Fixes: NB#192037, Multiline MTextedit doesn't expand to next line on word wrapping

RevBy: Pekka Vuorela
Details: Document text width and widget width were mixed up when
calculating sizeHint.

4 files changed, 82 insertions, 17 deletions

diff --git a/src/views/mtexteditview.cpp b/src/views/mtexteditview.cpp
index 3d4d727b..c81a9cfe 100644
--- a/src/views/mtexteditview.cpp
+++ b/src/views/mtexteditview.cpp
@@ -32,7 +32,6 @@
 #include <QAbstractTextDocumentLayout>
 #include <QTimer>
 #include <QStyleOptionGraphicsItem>
-#include <QDebug>
 
 #include "mfeedback.h"
 #include "mtextedit.h"
@@ -453,7 +452,6 @@ QTextDocument *MTextEditViewPrivate::activeDocument() const
             (echoMode == MTextEditModel::PasswordEchoOnEdit && editActive == true) ||
             maskedTextDocument == 0) {
         return document();
-
     } else {
         return maskedTextDocument;
     }
@@ -1010,20 +1008,7 @@ QSizeF MTextEditView::sizeHint(Qt::SizeHint which, const QSizeF &constraint) con
             } else {
                 // multi line
                 if (hint.width() > 0) {
-                    /* To find out the preferred height, we need to set the text document width
-                     * to the given constraint width.  But we don't want this to trigger
-                     * a documentsSizeChanged so we disconnect that signal and reconnect afterwards
-                     */
-                    qreal oldWidth = d->document()->textWidth();
-                    disconnect(d->document()->documentLayout(), SIGNAL(documentSizeChanged(QSizeF)),
-                            d, SLOT(handleDocumentSizeChange(QSizeF)));
-                    d->document()->setTextWidth(hint.width());
-                    hint.setHeight(d->document()->size().height() +
-                        style()->paddingTop() + style()->paddingBottom());
-                    d->document()->setTextWidth(oldWidth);
-                    connect(d->document()->documentLayout(), SIGNAL(documentSizeChanged(QSizeF)),
-                            d, SLOT(handleDocumentSizeChange(QSizeF)));
-
+                    hint.setHeight(d->heightForWidth(hint.width()));
                 } else {
                     //Use the current document width if we are given no constraints
                     hint.setWidth(d->document()->size().width() +
@@ -1056,6 +1041,31 @@ QSizeF MTextEditView::sizeHint(Qt::SizeHint which, const QSizeF &constraint) con
     return hint;
 }
 
+qreal MTextEditViewPrivate::heightForWidth(qreal width) const
+{
+    Q_Q(const MTextEditView);
+    /* To find out the preferred height, we need to set the text document width
+     * to the given constraint width.  But we don't want this to trigger
+     * a documentsSizeChanged so we disconnect that signal and reconnect afterwards
+     */
+    const qreal oldDocumentWidth = document()->textWidth();
+    const qreal horizontalPadding = q->style()->paddingLeft() + q->style()->paddingRight();
+    const qreal verticalPadding = q->style()->paddingTop() + q->style()->paddingBottom();
+
+    // Disconnect size change signal
+    disconnect(document()->documentLayout(), SIGNAL(documentSizeChanged(QSizeF)),
+               this, SLOT(handleDocumentSizeChange(QSizeF)));
+
+    // Set temporary width to document and read in corresponding height for widget.
+    document()->setTextWidth(width - horizontalPadding);
+    const qreal height = document()->size().height() + verticalPadding;
+
+    // Restore
+    document()->setTextWidth(oldDocumentWidth);
+    connect(document()->documentLayout(), SIGNAL(documentSizeChanged(QSizeF)),
+            this, SLOT(handleDocumentSizeChange(QSizeF)));
+    return height;
+}
 
 void MTextEditView::changeEvent(QEvent *event)
 {
@@ -1088,7 +1098,6 @@ void MTextEditView::cancelEvent(MCancelEvent *event)
                         d, SLOT(playTextFieldSelectionFeedback()));
 }
 
-
 QVariant MTextEditView::inputMethodQuery(Qt::InputMethodQuery query) const
 {
     Q_D(const MTextEditView);
diff --git a/src/views/mtexteditview_p.h b/src/views/mtexteditview_p.h
index e90b76ff..7ba46b21 100644
--- a/src/views/mtexteditview_p.h
+++ b/src/views/mtexteditview_p.h
@@ -63,6 +63,8 @@ public:
 
     QTextDocument *activeDocument() const;
 
+    qreal heightForWidth(qreal width) const;
+
 protected slots:
     void scrolling();
     void hideUnmaskedText();
diff --git a/tests/ut_mtexteditview/ut_mtexteditview.cpp b/tests/ut_mtexteditview/ut_mtexteditview.cpp
index 58966461..c92d5d09 100644
--- a/tests/ut_mtexteditview/ut_mtexteditview.cpp
+++ b/tests/ut_mtexteditview/ut_mtexteditview.cpp
@@ -19,6 +19,7 @@
 
 #include "ut_mtexteditview.h"
 
+#include <QGraphicsLinearLayout>
 #include <QGraphicsSceneMouseEvent>
 #include <QMetaType>
 #include <QSignalSpy>
@@ -150,6 +151,58 @@ void Ut_MTextEditView::testGrowing()
     QCOMPARE(newSize.height(), oldSize.height());
 }
 
+void Ut_MTextEditView::testMultilineGrowsOnWordWrap()
+{
+    // Initialize multiline text edit with one row and that row full of text.
+    // Then insert one character so that text edit wraps into two lines.
+    // This test verifies a fix for a bug where the text edit did not grow even though
+    // QTextDocument was updated correctly.
+
+    QString fullRowContent = "full row content";
+    m_controller->setText(fullRowContent);
+
+    const qreal horizontalPadding = m_subject->style()->paddingLeft() + m_subject->style()->paddingRight();
+    QFontMetrics fm(m_controller->document()->defaultFont());
+    qreal totalWidth = fm.width(fullRowContent)
+                       + horizontalPadding
+                       + m_controller->document()->documentMargin() * 2;
+
+    m_controller->setPreferredWidth(totalWidth);
+
+    QSizePolicy policy(m_controller->sizePolicy());
+    policy.setVerticalPolicy(QSizePolicy::Preferred);
+    m_controller->setSizePolicy(policy);
+
+    // Create container widget with vertical layout.
+    QGraphicsWidget container;
+    container.resize(totalWidth, 200); // vertically: enough
+
+    QGraphicsLinearLayout *vlayout = new QGraphicsLinearLayout(Qt::Vertical, &container);
+    vlayout->setContentsMargins(0,0,0,0);
+    vlayout->addItem(m_controller);
+    vlayout->addStretch();
+
+    // Activate layout before retrieving size.
+    vlayout->activate();
+    const QSizeF beforeInserting = m_controller->size();
+
+    // This causes word wrap to take place.
+    m_controller->textCursor().insertText("w");
+
+    // Activate layout before retrieving size.
+    vlayout->activate();
+    const QSizeF afterInserting = m_controller->size();
+
+    // Detach from parent
+    vlayout->removeItem(m_controller);
+    m_controller->setParentItem(0);
+    m_controller->setLayout(0);
+
+    qDebug() << "Size " << beforeInserting << " after inserting one extra character: " << afterInserting;
+    QVERIFY(afterInserting != beforeInserting);
+}
+
+
 void Ut_MTextEditView::testInputMethodQuery()
 {
     m_appWindow->scene()->addItem(m_controller);
diff --git a/tests/ut_mtexteditview/ut_mtexteditview.h b/tests/ut_mtexteditview/ut_mtexteditview.h
index 64f72b56..ee5c0837 100644
--- a/tests/ut_mtexteditview/ut_mtexteditview.h
+++ b/tests/ut_mtexteditview/ut_mtexteditview.h
@@ -47,6 +47,7 @@ private slots:
     void testStyleUpdated();
     void testResizeEvent();
     void testGrowing();
+    void testMultilineGrowsOnWordWrap();
     void testInputMethodQuery();
     void testMaskedCharacters();
     void testUpdateScrollWhenTextChanged();