diff options
author | Lars Knoll <lars.knoll@nokia.com> | 2011-05-07 00:02:01 +0200 |
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committer | Lars Knoll <lars.knoll@nokia.com> | 2011-05-07 00:02:01 +0200 |
commit | f67b8df3ebdba2d398b9cce686b7c644adffff08 (patch) | |
tree | 062dd469f7cf8daa01a32d3e7b767b8fbdb7573a /src/gui/util/qundostack.cpp | |
parent | 32ce4fe9e6a94e77828e976776cf08da85254ff2 (diff) |
library split
Diffstat (limited to 'src/gui/util/qundostack.cpp')
-rw-r--r-- | src/gui/util/qundostack.cpp | 1127 |
1 files changed, 0 insertions, 1127 deletions
diff --git a/src/gui/util/qundostack.cpp b/src/gui/util/qundostack.cpp deleted file mode 100644 index 6b038ee52e..0000000000 --- a/src/gui/util/qundostack.cpp +++ /dev/null @@ -1,1127 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). -** All rights reserved. -** Contact: Nokia Corporation (qt-info@nokia.com) -** -** This file is part of the QtGui module 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 Technology Preview License Agreement accompanying -** this package. -** -** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package. -** -** If you have questions regarding the use of this file, please contact -** Nokia at qt-info@nokia.com. -** -** -** -** -** -** -** -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -#include <QtCore/qdebug.h> -#include "qundostack.h" -#include "qundogroup.h" -#include "qundostack_p.h" - -#ifndef QT_NO_UNDOCOMMAND - -QT_BEGIN_NAMESPACE - -/*! - \class QUndoCommand - \brief The QUndoCommand class is the base class of all commands stored on a QUndoStack. - \since 4.2 - - For an overview of Qt's Undo Framework, see the - \l{Overview of Qt's Undo Framework}{overview document}. - - A QUndoCommand represents a single editing action on a document; for example, - inserting or deleting a block of text in a text editor. QUndoCommand can apply - a change to the document with redo() and undo the change with undo(). The - implementations for these functions must be provided in a derived class. - - \snippet doc/src/snippets/code/src_gui_util_qundostack.cpp 0 - - A QUndoCommand has an associated text(). This is a short string - describing what the command does. It is used to update the text - properties of the stack's undo and redo actions; see - QUndoStack::createUndoAction() and QUndoStack::createRedoAction(). - - QUndoCommand objects are owned by the stack they were pushed on. - QUndoStack deletes a command if it has been undone and a new command is pushed. For example: - -\snippet doc/src/snippets/code/src_gui_util_qundostack.cpp 1 - - In effect, when a command is pushed, it becomes the top-most command - on the stack. - - To support command compression, QUndoCommand has an id() and the virtual function - mergeWith(). These functions are used by QUndoStack::push(). - - To support command macros, a QUndoCommand object can have any number of child - commands. Undoing or redoing the parent command will cause the child - commands to be undone or redone. A command can be assigned - to a parent explicitly in the constructor. In this case, the command - will be owned by the parent. - - The parent in this case is usually an empty command, in that it doesn't - provide its own implementation of undo() and redo(). Instead, it uses - the base implementations of these functions, which simply call undo() or - redo() on all its children. The parent should, however, have a meaningful - text(). - - \snippet doc/src/snippets/code/src_gui_util_qundostack.cpp 2 - - Another way to create macros is to use the convenience functions - QUndoStack::beginMacro() and QUndoStack::endMacro(). - - \sa QUndoStack -*/ - -/*! - Constructs a QUndoCommand object with the given \a parent and \a text. - - If \a parent is not 0, this command is appended to parent's child list. - The parent command then owns this command and will delete it in its - destructor. - - \sa ~QUndoCommand() -*/ - -QUndoCommand::QUndoCommand(const QString &text, QUndoCommand *parent) -{ - d = new QUndoCommandPrivate; - if (parent != 0) - parent->d->child_list.append(this); - d->text = text; -} - -/*! - Constructs a QUndoCommand object with parent \a parent. - - If \a parent is not 0, this command is appended to parent's child list. - The parent command then owns this command and will delete it in its - destructor. - - \sa ~QUndoCommand() -*/ - -QUndoCommand::QUndoCommand(QUndoCommand *parent) -{ - d = new QUndoCommandPrivate; - if (parent != 0) - parent->d->child_list.append(this); -} - -/*! - Destroys the QUndoCommand object and all child commands. - - \sa QUndoCommand() -*/ - -QUndoCommand::~QUndoCommand() -{ - qDeleteAll(d->child_list); - delete d; -} - -/*! - Returns the ID of this command. - - A command ID is used in command compression. It must be an integer unique to - this command's class, or -1 if the command doesn't support compression. - - If the command supports compression this function must be overridden in the - derived class to return the correct ID. The base implementation returns -1. - - QUndoStack::push() will only try to merge two commands if they have the - same ID, and the ID is not -1. - - \sa mergeWith(), QUndoStack::push() -*/ - -int QUndoCommand::id() const -{ - return -1; -} - -/*! - Attempts to merge this command with \a command. Returns true on - success; otherwise returns false. - - If this function returns true, calling this command's redo() must have the same - effect as redoing both this command and \a command. - Similarly, calling this command's undo() must have the same effect as undoing - \a command and this command. - - QUndoStack will only try to merge two commands if they have the same id, and - the id is not -1. - - The default implementation returns false. - - \snippet doc/src/snippets/code/src_gui_util_qundostack.cpp 3 - - \sa id() QUndoStack::push() -*/ - -bool QUndoCommand::mergeWith(const QUndoCommand *command) -{ - Q_UNUSED(command); - return false; -} - -/*! - Applies a change to the document. This function must be implemented in - the derived class. Calling QUndoStack::push(), - QUndoStack::undo() or QUndoStack::redo() from this function leads to - undefined beahavior. - - The default implementation calls redo() on all child commands. - - \sa undo() -*/ - -void QUndoCommand::redo() -{ - for (int i = 0; i < d->child_list.size(); ++i) - d->child_list.at(i)->redo(); -} - -/*! - Reverts a change to the document. After undo() is called, the state of - the document should be the same as before redo() was called. This function must - be implemented in the derived class. Calling QUndoStack::push(), - QUndoStack::undo() or QUndoStack::redo() from this function leads to - undefined beahavior. - - The default implementation calls undo() on all child commands in reverse order. - - \sa redo() -*/ - -void QUndoCommand::undo() -{ - for (int i = d->child_list.size() - 1; i >= 0; --i) - d->child_list.at(i)->undo(); -} - -/*! - Returns a short text string describing what this command does; for example, - "insert text". - - The text is used when the text properties of the stack's undo and redo - actions are updated. - - \sa setText(), QUndoStack::createUndoAction(), QUndoStack::createRedoAction() -*/ - -QString QUndoCommand::text() const -{ - return d->text; -} - -/*! - Sets the command's text to be the \a text specified. - - The specified text should be a short user-readable string describing what this - command does. - - \sa text() QUndoStack::createUndoAction() QUndoStack::createRedoAction() -*/ - -void QUndoCommand::setText(const QString &text) -{ - d->text = text; -} - -/*! - \since 4.4 - - Returns the number of child commands in this command. - - \sa child() -*/ - -int QUndoCommand::childCount() const -{ - return d->child_list.count(); -} - -/*! - \since 4.4 - - Returns the child command at \a index. - - \sa childCount(), QUndoStack::command() -*/ - -const QUndoCommand *QUndoCommand::child(int index) const -{ - if (index < 0 || index >= d->child_list.count()) - return 0; - return d->child_list.at(index); -} - -#endif // QT_NO_UNDOCOMMAND - -#ifndef QT_NO_UNDOSTACK - -/*! - \class QUndoStack - \brief The QUndoStack class is a stack of QUndoCommand objects. - \since 4.2 - - For an overview of Qt's Undo Framework, see the - \l{Overview of Qt's Undo Framework}{overview document}. - - An undo stack maintains a stack of commands that have been applied to a - document. - - New commands are pushed on the stack using push(). Commands can be - undone and redone using undo() and redo(), or by triggering the - actions returned by createUndoAction() and createRedoAction(). - - QUndoStack keeps track of the \a current command. This is the command - which will be executed by the next call to redo(). The index of this - command is returned by index(). The state of the edited object can be - rolled forward or back using setIndex(). If the top-most command on the - stack has already been redone, index() is equal to count(). - - QUndoStack provides support for undo and redo actions, command - compression, command macros, and supports the concept of a - \e{clean state}. - - \section1 Undo and Redo Actions - - QUndoStack provides convenient undo and redo QAction objects, which - can be inserted into a menu or a toolbar. When commands are undone or - redone, QUndoStack updates the text properties of these actions - to reflect what change they will trigger. The actions are also disabled - when no command is available for undo or redo. These actions - are returned by QUndoStack::createUndoAction() and QUndoStack::createRedoAction(). - - \section1 Command Compression and Macros - - Command compression is useful when several commands can be compressed - into a single command that can be undone and redone in a single operation. - For example, when a user types a character in a text editor, a new command - is created. This command inserts the character into the document at the - cursor position. However, it is more convenient for the user to be able - to undo or redo typing of whole words, sentences, or paragraphs. - Command compression allows these single-character commands to be merged - into a single command which inserts or deletes sections of text. - For more information, see QUndoCommand::mergeWith() and push(). - - A command macro is a sequence of commands, all of which are undone and - redone in one go. Command macros are created by giving a command a list - of child commands. - Undoing or redoing the parent command will cause the child commands to - be undone or redone. Command macros may be created explicitly - by specifying a parent in the QUndoCommand constructor, or by using the - convenience functions beginMacro() and endMacro(). - - Although command compression and macros appear to have the same effect to the - user, they often have different uses in an application. Commands that - perform small changes to a document may be usefully compressed if there is - no need to individually record them, and if only larger changes are relevant - to the user. - However, for commands that need to be recorded individually, or those that - cannot be compressed, it is useful to use macros to provide a more convenient - user experience while maintaining a record of each command. - - \section1 Clean State - - QUndoStack supports the concept of a clean state. When the - document is saved to disk, the stack can be marked as clean using - setClean(). Whenever the stack returns to this state through undoing and - redoing commands, it emits the signal cleanChanged(). This signal - is also emitted when the stack leaves the clean state. This signal is - usually used to enable and disable the save actions in the application, - and to update the document's title to reflect that it contains unsaved - changes. - - \sa QUndoCommand, QUndoView -*/ - -#ifndef QT_NO_ACTION - -QUndoAction::QUndoAction(const QString &prefix, QObject *parent) - : QAction(parent) -{ - m_prefix = prefix; -} - -void QUndoAction::setPrefixedText(const QString &text) -{ - QString s = m_prefix; - if (!m_prefix.isEmpty() && !text.isEmpty()) - s.append(QLatin1Char(' ')); - s.append(text); - setText(s); -} - -#endif // QT_NO_ACTION - -/*! \internal - Sets the current index to \a idx, emitting appropriate signals. If \a clean is true, - makes \a idx the clean index as well. -*/ - -void QUndoStackPrivate::setIndex(int idx, bool clean) -{ - Q_Q(QUndoStack); - - bool was_clean = index == clean_index; - - if (idx != index) { - index = idx; - emit q->indexChanged(index); - emit q->canUndoChanged(q->canUndo()); - emit q->undoTextChanged(q->undoText()); - emit q->canRedoChanged(q->canRedo()); - emit q->redoTextChanged(q->redoText()); - } - - if (clean) - clean_index = index; - - bool is_clean = index == clean_index; - if (is_clean != was_clean) - emit q->cleanChanged(is_clean); -} - -/*! \internal - If the number of commands on the stack exceedes the undo limit, deletes commands from - the bottom of the stack. - - Returns true if commands were deleted. -*/ - -bool QUndoStackPrivate::checkUndoLimit() -{ - if (undo_limit <= 0 || !macro_stack.isEmpty() || undo_limit >= command_list.count()) - return false; - - int del_count = command_list.count() - undo_limit; - - for (int i = 0; i < del_count; ++i) - delete command_list.takeFirst(); - - index -= del_count; - if (clean_index != -1) { - if (clean_index < del_count) - clean_index = -1; // we've deleted the clean command - else - clean_index -= del_count; - } - - return true; -} - -/*! - Constructs an empty undo stack with the parent \a parent. The - stack will initially be in the clean state. If \a parent is a - QUndoGroup object, the stack is automatically added to the group. - - \sa push() -*/ - -QUndoStack::QUndoStack(QObject *parent) - : QObject(*(new QUndoStackPrivate), parent) -{ -#ifndef QT_NO_UNDOGROUP - if (QUndoGroup *group = qobject_cast<QUndoGroup*>(parent)) - group->addStack(this); -#endif -} - -/*! - Destroys the undo stack, deleting any commands that are on it. If the - stack is in a QUndoGroup, the stack is automatically removed from the group. - - \sa QUndoStack() -*/ - -QUndoStack::~QUndoStack() -{ -#ifndef QT_NO_UNDOGROUP - Q_D(QUndoStack); - if (d->group != 0) - d->group->removeStack(this); -#endif - clear(); -} - -/*! - Clears the command stack by deleting all commands on it, and returns the stack - to the clean state. - - Commands are not undone or redone; the state of the edited object remains - unchanged. - - This function is usually used when the contents of the document are - abandoned. - - \sa QUndoStack() -*/ - -void QUndoStack::clear() -{ - Q_D(QUndoStack); - - if (d->command_list.isEmpty()) - return; - - bool was_clean = isClean(); - - d->macro_stack.clear(); - qDeleteAll(d->command_list); - d->command_list.clear(); - - d->index = 0; - d->clean_index = 0; - - emit indexChanged(0); - emit canUndoChanged(false); - emit undoTextChanged(QString()); - emit canRedoChanged(false); - emit redoTextChanged(QString()); - - if (!was_clean) - emit cleanChanged(true); -} - -/*! - Pushes \a cmd on the stack or merges it with the most recently executed command. - In either case, executes \a cmd by calling its redo() function. - - If \a cmd's id is not -1, and if the id is the same as that of the - most recently executed command, QUndoStack will attempt to merge the two - commands by calling QUndoCommand::mergeWith() on the most recently executed - command. If QUndoCommand::mergeWith() returns true, \a cmd is deleted. - - In all other cases \a cmd is simply pushed on the stack. - - If commands were undone before \a cmd was pushed, the current command and - all commands above it are deleted. Hence \a cmd always ends up being the - top-most on the stack. - - Once a command is pushed, the stack takes ownership of it. There - are no getters to return the command, since modifying it after it has - been executed will almost always lead to corruption of the document's - state. - - \sa QUndoCommand::id() QUndoCommand::mergeWith() -*/ - -void QUndoStack::push(QUndoCommand *cmd) -{ - Q_D(QUndoStack); - cmd->redo(); - - bool macro = !d->macro_stack.isEmpty(); - - QUndoCommand *cur = 0; - if (macro) { - QUndoCommand *macro_cmd = d->macro_stack.last(); - if (!macro_cmd->d->child_list.isEmpty()) - cur = macro_cmd->d->child_list.last(); - } else { - if (d->index > 0) - cur = d->command_list.at(d->index - 1); - while (d->index < d->command_list.size()) - delete d->command_list.takeLast(); - if (d->clean_index > d->index) - d->clean_index = -1; // we've deleted the clean state - } - - bool try_merge = cur != 0 - && cur->id() != -1 - && cur->id() == cmd->id() - && (macro || d->index != d->clean_index); - - if (try_merge && cur->mergeWith(cmd)) { - delete cmd; - if (!macro) { - emit indexChanged(d->index); - emit canUndoChanged(canUndo()); - emit undoTextChanged(undoText()); - emit canRedoChanged(canRedo()); - emit redoTextChanged(redoText()); - } - } else { - if (macro) { - d->macro_stack.last()->d->child_list.append(cmd); - } else { - d->command_list.append(cmd); - d->checkUndoLimit(); - d->setIndex(d->index + 1, false); - } - } -} - -/*! - Marks the stack as clean and emits cleanChanged() if the stack was - not already clean. - - Whenever the stack returns to this state through the use of undo/redo - commands, it emits the signal cleanChanged(). This signal is also - emitted when the stack leaves the clean state. - - \sa isClean(), cleanIndex() -*/ - -void QUndoStack::setClean() -{ - Q_D(QUndoStack); - if (!d->macro_stack.isEmpty()) { - qWarning("QUndoStack::setClean(): cannot set clean in the middle of a macro"); - return; - } - - d->setIndex(d->index, true); -} - -/*! - If the stack is in the clean state, returns true; otherwise returns false. - - \sa setClean() cleanIndex() -*/ - -bool QUndoStack::isClean() const -{ - Q_D(const QUndoStack); - if (!d->macro_stack.isEmpty()) - return false; - return d->clean_index == d->index; -} - -/*! - Returns the clean index. This is the index at which setClean() was called. - - A stack may not have a clean index. This happens if a document is saved, - some commands are undone, then a new command is pushed. Since - push() deletes all the undone commands before pushing the new command, the stack - can't return to the clean state again. In this case, this function returns -1. - - \sa isClean() setClean() -*/ - -int QUndoStack::cleanIndex() const -{ - Q_D(const QUndoStack); - return d->clean_index; -} - -/*! - Undoes the command below the current command by calling QUndoCommand::undo(). - Decrements the current command index. - - If the stack is empty, or if the bottom command on the stack has already been - undone, this function does nothing. - - \sa redo() index() -*/ - -void QUndoStack::undo() -{ - Q_D(QUndoStack); - if (d->index == 0) - return; - - if (!d->macro_stack.isEmpty()) { - qWarning("QUndoStack::undo(): cannot undo in the middle of a macro"); - return; - } - - int idx = d->index - 1; - d->command_list.at(idx)->undo(); - d->setIndex(idx, false); -} - -/*! - Redoes the current command by calling QUndoCommand::redo(). Increments the current - command index. - - If the stack is empty, or if the top command on the stack has already been - redone, this function does nothing. - - \sa undo() index() -*/ - -void QUndoStack::redo() -{ - Q_D(QUndoStack); - if (d->index == d->command_list.size()) - return; - - if (!d->macro_stack.isEmpty()) { - qWarning("QUndoStack::redo(): cannot redo in the middle of a macro"); - return; - } - - d->command_list.at(d->index)->redo(); - d->setIndex(d->index + 1, false); -} - -/*! - Returns the number of commands on the stack. Macro commands are counted as - one command. - - \sa index() setIndex() command() -*/ - -int QUndoStack::count() const -{ - Q_D(const QUndoStack); - return d->command_list.size(); -} - -/*! - Returns the index of the current command. This is the command that will be - executed on the next call to redo(). It is not always the top-most command - on the stack, since a number of commands may have been undone. - - \sa undo() redo() count() -*/ - -int QUndoStack::index() const -{ - Q_D(const QUndoStack); - return d->index; -} - -/*! - Repeatedly calls undo() or redo() until the current command index reaches - \a idx. This function can be used to roll the state of the document forwards - of backwards. indexChanged() is emitted only once. - - \sa index() count() undo() redo() -*/ - -void QUndoStack::setIndex(int idx) -{ - Q_D(QUndoStack); - if (!d->macro_stack.isEmpty()) { - qWarning("QUndoStack::setIndex(): cannot set index in the middle of a macro"); - return; - } - - if (idx < 0) - idx = 0; - else if (idx > d->command_list.size()) - idx = d->command_list.size(); - - int i = d->index; - while (i < idx) - d->command_list.at(i++)->redo(); - while (i > idx) - d->command_list.at(--i)->undo(); - - d->setIndex(idx, false); -} - -/*! - Returns true if there is a command available for undo; otherwise returns false. - - This function returns false if the stack is empty, or if the bottom command - on the stack has already been undone. - - Synonymous with index() == 0. - - \sa index() canRedo() -*/ - -bool QUndoStack::canUndo() const -{ - Q_D(const QUndoStack); - if (!d->macro_stack.isEmpty()) - return false; - return d->index > 0; -} - -/*! - Returns true if there is a command available for redo; otherwise returns false. - - This function returns false if the stack is empty or if the top command - on the stack has already been redone. - - Synonymous with index() == count(). - - \sa index() canUndo() -*/ - -bool QUndoStack::canRedo() const -{ - Q_D(const QUndoStack); - if (!d->macro_stack.isEmpty()) - return false; - return d->index < d->command_list.size(); -} - -/*! - Returns the text of the command which will be undone in the next call to undo(). - - \sa QUndoCommand::text() redoText() -*/ - -QString QUndoStack::undoText() const -{ - Q_D(const QUndoStack); - if (!d->macro_stack.isEmpty()) - return QString(); - if (d->index > 0) - return d->command_list.at(d->index - 1)->text(); - return QString(); -} - -/*! - Returns the text of the command which will be redone in the next call to redo(). - - \sa QUndoCommand::text() undoText() -*/ - -QString QUndoStack::redoText() const -{ - Q_D(const QUndoStack); - if (!d->macro_stack.isEmpty()) - return QString(); - if (d->index < d->command_list.size()) - return d->command_list.at(d->index)->text(); - return QString(); -} - -#ifndef QT_NO_ACTION - -/*! - Creates an undo QAction object with the given \a parent. - - Triggering this action will cause a call to undo(). The text of this action - is the text of the command which will be undone in the next call to undo(), - 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. - - \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); - result->setEnabled(canUndo()); - result->setPrefixedText(undoText()); - connect(this, SIGNAL(canUndoChanged(bool)), - result, SLOT(setEnabled(bool))); - connect(this, SIGNAL(undoTextChanged(QString)), - result, SLOT(setPrefixedText(QString))); - connect(result, SIGNAL(triggered()), this, SLOT(undo())); - return result; -} - -/*! - Creates an redo QAction object with the given \a parent. - - Triggering this action will cause a call to redo(). The text of this action - is the text of the command which will be redone in the next call to redo(), - 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. - - \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); - result->setEnabled(canRedo()); - result->setPrefixedText(redoText()); - connect(this, SIGNAL(canRedoChanged(bool)), - result, SLOT(setEnabled(bool))); - connect(this, SIGNAL(redoTextChanged(QString)), - result, SLOT(setPrefixedText(QString))); - connect(result, SIGNAL(triggered()), this, SLOT(redo())); - return result; -} - -#endif // QT_NO_ACTION - -/*! - Begins composition of a macro command with the given \a text description. - - An empty command described by the specified \a text is pushed on the stack. - Any subsequent commands pushed on the stack will be appended to the empty - command's children until endMacro() is called. - - Calls to beginMacro() and endMacro() may be nested, but every call to - beginMacro() must have a matching call to endMacro(). - - While a macro is composed, the stack is disabled. This means that: - \list - \i indexChanged() and cleanChanged() are not emitted, - \i canUndo() and canRedo() return false, - \i calling undo() or redo() has no effect, - \i the undo/redo actions are disabled. - \endlist - - The stack becomes enabled and appropriate signals are emitted when endMacro() - is called for the outermost macro. - - \snippet doc/src/snippets/code/src_gui_util_qundostack.cpp 4 - - This code is equivalent to: - - \snippet doc/src/snippets/code/src_gui_util_qundostack.cpp 5 - - \sa endMacro() -*/ - -void QUndoStack::beginMacro(const QString &text) -{ - Q_D(QUndoStack); - QUndoCommand *cmd = new QUndoCommand(); - cmd->setText(text); - - if (d->macro_stack.isEmpty()) { - while (d->index < d->command_list.size()) - delete d->command_list.takeLast(); - if (d->clean_index > d->index) - d->clean_index = -1; // we've deleted the clean state - d->command_list.append(cmd); - } else { - d->macro_stack.last()->d->child_list.append(cmd); - } - d->macro_stack.append(cmd); - - if (d->macro_stack.count() == 1) { - emit canUndoChanged(false); - emit undoTextChanged(QString()); - emit canRedoChanged(false); - emit redoTextChanged(QString()); - } -} - -/*! - Ends composition of a macro command. - - If this is the outermost macro in a set nested macros, this function emits - indexChanged() once for the entire macro command. - - \sa beginMacro() -*/ - -void QUndoStack::endMacro() -{ - Q_D(QUndoStack); - if (d->macro_stack.isEmpty()) { - qWarning("QUndoStack::endMacro(): no matching beginMacro()"); - return; - } - - d->macro_stack.removeLast(); - - if (d->macro_stack.isEmpty()) { - d->checkUndoLimit(); - d->setIndex(d->index + 1, false); - } -} - -/*! - \since 4.4 - - Returns a const pointer to the command at \a index. - - This function returns a const pointer, because modifying a command, - once it has been pushed onto the stack and executed, almost always - causes corruption of the state of the document, if the command is - later undone or redone. - - \sa QUndoCommand::child() -*/ -const QUndoCommand *QUndoStack::command(int index) const -{ - Q_D(const QUndoStack); - - if (index < 0 || index >= d->command_list.count()) - return 0; - return d->command_list.at(index); -} - -/*! - Returns the text of the command at index \a idx. - - \sa beginMacro() -*/ - -QString QUndoStack::text(int idx) const -{ - Q_D(const QUndoStack); - - if (idx < 0 || idx >= d->command_list.size()) - return QString(); - return d->command_list.at(idx)->text(); -} - -/*! - \property QUndoStack::undoLimit - \brief the maximum number of commands on this stack. - \since 4.3 - - When the number of commands on a stack exceedes the stack's undoLimit, commands are - deleted from the bottom of the stack. Macro commands (commands with child commands) - are treated as one command. The default value is 0, which means that there is no - limit. - - This property may only be set when the undo stack is empty, since setting it on a - non-empty stack might delete the command at the current index. Calling setUndoLimit() - on a non-empty stack prints a warning and does nothing. -*/ - -void QUndoStack::setUndoLimit(int limit) -{ - Q_D(QUndoStack); - - if (!d->command_list.isEmpty()) { - qWarning("QUndoStack::setUndoLimit(): an undo limit can only be set when the stack is empty"); - return; - } - - if (limit == d->undo_limit) - return; - d->undo_limit = limit; - d->checkUndoLimit(); -} - -int QUndoStack::undoLimit() const -{ - Q_D(const QUndoStack); - - return d->undo_limit; -} - -/*! - \property QUndoStack::active - \brief the active status of this stack. - - An application often has multiple undo stacks, one for each opened document. The active - stack is the one associated with the currently active document. If the stack belongs - to a QUndoGroup, calls to QUndoGroup::undo() or QUndoGroup::redo() will be forwarded - to this stack when it is active. If the QUndoGroup is watched by a QUndoView, the view - will display the contents of this stack when it is active. If the stack does not belong to - a QUndoGroup, making it active has no effect. - - It is the programmer's responsibility to specify which stack is active by - calling setActive(), usually when the associated document window receives focus. - - \sa QUndoGroup -*/ - -void QUndoStack::setActive(bool active) -{ -#ifdef QT_NO_UNDOGROUP - Q_UNUSED(active); -#else - Q_D(QUndoStack); - - if (d->group != 0) { - if (active) - d->group->setActiveStack(this); - else if (d->group->activeStack() == this) - d->group->setActiveStack(0); - } -#endif -} - -bool QUndoStack::isActive() const -{ -#ifdef QT_NO_UNDOGROUP - return true; -#else - Q_D(const QUndoStack); - return d->group == 0 || d->group->activeStack() == this; -#endif -} - -/*! - \fn void QUndoStack::indexChanged(int idx) - - This signal is emitted whenever a command modifies the state of the document. - This happens when a command is undone or redone. When a macro - command is undone or redone, or setIndex() is called, this signal - is emitted only once. - - \a idx specifies the index of the current command, ie. the command which will be - executed on the next call to redo(). - - \sa index() setIndex() -*/ - -/*! - \fn void QUndoStack::cleanChanged(bool clean) - - This signal is emitted whenever the stack enters or leaves the clean state. - If \a clean is true, the stack is in a clean state; otherwise this signal - indicates that it has left the clean state. - - \sa isClean() setClean() -*/ - -/*! - \fn void QUndoStack::undoTextChanged(const QString &undoText) - - This signal is emitted whenever the value of undoText() changes. It is - used to update the text property of the undo action returned by createUndoAction(). - \a undoText specifies the new text. -*/ - -/*! - \fn void QUndoStack::canUndoChanged(bool canUndo) - - This signal is emitted whenever the value of canUndo() changes. It is - used to enable or disable the undo action returned by createUndoAction(). - \a canUndo specifies the new value. -*/ - -/*! - \fn void QUndoStack::redoTextChanged(const QString &redoText) - - This signal is emitted whenever the value of redoText() changes. It is - used to update the text property of the redo action returned by createRedoAction(). - \a redoText specifies the new text. -*/ - -/*! - \fn void QUndoStack::canRedoChanged(bool canRedo) - - This signal is emitted whenever the value of canRedo() changes. It is - used to enable or disable the redo action returned by createRedoAction(). - \a canRedo specifies the new value. -*/ - -QT_END_NAMESPACE - -#endif // QT_NO_UNDOSTACK |