Skip to content

BUGFIX: GraphicsView::setScene(nullptr) #495

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
paceholder merged 2 commits into from
Nov 14, 2025
Merged

BUGFIX: GraphicsView::setScene(nullptr) #495

Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
d870345
BUGFIX: GraphicsView::setScene(nullptr)
cxxamz Oct 30, 2025
91fd551
Make revisions based on the review results.
cxxamz Nov 13, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
175 changes: 109 additions & 66 deletions src/GraphicsView.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -78,75 +78,113 @@ void GraphicsView::setScene(BasicGraphicsScene *scene)

{
// setup actions
delete _clearSelectionAction;
_clearSelectionAction = new QAction(QStringLiteral("Clear Selection"), this);
_clearSelectionAction->setShortcut(Qt::Key_Escape);

connect(_clearSelectionAction, &QAction::triggered, scene, &QGraphicsScene::clearSelection);

addAction(_clearSelectionAction);
if (_clearSelectionAction)
{
delete _clearSelectionAction;
_clearSelectionAction = {};
}
if (scene)
{
_clearSelectionAction = new QAction(QStringLiteral("Clear Selection"), this);
_clearSelectionAction->setShortcut(Qt::Key_Escape);

connect(_clearSelectionAction, &QAction::triggered, scene, &QGraphicsScene::clearSelection);

addAction(_clearSelectionAction);
}
}

{
delete _deleteSelectionAction;
_deleteSelectionAction = new QAction(QStringLiteral("Delete Selection"), this);
_deleteSelectionAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
_deleteSelectionAction->setShortcut(QKeySequence(QKeySequence::Delete));
_deleteSelectionAction->setAutoRepeat(false);
connect(_deleteSelectionAction,
&QAction::triggered,
this,
&GraphicsView::onDeleteSelectedObjects);

addAction(_deleteSelectionAction);
if (_deleteSelectionAction)
{
delete _deleteSelectionAction;
_deleteSelectionAction = {};
}
if (scene)
{
_deleteSelectionAction = new QAction(QStringLiteral("Delete Selection"), this);
_deleteSelectionAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
_deleteSelectionAction->setShortcut(QKeySequence(QKeySequence::Delete));
_deleteSelectionAction->setAutoRepeat(false);
connect(_deleteSelectionAction,
&QAction::triggered,
this,
&GraphicsView::onDeleteSelectedObjects);

addAction(_deleteSelectionAction);
}
}

{
delete _duplicateSelectionAction;
_duplicateSelectionAction = new QAction(QStringLiteral("Duplicate Selection"), this);
_duplicateSelectionAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
_duplicateSelectionAction->setShortcut(QKeySequence(Qt::CTRL | Qt::Key_D));
_duplicateSelectionAction->setAutoRepeat(false);
connect(_duplicateSelectionAction,
&QAction::triggered,
this,
&GraphicsView::onDuplicateSelectedObjects);

addAction(_duplicateSelectionAction);
if (_duplicateSelectionAction)
{
delete _duplicateSelectionAction;
_duplicateSelectionAction = {};
}
if (scene)
{
_duplicateSelectionAction = new QAction(QStringLiteral("Duplicate Selection"), this);
_duplicateSelectionAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
_duplicateSelectionAction->setShortcut(QKeySequence(Qt::CTRL | Qt::Key_D));
_duplicateSelectionAction->setAutoRepeat(false);
connect(_duplicateSelectionAction,
&QAction::triggered,
this,
&GraphicsView::onDuplicateSelectedObjects);

addAction(_duplicateSelectionAction);
}
}

{
delete _copySelectionAction;
_copySelectionAction = new QAction(QStringLiteral("Copy Selection"), this);
_copySelectionAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
_copySelectionAction->setShortcut(QKeySequence(QKeySequence::Copy));
_copySelectionAction->setAutoRepeat(false);
connect(_copySelectionAction,
&QAction::triggered,
this,
&GraphicsView::onCopySelectedObjects);

addAction(_copySelectionAction);
if (_copySelectionAction)
{
delete _copySelectionAction;
_copySelectionAction = {};
}
if (scene)
{
_copySelectionAction = new QAction(QStringLiteral("Copy Selection"), this);
_copySelectionAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
_copySelectionAction->setShortcut(QKeySequence(QKeySequence::Copy));
_copySelectionAction->setAutoRepeat(false);
connect(_copySelectionAction,
&QAction::triggered,
this,
&GraphicsView::onCopySelectedObjects);

addAction(_copySelectionAction);
}
}

{
delete _pasteAction;
_pasteAction = new QAction(QStringLiteral("Paste Selection"), this);
_pasteAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
_pasteAction->setShortcut(QKeySequence(QKeySequence::Paste));
_pasteAction->setAutoRepeat(false);
connect(_pasteAction, &QAction::triggered, this, &GraphicsView::onPasteObjects);

addAction(_pasteAction);
if (_pasteAction)
{
delete _pasteAction;
_pasteAction = {};
}
if (scene)
{
_pasteAction = new QAction(QStringLiteral("Paste Selection"), this);
_pasteAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
_pasteAction->setShortcut(QKeySequence(QKeySequence::Paste));
_pasteAction->setAutoRepeat(false);
connect(_pasteAction, &QAction::triggered, this, &GraphicsView::onPasteObjects);

addAction(_pasteAction);
}
}

auto undoAction = scene->undoStack().createUndoAction(this, tr("&Undo"));
undoAction->setShortcuts(QKeySequence::Undo);
addAction(undoAction);

auto redoAction = scene->undoStack().createRedoAction(this, tr("&Redo"));
redoAction->setShortcuts(QKeySequence::Redo);
addAction(redoAction);
if (scene)
{
auto undoAction = scene->undoStack().createUndoAction(this, tr("&Undo"));
undoAction->setShortcuts(QKeySequence::Undo);
addAction(undoAction);

auto redoAction = scene->undoStack().createRedoAction(this, tr("&Redo"));
redoAction->setShortcuts(QKeySequence::Redo);
addAction(redoAction);
}
}

void GraphicsView::centerScene()
Expand All @@ -173,10 +211,13 @@ void GraphicsView::contextMenuEvent(QContextMenuEvent *event)

auto const scenePos = mapToScene(event->pos());

QMenu *menu = nodeScene()->createSceneMenu(scenePos);

if (menu) {
menu->exec(event->globalPos());
if (auto scene = nodeScene())
{
QMenu *menu = scene->createSceneMenu(scenePos);

if (menu) {
menu->exec(event->globalPos());
}
}
}

Expand Down Expand Up @@ -274,27 +315,29 @@ void GraphicsView::setupScale(double scale)

void GraphicsView::onDeleteSelectedObjects()
{
nodeScene()->undoStack().push(new DeleteCommand(nodeScene()));
if (auto scene = nodeScene()) scene->undoStack().push(new DeleteCommand(scene));
Copy link
Owner

@paceholder paceholder Nov 12, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Is there any valid configuration when scene != nodeScene?
Shouldn't we better assert this condition?

Copy link
Contributor Author

@cxxamz cxxamz Nov 13, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Is this acceptable?

void GraphicsView::onDeleteSelectedObjects()
{
    if (!nodeScene()) return; 

    nodeScene()->undoStack().push(new DeleteCommand(nodeScene()));
}

}

void GraphicsView::onDuplicateSelectedObjects()
{
qDebug() << "ON DUPLICATE";
QPointF const pastePosition = scenePastePosition();

nodeScene()->undoStack().push(new CopyCommand(nodeScene()));
nodeScene()->undoStack().push(new PasteCommand(nodeScene(), pastePosition));
if (auto scene = nodeScene())
{
scene->undoStack().push(new CopyCommand(scene));
scene->undoStack().push(new PasteCommand(scene, pastePosition));
}
}

void GraphicsView::onCopySelectedObjects()
{
nodeScene()->undoStack().push(new CopyCommand(nodeScene()));
if (auto scene = nodeScene()) scene->undoStack().push(new CopyCommand(scene));
}

void GraphicsView::onPasteObjects()
{
QPointF const pastePosition = scenePastePosition();
nodeScene()->undoStack().push(new PasteCommand(nodeScene(), pastePosition));
if (auto scene = nodeScene()) scene->undoStack().push(new PasteCommand(scene, pastePosition));
}

void GraphicsView::keyPressEvent(QKeyEvent *event)
Expand Down Expand Up @@ -335,7 +378,7 @@ void GraphicsView::mousePressEvent(QMouseEvent *event)
void GraphicsView::mouseMoveEvent(QMouseEvent *event)
{
QGraphicsView::mouseMoveEvent(event);
if (scene()->mouseGrabberItem() == nullptr && event->buttons() == Qt::LeftButton) {
if (scene() && scene()->mouseGrabberItem() == nullptr && event->buttons() == Qt::LeftButton) {
// Make sure shift is not being pressed
if ((event->modifiers() & Qt::ShiftModifier) == 0) {
QPointF difference = _clickPos - mapToScene(event->pos());
Expand Down