1 files changed, 168 insertions, 0 deletions
diff --git a/src/commands.cpp b/src/commands.cpp
new file mode 100644
index 0000000..5b99cbf
--- /dev/null
+++ b/src/commands.cpp
@@ -0,0 +1,168 @@
+#include "commands.h"
+#include <QUndoCommand>
+
+
+// Helper class to store single byte commands
+class CharCommand : public QUndoCommand
+{
+public:
+    enum CCmd {insert, removeAt, overwrite};
+
+    CharCommand(Chunks * chunks, CCmd cmd, qint64 charPos, char newChar,
+                       QUndoCommand *parent=0);
+
+    void undo();
+    void redo();
+    bool mergeWith(const QUndoCommand *command);
+    int id() const { return 1234; }
+
+private:
+    Chunks * _chunks;
+    qint64 _charPos;
+    bool _wasChanged;
+    char _newChar;
+    char _oldChar;
+    CCmd _cmd;
+};
+
+CharCommand::CharCommand(Chunks * chunks, CCmd cmd, qint64 charPos, char newChar, QUndoCommand *parent)
+    : QUndoCommand(parent)
+    , _chunks(chunks)
+    , _charPos(charPos)
+    , _wasChanged(false)
+    , _newChar(newChar)
+    , _oldChar('\0')
+    , _cmd(cmd)
+{
+}
+
+bool CharCommand::mergeWith(const QUndoCommand *command)
+{
+    const CharCommand *nextCommand = static_cast<const CharCommand *>(command);
+    bool result = false;
+
+    if (_cmd != CharCommand::removeAt)
+    {
+        if (nextCommand->_cmd == overwrite)
+            if (nextCommand->_charPos == _charPos)
+            {
+                _newChar = nextCommand->_newChar;
+                result = true;
+            }
+    }
+    return result;
+}
+
+void CharCommand::undo()
+{
+    switch (_cmd)
+    {
+        case insert:
+            _chunks->removeAt(_charPos);
+            break;
+        case overwrite:
+            _chunks->overwrite(_charPos, _oldChar);
+            _chunks->setDataChanged(_charPos, _wasChanged);
+            break;
+        case removeAt:
+            _chunks->insert(_charPos, _oldChar);
+            _chunks->setDataChanged(_charPos, _wasChanged);
+            break;
+    }
+}
+
+void CharCommand::redo()
+{
+    switch (_cmd)
+    {
+        case insert:
+            _chunks->insert(_charPos, _newChar);
+            break;
+        case overwrite:
+            _oldChar = (*_chunks)[_charPos];
+            _wasChanged = _chunks->dataChanged(_charPos);
+            _chunks->overwrite(_charPos, _newChar);
+            break;
+        case removeAt:
+            _oldChar = (*_chunks)[_charPos];
+            _wasChanged = _chunks->dataChanged(_charPos);
+            _chunks->removeAt(_charPos);
+            break;
+    }
+}
+
+UndoStack::UndoStack(Chunks * chunks, QObject * parent)
+    : QUndoStack(parent)
+{
+    _chunks = chunks;
+    _parent = parent;
+    this->setUndoLimit(1000);
+}
+
+void UndoStack::insert(qint64 pos, char c)
+{
+    if ((pos >= 0) && (pos <= _chunks->size()))
+    {
+        QUndoCommand *cc = new CharCommand(_chunks, CharCommand::insert, pos, c);
+        this->push(cc);
+    }
+}
+
+void UndoStack::insert(qint64 pos, const QByteArray &ba)
+{
+    if ((pos >= 0) && (pos <= _chunks->size()))
+    {
+        QString txt = QString(tr("Inserting %1 bytes")).arg(ba.size());
+        beginMacro(txt);
+        for (int idx=0; idx < ba.size(); idx++)
+        {
+            QUndoCommand *cc = new CharCommand(_chunks, CharCommand::insert, pos + idx, ba.at(idx));
+            this->push(cc);
+        }
+        endMacro();
+    }
+}
+
+void UndoStack::removeAt(qint64 pos, qint64 len)
+{
+    if ((pos >= 0) && (pos < _chunks->size()))
+    {
+        if (len==1)
+        {
+            QUndoCommand *cc = new CharCommand(_chunks, CharCommand::removeAt, pos, char(0));
+            this->push(cc);
+        }
+        else
+        {
+            QString txt = QString(tr("Delete %1 chars")).arg(len);
+            beginMacro(txt);
+            for (qint64 cnt=0; cnt<len; cnt++)
+            {
+                QUndoCommand *cc = new CharCommand(_chunks, CharCommand::removeAt, pos, char(0));
+                push(cc);
+            }
+            endMacro();
+        }
+    }
+}
+
+void UndoStack::overwrite(qint64 pos, char c)
+{
+    if ((pos >= 0) && (pos < _chunks->size()))
+    {
+        QUndoCommand *cc = new CharCommand(_chunks, CharCommand::overwrite, pos, c);
+        this->push(cc);
+    }
+}
+
+void UndoStack::overwrite(qint64 pos, int len, const QByteArray &ba)
+{
+    if ((pos >= 0) && (pos < _chunks->size()))
+    {
+        QString txt = QString(tr("Overwrite %1 chars")).arg(len);
+        beginMacro(txt);
+        removeAt(pos, len);
+        insert(pos, ba);
+        endMacro();
+    }
+}