Designer:Fix undo crash caused by special handling of key move.

Remove special handling and storing of commands. Customize
SetPropertyCommand such that it is able to perform a transformation
of the new value., thus, the same (relative) distance can be used
on all widgets and the normal command merging mechanism can be used
to merge subsequent moves correctly.
Task-number: QTBUG-8213

2 files changed, 113 insertions, 62 deletions

diff --git a/tools/designer/src/components/formeditor/formwindow.cpp b/tools/designer/src/components/formeditor/formwindow.cpp
index 3a7cd83..8b8351d 100644
--- a/tools/designer/src/components/formeditor/formwindow.cpp
+++ b/tools/designer/src/components/formeditor/formwindow.cpp
@@ -1428,26 +1428,123 @@ int FormWindow::calcValue(int val, bool forward, bool snap, int snapOffset) cons
     return (forward ? val + 1 : val - 1);
 }
 
-QRect FormWindow::applyValue(const QRect &rect, int val, int key, bool size) const
+// ArrowKeyOperation: Stores a keyboard move or resize (Shift pressed)
+// operation.
+struct ArrowKeyOperation {
+    ArrowKeyOperation() : resize(false), distance(0), arrowKey(Qt::Key_Left) {}
+
+    QRect apply(const QRect &in) const;
+
+    bool resize; // Resize: Shift-Key->drag bottom/right corner, else just move
+    int distance;
+    int arrowKey;
+};
+
+QRect ArrowKeyOperation::apply(const QRect &rect) const
 {
     QRect r = rect;
-    if (size) {
-        if (key == Qt::Key_Left || key == Qt::Key_Right)
-            r.setWidth(val);
+    if (resize) {
+        if (arrowKey == Qt::Key_Left || arrowKey == Qt::Key_Right)
+            r.setWidth(r.width() + distance);
         else
-            r.setHeight(val);
+            r.setHeight(r.height() + distance);
     } else {
-        if (key == Qt::Key_Left || key == Qt::Key_Right)
-            r.moveLeft(val);
+        if (arrowKey == Qt::Key_Left || arrowKey == Qt::Key_Right)
+            r.moveLeft(r.x() + distance);
         else
-            r.moveTop(val);
+            r.moveTop(r.y() + distance);
     }
     return r;
 }
 
+QDebug operator<<(QDebug in, const ArrowKeyOperation &op)
+{
+    in.nospace() << "Resize=" << op.resize << " dist=" << op.distance << " Key=" << op.arrowKey << ' ';
+    return in;
+}
+
+} // namespace qdesigner_internal
+
+Q_DECLARE_METATYPE(qdesigner_internal::ArrowKeyOperation)
+
+namespace qdesigner_internal {
+
+// ArrowKeyPropertyHelper: Applies a struct ArrowKeyOperation
+// (stored as new value) to a list of widgets using to calculate the
+// changed geometry of the widget in setValue(). Thus, the 'newValue'
+// of the property command is the relative move distance, which is the same
+// for all widgets (although resulting in different geometries for the widgets).
+// The command merging can then work as it would when applying the same text
+// to all QLabels.
+
+class ArrowKeyPropertyHelper : public PropertyHelper {
+public:
+    ArrowKeyPropertyHelper(QObject* o, SpecialProperty sp,
+                       QDesignerPropertySheetExtension *s, int i) :
+                       PropertyHelper(o, sp, s, i) {}
+
+    virtual Value setValue(QDesignerFormWindowInterface *fw, const QVariant &value, bool changed, unsigned subPropertyMask);
+};
+
+PropertyHelper::Value ArrowKeyPropertyHelper::setValue(QDesignerFormWindowInterface *fw, const QVariant &value, bool changed, unsigned subPropertyMask)
+{
+    // Apply operation to obtain the new geometry value.
+    QWidget *w = qobject_cast<QWidget*>(object());
+    const ArrowKeyOperation operation = qvariant_cast<ArrowKeyOperation>(value);
+    const QRect newGeom = operation.apply(w->geometry());
+    return PropertyHelper::setValue(fw, QVariant(newGeom), changed, subPropertyMask);
+}
+
+// ArrowKeyPropertyCommand: Helper factory overwritten to create
+// ArrowKeyPropertyHelper and a merge operation that merges values of
+// the same direction.
+class ArrowKeyPropertyCommand: public SetPropertyCommand {
+public:
+    explicit ArrowKeyPropertyCommand(QDesignerFormWindowInterface *fw,
+                                     QUndoCommand *p = 0);
+
+    void init(QWidgetList &l, const ArrowKeyOperation &op);
+
+protected:
+    virtual PropertyHelper *createPropertyHelper(QObject *o, SpecialProperty sp,
+                                                 QDesignerPropertySheetExtension *s, int i) const
+        { return new ArrowKeyPropertyHelper(o, sp, s, i); }
+    virtual QVariant mergeValue(const QVariant &newValue);
+};
+
+ArrowKeyPropertyCommand::ArrowKeyPropertyCommand(QDesignerFormWindowInterface *fw,
+                                                 QUndoCommand *p) :
+    SetPropertyCommand(fw, p)
+{
+    static const int mid = qRegisterMetaType<qdesigner_internal::ArrowKeyOperation>();
+    Q_UNUSED(mid)
+}
+
+void ArrowKeyPropertyCommand::init(QWidgetList &l, const ArrowKeyOperation &op)
+{
+    QObjectList ol;
+    foreach(QWidget *w, l)
+        ol.push_back(w);
+    SetPropertyCommand::init(ol, QLatin1String("geometry"), qVariantFromValue(op));
+
+    setText(op.resize ? FormWindow::tr("Key Resize") : FormWindow::tr("Key Move"));
+}
+
+QVariant ArrowKeyPropertyCommand::mergeValue(const QVariant &newMergeValue)
+{
+    // Merge move operations of the same arrow key
+    if (!qVariantCanConvert<ArrowKeyOperation>(newMergeValue))
+        return QVariant();
+    ArrowKeyOperation mergedOperation = qvariant_cast<ArrowKeyOperation>(newValue());
+    const ArrowKeyOperation newMergeOperation = qvariant_cast<ArrowKeyOperation>(newMergeValue);
+    if (mergedOperation.resize != newMergeOperation.resize || mergedOperation.arrowKey != newMergeOperation.arrowKey)
+        return QVariant();
+    mergedOperation.distance += newMergeOperation.distance;
+    return qVariantFromValue(mergedOperation);
+}
+
 void FormWindow::handleArrowKeyEvent(int key, Qt::KeyboardModifiers modifiers)
 {
-    bool startMacro = false;
     const QDesignerFormWindowCursorInterface *c = cursor();
     if (!c->hasSelection())
         return;
@@ -1480,57 +1577,14 @@ void FormWindow::handleArrowKeyEvent(int key, Qt::KeyboardModifiers modifiers)
 
     const int newValue = calcValue(oldValue, forward, snap, snapPoint);
 
-    const int offset = newValue - oldValue;
+    ArrowKeyOperation operation;
+    operation.resize = modifiers & Qt::ShiftModifier;
+    operation.distance = newValue - oldValue;
+    operation.arrowKey = key;
 
-    const int selCount = selection.count();
-    // check if selection is the same as last time
-    if (selCount != m_moveSelection.count() ||
-        m_lastUndoIndex != m_commandHistory->index()) {
-        m_moveSelection.clear();
-        startMacro = true;
-    } else {
-        for (int index = 0; index < selCount; ++index) {
-            if (m_moveSelection[index]->object() != selection.at(index)) {
-                m_moveSelection.clear();
-                startMacro = true;
-                break;
-            }
-        }
-    }
-
-    if (startMacro)
-        beginCommand(tr("Key Move"));
-
-    for (int index = 0; index < selCount; ++index) {
-        QWidget *w = selection.at(index);
-        const QRect oldGeom = w->geometry();
-        const QRect geom = applyValue(oldGeom, getValue(oldGeom, key, size) + offset, key, size);
-
-        SetPropertyCommand *cmd = 0;
-
-        if (m_moveSelection.count() > index)
-            cmd = m_moveSelection[index];
-
-        if (!cmd) {
-            cmd = new SetPropertyCommand(this);
-            cmd->init(w, QLatin1String("geometry"), geom);
-            cmd->setText(tr("Key Move"));
-            m_commandHistory->push(cmd);
-
-            if (m_moveSelection.count() > index)
-                m_moveSelection.replace(index, cmd);
-            else
-                m_moveSelection.append(cmd);
-        } else {
-            cmd->setNewValue(geom);
-            cmd->redo();
-        }
-    }
-
-    if (startMacro) {
-        endCommand();
-        m_lastUndoIndex = m_commandHistory->index();
-    }
+    ArrowKeyPropertyCommand *cmd = new ArrowKeyPropertyCommand(this);
+    cmd->init(selection, operation);
+    m_commandHistory->push(cmd);
 }
 
 bool FormWindow::handleKeyReleaseEvent(QWidget *, QWidget *, QKeyEvent *e)
diff --git a/tools/designer/src/components/formeditor/formwindow.h b/tools/designer/src/components/formeditor/formwindow.h
index 3eee476..1b2916c 100644
--- a/tools/designer/src/components/formeditor/formwindow.h
+++ b/tools/designer/src/components/formeditor/formwindow.h
@@ -263,7 +263,6 @@ private:
 
     int getValue(const QRect &rect, int key, bool size) const;
     int calcValue(int val, bool forward, bool snap, int snapOffset) const;
-    QRect applyValue(const QRect &rect, int val, int key, bool size) const;
     void handleClickSelection(QWidget *managedWidget, unsigned mouseFlags);
 
     bool frameNeeded(QWidget *w) const;
@@ -368,8 +367,6 @@ private:
     QString m_exportMacro;
     QStringList m_includeHints;
 
-    QList<SetPropertyCommand*> m_moveSelection;
-    int m_lastUndoIndex;
     QPoint m_contextMenuPosition;
 
 private: