Long live Qt 4.5!

1 files changed, 1612 insertions, 0 deletions

diff --git a/tools/designer/src/lib/shared/connectionedit.cpp b/tools/designer/src/lib/shared/connectionedit.cpp
new file mode 100644
index 0000000..579a59e
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+++ b/tools/designer/src/lib/shared/connectionedit.cpp
@@ -0,0 +1,1612 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the Qt Designer of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include "connectionedit_p.h"
+
+#include <QtDesigner/abstractformwindow.h>
+
+#include <QtGui/QPainter>
+#include <QtGui/QPaintEvent>
+#include <QtGui/QFontMetrics>
+#include <QtGui/QPixmap>
+#include <QtGui/QMatrix>
+#include <QtGui/QApplication>
+#include <QtGui/QContextMenuEvent>
+#include <QtGui/QMenu>
+#include <QtGui/QAction>
+
+#include <QtCore/QMultiMap>
+
+QT_BEGIN_NAMESPACE
+
+static const int BG_ALPHA =              32;
+static const int LINE_PROXIMITY_RADIUS =  3;
+static const int LOOP_MARGIN  =          20;
+static const int VLABEL_MARGIN =          1;
+static const int HLABEL_MARGIN =          3;
+static const int GROUND_W =              20;
+static const int GROUND_H =              25;
+
+/*******************************************************************************
+** Tools
+*/
+
+static QRect fixRect(const QRect &r)
+{
+    return QRect(r.x(), r.y(), r.width() - 1, r.height() - 1);
+}
+
+static QRect expand(const QRect &r, int i)
+{
+    return QRect(r.x() - i, r.y() - i, r.width() + 2*i, r.height() + 2*i);
+}
+
+static QRect endPointRectHelper(const QPoint &pos)
+{
+    const QRect r(pos + QPoint(-LINE_PROXIMITY_RADIUS, -LINE_PROXIMITY_RADIUS),
+                  QSize(2*LINE_PROXIMITY_RADIUS, 2*LINE_PROXIMITY_RADIUS));
+    return r;
+}
+
+static void paintGround(QPainter *p, QRect r)
+{
+    const QPoint mid = r.center();
+    p->drawLine(mid.x(), r.top(), mid.x(), mid.y());
+    p->drawLine(r.left(), mid.y(), r.right(), mid.y());
+    int y = r.top() + 4*r.height()/6;
+    int x = GROUND_W/6;
+    p->drawLine(r.left() + x, y, r.right() - x, y);
+    y = r.top() + 5*r.height()/6;
+    x = 2*GROUND_W/6;
+    p->drawLine(r.left() + x, y, r.right() - x, y);
+    p->drawLine(mid.x(), r.bottom(), mid.x() + 1, r.bottom());
+}
+
+static void paintEndPoint(QPainter *p, const QPoint &pos)
+{
+    const QRect r(pos + QPoint(-LINE_PROXIMITY_RADIUS, -LINE_PROXIMITY_RADIUS),
+                  QSize(2*LINE_PROXIMITY_RADIUS, 2*LINE_PROXIMITY_RADIUS));
+    p->fillRect(fixRect(r), p->pen().color());
+}
+
+static qdesigner_internal::CETypes::LineDir classifyLine(const QPoint &p1, const QPoint &p2)
+{
+    if (p1.x() == p2.x())
+        return p1.y() < p2.y() ? qdesigner_internal::CETypes::DownDir : qdesigner_internal::CETypes::UpDir;
+    Q_ASSERT(p1.y() == p2.y());
+    return p1.x() < p2.x() ? qdesigner_internal::CETypes::RightDir : qdesigner_internal::CETypes::LeftDir;
+}
+
+static QPoint pointInsideRect(const QRect &r, QPoint p)
+{
+    if (p.x() < r.left())
+        p.setX(r.left());
+    else if (p.x() > r.right())
+        p.setX(r.right());
+
+    if (p.y() < r.top())
+        p.setY(r.top());
+    else if (p.y() > r.bottom())
+        p.setY(r.bottom());
+
+    return p;
+}
+
+namespace qdesigner_internal {
+
+/*******************************************************************************
+** Commands
+*/
+
+AddConnectionCommand::AddConnectionCommand(ConnectionEdit *edit, Connection *con)
+    : CECommand(edit), m_con(con)
+{
+    setText(QApplication::translate("Command", "Add connection"));
+}
+
+void AddConnectionCommand::redo()
+{
+    edit()->selectNone();
+    emit edit()->aboutToAddConnection(edit()->m_con_list.size());
+    edit()->m_con_list.append(m_con);
+    m_con->inserted();
+    edit()->setSelected(m_con, true);
+    emit edit()->connectionAdded(m_con);
+}
+
+void AddConnectionCommand::undo()
+{
+    const int idx = edit()->indexOfConnection(m_con);
+    emit edit()->aboutToRemoveConnection(m_con);
+    edit()->setSelected(m_con, false);
+    m_con->update();
+    m_con->removed();
+    edit()->m_con_list.removeAll(m_con);
+    emit edit()->connectionRemoved(idx);
+}
+
+class AdjustConnectionCommand : public CECommand
+{
+public:
+    AdjustConnectionCommand(ConnectionEdit *edit, Connection *con,
+                            const QPoint &old_source_pos,
+                            const QPoint &old_target_pos,
+                            const QPoint &new_source_pos,
+                            const QPoint &new_target_pos);
+    virtual void redo();
+    virtual void undo();
+private:
+    Connection *m_con;
+    const QPoint m_old_source_pos;
+    const QPoint m_old_target_pos;
+    const QPoint m_new_source_pos;
+    const QPoint m_new_target_pos;
+};
+
+AdjustConnectionCommand::AdjustConnectionCommand(ConnectionEdit *edit, Connection *con,
+                                                    const QPoint &old_source_pos,
+                                                    const QPoint &old_target_pos,
+                                                    const QPoint &new_source_pos,
+                                                    const QPoint &new_target_pos) :
+    CECommand(edit),
+    m_con(con),
+    m_old_source_pos(old_source_pos),
+    m_old_target_pos(old_target_pos),
+    m_new_source_pos(new_source_pos),
+    m_new_target_pos(new_target_pos)
+{
+    setText(QApplication::translate("Command", "Adjust connection"));
+}
+
+void AdjustConnectionCommand::undo()
+{
+    m_con->setEndPoint(EndPoint::Source, m_con->widget(EndPoint::Source), m_old_source_pos);
+    m_con->setEndPoint(EndPoint::Target, m_con->widget(EndPoint::Target), m_old_target_pos);
+}
+
+void AdjustConnectionCommand::redo()
+{
+    m_con->setEndPoint(EndPoint::Source, m_con->widget(EndPoint::Source), m_new_source_pos);
+    m_con->setEndPoint(EndPoint::Target, m_con->widget(EndPoint::Target), m_new_target_pos);
+}
+
+DeleteConnectionsCommand::DeleteConnectionsCommand(ConnectionEdit *edit,
+                                                    const ConnectionList &con_list)
+    : CECommand(edit), m_con_list(con_list)
+{
+   setText(QApplication::translate("Command", "Delete connections"));
+}
+
+void DeleteConnectionsCommand::redo()
+{
+    foreach (Connection *con, m_con_list) {
+        const int idx = edit()->indexOfConnection(con);
+        emit edit()->aboutToRemoveConnection(con);
+        Q_ASSERT(edit()->m_con_list.contains(con));
+        edit()->setSelected(con, false);
+        con->update();
+        con->removed();
+        edit()->m_con_list.removeAll(con);
+        emit edit()->connectionRemoved(idx);
+    }
+}
+
+void DeleteConnectionsCommand::undo()
+{
+    foreach (Connection *con, m_con_list) {
+        Q_ASSERT(!edit()->m_con_list.contains(con));
+        emit edit()->aboutToAddConnection(edit()->m_con_list.size());
+        edit()->m_con_list.append(con);
+        edit()->setSelected(con, true);
+        con->update();
+        con->inserted();
+        emit edit()->connectionAdded(con);
+    }
+}
+
+class SetEndPointCommand : public CECommand
+{
+public:
+    SetEndPointCommand(ConnectionEdit *edit, Connection *con, EndPoint::Type type, QObject *object);
+    virtual void redo();
+    virtual void undo();
+private:
+    Connection *m_con;
+    const EndPoint::Type m_type;
+    QObject *m_old_widget, *m_new_widget;
+    const QPoint m_old_pos;
+    QPoint m_new_pos;
+};
+
+SetEndPointCommand::SetEndPointCommand(ConnectionEdit *edit, Connection *con,
+                                        EndPoint::Type type, QObject *object) :
+    CECommand(edit),
+    m_con(con),
+    m_type(type),
+    m_old_widget(con->object(type)),
+    m_new_widget(object),
+    m_old_pos(con->endPointPos(type))
+{
+    if (QWidget *widget = qobject_cast<QWidget*>(object)) {
+        m_new_pos = edit->widgetRect(widget).center();
+    }
+
+    if (m_type == EndPoint::Source)
+        setText(QApplication::translate("Command", "Change source"));
+    else
+        setText(QApplication::translate("Command", "Change target"));
+}
+
+void SetEndPointCommand::redo()
+{
+    m_con->setEndPoint(m_type, m_new_widget, m_new_pos);
+    emit edit()->connectionChanged(m_con);
+}
+
+void SetEndPointCommand::undo()
+{
+    m_con->setEndPoint(m_type, m_old_widget, m_old_pos);
+    emit edit()->connectionChanged(m_con);
+}
+
+/*******************************************************************************
+** Connection
+*/
+
+Connection::Connection(ConnectionEdit *edit) :
+    m_source_pos(QPoint(-1, -1)),
+    m_target_pos(QPoint(-1, -1)),
+    m_source(0),
+    m_target(0),
+    m_edit(edit),
+    m_visible(true)
+{
+
+}
+
+Connection::Connection(ConnectionEdit *edit, QObject *source, QObject *target) :
+    m_source_pos(QPoint(-1, -1)),
+    m_target_pos(QPoint(-1, -1)),
+    m_source(source),
+    m_target(target),
+    m_edit(edit),
+    m_visible(true)
+{
+}
+
+void Connection::setVisible(bool b)
+{
+    m_visible = b;
+}
+
+void Connection::updateVisibility()
+{
+    QWidget *source = widget(EndPoint::Source);
+    QWidget *target = widget(EndPoint::Target);
+
+    if (source == 0 || target == 0) {
+        setVisible(false);
+        return;
+    }
+
+    QWidget *w = source;
+    while (w && w->parentWidget()) {
+        if (!w->isVisibleTo(w->parentWidget())) {
+            setVisible(false);
+            return;
+        }
+        w = w->parentWidget();
+    }
+
+    w = target;
+    while (w && w->parentWidget()) {
+        if (!w->isVisibleTo(w->parentWidget())) {
+            setVisible(false);
+            return;
+        }
+        w = w->parentWidget();
+    }
+
+    setVisible(true);
+}
+
+bool Connection::isVisible() const
+{
+    return m_visible;
+}
+
+bool Connection::ground() const
+{
+    return m_target != 0 && m_target == m_edit->m_bg_widget;
+}
+
+QPoint Connection::endPointPos(EndPoint::Type type) const
+{
+    if (type == EndPoint::Source)
+        return m_source_pos;
+    else
+        return m_target_pos;
+}
+
+static QPoint lineEntryPos(const QPoint &p1, const QPoint &p2, const QRect &rect)
+{
+    QPoint result;
+
+    switch (classifyLine(p1, p2)) {
+        case CETypes::UpDir:
+            result = QPoint(p1.x(), rect.bottom());
+            break;
+        case CETypes::DownDir:
+            result = QPoint(p1.x(), rect.top());
+            break;
+        case CETypes::LeftDir:
+            result = QPoint(rect.right(), p1.y());
+            break;
+        case CETypes::RightDir:
+            result = QPoint(rect.left(), p1.y());
+            break;
+    }
+
+    return result;
+}
+
+static QPolygonF arrowHead(const QPoint &p1, const QPoint &p2)
+{
+    QPolygonF result;
+
+    switch (classifyLine(p1, p2)) {
+        case CETypes::UpDir:
+            result.append(p2 + QPoint(0, 1));
+            result.append(p2 + QPoint(LINE_PROXIMITY_RADIUS, LINE_PROXIMITY_RADIUS*2 + 1));
+            result.append(p2 + QPoint(-LINE_PROXIMITY_RADIUS, LINE_PROXIMITY_RADIUS*2 + 1));
+            break;
+        case CETypes::DownDir:
+            result.append(p2);
+            result.append(p2 + QPoint(LINE_PROXIMITY_RADIUS, -LINE_PROXIMITY_RADIUS*2));
+            result.append(p2 + QPoint(-LINE_PROXIMITY_RADIUS, -LINE_PROXIMITY_RADIUS*2));
+            break;
+        case CETypes::LeftDir:
+            result.append(p2 + QPoint(1, 0));
+            result.append(p2 + QPoint(2*LINE_PROXIMITY_RADIUS + 1, -LINE_PROXIMITY_RADIUS));
+            result.append(p2 + QPoint(2*LINE_PROXIMITY_RADIUS + 1, LINE_PROXIMITY_RADIUS));
+            break;
+        case CETypes::RightDir:
+            result.append(p2);
+            result.append(p2 + QPoint(-2*LINE_PROXIMITY_RADIUS, -LINE_PROXIMITY_RADIUS));
+            result.append(p2 + QPoint(-2*LINE_PROXIMITY_RADIUS, LINE_PROXIMITY_RADIUS));
+            break;
+    }
+
+    return result;
+}
+
+static CETypes::LineDir closestEdge(const QPoint &p, const QRect &r)
+{
+    CETypes::LineDir result = CETypes::UpDir;
+    int min = p.y() - r.top();
+
+    int d = p.x() - r.left();
+    if (d < min) {
+        min = d;
+        result = CETypes::LeftDir;
+    }
+
+    d = r.bottom() - p.y();
+    if (d < min) {
+        min = d;
+        result = CETypes::DownDir;
+    }
+
+    d = r.right() - p.x();
+    if (d < min) {
+        min = d;
+        result = CETypes::RightDir;
+    }
+
+    return result;
+}
+
+static bool pointAboveLine(const QPoint &l1, const QPoint &l2, const QPoint &p)
+{
+    if (l1.x() == l2.x())
+        return p.x() >= l1.x();
+    return p.y() <= l1.y() + (p.x() - l1.x())*(l2.y() - l1.y())/(l2.x() - l1.x());
+}
+
+void Connection::updateKneeList()
+{
+    const LineDir old_source_label_dir = labelDir(EndPoint::Source);
+    const LineDir old_target_label_dir = labelDir(EndPoint::Target);
+
+    QPoint s = endPointPos(EndPoint::Source);
+    QPoint t = endPointPos(EndPoint::Target);
+    const QRect sr = m_source_rect;
+    const QRect tr = m_target_rect;
+
+    m_knee_list.clear();
+    m_arrow_head.clear();
+
+    if (m_source == 0 || s == QPoint(-1, -1) || t == QPoint(-1, -1))
+        return;
+
+    const QRect r = sr | tr;
+
+    m_knee_list.append(s);
+    if (m_target == 0) {
+        m_knee_list.append(QPoint(t.x(), s.y()));
+    } else if (m_target == m_edit->m_bg_widget) {
+        m_knee_list.append(QPoint(s.x(), t.y()));
+    } else if (tr.contains(sr) || sr.contains(tr)) {
+/*
+        +------------------+
+        | +----------+     |
+        | |          |     |
+        | |   o      |     |
+        | +---|------+     |
+        |     |     x      |
+        +-----|-----|------+
+              +-----+
+
+        We find out which edge of the outer rectangle is closest to the target
+        point, and make a loop which exits and re-enters through that edge.
+*/
+        const LineDir dir = closestEdge(t, tr);
+        switch (dir) {
+            case UpDir:
+                m_knee_list.append(QPoint(s.x(), r.top() - LOOP_MARGIN));
+                m_knee_list.append(QPoint(t.x(), r.top() - LOOP_MARGIN));
+                break;
+            case DownDir:
+                m_knee_list.append(QPoint(s.x(), r.bottom() + LOOP_MARGIN));
+                m_knee_list.append(QPoint(t.x(), r.bottom() + LOOP_MARGIN));
+                break;
+            case LeftDir:
+                m_knee_list.append(QPoint(r.left() - LOOP_MARGIN, s.y()));
+                m_knee_list.append(QPoint(r.left() - LOOP_MARGIN, t.y()));
+                break;
+            case RightDir:
+                m_knee_list.append(QPoint(r.right() + LOOP_MARGIN, s.y()));
+                m_knee_list.append(QPoint(r.right() + LOOP_MARGIN, t.y()));
+                break;
+        }
+    } else {
+        if (r.height() < sr.height() + tr.height()) {
+            if ((s.y() >= tr.top() && s.y() <= tr.bottom()) || (t.y() >= sr.bottom() || t.y() <= sr.top())) {
+/*
+                +--------+
+                |        |   +--------+
+                |     o--+---+--x     |
+                |     o  |   |        |
+                +-----|--+   |        |
+                      +------+--x     |
+                             +--------+
+
+                When dragging one end point, move the other end point to the same y position,
+                if that does not cause it to exit it's rectangle.
+*/
+                if (m_edit->state() == ConnectionEdit::Dragging) {
+                    if (m_edit->m_drag_end_point.type == EndPoint::Source) {
+                        const QPoint p(t.x(), s.y());
+                        m_knee_list.append(p);
+                        if (tr.contains(p))
+                            t = m_target_pos = p;
+                    } else {
+                        const QPoint p(s.x(), t.y());
+                        m_knee_list.append(p);
+                        if (sr.contains(p))
+                            s = m_source_pos = p;
+                    }
+                } else {
+                    m_knee_list.append(QPoint(s.x(), t.y()));
+                }
+            } else {
+/*
+                +--------+
+                |   o----+-------+
+                |        |   +---|----+
+                +--------+   |   |    |
+                             |   x    |
+                             +--------+
+*/
+                m_knee_list.append(QPoint(t.x(), s.y()));
+            }
+        } else if (r.width() < sr.width() + tr.width()) {
+            if ((s.x() >= tr.left() && s.x() <= tr.right()) || t.x() >= sr.right() || t.x() <= sr.left()) {
+/*
+                +--------+
+                |        |
+                |    o  o+--+
+                +----|---+  |
+                   +-|------|-+
+                   | x      x |
+                   |          |
+                   +----------+
+
+                When dragging one end point, move the other end point to the same x position,
+                if that does not cause it to exit it's rectangle.
+*/
+                if (m_edit->state() == ConnectionEdit::Dragging) {
+                    if (m_edit->m_drag_end_point.type == EndPoint::Source) {
+                        const QPoint p(s.x(), t.y());
+                        m_knee_list.append(p);
+                        if (tr.contains(p))
+                            t = m_target_pos = p;
+                    } else {
+                        const QPoint p(t.x(), s.y());
+                        m_knee_list.append(p);
+                        if (sr.contains(p))
+                            s = m_source_pos = p;
+                    }
+                } else {
+                    m_knee_list.append(QPoint(t.x(), s.y()));
+                }
+            } else {
+/*
+                +--------+
+                |        |
+                |  o     |
+                +--|-----+
+                   |   +--------+
+                   +---+-x      |
+                       |        |
+                       +--------+
+
+*/
+                m_knee_list.append(QPoint(s.x(), t.y()));
+            }
+        } else {
+/*
+            +--------+
+            |        |
+            |  o   o-+--------+
+            +--|-----+        |
+               |        +-----|--+
+               |        |     x  |
+               +--------+-x      |
+                        +--------+
+
+            The line enters the target rectangle through the closest edge.
+*/
+            if (sr.topLeft() == r.topLeft()) {
+                if (pointAboveLine(tr.topLeft(), tr.bottomRight(), t))
+                    m_knee_list.append(QPoint(t.x(), s.y()));
+                else
+                    m_knee_list.append(QPoint(s.x(), t.y()));
+            } else if (sr.topRight() == r.topRight()) {
+                if (pointAboveLine(tr.bottomLeft(), tr.topRight(), t))
+                    m_knee_list.append(QPoint(t.x(), s.y()));
+                else
+                    m_knee_list.append(QPoint(s.x(), t.y()));
+            } else if (sr.bottomRight() == r.bottomRight()) {
+                if (pointAboveLine(tr.topLeft(), tr.bottomRight(), t))
+                    m_knee_list.append(QPoint(s.x(), t.y()));
+                else
+                    m_knee_list.append(QPoint(t.x(), s.y()));
+            } else {
+                if (pointAboveLine(tr.bottomLeft(), tr.topRight(), t))
+                    m_knee_list.append(QPoint(s.x(), t.y()));
+                else
+                    m_knee_list.append(QPoint(t.x(), s.y()));
+            }
+        }
+    }
+    m_knee_list.append(t);
+
+    if (m_knee_list.size() == 2)
+        m_knee_list.clear();
+
+    trimLine();
+
+    const LineDir new_source_label_dir = labelDir(EndPoint::Source);
+    const LineDir new_target_label_dir = labelDir(EndPoint::Target);
+    if (new_source_label_dir != old_source_label_dir)
+        updatePixmap(EndPoint::Source);
+    if (new_target_label_dir != old_target_label_dir)
+        updatePixmap(EndPoint::Target);
+}
+
+void Connection::trimLine()
+{
+    if (m_source == 0 || m_source_pos == QPoint(-1, -1) || m_target_pos == QPoint(-1, -1))
+        return;
+    int cnt = m_knee_list.size();
+    if (cnt < 2)
+        return;
+
+    const QRect sr = m_source_rect;
+    const QRect tr = m_target_rect;
+
+    if (sr.contains(m_knee_list.at(1)))
+        m_knee_list.removeFirst();
+
+    cnt = m_knee_list.size();
+    if (cnt < 2)
+        return;
+
+    if (!tr.contains(sr) && tr.contains(m_knee_list.at(cnt - 2)))
+        m_knee_list.removeLast();
+
+    cnt = m_knee_list.size();
+    if (cnt < 2)
+        return;
+
+    if (sr.contains(m_knee_list.at(0)) && !sr.contains(m_knee_list.at(1)))
+        m_knee_list[0] = lineEntryPos(m_knee_list.at(1), m_knee_list.at(0), sr);
+
+    if (tr.contains(m_knee_list.at(cnt - 1)) && !tr.contains(m_knee_list.at(cnt - 2))) {
+        m_knee_list[cnt - 1]
+            = lineEntryPos(m_knee_list.at(cnt - 2), m_knee_list.at(cnt - 1), tr);
+        m_arrow_head = arrowHead(m_knee_list.at(cnt - 2), m_knee_list.at(cnt - 1));
+    }
+}
+
+void Connection::setSource(QObject *source, const QPoint &pos)
+{
+    if (source == m_source && m_source_pos == pos)
+        return;
+
+    update(false);
+
+    m_source = source;
+    if (QWidget *widget = qobject_cast<QWidget*>(source)) {
+        m_source_pos = pos;
+        m_source_rect = m_edit->widgetRect(widget);
+        updateKneeList();
+    }
+
+    update(false);
+}
+
+void Connection::setTarget(QObject *target, const QPoint &pos)
+{
+    if (target == m_target && m_target_pos == pos)
+        return;
+
+    update(false);
+
+    m_target = target;
+    if (QWidget *widget = qobject_cast<QWidget*>(target)) {
+        m_target_pos = pos;
+        m_target_rect = m_edit->widgetRect(widget);
+        updateKneeList();
+    }
+
+    update(false);
+}
+
+static QRect lineRect(const QPoint &a, const QPoint &b)
+{
+    const QPoint c(qMin(a.x(), b.x()), qMin(a.y(), b.y()));
+    const QPoint d(qMax(a.x(), b.x()), qMax(a.y(), b.y()));
+
+    QRect result(c, d);
+    return expand(result, LINE_PROXIMITY_RADIUS);
+}
+
+QRect Connection::groundRect() const
+{
+    if (!ground())
+        return QRect();
+    if (m_knee_list.isEmpty())
+        return QRect();
+
+    const QPoint p = m_knee_list.last();
+    return QRect(p.x() - GROUND_W/2, p.y(), GROUND_W, GROUND_H);
+}
+
+QRegion Connection::region() const
+{
+    QRegion result;
+
+    for (int i = 0; i < m_knee_list.size() - 1; ++i)
+        result = result.unite(lineRect(m_knee_list.at(i), m_knee_list.at(i + 1)));
+
+    if (!m_arrow_head.isEmpty()) {
+        QRect r = m_arrow_head.boundingRect().toRect();
+        r = expand(r, 1);
+        result = result.unite(r);
+    } else if (ground()) {
+        result = result.unite(groundRect());
+    }
+
+    result = result.unite(labelRect(EndPoint::Source));
+    result = result.unite(labelRect(EndPoint::Target));
+
+    return result;
+}
+
+void Connection::update(bool update_widgets) const
+{
+    m_edit->update(region());
+    if (update_widgets) {
+        if (m_source != 0)
+            m_edit->update(m_source_rect);
+        if (m_target != 0)
+            m_edit->update(m_target_rect);
+    }
+
+    m_edit->update(endPointRect(EndPoint::Source));
+    m_edit->update(endPointRect(EndPoint::Target));
+}
+
+void Connection::paint(QPainter *p) const
+{
+    for (int i = 0; i < m_knee_list.size() - 1; ++i)
+        p->drawLine(m_knee_list.at(i), m_knee_list.at(i + 1));
+
+    if (!m_arrow_head.isEmpty()) {
+        p->save();
+        p->setBrush(p->pen().color());
+        p->drawPolygon(m_arrow_head);
+        p->restore();
+    } else if (ground()) {
+        paintGround(p, groundRect());
+    }
+}
+
+bool Connection::contains(const QPoint &pos) const
+{
+    return region().contains(pos);
+}
+
+QRect Connection::endPointRect(EndPoint::Type type) const
+{
+    if (type == EndPoint::Source) {
+        if (m_source_pos != QPoint(-1, -1))
+            return endPointRectHelper(m_source_pos);
+    } else {
+        if (m_target_pos != QPoint(-1, -1))
+            return endPointRectHelper(m_target_pos);
+    }
+    return QRect();
+}
+
+CETypes::LineDir Connection::labelDir(EndPoint::Type type) const
+{
+    const int cnt = m_knee_list.size();
+    if (cnt < 2)
+        return RightDir;
+
+    LineDir dir;
+    if (type == EndPoint::Source)
+        dir = classifyLine(m_knee_list.at(0), m_knee_list.at(1));
+    else
+        dir = classifyLine(m_knee_list.at(cnt - 2), m_knee_list.at(cnt - 1));
+
+    if (dir == LeftDir)
+        dir = RightDir;
+    if (dir == UpDir)
+        dir = DownDir;
+
+    return dir;
+}
+
+QRect Connection::labelRect(EndPoint::Type type) const
+{
+    const int cnt = m_knee_list.size();
+    if (cnt < 2)
+        return QRect();
+    const QString text = label(type);
+    if (text.isEmpty())
+        return QRect();
+
+    const QSize size = labelPixmap(type).size();
+    QPoint p1, p2;
+    if (type == EndPoint::Source) {
+        p1 = m_knee_list.at(0);
+        p2 = m_knee_list.at(1);
+    } else {
+        p1 = m_knee_list.at(cnt - 1);
+        p2 = m_knee_list.at(cnt - 2);
+    }
+    const LineDir dir = classifyLine(p1, p2);
+
+    QRect result;
+    switch (dir) {
+        case UpDir:
+            result = QRect(p1 + QPoint(-size.width()/2, 0), size);
+            break;
+        case DownDir:
+            result = QRect(p1 + QPoint(-size.width()/2, -size.height()), size);
+            break;
+        case LeftDir:
+            result = QRect(p1 + QPoint(0, -size.height()/2), size);
+            break;
+        case RightDir:
+            result = QRect(p1 + QPoint(-size.width(), -size.height()/2), size);
+            break;
+    }
+
+    return result;
+}
+
+void Connection::setLabel(EndPoint::Type type, const QString &text)
+{
+    if (text == label(type))
+        return;
+
+    if (type == EndPoint::Source)
+        m_source_label = text;
+    else
+        m_target_label = text;
+
+    updatePixmap(type);
+}
+
+void Connection::updatePixmap(EndPoint::Type type)
+{
+    QPixmap *pm = type == EndPoint::Source ? &m_source_label_pm : &m_target_label_pm;
+
+    const QString text = label(type);
+    if (text.isEmpty()) {
+        *pm = QPixmap();
+        return;
+    }
+
+    const QFontMetrics fm = m_edit->fontMetrics();
+    const QSize size = fm.size(Qt::TextSingleLine, text) + QSize(HLABEL_MARGIN*2, VLABEL_MARGIN*2);
+    *pm = QPixmap(size);
+    QColor color = m_edit->palette().color(QPalette::Normal, QPalette::Base);
+    color.setAlpha(190);
+    pm->fill(color);
+
+    QPainter p(pm);
+    p.setPen(m_edit->palette().color(QPalette::Normal, QPalette::Text));
+    p.drawText(-fm.leftBearing(text.at(0)) + HLABEL_MARGIN, fm.ascent() + VLABEL_MARGIN, text);
+    p.end();
+
+    const LineDir dir = labelDir(type);
+
+    if (dir == DownDir)
+        *pm = pm->transformed(QMatrix(0.0, -1.0, 1.0, 0.0, 0.0, 0.0));
+}
+
+void Connection::checkWidgets()
+{
+    bool changed = false;
+
+    if (QWidget *sourceWidget = qobject_cast<QWidget*>(m_source)) {
+        const QRect r = m_edit->widgetRect(sourceWidget);
+        if (r != m_source_rect) {
+            if (m_source_pos != QPoint(-1, -1) && !r.contains(m_source_pos)) {
+                QPoint offset = m_source_pos - m_source_rect.topLeft();
+                QPoint old_pos = m_source_pos;
+                m_source_pos = pointInsideRect(r, r.topLeft() + offset);
+            }
+            m_edit->update(m_source_rect);
+            m_source_rect = r;
+            changed = true;
+        }
+    }
+
+    if (QWidget *targetWidget = qobject_cast<QWidget*>(m_target)) {
+        const QRect r = m_edit->widgetRect(targetWidget);
+        if (r != m_target_rect) {
+            if (m_target_pos != QPoint(-1, -1) && !r.contains(m_target_pos)) {
+                const QPoint offset = m_target_pos - m_target_rect.topLeft();
+                const QPoint old_pos = m_target_pos;
+                m_target_pos = pointInsideRect(r, r.topLeft() + offset);
+            }
+            m_edit->update(m_target_rect);
+            m_target_rect = r;
+            changed = true;
+        }
+    }
+
+    if (changed) {
+        update();
+        updateKneeList();
+        update();
+    }
+}
+
+/*******************************************************************************
+** ConnectionEdit
+*/
+
+ConnectionEdit::ConnectionEdit(QWidget *parent, QDesignerFormWindowInterface *form) :
+    QWidget(parent),
+    m_bg_widget(0),
+    m_undo_stack(form->commandHistory()),
+    m_enable_update_background(false),
+    m_tmp_con(0),
+    m_start_connection_on_drag(true),
+    m_widget_under_mouse(0),
+    m_inactive_color(Qt::blue),
+    m_active_color(Qt::red)
+{
+    setAttribute(Qt::WA_MouseTracking, true);
+    setFocusPolicy(Qt::ClickFocus);
+
+    connect(form, SIGNAL(widgetRemoved(QWidget*)), this, SLOT(widgetRemoved(QWidget*)));
+    connect(form, SIGNAL(objectRemoved(QObject*)), this, SLOT(objectRemoved(QObject*)));
+}
+
+ConnectionEdit::~ConnectionEdit()
+{
+    qDeleteAll(m_con_list);
+}
+
+void ConnectionEdit::clear()
+{
+    m_con_list.clear();
+    m_sel_con_set.clear();
+    m_bg_widget = 0;
+    m_widget_under_mouse = 0;
+    m_tmp_con = 0;
+}
+
+void ConnectionEdit::setBackground(QWidget *background)
+{
+    if (background == m_bg_widget) {
+        // nothing to do
+        return;
+    }
+
+    m_bg_widget = background;
+    updateBackground();
+}
+
+void ConnectionEdit::enableUpdateBackground(bool enable)
+{
+    m_enable_update_background = enable;
+    if (enable)
+        updateBackground();
+}
+
+void ConnectionEdit::updateBackground()
+{
+    // Might happen while reloading a form.
+    if (m_bg_widget == 0)
+        return;
+
+    if (!m_enable_update_background)
+        return;
+
+    foreach(Connection *c, m_con_list)
+        c->updateVisibility();
+
+    updateLines();
+    update();
+}
+
+QWidget *ConnectionEdit::widgetAt(const QPoint &pos) const
+{
+    if (m_bg_widget == 0)
+        return 0;
+    QWidget *widget = m_bg_widget->childAt(pos);
+    if (widget == 0)
+        widget = m_bg_widget;
+
+    return widget;
+}
+
+
+QRect ConnectionEdit::widgetRect(QWidget *w) const
+{
+    if (w == 0)
+        return QRect();
+    QRect r = w->geometry();
+    QPoint pos = w->mapToGlobal(QPoint(0, 0));
+    pos = mapFromGlobal(pos);
+    r.moveTopLeft(pos);
+    return r;
+}
+
+ConnectionEdit::State ConnectionEdit::state() const
+{
+    if (m_tmp_con != 0)
+        return Connecting;
+    if (!m_drag_end_point.isNull())
+        return Dragging;
+    return Editing;
+}
+
+void ConnectionEdit::paintLabel(QPainter *p, EndPoint::Type type, Connection *con)
+{
+    if (con->label(type).isEmpty())
+        return;
+
+    const bool heavy = selected(con) || con == m_tmp_con;
+    p->setPen(heavy ? m_active_color : m_inactive_color);
+    p->setBrush(Qt::NoBrush);
+    const QRect r = con->labelRect(type);
+    p->drawPixmap(r.topLeft(), con->labelPixmap(type));
+    p->drawRect(fixRect(r));
+}
+
+void ConnectionEdit::paintConnection(QPainter *p, Connection *con,
+                                        WidgetSet *heavy_highlight_set,
+                                        WidgetSet *light_highlight_set) const
+{
+    QWidget *source = con->widget(EndPoint::Source);
+    QWidget *target = con->widget(EndPoint::Target);
+
+    const bool heavy = selected(con) || con == m_tmp_con;
+    WidgetSet *set = heavy ? heavy_highlight_set : light_highlight_set;
+    p->setPen(heavy ? m_active_color : m_inactive_color);
+    con->paint(p);
+
+    if (source != 0 && source != m_bg_widget)
+        set->insert(source, source);
+
+    if (target != 0 && target != m_bg_widget)
+        set->insert(target, target);
+}
+
+void ConnectionEdit::paintEvent(QPaintEvent *e)
+{
+    QPainter p(this);
+    p.setClipRegion(e->region());
+
+    WidgetSet heavy_highlight_set, light_highlight_set;
+
+    foreach (Connection *con, m_con_list) {
+        if (!con->isVisible())
+            continue;
+
+        paintConnection(&p, con, &heavy_highlight_set, &light_highlight_set);
+    }
+
+    if (m_tmp_con != 0)
+        paintConnection(&p, m_tmp_con, &heavy_highlight_set, &light_highlight_set);
+
+    if (!m_widget_under_mouse.isNull() && m_widget_under_mouse != m_bg_widget)
+        heavy_highlight_set.insert(m_widget_under_mouse, m_widget_under_mouse);
+
+    QColor c = m_active_color;
+    p.setPen(c);
+    c.setAlpha(BG_ALPHA);
+    p.setBrush(c);
+
+    foreach (QWidget *w, heavy_highlight_set) {
+        p.drawRect(fixRect(widgetRect(w)));
+        light_highlight_set.remove(w);
+    }
+
+    c = m_inactive_color;
+    p.setPen(c);
+    c.setAlpha(BG_ALPHA);
+    p.setBrush(c);
+
+    foreach (QWidget *w, light_highlight_set)
+        p.drawRect(fixRect(widgetRect(w)));
+
+    p.setBrush(palette().color(QPalette::Base));
+    p.setPen(palette().color(QPalette::Text));
+    foreach (Connection *con, m_con_list) {
+        if (!con->isVisible())
+            continue;
+
+        paintLabel(&p, EndPoint::Source, con);
+        paintLabel(&p, EndPoint::Target, con);
+    }
+
+    p.setPen(m_active_color);
+    p.setBrush(m_active_color);
+
+    foreach (Connection *con, m_con_list) {
+        if (!selected(con) || !con->isVisible())
+            continue;
+
+        paintEndPoint(&p, con->endPointPos(EndPoint::Source));
+
+        if (con->widget(EndPoint::Target) != 0)
+            paintEndPoint(&p, con->endPointPos(EndPoint::Target));
+    }
+}
+
+void ConnectionEdit::abortConnection()
+{
+    m_tmp_con->update();
+    delete m_tmp_con;
+    m_tmp_con = 0;
+#ifndef QT_NO_CURSOR
+    setCursor(QCursor());
+#endif
+    if (m_widget_under_mouse == m_bg_widget)
+        m_widget_under_mouse = 0;
+}
+
+void ConnectionEdit::mousePressEvent(QMouseEvent *e)
+{
+    // Right click only to cancel
+    const Qt::MouseButton button = e->button();
+    const State cstate = state();
+    if (button != Qt::LeftButton && !(button == Qt::RightButton && cstate == Connecting)) {
+        QWidget::mousePressEvent(e);
+        return;
+    }
+
+    e->accept();
+    // Prefer a non-background widget over the connection,
+    // otherwise, widgets covered by the connection labels cannot be accessed
+    Connection *con_under_mouse = 0;
+    if (!m_widget_under_mouse || m_widget_under_mouse == m_bg_widget)
+        con_under_mouse = connectionAt(e->pos());
+
+    m_start_connection_on_drag = false;
+    switch (cstate) {
+        case Connecting:
+            if (button == Qt::RightButton)
+                abortConnection();
+            break;
+        case Dragging:
+            break;
+        case Editing:
+            if (!m_end_point_under_mouse.isNull()) {
+                if (!(e->modifiers() & Qt::ShiftModifier)) {
+                    startDrag(m_end_point_under_mouse, e->pos());
+                }
+            } else if (con_under_mouse != 0) {
+                if (!(e->modifiers() & Qt::ShiftModifier)) {
+                    selectNone();
+                    setSelected(con_under_mouse, true);
+                } else {
+                    setSelected(con_under_mouse, !selected(con_under_mouse));
+                }
+            } else {
+                if (!(e->modifiers() & Qt::ShiftModifier)) {
+                    selectNone();
+                    if (!m_widget_under_mouse.isNull())
+                        m_start_connection_on_drag = true;
+                }
+            }
+            break;
+    }
+}
+
+void ConnectionEdit::mouseDoubleClickEvent(QMouseEvent *e)
+{
+    if (e->button() != Qt::LeftButton) {
+        QWidget::mouseDoubleClickEvent(e);
+        return;
+    }
+
+    e->accept();
+    switch (state()) {
+        case Connecting:
+            abortConnection();
+            break;
+        case Dragging:
+            break;
+        case Editing:
+            if (!m_widget_under_mouse.isNull()) {
+                emit widgetActivated(m_widget_under_mouse);
+            } else if (m_sel_con_set.size() == 1) {
+                Connection *con = m_sel_con_set.keys().first();
+                modifyConnection(con);
+            }
+            break;
+    }
+
+}
+
+void ConnectionEdit::mouseReleaseEvent(QMouseEvent *e)
+{
+    if (e->button() != Qt::LeftButton) {
+        QWidget::mouseReleaseEvent(e);
+        return;
+    }
+    e->accept();
+
+    switch (state()) {
+        case Connecting:
+            if (m_widget_under_mouse.isNull())
+                abortConnection();
+            else
+                endConnection(m_widget_under_mouse, e->pos());
+#ifndef QT_NO_CURSOR
+            setCursor(QCursor());
+#endif
+            break;
+        case Editing:
+            break;
+        case Dragging:
+            endDrag(e->pos());
+            break;
+    }
+}
+
+
+void ConnectionEdit::findObjectsUnderMouse(const QPoint &pos)
+{
+    Connection *con_under_mouse = connectionAt(pos);
+
+    QWidget *w = widgetAt(pos);
+    // Prefer a non-background widget over the connection,
+    // otherwise, widgets covered by the connection labels cannot be accessed
+    if (w == m_bg_widget && con_under_mouse)
+        w = 0;
+    else
+        con_under_mouse = 0;
+
+    if (w != m_widget_under_mouse) {
+        if (!m_widget_under_mouse.isNull())
+            update(widgetRect(m_widget_under_mouse));
+        m_widget_under_mouse = w;
+        if (!m_widget_under_mouse.isNull())
+            update(widgetRect(m_widget_under_mouse));
+    }
+
+    const EndPoint hs = endPointAt(pos);
+    if (hs != m_end_point_under_mouse) {
+#ifndef QT_NO_CURSOR
+        if (m_end_point_under_mouse.isNull())
+            setCursor(Qt::PointingHandCursor);
+        else
+            setCursor(QCursor());
+#endif
+        m_end_point_under_mouse = hs;
+    }
+}
+
+void ConnectionEdit::mouseMoveEvent(QMouseEvent *e)
+{
+    findObjectsUnderMouse(e->pos());
+    switch (state()) {
+        case Connecting:
+            continueConnection(m_widget_under_mouse, e->pos());
+            break;
+        case Editing:
+            if ((e->buttons() & Qt::LeftButton)
+                    && m_start_connection_on_drag
+                    && !m_widget_under_mouse.isNull()) {
+                m_start_connection_on_drag = false;
+                startConnection(m_widget_under_mouse, e->pos());
+#ifndef QT_NO_CURSOR
+                setCursor(Qt::CrossCursor);
+#endif
+            }
+            break;
+        case Dragging:
+            continueDrag(e->pos());
+            break;
+    }
+
+    e->accept();
+}
+
+void ConnectionEdit::keyPressEvent(QKeyEvent *e)
+{
+    switch (e->key()) {
+        case Qt::Key_Delete:
+            if (state() == Editing)
+                deleteSelected();
+            break;
+        case Qt::Key_Escape:
+            if (state() == Connecting)
+                abortConnection();
+            break;
+    }
+
+    e->accept();
+}
+
+void ConnectionEdit::startConnection(QWidget *source, const QPoint &pos)
+{
+    Q_ASSERT(m_tmp_con == 0);
+
+    m_tmp_con = new Connection(this);
+    m_tmp_con->setEndPoint(EndPoint::Source, source, pos);
+}
+
+void ConnectionEdit::endConnection(QWidget *target, const QPoint &pos)
+{
+    Q_ASSERT(m_tmp_con != 0);
+
+    m_tmp_con->setEndPoint(EndPoint::Target, target, pos);
+
+    QWidget *source = m_tmp_con->widget(EndPoint::Source);
+    Q_ASSERT(source != 0);
+    Q_ASSERT(target != 0);
+    setEnabled(false);
+    Connection *new_con = createConnection(source, target);
+    setEnabled(true);
+    if (new_con != 0) {
+        new_con->setEndPoint(EndPoint::Source, source, m_tmp_con->endPointPos(EndPoint::Source));
+        new_con->setEndPoint(EndPoint::Target, target, m_tmp_con->endPointPos(EndPoint::Target));
+        m_undo_stack->push(new AddConnectionCommand(this, new_con));
+        emit connectionChanged(new_con);
+    }
+
+    delete m_tmp_con;
+    m_tmp_con = 0;
+
+    findObjectsUnderMouse(mapFromGlobal(QCursor::pos()));
+}
+
+void ConnectionEdit::continueConnection(QWidget *target, const QPoint &pos)
+{
+    Q_ASSERT(m_tmp_con != 0);
+
+    m_tmp_con->setEndPoint(EndPoint::Target, target, pos);
+}
+
+void ConnectionEdit::modifyConnection(Connection *)
+{
+}
+
+Connection *ConnectionEdit::createConnection(QWidget *source, QWidget *target)
+{
+    Connection *con = new Connection(this, source, target);
+    return con;
+}
+
+// Find all connections which in which a sequence of objects is involved
+template <class ObjectIterator>
+static ConnectionEdit::ConnectionSet findConnectionsOf(const ConnectionEdit::ConnectionList &cl, ObjectIterator oi1, const ObjectIterator &oi2)
+{
+    ConnectionEdit::ConnectionSet rc;
+
+    const ConnectionEdit::ConnectionList::const_iterator ccend = cl.constEnd();
+    for ( ; oi1 != oi2; ++oi1) {
+        for (ConnectionEdit::ConnectionList::const_iterator cit = cl.constBegin(); cit != ccend; ++cit) {
+            Connection *con = *cit;
+            if (con->object(ConnectionEdit::EndPoint::Source) == *oi1 || con->object(ConnectionEdit::EndPoint::Target) == *oi1)
+                rc.insert(con, con);
+        }
+    }
+    return rc;
+}
+
+void ConnectionEdit::widgetRemoved(QWidget *widget)
+{
+    // Remove all connections of that widget and its children.
+    if (m_con_list.empty())
+        return;
+
+    QWidgetList child_list = qFindChildren<QWidget*>(widget);
+    child_list.prepend(widget);
+
+    const ConnectionSet remove_set = findConnectionsOf(m_con_list, child_list.constBegin(),  child_list.constEnd());
+
+    if (!remove_set.isEmpty())
+        m_undo_stack->push(new DeleteConnectionsCommand(this, remove_set.keys()));
+
+    updateBackground();
+}
+
+void ConnectionEdit::objectRemoved(QObject *o)
+{
+    // Remove all connections of that object and its children (in case of action groups).
+    if (m_con_list.empty())
+        return;
+
+    QObjectList child_list = o->children();
+    child_list.prepend(o);
+    const ConnectionSet remove_set = findConnectionsOf(m_con_list, child_list.constBegin(),  child_list.constEnd());
+    if (!remove_set.isEmpty())
+        m_undo_stack->push(new DeleteConnectionsCommand(this, remove_set.keys()));
+
+    updateBackground();
+}
+
+void ConnectionEdit::setSelected(Connection *con, bool sel)
+{
+    if (!con || sel == m_sel_con_set.contains(con))
+        return;
+
+    if (sel) {
+        m_sel_con_set.insert(con, con);
+        emit connectionSelected(con);
+    } else {
+        m_sel_con_set.remove(con);
+    }
+
+    con->update();
+}
+
+bool ConnectionEdit::selected(const Connection *con) const
+{
+    return m_sel_con_set.contains(const_cast<Connection*>(con));
+}
+
+void ConnectionEdit::selectNone()
+{
+    foreach (Connection *con, m_sel_con_set)
+        con->update();
+
+    m_sel_con_set.clear();
+}
+
+void ConnectionEdit::selectAll()
+{
+    if (m_sel_con_set.size() == m_con_list.size())
+        return;
+    foreach (Connection *con, m_con_list)
+        setSelected(con, true);
+}
+
+Connection *ConnectionEdit::connectionAt(const QPoint &pos) const
+{
+    foreach (Connection *con, m_con_list) {
+        if (con->contains(pos))
+            return con;
+    }
+    return 0;
+}
+
+CETypes::EndPoint ConnectionEdit::endPointAt(const QPoint &pos) const
+{
+    foreach (Connection *con, m_con_list) {
+        if (!selected(con))
+            continue;
+        const QRect sr = con->endPointRect(EndPoint::Source);
+        const QRect tr = con->endPointRect(EndPoint::Target);
+
+        if (sr.contains(pos))
+            return EndPoint(con, EndPoint::Source);
+        if (tr.contains(pos))
+            return EndPoint(con, EndPoint::Target);
+    }
+    return EndPoint();
+}
+
+void ConnectionEdit::startDrag(const EndPoint &end_point, const QPoint &pos)
+{
+    Q_ASSERT(m_drag_end_point.isNull());
+    m_drag_end_point = end_point;
+    m_old_source_pos = m_drag_end_point.con->endPointPos(EndPoint::Source);
+    m_old_target_pos = m_drag_end_point.con->endPointPos(EndPoint::Target);
+    adjustHotSopt(m_drag_end_point, pos);
+}
+
+void ConnectionEdit::continueDrag(const QPoint &pos)
+{
+    Q_ASSERT(!m_drag_end_point.isNull());
+    adjustHotSopt(m_drag_end_point, pos);
+}
+
+void ConnectionEdit::endDrag(const QPoint &pos)
+{
+    Q_ASSERT(!m_drag_end_point.isNull());
+    adjustHotSopt(m_drag_end_point, pos);
+
+    Connection *con = m_drag_end_point.con;
+    const QPoint new_source_pos = con->endPointPos(EndPoint::Source);
+    const QPoint new_target_pos = con->endPointPos(EndPoint::Target);
+    m_undo_stack->push(new AdjustConnectionCommand(this, con, m_old_source_pos, m_old_target_pos,
+                                                    new_source_pos, new_target_pos));
+
+    m_drag_end_point = EndPoint();
+}
+
+void ConnectionEdit::adjustHotSopt(const EndPoint &end_point, const QPoint &pos)
+{
+    QWidget *w = end_point.con->widget(end_point.type);
+    end_point.con->setEndPoint(end_point.type, w, pointInsideRect(widgetRect(w), pos));
+}
+
+void ConnectionEdit::deleteSelected()
+{
+    if (m_sel_con_set.isEmpty())
+        return;
+    m_undo_stack->push(new DeleteConnectionsCommand(this, m_sel_con_set.keys()));
+}
+
+void ConnectionEdit::addConnection(Connection *con)
+{
+    m_con_list.append(con);
+}
+
+void ConnectionEdit::updateLines()
+{
+    foreach (Connection *con, m_con_list)
+        con->checkWidgets();
+}
+
+void ConnectionEdit::resizeEvent(QResizeEvent *e)
+{
+    updateBackground();
+    QWidget::resizeEvent(e);
+}
+
+void ConnectionEdit::setSource(Connection *con, const QString &obj_name)
+{
+    QObject *object = 0;
+    if (!obj_name.isEmpty()) {
+        object = qFindChild<QObject*>(m_bg_widget, obj_name);
+        if (object == 0 && m_bg_widget->objectName() == obj_name)
+            object = m_bg_widget;
+
+        if (object == con->object(EndPoint::Source))
+            return;
+    }
+    m_undo_stack->push(new SetEndPointCommand(this, con, EndPoint::Source, object));
+}
+
+void ConnectionEdit::setTarget(Connection *con, const QString &obj_name)
+{
+    QObject *object = 0;
+    if (!obj_name.isEmpty()) {
+        object = qFindChild<QObject*>(m_bg_widget, obj_name);
+        if (object == 0 && m_bg_widget->objectName() == obj_name)
+            object = m_bg_widget;
+
+        if (object == con->object(EndPoint::Target))
+            return;
+    }
+    m_undo_stack->push(new SetEndPointCommand(this, con, EndPoint::Target, object));
+}
+
+Connection *ConnectionEdit::takeConnection(Connection *con)
+{
+    if (!m_con_list.contains(con))
+        return 0;
+    m_con_list.removeAll(con);
+    return con;
+}
+
+void ConnectionEdit::clearNewlyAddedConnection()
+{
+    delete m_tmp_con;
+    m_tmp_con = 0;
+}
+
+void ConnectionEdit::createContextMenu(QMenu &menu)
+{
+    // Select
+    QAction *selectAllAction = menu.addAction(tr("Select All"));
+    selectAllAction->setEnabled(connectionList().size());
+    connect(selectAllAction, SIGNAL(triggered()), this, SLOT(selectAll()));
+    QAction *deselectAllAction = menu.addAction(tr("Deselect All"));
+    deselectAllAction->setEnabled(selection().size());
+    connect(deselectAllAction, SIGNAL(triggered()), this, SLOT(selectNone()));
+    menu.addSeparator();
+    // Delete
+    QAction *deleteAction = menu.addAction(tr("Delete"));
+    deleteAction->setShortcut(QKeySequence::Delete);
+    deleteAction->setEnabled(!selection().isEmpty());
+    connect(deleteAction, SIGNAL(triggered()), this, SLOT(deleteSelected()));
+}
+
+void ConnectionEdit::contextMenuEvent(QContextMenuEvent * event)
+{
+    QMenu menu;
+    createContextMenu(menu);
+    menu.exec(event->globalPos());
+}
+
+} // namespace qdesigner_internal
+
+QT_END_NAMESPACE