Native style: add a function imageSize() rather than overriding minimumSize

When not using nine patch scaling, we used to override minimumSize to
instead be the actual size of the item, since we use minimumSize to also be
the size of the image we draw. But this turns out to be confusing, especially
while debugging. So introduce a more explicit imageSize() function instead, and
leave minimumSize unchanged.

Change-Id: I8d3ec25603d430a94b124713fad01bf6d277bbe5
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

2 files changed, 14 insertions, 9 deletions

diff --git a/src/imports/nativestyle/items/qquickstyleitem.cpp b/src/imports/nativestyle/items/qquickstyleitem.cpp
index 643b190e..5899e3ce 100644
--- a/src/imports/nativestyle/items/qquickstyleitem.cpp
+++ b/src/imports/nativestyle/items/qquickstyleitem.cpp
@@ -133,7 +133,7 @@ QSGNode *QQuickStyleItem::updatePaintNode(QSGNode *oldNode, QQuickItem::UpdatePa
         bounds.setWidth(ninePatchImageSize.width());
         padding.setLeft(0);
         padding.setRight(0);
-    } else if (boundingRect().width() < m_styleItemGeometry.minimumSize.width()) {
+    } else if (boundingRect().width() < imageSize().width()) {
         // If the item size is smaller that the image, using nine-patch scaling
         // ends up wrapping it. In that case we scale the whole image instead.
         padding.setLeft(0);
@@ -143,7 +143,7 @@ QSGNode *QQuickStyleItem::updatePaintNode(QSGNode *oldNode, QQuickItem::UpdatePa
         bounds.setHeight(ninePatchImageSize.height());
         padding.setTop(0);
         padding.setBottom(0);
-    } else if (boundingRect().height() < m_styleItemGeometry.minimumSize.height()) {
+    } else if (boundingRect().height() < imageSize().height()) {
         padding.setTop(0);
         padding.setBottom(0);
     }
@@ -174,7 +174,7 @@ void QQuickStyleItem::initStyleOptionBase(QStyleOption &styleOption)
     styleOption.control = const_cast<QQuickItem *>(control<QQuickItem>());
     styleOption.window = window();
     styleOption.palette = QQuickItemPrivate::get(m_control)->palette()->toQPalette();
-    styleOption.rect = QRect(QPoint(0, 0), m_styleItemGeometry.minimumSize);
+    styleOption.rect = QRect(QPoint(0, 0), imageSize());
 
     styleOption.state = QStyle::State_None;
     styleOption.state |= controlSize(styleOption.control);
@@ -251,9 +251,6 @@ void QQuickStyleItem::updateGeometry()
 
     setImplicitSize(m_styleItemGeometry.implicitSize.width(), m_styleItemGeometry.implicitSize.height());
 
-    if (!m_useNinePatchImage)
-        m_styleItemGeometry.minimumSize = size().toSize();
-
     qqc2Debug() << m_styleItemGeometry
                 << "bounding rect:" << boundingRect()
                 << "layout margins:" << layoutMargins()
@@ -269,7 +266,7 @@ void QQuickStyleItem::paintControlToImage()
 
     m_dirty.setFlag(DirtyFlag::Image, false);
     const qreal scale = window()->devicePixelRatio();
-    m_paintedImage = QImage(m_styleItemGeometry.minimumSize * scale, QImage::Format_ARGB32_Premultiplied);
+    m_paintedImage = QImage(imageSize() * scale, QImage::Format_ARGB32_Premultiplied);
     m_paintedImage.setDevicePixelRatio(scale);
     m_paintedImage.fill(Qt::transparent);
 
@@ -440,13 +437,20 @@ QQuickStyleMargins QQuickStyleItem::layoutMargins() const
     return QQuickStyleMargins(outerRect, m_styleItemGeometry.layoutRect);
 }
 
-QSize QQuickStyleItem::minimumSize()
+QSize QQuickStyleItem::minimumSize() const
 {
     // The style item should not be scaled below this size.
     // Otherwise the image will be truncated.
     return m_styleItemGeometry.minimumSize;
 }
 
+QSize QQuickStyleItem::imageSize() const
+{
+    // Returns the size of the QImage (unscaled) that
+    // is used to draw the control from QStyle.
+    return m_useNinePatchImage ? m_styleItemGeometry.minimumSize : size().toSize();
+}
+
 qreal QQuickStyleItem::focusFrameRadius() const
 {
     return m_styleItemGeometry.focusFrameRadius;
diff --git a/src/imports/nativestyle/items/qquickstyleitem.h b/src/imports/nativestyle/items/qquickstyleitem.h
index ece2572d..0834662c 100644
--- a/src/imports/nativestyle/items/qquickstyleitem.h
+++ b/src/imports/nativestyle/items/qquickstyleitem.h
@@ -215,7 +215,8 @@ public:
 
     QQuickStyleMargins contentPadding() const;
     QQuickStyleMargins layoutMargins() const;
-    QSize minimumSize();
+    QSize minimumSize() const;
+    QSize imageSize() const;
     qreal focusFrameRadius() const;
 
     Q_INVOKABLE virtual QFont styleFont(QQuickItem *control);