From f50c0af7532247b3a9c38244ec297da97a8e31ab Mon Sep 17 00:00:00 2001
From: Yann Bodson <yann.bodson@nokia.com>
Date: Thu, 3 May 2012 15:00:33 +1000
Subject: [PATCH] Fix alignment bug in QQuickText with multi-line text and
 implicit width

If the horizontal alignment is not left and the width of the text is not
known during the first pass, we need to relayout once we know the
maximum line width.

Task-number: QTBUG-18617
Change-Id: I0cad100946beda151034067e23439185684de144
Reviewed-by: Andrew den Exter <andrew.den-exter@nokia.com>
---
 src/quick/items/qquicktext.cpp                     |  6 ++-
 .../quick/qquicktext/data/hAlignImplicitWidth.qml  | 13 +++++
 tests/auto/quick/qquicktext/tst_qquicktext.cpp     | 55 ++++++++++++++++++++++
 3 files changed, 73 insertions(+), 1 deletion(-)
 create mode 100644 tests/auto/quick/qquicktext/data/hAlignImplicitWidth.qml

diff --git a/src/quick/items/qquicktext.cpp b/src/quick/items/qquicktext.cpp
index 4d39f0b..104a6ab 100644
--- a/src/quick/items/qquicktext.cpp
+++ b/src/quick/items/qquicktext.cpp
@@ -916,9 +916,13 @@ QRectF QQuickTextPrivate::setupTextLayout(qreal *const naturalWidth, qreal *cons
                     && (q->heightValid() || (maximumLineCountValid && canWrap));
 
             const qreal oldWidth = lineWidth;
-            lineWidth = q->widthValid() && q->width() > 0 ? q->width() : FLT_MAX;
+            lineWidth = q->widthValid() && q->width() > 0 ? q->width() : *naturalWidth;
             if (lineWidth != oldWidth && (singlelineElide || multilineElide || canWrap || horizontalFit))
                 continue;
+            // If the horizontal alignment is not left and the width was not valid we need to relayout
+            // now that we know the maximum line width.
+            if (!q->widthValid() && maxLineCount > 1 && q->effectiveHAlign() != QQuickText::AlignLeft)
+                continue;
         }
 
         // If the next needs to be elided and there's an abbreviated string available
diff --git a/tests/auto/quick/qquicktext/data/hAlignImplicitWidth.qml b/tests/auto/quick/qquicktext/data/hAlignImplicitWidth.qml
new file mode 100644
index 0000000..136e5d2
--- /dev/null
+++ b/tests/auto/quick/qquicktext/data/hAlignImplicitWidth.qml
@@ -0,0 +1,13 @@
+import QtQuick 2.0
+
+Rectangle {
+    width: 200
+    height: 100
+
+    Text {
+        objectName: "textItem"
+        text: "AA\nBBBBB\nCCCCCCCCCCCCCCCC"
+        anchors.centerIn: parent
+        horizontalAlignment: Text.AlignLeft
+    }
+}
diff --git a/tests/auto/quick/qquicktext/tst_qquicktext.cpp b/tests/auto/quick/qquicktext/tst_qquicktext.cpp
index a83a10e..d9395ca 100644
--- a/tests/auto/quick/qquicktext/tst_qquicktext.cpp
+++ b/tests/auto/quick/qquicktext/tst_qquicktext.cpp
@@ -90,6 +90,7 @@ private slots:
     void horizontalAlignment();
     void horizontalAlignment_RightToLeft();
     void verticalAlignment();
+    void hAlignImplicitWidth();
     void font();
     void style();
     void color();
@@ -158,6 +159,7 @@ private:
     QQmlEngine engine;
 
     QQuickView *createView(const QString &filename);
+    int numberOfNonWhitePixels(int fromX, int toX, const QImage &image);
 };
 
 tst_qquicktext::tst_qquicktext()
@@ -836,6 +838,59 @@ void tst_qquicktext::horizontalAlignment_RightToLeft()
     delete textObject;
 }
 
+int tst_qquicktext::numberOfNonWhitePixels(int fromX, int toX, const QImage &image)
+{
+    int pixels = 0;
+    for (int x = fromX; x < toX; ++x) {
+        for (int y = 0; y < image.height(); ++y) {
+            if (image.pixel(x, y) != qRgb(255, 255, 255))
+                pixels++;
+        }
+    }
+    return pixels;
+}
+
+void tst_qquicktext::hAlignImplicitWidth()
+{
+    QQuickView view(testFileUrl("hAlignImplicitWidth.qml"));
+    view.show();
+    view.requestActivateWindow();
+    QTest::qWaitForWindowShown(&view);
+
+    QQuickText *text = view.rootObject()->findChild<QQuickText*>("textItem");
+    QVERIFY(text != 0);
+
+    {
+        // Left Align
+        QImage image = view.grabFrameBuffer();
+        int left = numberOfNonWhitePixels(0, image.width() / 3, image);
+        int mid = numberOfNonWhitePixels(image.width() / 3, 2 * image.width() / 3, image);
+        int right = numberOfNonWhitePixels( 2 * image.width() / 3, image.width(), image);
+        QVERIFY(left > mid);
+        QVERIFY(mid > right);
+    }
+    {
+        // HCenter Align
+        text->setHAlign(QQuickText::AlignHCenter);
+        QImage image = view.grabFrameBuffer();
+        int left = numberOfNonWhitePixels(0, image.width() / 3, image);
+        int mid = numberOfNonWhitePixels(image.width() / 3, 2 * image.width() / 3, image);
+        int right = numberOfNonWhitePixels( 2 * image.width() / 3, image.width(), image);
+        QVERIFY(left < mid);
+        QVERIFY(mid > right);
+    }
+    {
+        // Right Align
+        text->setHAlign(QQuickText::AlignRight);
+        QImage image = view.grabFrameBuffer();
+        int left = numberOfNonWhitePixels(0, image.width() / 3, image);
+        int mid = numberOfNonWhitePixels(image.width() / 3, 2 * image.width() / 3, image);
+        int right = numberOfNonWhitePixels( 2 * image.width() / 3, image.width(), image);
+        QVERIFY(left < mid);
+        QVERIFY(mid < right);
+    }
+}
+
 void tst_qquicktext::verticalAlignment()
 {
     //test one align each, and then test if two align fails.
-- 
2.7.4