From: Mark Harmstone <hellas@burntcomma.com>
Subject: [PATCH] comctl32: Use DPI settings for checkbox size.
Message-Id: <555FCE03.5020204@burntcomma.com>
Date: Sat, 23 May 2015 01:46:59 +0100

At present, the size of a themed checkbox or radio button is hardcoded at
13px. This patch changes this to instead use GetThemePartSize, meaning
it will correctly take into account the screen DPI.

---
 dlls/comctl32/theme_button.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/dlls/comctl32/theme_button.c b/dlls/comctl32/theme_button.c
index bdeba93..327c76b 100644
--- a/dlls/comctl32/theme_button.c
+++ b/dlls/comctl32/theme_button.c
@@ -155,8 +155,7 @@ static void CB_draw(HTHEME theme, HWND hwnd, HDC hDC, ButtonState drawState, UIN
         { RBS_CHECKEDNORMAL, RBS_CHECKEDDISABLED, RBS_CHECKEDHOT, RBS_CHECKEDPRESSED, RBS_CHECKEDNORMAL }
     };
 
-    static const int cb_size = 13;
-
+    SIZE sz;
     RECT bgRect, textRect;
     HFONT font, hPrevFont = NULL;
     LRESULT checkState = SendMessageW(hwnd, BM_GETCHECK, 0, 0);
@@ -186,15 +185,18 @@ static void CB_draw(HTHEME theme, HWND hwnd, HDC hDC, ButtonState drawState, UIN
         hPrevFont = SelectObject(hDC, font);
     }
 
+    if (FAILED(GetThemePartSize(theme, hDC, part, state, NULL, TS_DRAW, &sz)))
+        sz.cx = sz.cy = 13;
+
     GetClientRect(hwnd, &bgRect);
     GetThemeBackgroundContentRect(theme, hDC, part, state, &bgRect, &textRect);
 
     if (dtFlags & DT_SINGLELINE) /* Center the checkbox / radio button to the text. */
-        bgRect.top = bgRect.top + (textRect.bottom - textRect.top - cb_size) / 2;
+        bgRect.top = bgRect.top + (textRect.bottom - textRect.top - sz.cy) / 2;
 
     /* adjust for the check/radio marker */
-    bgRect.bottom = bgRect.top + cb_size;
-    bgRect.right = bgRect.left + cb_size;
+    bgRect.bottom = bgRect.top + sz.cy;
+    bgRect.right = bgRect.left + sz.cx;
     textRect.left = bgRect.right + 6;
 
     DrawThemeParentBackground(hwnd, hDC, NULL);