I have made a custom class derived from QGraphicsRectItem.
class CornerPoint : public QGraphicsRectItem
{
public:
CornerPoint(QPointF centre);
enum { Type = UserType + 1 };
int type() const{ return Type; }
QVariant itemChange(GraphicsItemChange change, const QVariant &value);
public slots:
void updatePosition(QPointF);
};
CPP File
CornerPoint::CornerPoint(QPointF centre): QGraphicsRectItem(NULL)
{
setPos(55,22);
setRect(0,0,99,99);
}
QVariant CornerPoint::itemChange(QGraphicsItem::GraphicsItemChange change, const QVariant &value)
{
std::cout << "Change is" << change << std::endl;
if( QGraphicsItem::ItemPositionChange == change && scene())
{
std::cout << "New values " << value.toPointF().x() << value.toPointF().y() << std::endl;
}
return QGraphicsItem::itemChange(change, value);
}
I have made these objects selectable and moveable. But when I drag them, I dont receive the signal for position change of this rectangle. All I receive are the signals with value 4 (ItemSelectedChange) and 14 (ItemSelectedHasChanged).
This post says that I need to enable some flags. But I can't find any example of any one doing this, and using these flags is giving errors.
Crap.
I just had to enable this flag :
setFlag(GraphicsItemFlag::ItemSendsGeometryChanges);
Related
If I call removeRows on records which were read from the database a ! will be displayed in the first column of the tableView.
The only thing which I would like to achieve is that this row will not be displayed in the view. I tried it with QSortFilterProxyModel but I don't know where I can get the flag which is used to display the ! in the first column. Is there a way to set a filter in QSortFilterProxyModel that it only contains the rows which don't have this flag?
From where does the view take the information, that the removed row is marked with a "!" ? This information might be hidden somewhere in the model, but I cannot find out where.
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent),
m_ui(new Ui::MainWindow),
m_model(new QSqlTableModel(this)),
m_proxyModel(new QSortFilterProxyModel(this))
{
m_ui->setupUi(this);
m_model->setTable("test");
m_model->setEditStrategy(QSqlTableModel::OnManualSubmit);
m_model->select();
m_proxyModel->setSourceModel(m_model);
m_ui->tableView->setModel(m_proxyModel);
qDebug() << "Select : Row count:" << m_model->rowCount();
connect(m_ui->tableView->selectionModel(), &QItemSelectionModel::selectionChanged,
this, &MainWindow::on_selectionChanged);
}
MainWindow::~MainWindow()
{
delete m_ui;
}
void MainWindow::on_pushButtonNewRecord_clicked()
{
qDebug() << "New Record";
m_record = m_model->record();
m_record.setValue("firstname", "john");
m_record.setValue("lastname", "doe");
m_record.setValue("email", "john.doe#email.com");
m_model->insertRecord(-1, m_record);
qDebug() << "New Record : Row count:" << m_model->rowCount();
}
void MainWindow::on_pushButtonRemoveRow_clicked()
{
qDebug() << "Remove Row";
if (m_row >= 0) {
m_proxyModel->removeRow(m_row);
qDebug() << "Remove Record: Row count:" << m_model->rowCount();
}
for (int i = 0; i < m_model->rowCount(); i++) {
qDebug() << "\n";
qDebug() << "Remove Row: index :" << m_model->index(i, 0);
qDebug() << "Remove Row: isValid:" << m_model->index(i, 0).isValid();
qDebug() << "Remove Row: isDirty:" << m_model->isDirty(m_model->index(i, 0));
qDebug() << "Remove Row: flags :" << m_model->index(i, 0).flags();
qDebug() << "Remove Row: data :" << m_model->index(i, 0).data(Qt::DisplayRole);
qDebug() << "Remove Row: heaader:" << m_model->headerData(i, Qt::Vertical);
QVariant verticalHeader = m_model->headerData(i, Qt::Vertical);
if (verticalHeader == "!") {
qDebug() << "Deleted";
}
//qDebug() << m_model->record(i);
}
}
void MainWindow::on_pushButtonSubmit_clicked()
{
qDebug() << "Submit";
m_model->submitAll();
m_model->select();
}
void MainWindow::on_selectionChanged(const QItemSelection &selected, const QItemSelection &deselected)
{
Q_UNUSED(deselected)
if (!selected.isEmpty()) {
m_row = selected.indexes().first().row();
}
}
You have to implement a QSortFilterProxyModel that filters the rows that are Dirty and whose vertical header text is "!", You must also call the invalidate() method to force the application of the filter.
dirtyfilterproxymodel.h
#ifndef DIRTYFILTERPROXYMODEL_H
#define DIRTYFILTERPROXYMODEL_H
#include <QSortFilterProxyModel>
#include <QSqlTableModel>
class DirtyFilterProxyModel : public QSortFilterProxyModel
{
public:
using QSortFilterProxyModel::QSortFilterProxyModel;
protected:
bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
{
if(QSqlTableModel *source_model = qobject_cast<QSqlTableModel *>(sourceModel())){
QModelIndex ix = source_model->index(source_row, 0, source_parent);
QString row_header_item = source_model->headerData(source_row, Qt::Vertical, Qt::DisplayRole).toString();
return !(source_model->isDirty(ix) && row_header_item == QLatin1String("!"));
}
return QSortFilterProxyModel::filterAcceptsRow(source_row, source_parent);
}
};
#endif // DIRTYFILTERPROXYMODEL_H
mainwindow.h
// ...
class DirtyFilterProxyModel;
// ...
class MainWindow : public QMainWindow
{
// ...
private:
Ui::MainWindow *m_ui;
DirtyFilterProxyModel *m_proxyModel;
// ...
mainwindow.cpp
#include "dirtyfilterproxymodel.h"
// ...
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent),
m_ui(new Ui::MainWindow),
m_model(new QSqlTableModel(this)),
m_proxyModel(new DirtyFilterProxyModel(this))
{
// ...
}
void MainWindow::on_pushButtonNewRecord_clicked()
{
// ...
m_model->insertRecord(-1, m_record);
m_proxyModel->invalidate();
}
// ...
void MainWindow::on_pushButtonRemoveRow_clicked()
{ if (m_row >= 0) {
m_proxyModel->removeRow(m_row);
m_proxyModel->invalidate();
}
}
The items in the tree view hold a instance of class container.
I want to implement drag and drop functionality in the view.
According to the QT tutorial for the data to copy i need specify the mime type and than write the Mimedata and dropMimeData functions.
The QT Example is dealing with a simple string so i am totally clueless of how to implement these function in case of custom objects.
1) What should be the mime type in my case ?
2) How to implement the current mimedata function for Container object data?
3) How to implement the current dropmimedata function for Container object data?
/////////////////////////////////////////
class Container
{
private:
std::string stdstrContainerName;
std::string stdstrPluginType;
int iSegments;
float fRadius;
public:
Container();
Container(std::string , std::string , int , float);
Container(const Container& obj);
~Container();
std::string GetName();
std::string GetType();
void SetName(std::string stdstrName);
};
Q_DECLARE_METATYPE( Container )
////////////////////////////////////////////////////////////
QMimeData *DragDropListModel::mimeData(const QModelIndexList &indexes)
const
{
QMimeData *mimeData = new QMimeData();
QByteArray encodedData;
QDataStream stream(&encodedData, QIODevice::WriteOnly);
foreach (const QModelIndex &index, indexes) {
if (index.isValid()) {
QString text = data(index, Qt::DisplayRole).toString();
// I have a GetContainer function which returns the Container
//object and i can use the GetContainer instead of data function.
stream << text;
}
}
mimeData->setData("application/vnd.text.list", encodedData);
return mimeData;
}
//////////////////////////////////////////////////////////////////
bool DragDropListModel::dropMimeData(const QMimeData *data,
Qt::DropAction action, int row, int column, const QModelIndex
&parent)
{
if (action == Qt::IgnoreAction)
return true;
if (!data->hasFormat("application/vnd.text.list"))
return false;
if (column > 0)
return false;
int beginRow;
if (row != -1)
beginRow = row;
else if (parent.isValid())
beginRow = parent.row();
else
beginRow = rowCount(QModelIndex());
QByteArray encodedData = data->data("application/vnd.text.list");
QDataStream stream(&encodedData, QIODevice::ReadOnly);
QStringList newItems;
int rows = 0;
while (!stream.atEnd()) {
QString text;
stream >> text;
newItems << text;
++rows;
}
insertRows(beginRow, rows, QModelIndex());
foreach (const QString &text, newItems) {
QModelIndex idx = index(beginRow, 0, QModelIndex());
setData(idx, text);
beginRow++;
}
return true;
}
The header file for TreeItem.
class TreeItem
{
public:
explicit TreeItem( const Container &data , TreeItem *parent = 0 );
~TreeItem();
TreeItem *parent();
void appendChild(TreeItem *child);
TreeItem *child(int iNumber);
int childCount() const;
int childNumber() const;
Container data() const;
bool setData(const Container &data , QVariant value);
void setContainer(const Container &data);
bool insertChildren(int position, int count );
bool removeChildren( int position , int count );
private:
QList<TreeItem*> childItems;
Container itemData;
TreeItem* parentItem;
}
You can add your custom mime types to specify the type of container you want to drag/drop. See this post for details.
The QDrag object constructed by the source contains a list of MIME types that it uses to represent the data (ordered from most appropriate to least appropriate), and the drop target uses one of these to access the data.
First of all, try to find a compatible standard mime type. Those are the most common one assigned by the IANA.
If the one you are looking for is not in the list, then you can label your custom one and serialize your data into a QByteArray to share it.
QByteArray output;
// do whatever
mimeData->setData("my-awesome-mime-type", output);
Now, in your custom widget, don't forget to accept the drops of this mime type:
void Window::dragEnterEvent(QDragEnterEvent *event) {
if (event->mimeData()->hasFormat("my-awesome-mime-type"))
event->acceptProposedAction();
}
You can find a complete example in this project.
I want to use QSettings to save my window's dimensions so I came up with these two functions to save & load the settings:
void MainWindow::loadSettings()
{
settings = new QSettings("Nothing","KTerminal");
int MainWidth = settings->value("MainWidth").toInt();
int MainHeight = settings->value("MainHeight").toInt();
std::cout << "loadSettings " << MainWidth << "x" << MainHeight << std::endl;
std::cout << "file: " << settings->fileName().toLatin1().data() << std::endl;
if (MainWidth && MainHeight)
this->resize(MainWidth,MainHeight);
else
this->resize(1300, 840);
}
void MainWindow::saveSettings()
{
int MainHeight = this->size().height();
int MainWidth = this->size().width();
std::cout << "file: " << settings->fileName().toLatin1().data() << std::endl;
std::cout << "saveSettings " << MainWidth << "x" << MainHeight << std::endl;
settings->setValue("MainHeight",MainHeight);
settings->setValue("MainWidth",MainWidth);
}
Now, I can see the demensions being extracted in saveSettings as expected but no file gets created and hence loadSettings will always load 0 only. Why is this?
QSettings isn't normally instantiated on the heap. To achieve the desired effect that you are looking for, follow the Application Example and how it is shown in the QSettings documentation.
void MainWindow::readSettings()
{
QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
const QByteArray geometry = settings.value("geometry", QByteArray()).toByteArray();
if (geometry.isEmpty()) {
const QRect availableGeometry = QApplication::desktop()->availableGeometry(this);
resize(availableGeometry.width() / 3, availableGeometry.height() / 2);
move((availableGeometry.width() - width()) / 2,
(availableGeometry.height() - height()) / 2);
} else {
restoreGeometry(geometry);
}
}
void MainWindow::writeSettings()
{
QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
settings.setValue("geometry", saveGeometry());
}
Also note the use of saveGeometry() and restoreGeometry(). Other similarly useful functions for QWidget based GUIs are saveState() and restoreState() (not shown in the above example).
I strongly recommend the zero parameter constructor of QSettings, and to setup the defaults in your main.cpp, like so:
QSettings::setDefaultFormat(QSettings::IniFormat); // personal preference
qApp->setOrganizationName("Moose Soft");
qApp->setApplicationName("Facturo-Pro");
Then when you want to use QSettings in any part of your application, you simply do:
QSettings settings;
settings.setValue("Category/name", value);
// or
QString name_str = settings.value("Category/name", default_value).toString();
QSettings in general is highly optimized, and works really well.
Hope that helps.
Some other places where I've talked up usage of QSettings:
Using QSettings in a global static class
https://stackoverflow.com/a/14365937/999943
I have in my app a table view called "partsview" which is descended from a QTableView, this is on the main form. The relevant header code looks like:
class partsiew : public QTableView
{
Q_OBJECT
public:
explicit partsview(QWidget *parent = 0);
public:
QStringList mimeTypes() const;
QMimeData *mimeData(const QModelIndexList &indexes) const;
};
I have also added the following into the constructor of "partsview":
this->setSelectionMode(QAbstractItemView::ExtendedSelection);
this->setDragEnabled(true);
this->setAcceptDrops(true);
this->setDropIndicatorShown(true);
though the last two are probably not needed.
When dragging, I can pick up a row and drag it to a target - a QTreeView - and I get the appropriate cursor and even a dropMimeData event is fired on the treeview.
However, the row and column values in the dropMimeData() method are always -1 and the two methods in the "partsview" are not called.
I'm guessing that the first error may have something to do with the second. Have I declared the mimeType() and mimeData() methods correctly for them to be called during a drag operation.
I have been following this page in the documentation QT4.6 - Using Model/View Classes
Here is the link for the most recent documentation on it:
http://doc.qt.io/qt-5/model-view-programming.html#using-drag-and-drop-with-item-views
I recently worked on some code for doing an internal move of cells on a single table, but while I was researching it, I found some other useful links.
http://qt-project.org/forums/viewthread/14197
I used the code in the above link and translated it to use QTableView instead of QTableWidget:
void MyTableView::dropEvent(QDropEvent *event)
{
// TODO: switch to using EyeTrackerModel::dropMimeData instead
QPoint old_coordinates = QPoint(-1,-1);
int dropAction = event->dropAction();
if(currentIndex().isValid()) //Check if user is not accessing empty cell
{
old_coordinates = QPoint( currentIndex().row(), currentIndex().column() );
}
QTableView::dropEvent(event);
qDebug() << "Detected drop event...";
event->acceptProposedAction();
if( this->indexAt(event->pos()).isValid() && old_coordinates != QPoint(-1, -1))
{
qDebug() << "Drop Event Accepted.";
qDebug() << "Source: " << old_coordinates.x() << old_coordinates.y()
<< "Destination: " << this->indexAt(event->pos()).row()
<< this->indexAt(event->pos()).column()
<< "Type: " << dropAction;
emit itemDropped( old_coordinates.x(), old_coordinates.y(),
this->indexAt(event->pos()).row(),
this->indexAt(event->pos()).column(),
dropAction);
}
// resize rows and columns right after a move!
this->doAdjustSize();
}
Even though the following answer is for Python, it still helped me when checking for what I could be missing.
QT: internal drag and drop of rows in QTableView, that changes order of rows in QTableModel
Here are some code snippets from my recent project related to drag and drop. I think you have most of them already, but I included them below for completeness.
QAbstractTableModel::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent)
Qt::ItemFlags QAbstractTableModel::flags(const QModelIndex &index) const
{
Q_UNUSED(index)
// if(index.isValid())
return Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled | Qt::ItemIsEditable | Qt::ItemIsEnabled | Qt::ItemIsSelectable;
// else
// return Qt::ItemIsDropEnabled | Qt::ItemIsEditable | Qt::ItemIsEnabled | Qt::ItemIsSelectable;
}
QAbstractTableView(QWidget *parent) :
QTableView(parent)
{
setAcceptDrops(true);
setDefaultDropAction(Qt::MoveAction);
}
Hope that helps.
I want to debug event handling code and would like to convert QEvent::Type enum's value to a human-readable string. QEvent has a Q_GADGET macro, so presumably there's a way of pulling that off?
Recent versions of Qt do the right thing when outputting events to the debug stream, so the below isn't neccessary. If you get an error similar to warning C4273: 'operator <<' : inconsistent dll linkage, it means that your version of Qt already supports this without need for the code below.
The Q_GADGET macro adds a QMetaObject staticMetaObject member to the class. The static metaobject's definition is generated by moc, and it - in the case of QEvent - contains the enumeration information.
Below is an example of how to leverage that to give a more reasonable QDebug output of events.
#include <QEvent>
#include <QMetaEnum>
#include <QDebug>
/// Gives human-readable event type information.
QDebug operator<<(QDebug str, const QEvent * ev) {
static int eventEnumIndex = QEvent::staticMetaObject
.indexOfEnumerator("Type");
str << "QEvent";
if (ev) {
QString name = QEvent::staticMetaObject
.enumerator(eventEnumIndex).valueToKey(ev->type());
if (!name.isEmpty()) str << name; else str << ev->type();
} else {
str << (void*)ev;
}
return str.maybeSpace();
}
Use example:
void MyObject::event(QEvent* ev) {
qDebug() << "handling an event" << ev;
}
Q_GADGET and Q_ENUM can be combined to get the following template:
template<typename EnumType>
QString ToString(const EnumType& enumValue)
{
const char* enumName = qt_getEnumName(enumValue);
const QMetaObject* metaObject = qt_getEnumMetaObject(enumValue);
if (metaObject)
{
const int enumIndex = metaObject->indexOfEnumerator(enumName);
return QString("%1::%2::%3").arg(metaObject->className(), enumName, metaObject->enumerator(enumIndex).valueToKey(enumValue));
}
return QString("%1::%2").arg(enumName).arg(static_cast<int>(enumValue));
}
Example:
void MyObject::event(QEvent* ev)
{
qDebug() << ToString(ev->type());
}