fix misplacement of placeholder text in QLineEdit with RTL content

Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=dc794f7622bc00f7
Last-Update: 2021-06-16

The placeholder text was rendered in the wrong position after clicking
on the clear button in a QLineEdit with right-to-left content. The
button was still taking up space while it was fading out, so the first
paintEvent rendered the placeholder with space reserved for the clear
button. Once the button gets hidden, no new update was issued, so
garbage was left behind.

Fix this by not giving a fading-out clear button any margin space. The
result of this is that the placeholder text is visible underneath the
fading-out clear button. This is preferable to the placeholder text
being first rendered next to the fading-out clear button, and then
popping to the edge when the clear button is hidden (which would have
been the result of issuing a complete update for the line edit at the
end of the fade-out animation).

Gbp-Pq: Name fix-misplacement-of-placeholder-text-in-QLineEdit.diff

diff --git a/src/widgets/widgets/qlineedit_p.cpp b/src/widgets/widgets/qlineedit_p.cpp
index 36d818d00c246b1863bd64444c6967a645e84eb3..1d4be0fde9123610141c4f12b14764905825f7a2 100644 (file)
--- a/src/widgets/widgets/qlineedit_p.cpp
+++ b/src/widgets/widgets/qlineedit_p.cpp
@@ -664,10 +664,18 @@ static int effectiveTextMargin(int defaultMargin, const QLineEditPrivate::SideWi
     if (widgets.empty())
         return defaultMargin;
 
-    return defaultMargin + (parameters.margin + parameters.widgetWidth) *
-           int(std::count_if(widgets.begin(), widgets.end(),
+    const auto visibleSideWidgetCount = std::count_if(widgets.begin(), widgets.end(),
                              [](const QLineEditPrivate::SideWidgetEntry &e) {
-                                 return e.widget->isVisibleTo(e.widget->parentWidget()); }));
+#if QT_CONFIG(animation)
+        // a button that's fading out doesn't get any space
+        if (auto* iconButton = qobject_cast<QLineEditIconButton*>(e.widget))
+            return iconButton->needsSpace();
+
+#endif
+        return e.widget->isVisibleTo(e.widget->parentWidget());
+    });
+
+    return defaultMargin + (parameters.margin + parameters.widgetWidth) * visibleSideWidgetCount;
 }
 
 QMargins QLineEditPrivate::effectiveTextMargins() const

diff --git a/src/widgets/widgets/qlineedit_p.h b/src/widgets/widgets/qlineedit_p.h
index 5ae402b992c2a18ce8acbbb5a946348896465982..bbe3e8ea640b756246c76a6477ec91836f18a0e5 100644 (file)
--- a/src/widgets/widgets/qlineedit_p.h
+++ b/src/widgets/widgets/qlineedit_p.h
@@ -95,6 +95,8 @@ public:
 
     bool shouldHideWithText() const;
     void setHideWithText(bool hide);
+    // m_wasHidden is true unless the button is fading out
+    bool needsSpace() const { return m_wasHidden; }
 #endif
 
 protected: