notebook: add tricks for faster rendering

Win10 in particular sucks at stretching a completely white bitmap

2 files changed, 89 insertions, 15 deletions

diff --git a/alf/alfgroupbox.cpp b/alf/alfgroupbox.cpp
index 9786323..5c459dc 100644
--- a/alf/alfgroupbox.cpp
+++ b/alf/alfgroupbox.cpp
@@ -62,6 +62,15 @@ ALF_GroupBox_PaintFrameUxtheme(ALFGroupBoxPriv *priv, HWND hwnd, HDC dc, RECT *r
     RECT rc;
     GetClientRect(hwnd, &rc);
 
+    // Skip drawing the border if that is not requested, since stretching that bitmap might be expensive.
+    // Will happen when a transparent child calls DrawThemeParentBackground.
+    RECT rcTop = { 0, 0, rc.right-rc.left, priv->layout.containerMargins.top };
+    RECT rcLeft = { 0, 0, priv->layout.containerMargins.left, rc.bottom-rc.top };
+    RECT rcRight = { rc.right-rc.left-priv->layout.containerMargins.right, 0, rc.right-rc.left, rc.bottom-rc.top };
+    RECT rcBottom = { 0, rc.bottom-rc.top-priv->layout.containerMargins.bottom, rc.right-rc.left, rc.bottom-rc.top };
+    if (!RectVisible(dc, &rcTop) && !RectVisible(dc, &rcLeft) && !RectVisible(dc, &rcRight) && !RectVisible(dc, &rcBottom))
+        return;
+
     rc.top += priv->calculatedLabelSize.cy / 2;
 
     HRGN oldClipR = CreateRectRgn(0, 0, 0, 0);
diff --git a/alf/alfnotebook.cpp b/alf/alfnotebook.cpp
index 73b0c85..ea4517c 100644
--- a/alf/alfnotebook.cpp
+++ b/alf/alfnotebook.cpp
@@ -15,7 +15,7 @@ TCHAR *_alf_notebookClass = NULL;
 typedef struct {
     HWND     hwndTabCtrl;
     HTHEME   hTheme;
-    ALFColor themeTabBgColor;
+    ALFColor tabPaneBgColor;
     DWORD    flags;
     int      dpi;
 } ALFNotebookPriv;
@@ -31,7 +31,7 @@ ALF_Notebook_CreatePriv(void)
 {
     ALFNotebookPriv *priv = ALF_New(ALFNotebookPriv, 1);
 
-    priv->themeTabBgColor = ALF_COLOR_SYS(COLOR_BTNFACE);
+    priv->tabPaneBgColor = ALF_COLOR_SYS(COLOR_BTNFACE);
 
     return priv;
 }
@@ -96,11 +96,7 @@ static void
 ALF_Notebook_SetSingleTabBackground(HWND hwndNotebook, ALFNotebookPriv *priv, HWND panel)
 {
     (void)hwndNotebook;
-    if (priv->hTheme && !(priv->flags & ALF_NOTEBOOK_SOLID_TAB_BACKGROUND)) {
-        SendMessage(panel, ALF_WM_SETBGCOLOR, 0, (LPARAM)ALF_COLOR_TRANSPARENT);
-    } else {
-        SendMessage(panel, ALF_WM_SETBGCOLOR, 0, (LPARAM)priv->themeTabBgColor);
-    }
+    SendMessage(panel, ALF_WM_SETBGCOLOR, 0, (LPARAM)priv->tabPaneBgColor);
 }
 
 static void
@@ -147,23 +143,88 @@ ALF_Notebook_PropagateDpiChange(HWND hwndNotebook, ALFNotebookPriv *priv, WPARAM
     }
 }
 
+static BOOL
+ALF_Notebook_CheckSingleColorBits(void *bits, SIZE s, COLORREF *outColor)
+{
+    int l = s.cx * s.cy;
+
+    DWORD c;
+    CopyMemory(&c, bits, 4);
+    c &= 0x00FFFFFF;
+
+    for (int i = 1; i < l; ++i) {
+        DWORD c2;
+        CopyMemory(&c2, (char*)bits + i*4, 4);
+        c2 &= 0x00FFFFFF;
+
+        if (c2 != c)
+            return FALSE;
+    }
+
+    *outColor = c;
+    return TRUE;
+}
+
 static void
 ALF_Notebook_InternalHandleThemeChange(HWND hwndNotebook, ALFNotebookPriv *priv)
 {
     ALF_Compat_CloseThemeData(priv->hTheme);
     priv->hTheme = NULL;
+    priv->tabPaneBgColor = ALF_COLOR_SYS(COLOR_BTNFACE);
+
     if (ALF_Compat_IsAppThemed())
         priv->hTheme = ALF_Compat_OpenThemeData(hwndNotebook, L"Tab");
 
     InvalidateRect(hwndNotebook, NULL, TRUE);
     ALF_InvalidateLayout(hwndNotebook);
 
-    // tab fill color for solid bg color mode
-    priv->themeTabBgColor = ALF_COLOR_SYS(COLOR_BTNFACE);
     if (priv->hTheme) {
-        COLORREF c;
-        if (SUCCEEDED(ALF_Compat_GetThemeColor(priv->hTheme, TABP_BODY, 0, TMT_FILLCOLORHINT, &c))) {
-            priv->themeTabBgColor = (ALFColor)c;
+        if (priv->flags & ALF_NOTEBOOK_SOLID_TAB_BACKGROUND) {
+            COLORREF c;
+            if (SUCCEEDED(ALF_Compat_GetThemeColor(priv->hTheme, TABP_BODY, 0, TMT_FILLCOLORHINT, &c))) {
+                priv->tabPaneBgColor = (ALFColor)c;
+            }
+        } else {
+            priv->tabPaneBgColor = ALF_COLOR_TRANSPARENT;
+
+            // SPEED HACK: check if tab pane background is a single solid color
+            // Windows 10 really sucks at stretching a completely white bitmap
+            HDC dcNotebook = GetDC(hwndNotebook);
+            HDC dcMem = CreateCompatibleDC(dcNotebook);
+            SIZE s;
+            if (SUCCEEDED(ALF_Compat_GetThemePartSize(priv->hTheme, dcNotebook, TABP_BODY, 0, NULL, TS_TRUE, &s))) {
+                BITMAPINFO bi;
+                ZeroMemory(&bi, sizeof(bi));
+
+                bi.bmiHeader.biSize = sizeof(bi.bmiHeader);
+                bi.bmiHeader.biWidth = s.cx;
+                bi.bmiHeader.biHeight = s.cy;
+                bi.bmiHeader.biPlanes = 1;
+                bi.bmiHeader.biBitCount = 32;
+                bi.bmiHeader.biCompression = BI_RGB;
+
+                void *bits = NULL;
+                HBITMAP hDib = CreateDIBSection(dcMem, &bi, DIB_RGB_COLORS, &bits, NULL, 0);
+                if (hDib) {
+                    HBITMAP hbmOld = SelectBitmap(dcMem, hDib);
+
+                    RECT r = { 0, 0, s.cx, s.cy };
+                    if (SUCCEEDED(ALF_Compat_DrawThemeBackground(priv->hTheme, dcMem, TABP_BODY, 0, &r, NULL))) {
+                        GdiFlush();
+
+                        COLORREF c = 0;
+                        if (ALF_Notebook_CheckSingleColorBits(bits, s, &c)) {
+                            priv->tabPaneBgColor = (ALFColor)c;
+                        }
+                    }
+
+                    SelectBitmap(dcMem, hbmOld);
+                    DeleteObject(hDib);
+                }
+            }
+
+            DeleteDC(dcMem);
+            ReleaseDC(hwndNotebook, dcNotebook);
         }
     }
 
@@ -252,7 +313,11 @@ ALF_Notebook_InternalPaint(HWND hwnd, ALFNotebookPriv *priv, HDC dc, RECT *f)
                 if (r2.right > r.right)
                     r2.right = r.right;
 
-                ALF_Compat_DrawThemeBackground(priv->hTheme, dc, TABP_BODY, 0, &r2, NULL);
+                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);
             }
         } else {
             // old version - let uxtheme stretch it
@@ -421,7 +486,7 @@ ALF__NotebookWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
             EndDeferWindowPos(hdwp);
 
             if (priv->hTheme
-                    && !(priv->flags & ALF_NOTEBOOK_SOLID_TAB_BACKGROUND)
+                    && priv->tabPaneBgColor == ALF_COLOR_TRANSPARENT
                     && ((oldR.bottom - oldR.top) != (r.bottom - r.top))) {
                 // only needed when height changes, since bg is tiled horizontally
                 HWND panel = ALF_NotebookSelectedPanel(hwnd);
@@ -464,7 +529,7 @@ ALF__NotebookWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
         priv->flags = (DWORD)lParam;
 
         if ((oldFlags & ALF_NOTEBOOK_SOLID_TAB_BACKGROUND) != (priv->flags & ALF_NOTEBOOK_SOLID_TAB_BACKGROUND)) {
-            ALF_Notebook_SetAllTabBackgrounds(hwnd, priv);
+            ALF_Notebook_InternalHandleThemeChange(hwnd, priv);
         }
     } else if (uMsg == ALF_WM_LYT_GETWDGTFLAGS) {
         return (LRESULT)ALF_Notebook_GetWidgetFlags(hwnd, priv, (HWND)wParam);