Reduce the number of unnecessary layouts on geometry changes.

Improve checks for geometry changes that don't affect layout, i.e
width increasing when the previous layout didn't wrap or elide.

Set implicit sizes just once during layout rather than setting the
implicit width during and the implicit height after to limit the when
an implicit size change can change geometry.

And if there are multiple layouts of the same text/font combination
re-use cached layout data as much as possible by guarding against
unnecessary property changes on the layout, and not creating a new
layout for calculating the implicit size of truncated text.

Change-Id: Ia05e52e9170e1f5d3364896ab119e00d8a318299
Reviewed-by: Michael Brasser <michael.brasser@nokia.com>

1 files changed, 260 insertions, 0 deletions

diff --git a/tests/auto/quick/qquicktext/tst_qquicktext.cpp b/tests/auto/quick/qquicktext/tst_qquicktext.cpp
index 0adddb9c85..7a7f5cc053 100644
--- a/tests/auto/quick/qquicktext/tst_qquicktext.cpp
+++ b/tests/auto/quick/qquicktext/tst_qquicktext.cpp
@@ -62,6 +62,10 @@ DEFINE_BOOL_CONFIG_OPTION(qmlDisableDistanceField, QML_DISABLE_DISTANCEFIELD)
 
 Q_DECLARE_METATYPE(QQuickText::TextFormat)
 
+QT_BEGIN_NAMESPACE
+extern void qt_setQtEnableTestFont(bool value);
+QT_END_NAMESPACE
+
 class tst_qquicktext : public QQmlDataTest
 {
     Q_OBJECT
@@ -116,6 +120,7 @@ private slots:
     void contentSize();
     void implicitSizeBinding_data();
     void implicitSizeBinding();
+    void geometryChanged();
 
     void boundingRect_data();
     void boundingRect();
@@ -218,6 +223,7 @@ tst_qquicktext::tst_qquicktext()
     // << "#AA0011DD"
     // << "#00F16B11";
     //
+    qt_setQtEnableTestFont(true);
 }
 
 QQuickView *tst_qquicktext::createView(const QString &filename)
@@ -2031,6 +2037,260 @@ void tst_qquicktext::contentSize()
     QCOMPARE(spy.count(), ++spyCount);
 }
 
+void tst_qquicktext::geometryChanged()
+{
+    // Test that text is re-laid out when the geometry of the item by verifying changes in content
+    // size.  Implicit width is also tested as that in combination with item geometry provides a
+    // reference for expected content sizes.
+
+    QString componentStr = "import QtQuick 2.0\nText { font.family: \"__Qt__Box__Engine__\"; font.pixelSize: 10 }";
+    QQmlComponent textComponent(&engine);
+    textComponent.setData(componentStr.toLatin1(), QUrl::fromLocalFile(""));
+    QScopedPointer<QObject> object(textComponent.create());
+    QQuickText *textObject = qobject_cast<QQuickText *>(object.data());
+
+    const qreal implicitHeight = textObject->implicitHeight();
+
+    const qreal widths[] = { 100, 2000, 3000, -100, 100 };
+    const qreal heights[] = { implicitHeight, 2000, 3000, -implicitHeight, implicitHeight };
+
+    QCOMPARE(textObject->implicitWidth(), 0.);
+    QVERIFY(implicitHeight > 0.);
+    QCOMPARE(textObject->width(), textObject->implicitWidth());
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), textObject->implicitWidth());
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setText("The quick red fox jumped over the lazy brown dog");
+
+    const qreal implicitWidth = textObject->implicitWidth();
+
+    QVERIFY(implicitWidth > 0.);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), textObject->implicitWidth());
+    QCOMPARE(textObject->height(), textObject->implicitHeight());
+    QCOMPARE(textObject->contentWidth(), textObject->implicitWidth());
+    QCOMPARE(textObject->contentHeight(), textObject->implicitHeight());
+
+    // Changing the geometry with no eliding, or wrapping doesn't change the content size.
+    for (int i = 0; i < 5; ++i) {
+        textObject->setWidth(widths[i]);
+        QCOMPARE(textObject->implicitWidth(), implicitWidth);
+        QCOMPARE(textObject->implicitHeight(), implicitHeight);
+        QCOMPARE(textObject->width(), widths[i]);
+        QCOMPARE(textObject->height(), implicitHeight);
+        QCOMPARE(textObject->contentWidth(), implicitWidth);
+        QCOMPARE(textObject->contentHeight(), implicitHeight);
+    }
+
+    // With eliding enabled the content width is bounded to the item width, but is never
+    // larger than the implicit width.
+    textObject->setElideMode(QQuickText::ElideRight);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(2000.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), 2000.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), implicitWidth);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(3000.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), 3000.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), implicitWidth);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(-100);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), -100.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), 0.);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(100.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    // With wrapping enabled the implicit height changes with the width.
+    textObject->setElideMode(QQuickText::ElideNone);
+    textObject->setWrapMode(QQuickText::Wrap);
+    const qreal wrappedImplicitHeight = textObject->implicitHeight();
+
+    QVERIFY(wrappedImplicitHeight > implicitHeight);
+
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), wrappedImplicitHeight);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), wrappedImplicitHeight);
+
+    textObject->setWidth(2000.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), 2000.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), implicitWidth);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(3000.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), 3000.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), implicitWidth);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(-100);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), -100.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), implicitWidth);    // 0 or negative width item won't wrap.
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(100.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), wrappedImplicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), wrappedImplicitHeight);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), wrappedImplicitHeight);
+
+    // With no eliding or maximum line count the content height is the same as the implicit height.
+    for (int i = 0; i < 5; ++i) {
+        textObject->setHeight(heights[i]);
+        QCOMPARE(textObject->implicitWidth(), implicitWidth);
+        QCOMPARE(textObject->implicitHeight(), wrappedImplicitHeight);
+        QCOMPARE(textObject->width(), 100.);
+        QCOMPARE(textObject->height(), heights[i]);
+        QVERIFY(textObject->contentWidth() <= 100.);
+        QCOMPARE(textObject->contentHeight(), wrappedImplicitHeight);
+    }
+
+    // The implicit height is unaffected by eliding but the content height will change.
+    textObject->setElideMode(QQuickText::ElideRight);
+
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), wrappedImplicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setHeight(2000);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), wrappedImplicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), 2000.);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), wrappedImplicitHeight);
+
+    textObject->setHeight(3000);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), wrappedImplicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), 3000.);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), wrappedImplicitHeight);
+
+    textObject->setHeight(-implicitHeight);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), wrappedImplicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), -implicitHeight);
+    QVERIFY(textObject->contentWidth() <= 0.);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);  // content height is never less than font height. seems a little odd in this instance.
+
+    textObject->setHeight(implicitHeight);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), wrappedImplicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    // Varying the height with a maximum line count but no eliding won't affect the content height.
+    textObject->setElideMode(QQuickText::ElideNone);
+    textObject->setMaximumLineCount(2);
+    textObject->resetHeight();
+
+    const qreal maxLineCountImplicitHeight = textObject->implicitHeight();
+    QVERIFY(maxLineCountImplicitHeight > implicitHeight);
+    QVERIFY(maxLineCountImplicitHeight < wrappedImplicitHeight);
+
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), maxLineCountImplicitHeight);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), maxLineCountImplicitHeight);
+
+    for (int i = 0; i < 5; ++i) {
+        textObject->setHeight(heights[i]);
+        QCOMPARE(textObject->implicitWidth(), implicitWidth);
+        QCOMPARE(textObject->implicitHeight(), maxLineCountImplicitHeight);
+        QCOMPARE(textObject->width(), 100.);
+        QCOMPARE(textObject->height(), heights[i]);
+        QVERIFY(textObject->contentWidth() <= 100.);
+        QCOMPARE(textObject->contentHeight(), maxLineCountImplicitHeight);
+    }
+
+    // Varying the width with a maximum line count won't increase the implicit height beyond the
+    // height of the maximum number of lines.
+    textObject->setWidth(2000.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), 2000.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), implicitWidth);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(3000.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), 3000.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), implicitWidth);
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(-100);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), implicitHeight);
+    QCOMPARE(textObject->width(), -100.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QCOMPARE(textObject->contentWidth(), implicitWidth);    // 0 or negative width item won't wrap.
+    QCOMPARE(textObject->contentHeight(), implicitHeight);
+
+    textObject->setWidth(50.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), maxLineCountImplicitHeight);
+    QCOMPARE(textObject->width(), 50.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QVERIFY(textObject->contentWidth() <= 50.);
+    QCOMPARE(textObject->contentHeight(), maxLineCountImplicitHeight);
+
+    textObject->setWidth(100.);
+    QCOMPARE(textObject->implicitWidth(), implicitWidth);
+    QCOMPARE(textObject->implicitHeight(), maxLineCountImplicitHeight);
+    QCOMPARE(textObject->width(), 100.);
+    QCOMPARE(textObject->height(), implicitHeight);
+    QVERIFY(textObject->contentWidth() <= 100.);
+    QCOMPARE(textObject->contentHeight(), maxLineCountImplicitHeight);
+}
+
 void tst_qquicktext::implicitSizeBinding_data()
 {
     implicitSize_data();