QStyle: allow styles to control the margin around icons in QLineEdit

The styles can't control the margin of the icon container, and its value
is hardcoded to a quarter of the iconSize, which is very unfriendly.
Add a PixelMetric enum value to allow styles to control the margin.

Change-Id: I21274b68d24150db7be78513fe9125f775aa2b00
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

3 files changed, 7 insertions, 1 deletions

diff --git a/src/widgets/styles/qcommonstyle.cpp b/src/widgets/styles/qcommonstyle.cpp
index d784315ca7..6f6ddfec44 100644
--- a/src/widgets/styles/qcommonstyle.cpp
+++ b/src/widgets/styles/qcommonstyle.cpp
@@ -4807,6 +4807,9 @@ int QCommonStyle::pixelMetric(PixelMetric m, const QStyleOption *opt, const QWid
     case PM_LineEditIconSize:
         ret = proxy()->pixelMetric(PM_SmallIconSize, opt, widget);
         break;
+    case PM_LineEditIconMargin:
+        ret = proxy()->pixelMetric(PM_LineEditIconSize, opt, widget) / 4;
+        break;
 
     case PM_LargeIconSize:
         ret = int(QStyleHelper::dpiScaled(32, opt));
diff --git a/src/widgets/styles/qstyle.cpp b/src/widgets/styles/qstyle.cpp
index 368eda3396..f26f1a16c8 100644
--- a/src/widgets/styles/qstyle.cpp
+++ b/src/widgets/styles/qstyle.cpp
@@ -1519,6 +1519,9 @@ void QStyle::drawItemPixmap(QPainter *painter, const QRect &rect, int alignment,
     \value PM_LineEditIconSize The default size for icons in a line edit.
            This enum value has been introduced in Qt 6.2.
 
+    \value PM_LineEditIconMargin The margin around icons in a line edit.
+           This enum value has been introduced in Qt 6.3.
+
     \value PM_CustomBase Base value for custom pixel metrics.  Custom
     values must be greater than this value.
 
diff --git a/src/widgets/styles/qstyle.h b/src/widgets/styles/qstyle.h
index fc94ed2bf5..6d094cc4f2 100644
--- a/src/widgets/styles/qstyle.h
+++ b/src/widgets/styles/qstyle.h
@@ -568,7 +568,7 @@ public:
         PM_TitleBarButtonSize,
 
         PM_LineEditIconSize,
-
+        PM_LineEditIconMargin,
         // do not add any values below/greater than this
         PM_CustomBase = 0xf0000000
     };