QQuickText: Signal content height/width changes also when resetting

If we change the content height or content width to the initial one, we
still need to signal the change.

Fixes: QTBUG-71684
Change-Id: Idf6e3f89423eab3d8f5310c164c5acc5108e0d8b
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@qt.io>

src/quick/items/qquicktext.cpp

@@ -343,6 +343,19 @@ void QQuickTextPrivate::updateBaseline(qreal baseline, qreal dy)
     q->setBaselineOffset(baseline + yoff + q->topPadding());
 }
 
+void QQuickTextPrivate::signalSizeChange(const QSizeF &previousSize)
+{
+    Q_Q(QQuickText);
+
+    if (layedOutTextRect.size() != previousSize) {
+        emit q->contentSizeChanged();
+        if (layedOutTextRect.width() != previousSize.width())
+            emit q->contentWidthChanged(layedOutTextRect.width());
+        if (layedOutTextRect.height() != previousSize.height())
+            emit q->contentHeightChanged(layedOutTextRect.height());
+    }
+}
+
 void QQuickTextPrivate::updateSize()
 {
     Q_Q(QQuickText);
@@ -363,6 +376,8 @@ void QQuickTextPrivate::updateSize()
     qreal hPadding = q->leftPadding() + q->rightPadding();
     qreal vPadding = q->topPadding() + q->bottomPadding();
 
+    const QSizeF previousSize = layedOutTextRect.size();
+
     if (text.isEmpty() && !isLineLaidOutConnected() && fontSizeMode() == QQuickText::FixedSize) {
         // How much more expensive is it to just do a full layout on an empty string here?
         // There may be subtle differences in the height and baseline calculations between
@@ -379,14 +394,13 @@ void QQuickTextPrivate::updateSize()
         q->setImplicitSize(hPadding, fontHeight + vPadding);
         layedOutTextRect = QRectF(0, 0, 0, fontHeight);
         advance = QSizeF();
-        emit q->contentSizeChanged();
+        signalSizeChange(previousSize);
         updateType = UpdatePaintNode;
         q->update();
         return;
     }
 
     QSizeF size(0, 0);
-    QSizeF previousSize = layedOutTextRect.size();
 
     //setup instance of QTextLayout for all cases other than richtext
     if (!richText) {
@@ -483,13 +497,7 @@ void QQuickTextPrivate::updateSize()
         }
     }
 
-
-    if (layedOutTextRect.size() != previousSize)
-        emit q->contentSizeChanged();
-    if (layedOutTextRect.width() != previousSize.width())
-        emit q->contentWidthChanged(layedOutTextRect.width());
-    if (layedOutTextRect.height() != previousSize.height())
-        emit q->contentHeightChanged(layedOutTextRect.height());
+    signalSizeChange(previousSize);
     updateType = UpdatePaintNode;
     q->update();
 }

src/quick/items/qquicktext_p_p.h

@@ -75,6 +75,7 @@ public:
 
     void updateBaseline(qreal baseline, qreal dy);
     void updateSize();
+    void signalSizeChange(const QSizeF &previousSize);
     void updateLayout();
     bool determineHorizontalAlignment();
     bool setHAlign(QQuickText::HAlignment, bool forceAlign = false);

tests/auto/quick/qquicktext/data/contentHeight.qml

@@ -0,0 +1,7 @@
+import QtQuick 2.9
+
+Text{
+    width: 200
+    height: contentHeight
+    text: ''
+}

tests/auto/quick/qquicktext/tst_qquicktext.cpp

@@ -159,6 +159,8 @@ private slots:
 
     void fontInfo();
 
+    void initialContentHeight();
+
 private:
     QStringList standard;
     QStringList richText;
@@ -4383,6 +4385,18 @@ void tst_qquicktext::fontInfo()
     QVERIFY(copy->font().pixelSize() < 1000);
 }
 
+void tst_qquicktext::initialContentHeight()
+{
+    QQmlComponent component(&engine, testFile("contentHeight.qml"));
+    QVERIFY(component.isReady());
+    QScopedPointer<QObject> object(component.create());
+    QObject *root = object.data();
+    QVERIFY(root);
+    QQuickText *text = qobject_cast<QQuickText *>(root);
+    QVERIFY(text);
+    QCOMPARE(text->height(), text->contentHeight());
+}
+
 void tst_qquicktext::implicitSizeChangeRewrap()
 {
     QScopedPointer<QQuickView> window(new QQuickView);