Make TextField.implicitWidth fixed

Previously, implicitWidth was based on contentSize() (which was based
on the full textwidth inside the TextField)
This had the unfortunate consequence that an empty TextField (which is
very normal) was very narrow on startup (18 pixels on macOS style), but
would grow wider as the user kept on typing. When the TextField was in a
layout, this would in addition lead to a relayout, even though it
usually was barely noticeable. This change aligns that behavior to the
other non-native styles.

This also fixes a test on native style windows:
TextField::test_implicitWidth where it assumes that the implicitWidth of
TextField without a background is simply equal to left+right padding.
This failed because the calculation of the geometry of the placeholder
item was wrong.

Task-number: QTBUG-95679
Pick-to: 6.2
Change-Id: Ie658411664d88df6cb6a337376bdcf897e8c1790
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

3 files changed, 14 insertions, 19 deletions

diff --git a/src/quicknativestyle/controls/DefaultTextField.qml b/src/quicknativestyle/controls/DefaultTextField.qml
index 8f8c8e4d0a..f9279974df 100644
--- a/src/quicknativestyle/controls/DefaultTextField.qml
+++ b/src/quicknativestyle/controls/DefaultTextField.qml
@@ -45,9 +45,9 @@ T.TextField {
 
     readonly property bool __nativeBackground: background instanceof NativeStyle.StyleItem
 
-    implicitWidth: Math.max(Math.max(contentWidth, placeholder.implicitWidth) + leftPadding + rightPadding,
-                            implicitBackgroundWidth + leftInset + rightInset,
-                            90 /* minimum */ )
+    implicitWidth: implicitBackgroundWidth + leftInset + rightInset
+                   || Math.max(contentWidth, placeholder.implicitWidth) + leftPadding + rightPadding
+
     implicitHeight: Math.max(implicitBackgroundHeight + topInset + bottomInset,
                              contentHeight + topPadding + bottomPadding,
                              placeholder.implicitHeight + topPadding + bottomPadding)
@@ -67,11 +67,10 @@ T.TextField {
 
     PlaceholderText {
         id: placeholder
-        height: control.height
-        topPadding: control.topPadding
-        bottomPadding: control.bottomPadding
-        leftPadding: control.leftPadding
-        rightPadding: control.rightPadding
+        x: control.leftPadding
+        y: control.topPadding
+        width: control.availableWidth
+        height: control.availableHeight
         text: control.placeholderText
         font: control.font
         color: control.placeholderTextColor
diff --git a/src/quicknativestyle/items/qquickstyleitemtextfield.cpp b/src/quicknativestyle/items/qquickstyleitemtextfield.cpp
index cd7d35aa67..0a5eabeb8d 100644
--- a/src/quicknativestyle/items/qquickstyleitemtextfield.cpp
+++ b/src/quicknativestyle/items/qquickstyleitemtextfield.cpp
@@ -56,7 +56,13 @@ StyleItemGeometry QQuickStyleItemTextField::calculateGeometry()
     StyleItemGeometry geometry;
 
     geometry.minimumSize = style()->sizeFromContents(QStyle::CT_LineEdit, &styleOption, QSize(0, 0));
-    geometry.implicitSize = style()->sizeFromContents(QStyle::CT_LineEdit, &styleOption, contentSize());
+
+    // Inspired by QLineEdit::sizeHint()
+    QFontMetricsF fm(styleFont(const_cast<QQuickItem*>(control<QQuickItem>())));
+    const QSize sz(qCeil(fm.horizontalAdvance(QLatin1Char('x')) * 17),
+                   contentSize().height());
+    geometry.implicitSize = style()->sizeFromContents(QStyle::CT_LineEdit, &styleOption, sz);
+
     styleOption.rect = QRect(QPoint(0, 0), geometry.implicitSize);
     geometry.layoutRect = styleOption.rect;
     geometry.contentRect = style()->subElementRect(QStyle::SE_LineEditContents, &styleOption);
diff --git a/tests/auto/quickcontrols2/controls/windows/BLACKLIST b/tests/auto/quickcontrols2/controls/windows/BLACKLIST
index 422683648a..b69aa99619 100644
--- a/tests/auto/quickcontrols2/controls/windows/BLACKLIST
+++ b/tests/auto/quickcontrols2/controls/windows/BLACKLIST
@@ -17,14 +17,6 @@
 *
 [ComboBox::test_font]
 *
-[ComboBox::test_implicitContentWidthPolicy_WidestText:Array]
-*
-[ComboBox::test_implicitContentWidthPolicy_WidestText:ListModel]
-*
-[ComboBox::test_implicitContentWidthPolicy_WidestTextWhenCompleted:Array]
-*
-[ComboBox::test_implicitContentWidthPolicy_WidestTextWhenCompleted:ListModel]
-*
 [Popup::test_font]
 *
 [ScrollBar::test_flashing]
@@ -89,5 +81,3 @@
 *
 [TextArea::test_implicitSize]
 *
-[TextField::test_implicitSize]
-*