Add side widgets to QLineEdit via QAction.

Add QLineEdit::addAction() overloads,
allowing for a variable number of icons or user-defined
widgets.

Change-Id: Id298f18c2f47cc998170357e65cc6098df851aab
Done-with: Kevin.Ottens@kdab.com
Reviewed-by: Thomas Zander <zander@kde.org>
Reviewed-by: Richard J. Moore <rich@kde.org>
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>

5 files changed, 363 insertions, 12 deletions

diff --git a/src/widgets/widgets/qlineedit.cpp b/src/widgets/widgets/qlineedit.cpp
index 9efae802c6..c704eb5c35 100644
--- a/src/widgets/widgets/qlineedit.cpp
+++ b/src/widgets/widgets/qlineedit.cpp
@@ -420,6 +420,60 @@ bool QLineEdit::hasFrame() const
     return d->frame;
 }
 
+/*!
+    \enum QLineEdit::ActionPosition
+
+    This enum type describes how a line edit should display the action widgets to be
+    added.
+
+    \value LeadingPosition  The widget is displayed to the left of the text
+                            when using layout direction \c Qt::LeftToRight or to
+                            the right when using \c Qt::RightToLeft, respectively.
+
+    \value TrailingPosition The widget is displayed to the right of the text
+                            when using layout direction \c Qt::LeftToRight or to
+                            the left when using \c Qt::RightToLeft, respectively.
+
+    \sa addAction(), removeAction(), QWidget::layoutDirection
+
+    \since 5.2
+*/
+
+/*!
+    \fn void QLineEdit::addAction(QAction *action)
+    \overload
+    \internal
+*/
+
+/*!
+    \overload
+
+    Adds the \a action to the list of actions at the \a position.
+
+    \since 5.2
+*/
+
+void QLineEdit::addAction(QAction *action, ActionPosition position)
+{
+    Q_D(QLineEdit);
+    QWidget::addAction(action);
+    d->addAction(action, 0, position);
+}
+
+/*!
+    \overload
+
+    Creates a new action with the given \a icon at the \a position.
+
+    \since 5.2
+*/
+
+QAction *QLineEdit::addAction(const QIcon &icon, ActionPosition position)
+{
+    QAction *result = new QAction(icon, QString(), this);
+    addAction(result, position);
+    return result;
+}
 
 void QLineEdit::setFrame(bool enable)
 {
@@ -606,7 +660,7 @@ QSize QLineEdit::sizeHint() const
             + d->topTextMargin + d->bottomTextMargin
             + d->topmargin + d->bottommargin;
     int w = fm.width(QLatin1Char('x')) * 17 + 2*d->horizontalMargin
-            + d->leftTextMargin + d->rightTextMargin
+            + d->effectiveLeftTextMargin() + d->effectiveRightTextMargin()
             + d->leftmargin + d->rightmargin; // "some"
     QStyleOptionFrameV2 opt;
     initStyleOption(&opt);
@@ -967,7 +1021,6 @@ void QLineEdit::setDragEnabled(bool b)
     d->dragEnabled = b;
 }
 
-
 /*!
   \property QLineEdit::cursorMoveStyle
   \brief the movement style of cursor in this line edit
@@ -1350,8 +1403,11 @@ bool QLineEdit::event(QEvent * e)
                 || style()->styleHint(QStyle::SH_BlinkCursorWhenTextSelected, &opt, this))
                 d->setCursorVisible(true);
         }
+    } else if (e->type() == QEvent::ActionRemoved) {
+        d->removeAction(static_cast<QActionEvent *>(e));
+    } else if (e->type() == QEvent::Resize) {
+        d->positionSideWidgets();
     }
-
 #ifdef QT_KEYPAD_NAVIGATION
     if (QApplication::keypadNavigationEnabled()) {
         if (e->type() == QEvent::EnterEditFocus) {
@@ -1777,9 +1833,9 @@ void QLineEdit::paintEvent(QPaintEvent *)
     initStyleOption(&panel);
     style()->drawPrimitive(QStyle::PE_PanelLineEdit, &panel, &p, this);
     r = style()->subElementRect(QStyle::SE_LineEditContents, &panel, this);
-    r.setX(r.x() + d->leftTextMargin);
+    r.setX(r.x() + d->effectiveLeftTextMargin());
     r.setY(r.y() + d->topTextMargin);
-    r.setRight(r.right() - d->rightTextMargin);
+    r.setRight(r.right() - d->effectiveRightTextMargin());
     r.setBottom(r.bottom() - d->bottomTextMargin);
     p.setClipRect(r);
 
@@ -2083,8 +2139,12 @@ void QLineEdit::changeEvent(QEvent *ev)
             initStyleOption(&opt);
             d->control->setPasswordCharacter(style()->styleHint(QStyle::SH_LineEdit_PasswordCharacter, &opt, this));
         }
+        d->m_iconSize = QSize();
         update();
         break;
+    case QEvent::LayoutDirectionChange:
+        d->positionSideWidgets();
+        break;
     default:
         break;
     }
diff --git a/src/widgets/widgets/qlineedit.h b/src/widgets/widgets/qlineedit.h
index e2b944314b..3d16e527b6 100644
--- a/src/widgets/widgets/qlineedit.h
+++ b/src/widgets/widgets/qlineedit.h
@@ -59,12 +59,14 @@ class QCompleter;
 class QStyleOptionFrame;
 class QAbstractSpinBox;
 class QDateTimeEdit;
+class QIcon;
+class QToolButton;
 
 class Q_WIDGETS_EXPORT QLineEdit : public QWidget
 {
     Q_OBJECT
 
-    Q_ENUMS(EchoMode)
+    Q_ENUMS(ActionPosition EchoMode)
     Q_PROPERTY(QString inputMask READ inputMask WRITE setInputMask)
     Q_PROPERTY(QString text READ text WRITE setText NOTIFY textChanged USER true)
     Q_PROPERTY(int maxLength READ maxLength WRITE setMaxLength)
@@ -83,8 +85,12 @@ class Q_WIDGETS_EXPORT QLineEdit : public QWidget
     Q_PROPERTY(bool acceptableInput READ hasAcceptableInput)
     Q_PROPERTY(QString placeholderText READ placeholderText WRITE setPlaceholderText)
     Q_PROPERTY(Qt::CursorMoveStyle cursorMoveStyle READ cursorMoveStyle WRITE setCursorMoveStyle)
-
 public:
+    enum ActionPosition {
+        LeadingPosition,
+        TrailingPosition
+    };
+
     explicit QLineEdit(QWidget* parent=0);
     explicit QLineEdit(const QString &, QWidget* parent=0);
     ~QLineEdit();
@@ -164,6 +170,16 @@ public:
     void getTextMargins(int *left, int *top, int *right, int *bottom) const;
     QMargins textMargins() const;
 
+#ifdef Q_NO_USING_KEYWORD
+    inline void addAction(QAction *action)
+    { QWidget::addAction(action); }
+#else
+    using QWidget::addAction;
+#endif
+
+    void addAction(QAction *action, ActionPosition position);
+    QAction *addAction(const QIcon &icon, ActionPosition position);
+
 public Q_SLOTS:
     void setText(const QString &);
     void clear();
@@ -240,6 +256,7 @@ private:
 #endif
     Q_PRIVATE_SLOT(d_func(), void _q_selectionChanged())
     Q_PRIVATE_SLOT(d_func(), void _q_updateNeeded(const QRect &))
+    Q_PRIVATE_SLOT(d_func(), void _q_textChanged(const QString &))
 };
 
 #endif // QT_NO_LINEEDIT
diff --git a/src/widgets/widgets/qlineedit_p.cpp b/src/widgets/widgets/qlineedit_p.cpp
index 1999216e65..028675f845 100644
--- a/src/widgets/widgets/qlineedit_p.cpp
+++ b/src/widgets/widgets/qlineedit_p.cpp
@@ -44,8 +44,10 @@
 
 #ifndef QT_NO_LINEEDIT
 
+#include "qvariant.h"
 #include "qabstractitemview.h"
 #include "qdrag.h"
+#include "qwidgetaction.h"
 #include "qclipboard.h"
 #ifndef QT_NO_ACCESSIBILITY
 #include "qaccessible.h"
@@ -53,6 +55,7 @@
 #ifndef QT_NO_IM
 #include "qinputmethod.h"
 #include "qlist.h"
+#include <qpropertyanimation.h>
 #endif
 
 QT_BEGIN_NAMESPACE
@@ -219,9 +222,9 @@ QRect QLineEditPrivate::adjustedContentsRect() const
     QStyleOptionFrameV2 opt;
     q->initStyleOption(&opt);
     QRect r = q->style()->subElementRect(QStyle::SE_LineEditContents, &opt, q);
-    r.setX(r.x() + leftTextMargin);
+    r.setX(r.x() + effectiveLeftTextMargin());
     r.setY(r.y() + topTextMargin);
-    r.setRight(r.right() - rightTextMargin);
+    r.setRight(r.right() - effectiveRightTextMargin());
     r.setBottom(r.bottom() - bottomTextMargin);
     return r;
 }
@@ -297,6 +300,160 @@ void QLineEditPrivate::drag()
 
 #endif // QT_NO_DRAGANDDROP
 
+QLineEditIconButton::QLineEditIconButton(QWidget *parent)
+    : QToolButton(parent)
+    , m_opacity(0)
+{
+#ifndef QT_NO_CURSOR
+    setCursor(Qt::ArrowCursor);
+#endif
+    setFocusPolicy(Qt::NoFocus);
+}
+
+void QLineEditIconButton::paintEvent(QPaintEvent *)
+{
+    QPainter painter(this);
+    // Note isDown should really use the active state but in most styles
+    // this has no proper feedback
+    QIcon::Mode state = QIcon::Disabled;
+    if (isEnabled())
+        state = isDown() ? QIcon::Selected : QIcon::Normal;
+    const QPixmap iconPixmap = icon().pixmap(QSize(IconButtonSize, IconButtonSize),
+                                             state, QIcon::Off);
+    QRect pixmapRect = QRect(0, 0, iconPixmap.width(), iconPixmap.height());
+    pixmapRect.moveCenter(rect().center());
+    painter.setOpacity(m_opacity);
+    painter.drawPixmap(pixmapRect, iconPixmap);
+}
+
+void QLineEditIconButton::setOpacity(qreal value)
+{
+    if (!qFuzzyCompare(m_opacity, value)) {
+        m_opacity = value;
+        update();
+    }
+}
+
+void QLineEditIconButton::startOpacityAnimation(qreal endValue)
+{
+    QPropertyAnimation *animation = new QPropertyAnimation(this, QByteArrayLiteral("opacity"));
+    animation->setDuration(160);
+    animation->setEndValue(endValue);
+    animation->start(QAbstractAnimation::DeleteWhenStopped);
+}
+
+void QLineEditPrivate::_q_textChanged(const QString &text)
+{
+    if (hasSideWidgets()) {
+        const int newTextSize = text.size();
+        if (!newTextSize || !lastTextSize) {
+            lastTextSize = newTextSize;
+            const bool fadeIn = newTextSize > 0;
+            foreach (const SideWidgetEntry &e, leadingSideWidgets) {
+                if (e.flags & SideWidgetFadeInWithText)
+                   static_cast<QLineEditIconButton *>(e.widget)->animateShow(fadeIn);
+            }
+            foreach (const SideWidgetEntry &e, trailingSideWidgets) {
+                if (e.flags & SideWidgetFadeInWithText)
+                   static_cast<QLineEditIconButton *>(e.widget)->animateShow(fadeIn);
+            }
+        }
+    }
+}
+
+QSize QLineEditPrivate::iconSize() const
+{
+    if (!m_iconSize.isValid()) // This might require style-specific handling (pixel metric).
+        m_iconSize = QSize(QLineEditIconButton::IconButtonSize + 6, QLineEditIconButton::IconButtonSize + 2);
+    return m_iconSize;
+}
+
+void QLineEditPrivate::positionSideWidgets()
+{
+    Q_Q(QLineEdit);
+    if (hasSideWidgets()) {
+        const QRect contentRect = q->rect();
+        const QSize iconSize = QLineEditPrivate::iconSize();
+        const int delta = QLineEditIconButton::IconMargin + iconSize.width();
+        QRect widgetGeometry(QPoint(QLineEditIconButton::IconMargin, (contentRect.height() - iconSize.height()) / 2), iconSize);
+        foreach (const SideWidgetEntry &e, leftSideWidgetList()) {
+            e.widget->setGeometry(widgetGeometry);
+            widgetGeometry.moveLeft(widgetGeometry.left() + delta);
+        }
+        widgetGeometry.moveLeft(contentRect.width() - iconSize.width() - QLineEditIconButton::IconMargin);
+        foreach (const SideWidgetEntry &e, rightSideWidgetList()) {
+            e.widget->setGeometry(widgetGeometry);
+            widgetGeometry.moveLeft(widgetGeometry.left() - delta);
+        }
+    }
+}
+
+QLineEditPrivate::PositionIndexPair QLineEditPrivate::findSideWidget(const QAction *a) const
+{
+    for (int i = 0; i < leadingSideWidgets.size(); ++i) {
+        if (a == leadingSideWidgets.at(i).action)
+            return PositionIndexPair(QLineEdit::LeadingPosition, i);
+    }
+    for (int i = 0; i < trailingSideWidgets.size(); ++i) {
+        if (a == trailingSideWidgets.at(i).action)
+            return PositionIndexPair(QLineEdit::TrailingPosition, i);
+    }
+    return PositionIndexPair(QLineEdit::LeadingPosition, -1);
+}
+
+QWidget *QLineEditPrivate::addAction(QAction *newAction, QAction *before, QLineEdit::ActionPosition position, int flags)
+{
+    Q_Q(QLineEdit);
+    if (!newAction)
+        return 0;
+    QWidget *w = 0;
+    // Store flags about QWidgetAction here since removeAction() may be called from ~QAction,
+    // in which a qobject_cast<> no longer works.
+    if (QWidgetAction *widgetAction = qobject_cast<QWidgetAction *>(newAction)) {
+        if ((w = widgetAction->requestWidget(q)))
+            flags |= SideWidgetCreatedByWidgetAction;
+    }
+    if (!w) {
+        QLineEditIconButton *toolButton = new QLineEditIconButton(q);
+        toolButton->setIcon(newAction->icon());
+        toolButton->setOpacity(lastTextSize > 0 || !(flags & SideWidgetFadeInWithText) ? 1 : 0);
+        toolButton->setDefaultAction(newAction);
+        w = toolButton;
+    }
+    if (!hasSideWidgets()) { // initial setup.
+        QObject::connect(q, SIGNAL(textChanged(QString)), q, SLOT(_q_textChanged(QString)));
+        lastTextSize = q->text().size();
+    }
+    // If there is a 'before' action, it takes preference
+    PositionIndexPair positionIndex = before ? findSideWidget(before) : PositionIndexPair(position, -1);
+    SideWidgetEntryList &list = positionIndex.first == QLineEdit::TrailingPosition ? trailingSideWidgets : leadingSideWidgets;
+    if (positionIndex.second < 0)
+        positionIndex.second = list.size();
+    list.insert(positionIndex.second, SideWidgetEntry(w, newAction, flags));
+    positionSideWidgets();
+    w->show();
+    return w;
+}
+
+void QLineEditPrivate::removeAction(const QActionEvent *e)
+{
+    Q_Q(QLineEdit);
+    QAction *action = e->action();
+    const PositionIndexPair positionIndex = findSideWidget(action);
+    if (positionIndex.second == -1)
+        return;
+     SideWidgetEntryList &list = positionIndex.first == QLineEdit::TrailingPosition ? trailingSideWidgets : leadingSideWidgets;
+     SideWidgetEntry entry = list.takeAt(positionIndex.second);
+     if (entry.flags & SideWidgetCreatedByWidgetAction)
+         static_cast<QWidgetAction *>(entry.action)->releaseWidget(entry.widget);
+     else
+         delete entry.widget;
+     positionSideWidgets();
+     if (!hasSideWidgets()) // Last widget, remove connection
+         QObject::disconnect(q, SIGNAL(textChanged(QString)), q, SLOT(_q_textChanged(QString)));
+     q->update();
+}
+
 QT_END_NAMESPACE
 
 #endif
diff --git a/src/widgets/widgets/qlineedit_p.h b/src/widgets/widgets/qlineedit_p.h
index 4eb35b7dc6..19dbde6558 100644
--- a/src/widgets/widgets/qlineedit_p.h
+++ b/src/widgets/widgets/qlineedit_p.h
@@ -58,7 +58,9 @@
 #ifndef QT_NO_LINEEDIT
 #include "private/qwidget_p.h"
 #include "QtWidgets/qlineedit.h"
+#include "QtWidgets/qtoolbutton.h"
 #include "QtGui/qtextlayout.h"
+#include "QtGui/qicon.h"
 #include "QtWidgets/qstyleoption.h"
 #include "QtCore/qbasictimer.h"
 #include "QtWidgets/qcompleter.h"
@@ -69,16 +71,54 @@
 
 QT_BEGIN_NAMESPACE
 
+// QLineEditIconButton: This is a simple helper class that represents clickable icons that fade in with text
+
+class QLineEditIconButton : public QToolButton
+{
+    Q_OBJECT
+    Q_PROPERTY(qreal opacity READ opacity WRITE setOpacity)
+public:
+    enum { IconMargin = 4, IconButtonSize = 16 };
+
+    explicit QLineEditIconButton(QWidget *parent =  0);
+
+    qreal opacity() const { return m_opacity; }
+    void setOpacity(qreal value);
+    void animateShow(bool visible) { startOpacityAnimation(visible ? 1.0 : 0.0); }
+
+protected:
+    void paintEvent(QPaintEvent *event);
+
+private:
+    void startOpacityAnimation(qreal endValue);
+
+    qreal m_opacity;
+};
+
 class Q_AUTOTEST_EXPORT QLineEditPrivate : public QWidgetPrivate
 {
     Q_DECLARE_PUBLIC(QLineEdit)
 public:
+    enum SideWidgetFlag {
+        SideWidgetFadeInWithText = 0x1,
+        SideWidgetCreatedByWidgetAction = 0x2
+    };
+
+    struct SideWidgetEntry {
+        SideWidgetEntry(QWidget *w = 0, QAction *a = 0, int _flags = 0) : widget(w), action(a), flags(_flags) {}
+
+        QWidget *widget;
+        QAction *action;
+        int flags;
+    };
+    typedef QList<SideWidgetEntry> SideWidgetEntryList;
 
     QLineEditPrivate()
         : control(0), frame(1), contextMenuEnabled(1), cursorVisible(0),
         dragEnabled(0), clickCausedFocus(0), hscroll(0), vscroll(0),
         alignment(Qt::AlignLeading | Qt::AlignVCenter),
-        leftTextMargin(0), topTextMargin(0), rightTextMargin(0), bottomTextMargin(0)
+        leftTextMargin(0), topTextMargin(0), rightTextMargin(0), bottomTextMargin(0),
+        lastTextSize(0)
     {
     }
 
@@ -145,15 +185,49 @@ public:
     QBasicTimer dndTimer;
     void drag();
 #endif
+    void _q_textChanged(const QString &);
 
-    int leftTextMargin;
+    int leftTextMargin; // use effectiveLeftTextMargin() in case of icon.
     int topTextMargin;
-    int rightTextMargin;
+    int rightTextMargin; // use effectiveRightTextMargin() in case of icon.
     int bottomTextMargin;
 
     QString placeholderText;
+
+    QWidget *addAction(QAction *newAction, QAction *before, QLineEdit::ActionPosition, int flags = 0);
+    void removeAction(const QActionEvent *e);
+    QSize iconSize() const;
+    void positionSideWidgets();
+    inline bool hasSideWidgets() const { return !leadingSideWidgets.isEmpty() || !trailingSideWidgets.isEmpty(); }
+    inline const SideWidgetEntryList &leftSideWidgetList() const
+        { return q_func()->layoutDirection() == Qt::LeftToRight ? leadingSideWidgets : trailingSideWidgets; }
+    inline const SideWidgetEntryList &rightSideWidgetList() const
+        { return q_func()->layoutDirection() == Qt::LeftToRight ? trailingSideWidgets : leadingSideWidgets; }
+
+    int effectiveLeftTextMargin() const;
+    int effectiveRightTextMargin() const;
+
+private:
+    typedef QPair<QLineEdit::ActionPosition, int> PositionIndexPair;
+
+    PositionIndexPair findSideWidget(const QAction *a) const;
+
+    SideWidgetEntryList leadingSideWidgets;
+    SideWidgetEntryList trailingSideWidgets;
+    int lastTextSize;
+    mutable QSize m_iconSize;
 };
 
+inline int QLineEditPrivate::effectiveLeftTextMargin() const
+{
+    return leftTextMargin + leftSideWidgetList().size() * (QLineEditIconButton::IconMargin + iconSize().width());
+}
+
+inline int QLineEditPrivate::effectiveRightTextMargin() const
+{
+    return rightTextMargin + rightSideWidgetList().size() * (QLineEditIconButton::IconMargin + iconSize().width());
+}
+
 #endif // QT_NO_LINEEDIT
 
 QT_END_NAMESPACE
diff --git a/tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp b/tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp
index ae3fefc45a..cd715b7b06 100644
--- a/tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp
+++ b/tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp
@@ -46,6 +46,9 @@
 #include "qstringlist.h"
 #include "qstyle.h"
 #include "qvalidator.h"
+#include "qwidgetaction.h"
+#include "qimage.h"
+#include "qicon.h"
 #include "qcompleter.h"
 #include "qstandarditemmodel.h"
 #include <qpa/qplatformtheme.h>
@@ -61,8 +64,12 @@
 #include <private/qlineedit_p.h>
 #include <private/qwidgetlinecontrol_p.h>
 #include <qmenu.h>
+#include <qlabel.h>
 #include <qlayout.h>
 #include <qspinbox.h>
+#include <qlistview.h>
+#include <qstringlistmodel.h>
+#include <qsortfilterproxymodel.h>
 #include <qdebug.h>
 
 #include "qcommonstyle.h"
@@ -290,6 +297,8 @@ private slots:
     void undoRedoAndEchoModes_data();
     void undoRedoAndEchoModes();
 
+    void sideWidgets();
+
 protected slots:
     void editingFinished();
 
@@ -4048,5 +4057,39 @@ void tst_QLineEdit::undoRedoAndEchoModes()
     QCOMPARE(testWidget->text(), expected.at(2));
 }
 
+void tst_QLineEdit::sideWidgets()
+{
+    QWidget testWidget;
+    QVBoxLayout *l = new QVBoxLayout(&testWidget);
+    QLineEdit *lineEdit = new QLineEdit(&testWidget);
+    l->addWidget(lineEdit);
+    l->addSpacerItem(new QSpacerItem(0, 50, QSizePolicy::Ignored, QSizePolicy::Fixed));
+    QImage image(QSize(20, 20), QImage::Format_ARGB32);
+    image.fill(Qt::yellow);
+    QAction *iconAction = new QAction(QIcon(QPixmap::fromImage(image)), QString(), lineEdit);
+    QWidgetAction *label1Action = new QWidgetAction(lineEdit);
+    label1Action->setDefaultWidget(new QLabel(QStringLiteral("l1")));
+    QWidgetAction *label2Action = new QWidgetAction(lineEdit);
+    label2Action->setDefaultWidget(new QLabel(QStringLiteral("l2")));
+    QWidgetAction *label3Action = new QWidgetAction(lineEdit);
+    label3Action->setDefaultWidget(new QLabel(QStringLiteral("l3")));
+    lineEdit->addAction(iconAction, QLineEdit::LeadingPosition);
+    lineEdit->addAction(label2Action, QLineEdit::LeadingPosition);
+    lineEdit->addAction(label1Action, QLineEdit::TrailingPosition);
+    lineEdit->addAction(label3Action, QLineEdit::TrailingPosition);
+    testWidget.move(300, 300);
+    testWidget.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&testWidget));
+    // Arbitrarily add/remove actions, trying to detect crashes. Add QTRY_VERIFY(false) to view the result.
+    delete label3Action;
+    lineEdit->removeAction(label2Action);
+    lineEdit->removeAction(iconAction);
+    lineEdit->removeAction(label1Action);
+    lineEdit->removeAction(iconAction);
+    lineEdit->removeAction(label1Action);
+    lineEdit->addAction(iconAction);
+    lineEdit->addAction(iconAction);
+}
+
 QTEST_MAIN(tst_QLineEdit)
 #include "tst_qlineedit.moc"