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updated new document changed code to work with undo/redo
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because the cursor is not moved to the end of the change by an undo or
redo operation when the document contents change signal is received, the
current cursor cannot be used, so the document changed slot was modified
to obtain the document text cursor, change the position of the cursor to
the position of the start of the change, obtain info about this
position, moved to the end of the position (using the number of
characters added), and then get the info for this position (which the
cursor will be moved to afterward) - this change will also work with all
other kinds of changes

also renamed some local variables in the document changed function
removed the reimplemented undo and redo functions - not needed
removed checks for undo and redo key sequences
removed the undoAdded() slot - no need to keep track of line undos/redos
removed m_lineModCount and m_undoActive - not needed
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@thunder422
thunder422 committed Mar 8, 2013
1 parent ebffb44 commit a9db922
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Showing 2 changed files with 17 additions and 135 deletions.
147 changes: 17 additions & 130 deletions editbox.cpp
View file
Expand Up @@ -35,9 +35,7 @@
EditBox::EditBox(QWidget *parent) :
QPlainTextEdit(parent),
m_lineModified(-1),
m_lineModCount(0),
m_lineModifiedIsNew(false),
m_undoActive(false),
m_ignoreChange(false)
{
// set the edit box to a fixed width font
Expand All @@ -54,10 +52,6 @@ EditBox::EditBox(QWidget *parent) :
// connect to catch cursor position changes
connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(cursorMoved()));

// connect to catch when undo commands are added
connect(document(), SIGNAL(undoCommandAdded()),
this, SLOT(undoAdded()));

// create line number area width and connect signal to update it
m_lineNumberWidget = new LineNumberWidget(this);

Expand Down Expand Up @@ -123,16 +117,6 @@ void EditBox::keyPressEvent(QKeyEvent *event)
break;

default: // check for key sequences
if (event->matches(QKeySequence::Undo))
{
undo(); // do undo here
return;
}
if (event->matches(QKeySequence::Redo))
{
redo(); // do redo here
return;
}
}
QPlainTextEdit::keyPressEvent(event);
m_ignoreChange = false;
Expand Down Expand Up @@ -215,20 +199,22 @@ void EditBox::documentChanged(int position, int charsRemoved, int charsAdded)
int linesDeleted = 0;
QStringList lines;

QTextBlock block = document()->findBlock(position);
int lineNumber = block.blockNumber();
bool positionAtLineBegin = position == block.position();

// get information about position at start of change
QTextCursor cursor = textCursor();
int linesModified = cursor.blockNumber() - lineNumber;
cursor.setPosition(position);
int changeLine = cursor.blockNumber();
bool changeAtLineBegin = cursor.atBlockStart();

// move cursor to end of change and get information about end position
cursor.movePosition(QTextCursor::Right, QTextCursor::MoveAnchor,
charsAdded);
int linesModified = cursor.blockNumber() - changeLine;
int newLineCount = document()->blockCount();
int netLineCount = newLineCount - m_lineCount;

// TODO may need to handle if m_lineModType == LineInserted here

if (linesModified != 0 || netLineCount != 0) // multiple lines affected?
{
if (linesModified == netLineCount && positionAtLineBegin)
if (linesModified == netLineCount && changeAtLineBegin)
{
// single line changed and at begin of line
linesInserted = netLineCount;
Expand All @@ -237,7 +223,7 @@ void EditBox::documentChanged(int position, int charsRemoved, int charsAdded)
else // changed multiple lines or single line and not at begin of line
{
// check if last line is new before linesModified is changed
if (linesModified == netLineCount && !positionAtLineBegin
if (linesModified == netLineCount && !changeAtLineBegin
|| cursor.atBlockEnd() && charsAdded > 0)
{
m_lineModifiedIsNew = true;
Expand All @@ -253,12 +239,12 @@ void EditBox::documentChanged(int position, int charsRemoved, int charsAdded)
// reset new line status, and no lines deleted
m_lineModifiedIsNew = false;
netLineCount = 0;
lineNumber = -1; // prevent empty signal
changeLine = -1; // prevent empty signal
}
// check if result is a single line and was not at begin of line
else if (linesModified == 0 && !positionAtLineBegin)
else if (linesModified == 0 && !changeAtLineBegin)
{
lineNumber++; // first line deleted is after current line
changeLine++; // first line deleted is after current line
}
linesDeleted = -netLineCount;
}
Expand All @@ -275,23 +261,22 @@ void EditBox::documentChanged(int position, int charsRemoved, int charsAdded)
}
}
}
if (lineNumber != -1)
if (changeLine != -1)
{
if (linesModified + linesInserted > 0)
{
// get list of lines changed and inserted
for (int i = 0; i < linesModified + linesInserted; i++)
{
lines << document()->findBlockByNumber(lineNumber
lines << document()->findBlockByNumber(changeLine
+ i).text();
}
}
emit linesChanged(lineNumber, linesDeleted, linesInserted, lines);
emit linesChanged(changeLine, linesDeleted, linesInserted, lines);
}
m_lineCount = newLineCount;
}
m_lineModified = cursor.blockNumber();
m_lineModCount = 0;
}


Expand All @@ -308,104 +293,6 @@ void EditBox::cursorMoved(void)
}


// function to keep track of when undo commands are added

void EditBox::undoAdded(void)
{
// if modified line, then increment number of changes on line
if (m_lineModified >= 0)
{
m_lineModCount++;
}
}


// function to catch the undo action before passing it on to the base class
//
// - if there is no modified line or undo is active then indicates that
// document changes from undo should be ignored (don't set modified line)
// - calls the base class undo to perform the undo
// - if the undo moved the cursor, then set the modified line and set
// to indicate that undo is active (count undos as line modifications)
// - if cursor didn't move and undo is active, increment line change count
// - else if line change count is zero, then reset the modified line
// - else decrement the line change count

void EditBox::undo(void)
{
// if no modified line or undo active, indicate to ignore next change
if (m_lineModified == -1 || m_undoActive)
{
// FIXME m_ignoreChange = true;
}
int line = textCursor().blockNumber();
QPlainTextEdit::undo();
m_ignoreChange = false; // reset flag if still set

if (line != textCursor().blockNumber())
{
// set new modified line and indicate undo active if on a new line
m_lineModified = textCursor().blockNumber();
m_lineModCount = 0;
m_undoActive = true;
}
else if (m_undoActive)
{
m_lineModCount++; // increment line change count if undo active
}
else if (m_lineModCount == 0)
{
m_lineModified = -1; // if last change on line, reset modified line
}
else
{
m_lineModCount--; // otherwise, decrement line change count
}
}


// function to catch the redo action before passing it on to the base class
//
// - if there is no modified line then indicates that document changes
// from redo should be ignored (don't set the modified line)
// - if there is no modified line, then set the modified line
// - else if undo active, then if the line change count is zero, deactivates
// undo, otherwise decrements the line change count
// - else increments the line change count

void EditBox::redo(void)
{
if (m_lineModified == -1)
{
// FIXME m_ignoreChange = true;
}
QPlainTextEdit::redo();
m_ignoreChange = false; // reset flag if still set

if (m_lineModified == -1)
{
// set the modified line if there was none
m_lineModified = textCursor().blockNumber();
m_lineModCount = 0;
}
else if (m_undoActive)
{
if (m_lineModCount == 0)
{
m_undoActive = false; // if all undos use, then deactivate undo
}
else
{
m_lineModCount--; // otherwise, decrement line change count
}
}
else
{
m_lineModCount++; // increment line change count if undo not active
}
}


// function to check if current line was modified and to process it

void EditBox::captureModifiedLine(void)
Expand Down
5 changes: 0 additions & 5 deletions editbox.h
View file
Expand Up @@ -55,9 +55,6 @@ class EditBox : public QPlainTextEdit
public slots:
void documentChanged(int position, int charsRemoved, int charsAdded);
void cursorMoved(void);
void undo(void);
void redo(void);
void undoAdded(void);

private slots:
void updateLineNumberWidgetWidth(void);
Expand All @@ -72,9 +69,7 @@ private slots:
};

int m_lineModified; // current line that has been modified
int m_lineModCount; // number of modifications to line
bool m_lineModifiedIsNew; // modified line is a new line flag
bool m_undoActive; // line modified due to undo
bool m_ignoreChange; // ignore next document change flag
QWidget *m_lineNumberWidget; // widget to display line numbers
int m_lineCount; // total document line count
Expand Down

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