[PATCH 1/3] comctl32: Use selected font to determine default min tab width

[Brendan McGrath]

From: Brendan McGrath

This fixes the layout of the tabcontrol when a font other than the
system font is used.
---
 dlls/comctl32/tab.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/dlls/comctl32/tab.c b/dlls/comctl32/tab.c
index 13abbd8078d..a3766bdbc01 100644
--- a/dlls/comctl32/tab.c
+++ b/dlls/comctl32/tab.c
@@ -138,14 +138,12 @@ typedef struct
 #define BUTTON_SPACINGX         3
 #define BUTTON_SPACINGY         3
 #define FLAT_BTN_SPACINGX       8
-#define DEFAULT_MIN_TAB_WIDTH   54
 #define DEFAULT_PADDING_X       6
 #define EXTRA_ICON_PADDING      3
+#define MIN_CHAR_LENGTH         6

#define TAB_GetInfoPtr(hwnd) ((TAB_INFO *)GetWindowLongPtrW(hwnd,0))

-#define GET_DEFAULT_MIN_TAB_WIDTH(infoPtr) (DEFAULT_MIN_TAB_WIDTH - (DEFAULT_PADDING_X - (infoPtr)->uHItemPadding) * 2)
-
 /******************************************************************************
  * Hot-tracking timer constants
  */
@@ -1115,6 +1113,8 @@ static void TAB_SetItemBounds (TAB_INFO *infoPtr)
   RECT*       rcItem;
   INT         iIndex;
   INT         icon_width = 0;
+  INT         default_min_tab_width;
+  TEXTMETRICW text_metrics;

/*
    * We need to get text information so we need a DC and we need to select
@@ -1144,6 +1144,9 @@ static void TAB_SetItemBounds (TAB_INFO *infoPtr)
   /* Now use hPadding and vPadding */
   infoPtr->uHItemPadding = infoPtr->uHItemPadding_s;
   infoPtr->uVItemPadding = infoPtr->uVItemPadding_s;
+
+  GetTextMetricsW(hdc, &text_metrics);
+  default_min_tab_width = text_metrics.tmAveCharWidth * MIN_CHAR_LENGTH + infoPtr->uHItemPadding * 2;

/* The leftmost item will be "0" aligned */
   curItemLeftPos = 0;
@@ -1210,13 +1213,13 @@ static void TAB_SetItemBounds (TAB_INFO *infoPtr)
     {
       /* If no text use minimum tab width including padding. */
       if (infoPtr->tabMinWidth < 0)
-        curr->rect.right = curr->rect.left + GET_DEFAULT_MIN_TAB_WIDTH(infoPtr);
+        curr->rect.right = curr->rect.left + default_min_tab_width;
       else
       {
         curr->rect.right = curr->rect.left + infoPtr->tabMinWidth;

/* Add extra padding if icon is present */
-        if (infoPtr->himl && infoPtr->tabMinWidth > 0 && infoPtr->tabMinWidth < DEFAULT_MIN_TAB_WIDTH
+        if (infoPtr->himl && infoPtr->tabMinWidth > 0 && infoPtr->tabMinWidth < MIN_CHAR_LENGTH * text_metrics.tmAveCharWidth
             && infoPtr->uHItemPadding > 1)
           curr->rect.right += EXTRA_ICON_PADDING * (infoPtr->uHItemPadding-1);
       }
@@ -1232,7 +1235,7 @@ static void TAB_SetItemBounds (TAB_INFO *infoPtr)
       tabwidth = size.cx + icon_width + 2 * infoPtr->uHItemPadding;

if (infoPtr->tabMinWidth < 0)
-        tabwidth = max(tabwidth, GET_DEFAULT_MIN_TAB_WIDTH(infoPtr));
+        tabwidth = max(tabwidth, default_min_tab_width);
       else
         tabwidth = max(tabwidth, infoPtr->tabMinWidth);

@@ -2694,10 +2697,17 @@ static inline LRESULT TAB_SetMinTabWidth (TAB_INFO *infoPtr, INT cx)

TRACE("(%p,%d)\n", infoPtr, cx);

-  if (infoPtr->tabMinWidth < 0)
-    oldcx = DEFAULT_MIN_TAB_WIDTH;
-  else
+  if (infoPtr->tabMinWidth < 0) {
+    TEXTMETRICW text_metrics;
+    HDC hdc = GetDC(infoPtr->hwnd);
+    HFONT oldFont = SelectObject(hdc, infoPtr->hFont);
+    GetTextMetricsW(hdc, &text_metrics);
+    oldcx = text_metrics.tmAveCharWidth * MIN_CHAR_LENGTH + infoPtr->uHItemPadding * 2;
+    SelectObject(hdc, oldFont);
+    ReleaseDC(infoPtr->hwnd, hdc);
+  } else {
     oldcx = infoPtr->tabMinWidth;
+  }
   infoPtr->tabMinWidth = cx;
   TAB_SetItemBounds(infoPtr);
   return oldcx;