Fixed size hint for combo box on windows

When you use larger fonts or DPI on windows, the combobox can
calculate a size hint that results of text eliding on items.
This fix removes some duplicate code in Vista style and adds
a dpi dependant size hint for XP style.

Task-number: QTBUG-7552
Reviewed-by: richard
(cherry picked from commit 8577353b2a5155600e672955e7c6a61e9e9519ca)

2 files changed, 4 insertions, 25 deletions

diff --git a/src/gui/styles/qwindowsvistastyle.cpp b/src/gui/styles/qwindowsvistastyle.cpp
index 3506c00..fd760f3 100644
--- a/src/gui/styles/qwindowsvistastyle.cpp
+++ b/src/gui/styles/qwindowsvistastyle.cpp
@@ -1926,30 +1926,7 @@ QSize QWindowsVistaStyle::sizeFromContents(ContentsType type, const QStyleOption
         return QWindowsStyle::sizeFromContents(type, option, size, widget);
 
     QSize sz(size);
-
-    QSize newSize = QWindowsXPStyle::sizeFromContents(type, option, size, widget);
     switch (type) {
-    case CT_LineEdit:
-    case CT_ComboBox:
-        {
-            HTHEME theme = pOpenThemeData(0, L"Button");
-            MARGINS borderSize;
-            if (theme) {
-                int result = pGetThemeMargins(theme,
-                                              NULL,
-                                              BP_PUSHBUTTON,
-                                              PBS_NORMAL,
-                                              TMT_CONTENTMARGINS,
-                                              NULL,
-                                              &borderSize);
-                if (result == S_OK) {
-                    sz += QSize(borderSize.cxLeftWidth + borderSize.cxRightWidth - 2,
-                                borderSize.cyBottomHeight + borderSize.cyTopHeight - 2);
-                }
-                sz += QSize(23, 0); //arrow button
-            }
-        }
-        return sz;
     case CT_MenuItem:
         sz = QWindowsXPStyle::sizeFromContents(type, option, size, widget);
         int minimumHeight;
@@ -1990,7 +1967,7 @@ QSize QWindowsVistaStyle::sizeFromContents(ContentsType type, const QStyleOption
     default:
         break;
     }
-    return newSize;
+    return QWindowsXPStyle::sizeFromContents(type, option, size, widget);
 }
 
 /*!
diff --git a/src/gui/styles/qwindowsxpstyle.cpp b/src/gui/styles/qwindowsxpstyle.cpp
index c8fa44f..b5ad916 100644
--- a/src/gui/styles/qwindowsxpstyle.cpp
+++ b/src/gui/styles/qwindowsxpstyle.cpp
@@ -3678,7 +3678,9 @@ QSize QWindowsXPStyle::sizeFromContents(ContentsType ct, const QStyleOption *opt
                     sz += QSize(borderSize.cxLeftWidth + borderSize.cxRightWidth - 2,
                                 borderSize.cyBottomHeight + borderSize.cyTopHeight - 2);
                 }
-                sz += QSize(23, 0); //arrow button
+                const int textMargins = 2*(proxy()->pixelMetric(PM_FocusFrameHMargin) + 1);
+                sz += QSize(qMax(pixelMetric(QStyle::PM_ScrollBarExtent, option, widget)
+                                 + textMargins, 23), 0); //arrow button
             }
         }
         break;