StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POQt tracing QGraphicsScene::itemAt() back to data model
primarykey
Id
6726754
data
AcceptedAnswerId
6734042
AnswerCount
2
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2011-07-17T21:04:23.847
FavoriteCount
0
LastActivityDate
2011-07-18T13:57:32.257
LastEditDate
LastEditorUserId
0
OwnerUserId
809908
ParentId
0
PostTypeId
1
Score
0
ViewCount
518
LastEditorDisplayName
text
Body
I have a list of objects that I use to add objects into a QGraphicsScene: <pre><code>for(int i = 0; i < levelObjects.length(); i++) { QRect objRect; objRect = spriteSheetLocations.value(levelObjects.at(i).value("frame_name")); //Q_ASSERT_X(objRect != QRect(0,0,0,0), "MainWindow::loadFile()", "Could not find sprite location!"); QImage img = spriteSheet.copy(objRect); int height = levelObjects.at(i).value("height").toInt(); int width = levelObjects.at(i).value("width").toInt(); int x = levelObjects.at(i).value("x").toInt(); int y = levelObjects.at(i).value("y").toInt(); img = img.scaled(QSize(width, height), Qt::IgnoreAspectRatio); item = scene->addPixmap(QPixmap::fromImage(img)); int xPos = x - width/2; int yPos = levelPlist.value("level_height").toInt() - (y + height/2); item->setPos(xPos, yPos); } </code></pre> Later on, in the GraphicsScene class, I detect when the user clicks on an item and drags it to move it: <pre><code>void LevelGraphicsView::mousePressEvent(QMouseEvent *event) { if (QGraphicsItem *item = itemAt(event->pos())) { qDebug() << "You clicked on item" << item; draggedItem = item; int mouseX = draggedItem->pos().x() - mapToScene(event->pos()).x(); int mouseY = draggedItem->pos().y() - mapToScene(event->pos()).y(); mouseOffset = QPointF(mouseX, mouseY); } else { qDebug() << "You didn't click on an item."; draggedItem = NULL; mouseOffset = QPointF(0,0); } } void LevelGraphicsView::mouseMoveEvent(QMouseEvent *event) { if(!draggedItem) // no item selected return; QPointF pos = mapToScene(event->pos()) + mouseOffset; draggedItem->setPos(pos); } </code></pre> This works fine for moving the items in the graphics view, but I'm having trouble tracing the QGraphicsItem back to the list item that created it. What's the best way to link the QGraphicsItem with the list item from which it was made so that the list item can be changed to reflect the change of position?
Tags
<qt><qgraphicsscene>
Title
Qt tracing QGraphicsScene::itemAt() back to data model
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. This table or related slice is empty.
UserOwnerUserId
1. USnumegil
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. This table or related slice is empty.
CommentsPostId
1. This table or related slice is empty.

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.