 
@@ -209,6 +223,12 @@ ALF_Notebook_CalculateTabContentSize(ALFNotebookPriv *priv, ALFNotebookPage *pag
 
     page->contentSize.cx = rc.right - rc.left;
     page->contentSize.cy = priv->fontHeight;
+
+    // FIXME! emulate min size of original tab control
+    // maybe its actually font-dependent instead of dpi?
+    // should we even set a minimum size?
+    if (page->contentSize.cx < MulDiv(30, priv->dpi, 96))
+        page->contentSize.cx = MulDiv(30, priv->dpi, 96);
 }
 
 static void
@@ -269,7 +289,11 @@ static void
 ALF_Notebook_InternalHandleThemeChange(HWND hwndNotebook, ALFNotebookPriv *priv)
 {
     ALF_Compat_CloseThemeData(priv->hTheme);
+    DeleteBrush(priv->tabPaneBgBrush);
+    DeleteBitmap(priv->tabPaneBgBrushBitmap);
     priv->hTheme = NULL;
+    priv->tabPaneBgBrush = NULL;
+    priv->tabPaneBgBrushBitmap = NULL;
     priv->tabPaneBgColor = ALF_COLOR_SYS(COLOR_BTNFACE);
 
     if (ALF_Compat_IsAppThemed())
@@ -315,6 +339,20 @@ ALF_Notebook_InternalHandleThemeChange(HWND hwndNotebook, ALFNotebookPriv *priv)
                 SelectBitmap(dcMem, hbmOld);
                 DeleteObject(hDib);
             }
+
+            if (priv->tabPaneBgColor == ALF_COLOR_TRANSPARENT) {
+                // no luck at finding a single color, create a brush now
+                priv->tabPaneBgBrushBitmap = CreateCompatibleBitmap(dcNotebook, s.cx, s.cy);
+                HBITMAP hbmOld = SelectBitmap(dcMem, priv->tabPaneBgBrushBitmap);
+
+                RECT r = { 0, 0, s.cx, s.cy };
+                ALF_Compat_DrawThemeBackground(priv->hTheme, dcMem, TABP_BODY, 0, &r, NULL);
+                GdiFlush();
+
+                SelectBitmap(dcMem, hbmOld);
+
+                priv->tabPaneBgBrush = CreatePatternBrush(priv->tabPaneBgBrushBitmap);
+            }
         }
 
         DeleteDC(dcMem);
@@ -362,7 +400,7 @@ ALF_Notebook_DoRectsIntersect(const RECT *rc1, const RECT *rc2)
 }
 
 static void
-ALF_Notebook_SwitcherPaint(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
+ALF_Notebook_SwitcherPaintClassic(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
 {
     ALF_Notebook_ValidateTabRects(priv);
 
@@ -381,15 +419,15 @@ ALF_Notebook_SwitcherPaint(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
         RECT rcLeftTopClip = { 0, 0, 2, rcClient.bottom - rcClient.top };
         if (ALF_Notebook_DoRectsIntersect(&rcLeftTopClip, rcDraw)) {
             RECT rcLeftTop = { 0,
-                            rcClient.bottom - rcClient.top - 1,
-                            2,
-                            rcClient.bottom - rcClient.top };
+                               rcClient.bottom - rcClient.top - 2,
+                               2,
+                               rcClient.bottom - rcClient.top };
             DrawEdge(dc, &rcLeftTop, EDGE_RAISED, BF_SOFT|BF_TOPLEFT);
 
             RECT rcLeftSpace = { 0,
-                                0,
-                                rcLeftTop.right,
-                                rcLeftTop.top };
+                                 0,
+                                 rcLeftTop.right,
+                                 rcLeftTop.top };
             FillRect(dc, &rcLeftSpace, hbrBtnFace);
         }
     }
@@ -402,11 +440,11 @@ ALF_Notebook_SwitcherPaint(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
                 continue; // FIXME! correct clip rect calculation when next to active tab
 
             RECT rBottom = { r.left + 2,
-                             r.bottom - 1,
+                             r.bottom - 2,
                              r.right - 2,
                              r.bottom };
 
-            r.bottom -= 1;
+            r.bottom -= 2;
             r.top += 2;
 
             if (!priv->selectedPage || p->list.prev != &priv->selectedPage->list) {
@@ -458,18 +496,37 @@ ALF_Notebook_SwitcherPaint(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
             if (!ALF_Notebook_DoRectsIntersect(&r, rcDraw))
                 continue;
 
-            RECT rLeft =  { r.left,
-                            r.top + 2,
-                            r.left + 2,
-                            r.bottom };
-            RECT rRight = { r.right - 2,
-                            r.top + 2,
-                            r.right,
-                            r.bottom };
-            RECT rTop =   { r.left + 2,
-                            r.top,
-                            r.right - 2,
-                            r.top + 1 };
+            RECT rLeft =    {   r.left,
+                                r.top + 2,
+                                r.left + 2,
+                                r.bottom - 1 };
+            RECT rRight =   {   r.right - 2,
+                                r.top + 2,
+                                r.right,
+                                r.bottom - 1 };
+            RECT rTop =     {   r.left + 2,
+                                r.top,
+                                r.right - 2,
+                                r.top + 2 };
+            RECT rBottom1 = {   r.left + 2,
+                                r.bottom - 4,
+                                r.right - 2,
+                                r.bottom - 1 };
+            RECT rBottom2 = {   r.left,
+                                r.bottom - 1,
+                                r.right,
+                                r.bottom };
+
+            if (r.left == 0) {
+                rLeft.bottom  += 1;
+                rBottom2.left += 2;
+            }
+
+            if (r.right == rcClient.right-rcClient.left) {
+                rRight.bottom += 1;
+                rBottom2.right -= 2;
+            }
+
 
             DrawEdge(dc, &rLeft, EDGE_RAISED, BF_SOFT|BF_LEFT);
             DrawEdge(dc, &rRight, EDGE_RAISED, BF_SOFT|BF_RIGHT);
@@ -490,16 +547,15 @@ ALF_Notebook_SwitcherPaint(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
             SetPixel(dc, r.right - 1, r.top, clrBtnFace);
             SetPixel(dc, r.right - 1, r.top + 1, clrBtnFace);
 
-            r.left  += 2;
-            r.right -= 2;
-
-            RECT rBottom = { r.left, r.bottom - 2, r.right, r.bottom };
-            FillRect(dc, &rBottom, hbrBtnFace);
+            FillRect(dc, &rBottom1, hbrBtnFace);
+            FillRect(dc, &rBottom2, hbrBtnFace);
 
-            r.bottom -= 2;
+            r.left   += 2;
+            r.right  -= 2;
+            r.bottom -= 4;
         }
 
-        r.top += 1;
+        r.top += 2;
 
         SetBkColor(dc, clrBtnFace);
         SetBkMode(dc, OPAQUE);
@@ -514,12 +570,12 @@ ALF_Notebook_SwitcherPaint(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
             RECT rcFocus = { p->calculatedTabRect.left + 1,
                              p->calculatedTabRect.top + 3,
                              p->calculatedTabRect.right - 1,
-                             p->calculatedTabRect.bottom - 2 };
+                             p->calculatedTabRect.bottom - 3 };
             DrawFocusRect(dc, &rcFocus);
         }
     }
 
-    RECT rcRightTop = { priv->totalSwitcherWidth, rcClient.bottom - rcClient.top - 1,
+    RECT rcRightTop = { priv->totalSwitcherWidth, rcClient.bottom - rcClient.top - 2,
         rcClient.right-rcClient.left, rcClient.bottom - rcClient.top };
 
     if (!priv->selectedPage || priv->pages.prev != &priv->selectedPage->list) {
@@ -533,14 +589,148 @@ ALF_Notebook_SwitcherPaint(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
 
             RECT rcRightSpace = { rcRightTop.left, 0,
                                 rcRightTop.right, rcRightTop.top };
-            FillRect(dc, &rcRightSpace, GetSysColorBrush(COLOR_BTNFACE));
+            FillRect(dc, &rcRightSpace, hbrBtnFace);
+        }
+    }
+
+    SelectFont(dc, oldfont);
+}
+
+static void
+ALF_Notebook_SwitcherPaintUx(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
+{
+    HFONT oldfont = SelectFont(dc, priv->font);
+
+    RECT rcClient;
+    GetClientRect(priv->hwndSwitcher, &rcClient);
+
+    HBRUSH hbrBtnFace = GetSysColorBrush(COLOR_BTNFACE);
+
+    // fill left top space
+    if (!priv->selectedPage || priv->pages.next != &priv->selectedPage->list) {
+        RECT rcLeftTopClip = { 0, 0, 2, rcClient.bottom - rcClient.top };
+        if (ALF_Notebook_DoRectsIntersect(&rcLeftTopClip, rcDraw)) {
+            RECT rcLeftSpace = { 0,
+                                 0,
+                                 2,
+                                 rcClient.bottom - rcClient.top - 2 };
+            FillRect(dc, &rcLeftSpace, hbrBtnFace);
+        }
+    }
+
+    ALF_FOR_LIST(ALFNotebookPage, list, &priv->pages, p) {
+        RECT r = p->calculatedTabRect;
+
+        int part = TABP_TOPTABITEM;
+        if (r.left <= 4 && r.right >= rcClient.right - rcClient.left - 4) {
+            part = TABP_TOPTABITEMBOTHEDGE;
+        } else if (r.left <= 4) {
+            part = TABP_TOPTABITEMLEFTEDGE;
+        } else if (r.right >= rcClient.right - rcClient.left - 4) {
+            part = TABP_TOPTABITEMRIGHTEDGE;
+        }
+
+        if (p != priv->selectedPage) {
+            r.bottom -= 2;
+
+            if (!ALF_Notebook_DoRectsIntersect(&r, rcDraw))
+                continue; // FIXME! correct clip rect calculation when next to active tab
+
+            r.top += 2;
+
+            RECT rTabDraw = r;
+            RECT rClip    = { r.left + 2, r.top, r.right - 2, r.bottom };
+
+            if (!priv->selectedPage || p->list.prev != &priv->selectedPage->list) {
+                rClip.left -= 2;
+            }
+
+            if (!priv->selectedPage || p->list.next != &priv->selectedPage->list) {
+                rClip.right += 2;
+            }
+
+            RECT rTopSpace = { rClip.left, r.top-2, rClip.right, r.top };
+            FillRect(dc, &rTopSpace, hbrBtnFace);
+
+            ALF_Compat_DrawThemeBackground(priv->hTheme, dc, part, TIS_NORMAL, &rTabDraw, &rClip);
+
+            r.left  += 2;
+            r.right -= 2;
+        } else {
+            InflateRect(&r, 2, 0);
+
+            if (!ALF_Notebook_DoRectsIntersect(&r, rcDraw))
+                continue;
+
+            RECT rTabDraw = { r.left, r.top, r.right, r.bottom };
+
+            ALF_Compat_DrawThemeBackground(priv->hTheme, dc, part, TIS_SELECTED, &rTabDraw, rcDraw);
+
+            r.left   += 2;
+            r.right  -= 2;
+            r.bottom -= 2;
+        }
+
+        r.top += 1;
+
+        SetBkMode(dc, TRANSPARENT);
+        SetTextColor(dc, GetSysColor(COLOR_BTNTEXT)); // FIXME! theme color
+
+        DrawText(dc, p->title, -1, &r, DT_NOPREFIX|DT_SINGLELINE|DT_CENTER|DT_VCENTER);
+
+        if (p == priv->selectedPage && priv->flags & ALF_NB_FLAG_SWITCHER_FOCUSED && !(priv->flags & ALF_NB_FLAG_SWITCHER_HIDEFOCUS)) {
+            RECT rcFocus = { p->calculatedTabRect.left + 1,
+                             p->calculatedTabRect.top + 3,
+                             p->calculatedTabRect.right - 1,
+                             p->calculatedTabRect.bottom - 2 };
+            DrawFocusRect(dc, &rcFocus);
+        }
+    }
+
+    // fill right top space
+    RECT rcRightTop = { priv->totalSwitcherWidth, 0,
+        rcClient.right-rcClient.left, rcClient.bottom - rcClient.top - 2 };
+
+    if (!priv->selectedPage || priv->pages.prev != &priv->selectedPage->list) {
+        rcRightTop.left -= 2;
+    }
+
+    if (rcRightTop.left < rcRightTop.right) {
+        RECT rcRightTopClip = { rcRightTop.left, 0, rcClient.right-rcClient.left, rcClient.bottom-rcClient.top };
+        if (ALF_Notebook_DoRectsIntersect(&rcRightTopClip, rcDraw)) {
+            FillRect(dc, &rcRightTop, hbrBtnFace);
         }
     }
 
+    // at last, paint the bottom border
+    if (priv->selectedPage) {
+        RECT rcSelected = priv->selectedPage->calculatedTabRect;
+        InflateRect(&rcSelected, 2, 0);
+        ExcludeClipRect(dc, rcSelected.left, rcSelected.top, rcSelected.right, rcSelected.bottom);
+    }
+
+    RECT rcContainerClient;
+    GetClientRect(priv->hwndContainer, &rcContainerClient);
+
+    RECT rcBottomClip = { 0, rcClient.bottom-rcClient.top-2, rcClient.right-rcClient.left, rcClient.bottom-rcClient.top };
+    RECT rcBottomFake = { rcBottomClip.left, rcBottomClip.top, rcBottomClip.right,
+                          rcContainerClient.bottom-rcContainerClient.top };
+    ALF_Compat_DrawThemeBackground(priv->hTheme, dc, TABP_PANE, 0, &rcBottomFake, &rcBottomClip);
+
     SelectFont(dc, oldfont);
 }
 
 static void
+ALF_Notebook_SwitcherPaint(ALFNotebookPriv *priv, HDC dc, RECT *rcDraw)
+{
+    if (priv->hTheme) {
+        ALF_Notebook_SwitcherPaintUx(priv, dc, rcDraw);
+    } else {
+        ALF_Notebook_SwitcherPaintClassic(priv, dc, rcDraw);
+    }
+}
+
+static void
 ALF_Notebook_HandleSwitcherUIState(ALFNotebookPriv *priv)
 {
     LRESULT uistate = SendMessage(priv->hwndSwitcher, WM_QUERYUISTATE, 0, 0);
@@ -598,18 +788,40 @@ ALF_Notebook_SwitcherWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
                 // height changed - this should basically never happen, do it the easy way
                 InvalidateRect(hwnd, NULL, TRUE);
             }
-            if (rcClient.right - rcClient.left > priv->oldSwitcherSize.cx) {
-                // width increased
-                RECT rc = { priv->oldSwitcherSize.cx - 2, 0,
-                            rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
-                InvalidateRect(hwnd, &rc, TRUE);
+
+            if (priv->hTheme) {
+                // bottom border might be a stretched bitmap, just redraw the whole thing
+                if (rcClient.right - rcClient.left != priv->oldSwitcherSize.cx) {
+                    RECT rc = { 0, rcClient.bottom-rcClient.top-2,
+                                rcClient.right-rcClient.left, rcClient.bottom-rcClient.top };
+                    InvalidateRect(hwnd, &rc, TRUE);
+                }
+            } else {
+                if (rcClient.right - rcClient.left > priv->oldSwitcherSize.cx) {
+                    // width increased
+                    RECT rc = { priv->oldSwitcherSize.cx - 2, 0,
+                                rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
+                    InvalidateRect(hwnd, &rc, TRUE);
+                }
+                if (rcClient.right - rcClient.left < priv->oldSwitcherSize.cx) {
+                    // width decreased
+                    RECT rc = { rcClient.right - rcClient.left - 2,
+                                rcClient.bottom - rcClient.top - 2,
+                                rcClient.right - rcClient.left,
+                                rcClient.bottom - rcClient.top };
+                    InvalidateRect(hwnd, &rc, TRUE);
+                }
             }
-            if (rcClient.right - rcClient.left < priv->oldSwitcherSize.cx) {
-                // width decreased
-                RECT rc = { rcClient.right - rcClient.left - 2,
-                            rcClient.bottom - rcClient.top - 1,
-                            rcClient.right - rcClient.left,
-                            rcClient.bottom - rcClient.top };
+
+            // if the right border now straddles the rightmost tab or has done
+            // so before the resize, redraw the rightmost tab (uxtheme only)
+            // uxtheme draws a different bitmap when it straddles the border
+            if (priv->hTheme && !ALF_ListIsEmpty(&priv->pages) &&
+                    ((rcClient.right - rcClient.left) - 4 <= ALF_LIST_CONTAINER(ALFNotebookPage, list, priv->pages.prev)->calculatedTabRect.right)
+                        != (priv->oldSwitcherSize.cx - 4 <= ALF_LIST_CONTAINER(ALFNotebookPage, list, priv->pages.prev)->calculatedTabRect.right)) {
+                ALFNotebookPage *lastpage = ALF_LIST_CONTAINER(ALFNotebookPage, list, priv->pages.prev);
+                RECT rc = { lastpage->calculatedTabRect.left, 0,
+                    rcClient.right-rcClient.left, rcClient.bottom-rcClient.top };
                 InvalidateRect(hwnd, &rc, TRUE);
             }
 
@@ -659,37 +871,36 @@ ALF_Notebook_ContainerPaint(ALFNotebookPriv *priv, HDC dc, RECT *f)
         RECT r;
         ALF_Notebook_PanelRect(priv, &r);
 
-        SIZE s;
-        if (SUCCEEDED(ALF_Compat_GetThemePartSize(priv->hTheme, dc, TABP_BODY, 0, NULL, TS_TRUE, &s))) {
-            // windows dialog tab panes tile the background horizontally
-            for (int x = r.left; x < r.right; x += s.cx) {
-                RECT r2 = { x, r.top, x + s.cx, r.bottom };
-                if (r2.right > r.right)
-                    r2.right = r.right;
-
-                if (f && r2.left > f->right && r2.right < f->left)
-                    continue;
-
-                if (RectVisible(dc, &r2))
-                    ALF_Compat_DrawThemeBackground(priv->hTheme, dc, TABP_BODY, 0, &r2, NULL);
+        if (priv->tabPaneBgBrush != NULL) {
+            POINT vpo;
+            if (GetViewportOrgEx(dc, &vpo)) {
+                SetBrushOrgEx(dc, vpo.x, vpo.y, NULL);
             }
+            FillRect(dc, &r, priv->tabPaneBgBrush);
         } else {
             // old version - let uxtheme stretch it
-            ALF_Compat_DrawThemeBackground(priv->hTheme, dc, TABP_BODY, 0, &r, NULL);
+            ALF_Compat_DrawThemeBackground(priv->hTheme, dc, TABP_BODY, 0, &r, f);
         }
 
         ExcludeClipRect(dc, r.left, r.top, r.right, r.bottom);
-    }
 
-    RECT rcClient;
-    GetClientRect(priv->hwndContainer, &rcClient);
+        r.left   -= 4;
+        r.top    -= 2;
+        r.right  += 4;
+        r.bottom += 4;
+        ALF_Compat_DrawThemeBackground(priv->hTheme, dc, TABP_PANE, 0, &r, f);
 
-    RECT rcBorder = { 0, ALF_Notebook_SwitcherHeight(priv),
-        rcClient.right - rcClient.left,
-        rcClient.bottom - rcClient.top
-    };
-    DrawEdge(dc, &rcBorder, EDGE_RAISED, BF_SOFT|BF_LEFT|BF_RIGHT|BF_BOTTOM|BF_ADJUST);
-    FillRect(dc, &rcBorder, GetSysColorBrush(COLOR_BTNFACE));
+    } else {
+        RECT rcClient;
+        GetClientRect(priv->hwndContainer, &rcClient);
+
+        RECT rcBorder = { 0, ALF_Notebook_SwitcherHeight(priv),
+            rcClient.right - rcClient.left,
+            rcClient.bottom - rcClient.top
+        };
+        DrawEdge(dc, &rcBorder, EDGE_RAISED, BF_SOFT|BF_LEFT|BF_RIGHT|BF_BOTTOM|BF_ADJUST);
+        FillRect(dc, &rcBorder, GetSysColorBrush(COLOR_BTNFACE));
+    }
 }
 
 static DWORD
@@ -845,34 +1056,40 @@ ALF_Notebook_ContainerWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lPa
 
             if (priv->selectedPage && priv->hTheme
                     && priv->tabPaneBgColor == ALF_COLOR_TRANSPARENT
-                    && ((oldPanelRect.bottom - oldPanelRect.top) != (rcClient.bottom - rcClient.top))) {
+                    && ((oldPanelRect.bottom - oldPanelRect.top) != (rcPanel.bottom - rcPanel.top))) {
                 // only needed when height changes, since bg is tiled horizontally
                 ALF_InvalidateBackground(priv->selectedPage->hwndPanel);
             }
 
-            if (rcClient.bottom - rcClient.top > priv->oldContainerSize.cy) {
-                // height increased
-                RECT rc = { 0, priv->oldContainerSize.cy - 4,
-                            rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
-                InvalidateRect(hwnd, &rc, TRUE);
-            }
-            if (rcClient.bottom - rcClient.top < priv->oldContainerSize.cy) {
-                // height decreased
-                RECT rc = { 0, rcClient.bottom - rcClient.top - 4,
-                            rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
-                InvalidateRect(hwnd, &rc, TRUE);
-            }
-            if (rcClient.right - rcClient.left > priv->oldContainerSize.cx) {
-                // width increased
-                RECT rc = { priv->oldContainerSize.cx - 4, 0,
-                            rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
-                InvalidateRect(hwnd, &rc, TRUE);
-            }
-            if (rcClient.right - rcClient.left < priv->oldContainerSize.cx) {
-                // width decreased
-                RECT rc = { rcClient.right - rcClient.left - 4, 0,
-                            rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
-                InvalidateRect(hwnd, &rc, TRUE);
+            if (priv->hTheme) {
+                // themed background does contain gradients on XP
+                // FIXME! do we always need to invalidate everyting?
+                InvalidateRect(hwnd, NULL, TRUE);
+            } else {
+                if (rcClient.bottom - rcClient.top > priv->oldContainerSize.cy) {
+                    // height increased
+                    RECT rc = { 0, priv->oldContainerSize.cy - 4,
+                                rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
+                    InvalidateRect(hwnd, &rc, TRUE);
+                }
+                if (rcClient.bottom - rcClient.top < priv->oldContainerSize.cy) {
+                    // height decreased
+                    RECT rc = { 0, rcClient.bottom - rcClient.top - 4,
+                                rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
+                    InvalidateRect(hwnd, &rc, TRUE);
+                }
+                if (rcClient.right - rcClient.left > priv->oldContainerSize.cx) {
+                    // width increased
+                    RECT rc = { priv->oldContainerSize.cx - 4, 0,
+                                rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
+                    InvalidateRect(hwnd, &rc, TRUE);
+                }
+                if (rcClient.right - rcClient.left < priv->oldContainerSize.cx) {
+                    // width decreased
+                    RECT rc = { rcClient.right - rcClient.left - 4, 0,
+                                rcClient.right - rcClient.left, rcClient.bottom - rcClient.top };
+                    InvalidateRect(hwnd, &rc, TRUE);
+                }
             }
 
             priv->oldContainerSize.cx = rcClient.right - rcClient.left;