Allow using not only prefixes for undo command text

Functions QUndo{Group,Stack}::create{Undo,Redo}Action() now use action
text templates "Undo %1" and "Redo %1" if no custom prefix was provided.

This makes more flexible translations possible. The surrounding text
(like "Undo" and "Redo") can now be suffixed to the command name as
German and Korean languages require ("%1 rueckgaengig machen" for German).

Also, now the default action text (when no command can be undone) can be
translated differently from the prefix. For example, it can be
translated as "Undo action", not just "Undo".

When a non-empty prefix is passed to QUndo*****::create****Action(),
those functions work as before, and the features described above become
unavailable.

Task-number: QTBUG-14442
Merge-request: 1212
Reviewed-by: ossi
(cherry picked from commit 213c25ad24e4f3b0a44f82f23d34746cd294f8d6)

3 files changed, 44 insertions, 17 deletions

diff --git a/src/gui/util/qundogroup.cpp b/src/gui/util/qundogroup.cpp
index 42cda7462a..a24ce8dce8 100644
--- a/src/gui/util/qundogroup.cpp
+++ b/src/gui/util/qundogroup.cpp
@@ -375,15 +375,18 @@ bool QUndoGroup::isClean() const
     for undo, if the group is empty or if none of the stacks are active, this action will
     be disabled.
 
-    If \a prefix is empty, the default prefix "Undo" is used.
+    If \a prefix is empty, the default template "Undo %1" is used instead of prefix.
+    Before Qt 4.8, the prefix "Undo" was used by default.
 
     \sa createRedoAction() canUndo() QUndoCommand::text()
 */
 
 QAction *QUndoGroup::createUndoAction(QObject *parent, const QString &prefix) const
 {
-    QString pref = prefix.isEmpty() ? tr("Undo") : prefix;
-    QUndoAction *result = new QUndoAction(pref, parent);
+    QUndoAction *result = new QUndoAction(prefix, parent);
+    if (prefix.isEmpty())
+        result->setTextFormat(tr("Undo %1"), tr("Undo", "Default text for undo action"));
+
     result->setEnabled(canUndo());
     result->setPrefixedText(undoText());
     connect(this, SIGNAL(canUndoChanged(bool)),
@@ -403,15 +406,18 @@ QAction *QUndoGroup::createUndoAction(QObject *parent, const QString &prefix) co
     for redo, if the group is empty or if none of the stacks are active, this action will
     be disabled.
 
-    If \a prefix is empty, the default prefix "Undo" is used.
+    If \a prefix is empty, the default template "Redo %1" is used instead of prefix.
+    Before Qt 4.8, the prefix "Redo" was used by default.
 
     \sa createUndoAction() canRedo() QUndoCommand::text()
 */
 
 QAction *QUndoGroup::createRedoAction(QObject *parent, const QString &prefix) const
 {
-    QString pref = prefix.isEmpty() ? tr("Redo") : prefix;
-    QUndoAction *result = new QUndoAction(pref, parent);
+    QUndoAction *result = new QUndoAction(prefix, parent);
+    if (prefix.isEmpty())
+        result->setTextFormat(tr("Redo %1"), tr("Redo", "Default text for redo action"));
+
     result->setEnabled(canRedo());
     result->setPrefixedText(redoText());
     connect(this, SIGNAL(canRedoChanged(bool)),
diff --git a/src/gui/util/qundostack.cpp b/src/gui/util/qundostack.cpp
index 6b038ee52e..417f02e4b2 100644
--- a/src/gui/util/qundostack.cpp
+++ b/src/gui/util/qundostack.cpp
@@ -374,11 +374,24 @@ QUndoAction::QUndoAction(const QString &prefix, QObject *parent)
 
 void QUndoAction::setPrefixedText(const QString &text)
 {
-    QString s = m_prefix;
-    if (!m_prefix.isEmpty() && !text.isEmpty())
-        s.append(QLatin1Char(' '));
-    s.append(text);
-    setText(s);
+    if (m_defaultText.isEmpty()) {
+        QString s = m_prefix;
+        if (!m_prefix.isEmpty() && !text.isEmpty())
+            s.append(QLatin1Char(' '));
+        s.append(text);
+        setText(s);
+    } else {
+        if (text.isEmpty())
+            setText(m_defaultText);
+        else
+            setText(m_prefix.arg(text));
+    }
+}
+
+void QUndoAction::setTextFormat(const QString &textFormat, const QString &defaultText)
+{
+    m_prefix = textFormat;
+    m_defaultText = defaultText;
 }
 
 #endif // QT_NO_ACTION
@@ -822,15 +835,18 @@ QString QUndoStack::redoText() const
     prefixed by the specified \a prefix. If there is no command available for undo,
     this action will be disabled.
 
-    If \a prefix is empty, the default prefix "Undo" is used.
+    If \a prefix is empty, the default template "Undo %1" is used instead of prefix.
+    Before Qt 4.8, the prefix "Undo" was used by default.
 
     \sa createRedoAction(), canUndo(), QUndoCommand::text()
 */
 
 QAction *QUndoStack::createUndoAction(QObject *parent, const QString &prefix) const
 {
-    QString pref = prefix.isEmpty() ? tr("Undo") : prefix;
-    QUndoAction *result = new QUndoAction(pref, parent);
+    QUndoAction *result = new QUndoAction(prefix, parent);
+    if (prefix.isEmpty())
+        result->setTextFormat(tr("Undo %1"), tr("Undo", "Default text for undo action"));
+
     result->setEnabled(canUndo());
     result->setPrefixedText(undoText());
     connect(this, SIGNAL(canUndoChanged(bool)),
@@ -849,15 +865,18 @@ QAction *QUndoStack::createUndoAction(QObject *parent, const QString &prefix) co
     prefixed by the specified \a prefix. If there is no command available for redo,
     this action will be disabled.
 
-    If \a prefix is empty, the default prefix "Redo" is used.
+    If \a prefix is empty, the default template "Redo %1" is used instead of prefix.
+    Before Qt 4.8, the prefix "Redo" was used by default.
 
     \sa createUndoAction(), canRedo(), QUndoCommand::text()
 */
 
 QAction *QUndoStack::createRedoAction(QObject *parent, const QString &prefix) const
 {
-    QString pref = prefix.isEmpty() ? tr("Redo") : prefix;
-    QUndoAction *result = new QUndoAction(pref, parent);
+    QUndoAction *result = new QUndoAction(prefix, parent);
+    if (prefix.isEmpty())
+        result->setTextFormat(tr("Redo %1"), tr("Redo", "Default text for redo action"));
+
     result->setEnabled(canRedo());
     result->setPrefixedText(redoText());
     connect(this, SIGNAL(canRedoChanged(bool)),
diff --git a/src/gui/util/qundostack_p.h b/src/gui/util/qundostack_p.h
index 3c7d0e7d85..2906fd8564 100644
--- a/src/gui/util/qundostack_p.h
+++ b/src/gui/util/qundostack_p.h
@@ -98,10 +98,12 @@ class QUndoAction : public QAction
     Q_OBJECT
 public:
     QUndoAction(const QString &prefix, QObject *parent = 0);
+    void setTextFormat(const QString &textFormat, const QString &defaultText);
 public Q_SLOTS:
     void setPrefixedText(const QString &text);
 private:
     QString m_prefix;
+    QString m_defaultText;
 };
 #endif // QT_NO_ACTION