I have a UIForm named "Spell" that contains inter alia QGridLayout with custom widgets named "PElement". The amount of PElement widgets depends on number of spells in my database. So, I fill QGridLayout by ui->spellLayout->addWidget(...)
When PElement is clicked it emits signal. I need to connect each of PElement in QGridLayout with slot in Spell class. I have no idea how to do it.
Thanks for help!
#edit
this is a function that add PictureElement to QGridLayout
void Spells::setSpellList(QString lore)
{
QList<QStringList> elementList = Database::instance()->getSpellElement(lore);
while(ui->spellLayout->count() > 0) {
QWidget *w = ui->spellLayout->itemAt(0)->widget();
ui->spellLayout->removeWidget(w);
delete w;
}
int w,h;
w = 162;
h = 203;
int maxCol = ui->spellScrollArea->width() / (w + ui->spellLayout->spacing());
if(maxCol<=0) {
Indicator::instance()->hide();
return;
}
foreach(QStringList list, elementList){
PictureElement *spellElement = new PictureElement;
spellElement->setText(list.at(0));
spellElement->setPixmap(list.at(1));
spellElement->setMinimumSize(w, h);
ui->spellLayout->addWidget(spellElement,
ui->spellLayout->count() / maxCol,
ui->spellLayout->count() % maxCol);
spellElement->show();
}
Indicator::instance()->hide();
}
What I want:
connect every PictureElement (SIGNAL clicked) from QGridLayout with slot in Spells class.
I am not quite sure where the issue ist. Assuming your class PictureElement inherits QObject, contains the Q_OBJECT macro and emits the signal, your simply add a connect line in your foreach loop:
foreach(QStringList list, elementList){
PictureElement *spellElement = new PictureElement;
...
QObject::connect(spellElement, SIGNAL(clicked()), this, SLOT(slotname()));
}
You are already in the Spells class so theaccess shouldn't be an issue. Of course the slotname() function needs to be defined as a slot in the header. To identify which PictureElement emitted the signal within the slot you can use the QObject::sender() method.
Related
I have a TreeModel which has some data loaded in it. There is a radio button in my application, which when clicked should update the TreeModel with a new data.
I have tried the following things on switching the radio button and none is working:
emit layoutChanged
emit layoutChanged();
emit dataChanged
emit dataChanged(QModelIndex(), QModelIndex());
Referenced from:
What does 'bottomRight' mean when using dataChanged() with a QTreeView in Qt?
Recursively visiting each node in the tree and emitting dataChanged
void TreeView::getLastExpandedState(const QModelIndex& parent)
{
bool isExpand = isExpanded(parent);
if (!isExpand) {
return;
}
int rows = model()->rowCount(parent);
for (int rowNum = 0; rowNum < rows ; ++rowNum) {
QModelIndex childIndex = model()->index(rowNum, 0, parent);
model->emitChange(parent,childIndex);
getLastExpandedState(childIndex);
}
}
void TreeModel::emitChange(const QModelIndex& parent,const QModelIndex& childIndex) {
emit dataChanged(parent,childIndex);
}
How to solve that?
The answer you reference is at best confusing and probably wrong.
Your model code needs to emit a dataChanged signal for any rectangle of cells where the data returned by the model data method has changed. See, for example, this question and answer, which goes into some detail.
Note that the parameters in the dataChanged signal should not be parent and child - they should be "topLeft" and "bottomRight". They need to have the same parent and also to be different. So you don't need to iterate over the rows and emit the signal for each row. You can send a combined signal for all the rows that have changed.
But you do need to send a signal for each parent (where data has changed) that signals the top left cell and bottom right cell for that parent. So you might end up creating an index for the top left cell for that parent at (0, 0, parent) and another for the bottom right cell at (rows, cols, parent) and then sending the signal for that pair of indices.
I have an application which contains such lines.
emit WindowAdded(settings->WindowType);//!!!!!!!!!!!!!!
MyWindow *widget = new MyWindow(0,settings,currentWindowIndex);
The signal changes value of currentWindowIndex, but it didn't work because of slot, it doesn't change its value in time. Some one advices me to use QEventLoop, but i don't understand how to do this. Give me an example, please.
Another part of the code:
connect(area,SIGNAL(WindowAdded(QString)),this,SLOT(addWindowOnTab(QString)));
void WorkSpace::addWindowOnTab(QString title)
{
qint32 i = TabsList->addTab(title);/////!!!!!!!!!!!!!!!!!!!!!!!!!
emit addedWindowIndex(i);
TabsList->setVisible(true);
}
connect(this,SIGNAL(addedWindowIndex(qint32)),area,SLOT(WindowIndexChanged(qint32)));
void MyMdiArea::WindowIndexChanged(qint32 index)
{
currentWindowIndex=index;
}
I think it can help.
MyMdArea is сlass inherited from QMdiArea, WorkSpace is a QWidget, TabsList is a QTabBar.
And there is another fact: I tried to understand execution sequence of slots and added some lines to code:
QLabel *n= new QLabel("1");
n->show();
after emiting WindowAdded signal
QLabel *n= new QLabel("2");
n->show();
after emiting addedWindowIndex signal
and
QLabel *n= new QLabel("3");
n->show();
after changing currentWindowIndex's value
and that is what i saw "1 2 3" and its exploded my brain. Maybe i don't understand something?
I have a widget containing a QSpinBox. This widget also has a QVector<int> Values. What I would like to do is get the QSpinBox to display values issued from Values only.
At first I thought that a new slot and signal in my widget would do the trick, something like
slot :
void ChangeSomeValue()
{
// QVector<int> Values;
// int Index;
int val = Values[ Index ];
emit( SomeValueChanged( val ) );
}
connects :
connect( UI->MySpinBox, SIGNAL( valueChanged(int) ), this, SLOT( ChangeSomeValue() ) );
connect( this, SIGNAL( SomeValueChanged(int ) ), UI->MySpinBox, SLOT( setValue(int) ) );
But then several problems arise :
QSpinBox emit another valueChanged after I call its setValue, resulting in an infinite loop (until my QVector explodes).
I still have to find a way to keep track of Index, depending on which of the QSpinBox arrows was clicked (up or down... I don't even think this is possible).
So my solution, with its problems, seems to be a dead end. Any idea?. I'd like to stick to QSpinBox, if possible.
Thanks !
[EDIT]
Subclassing :
class SpinBox : public QSpinBox
{
Q_OBJECT
public:
explicit SpinBox(const QVector<int> & values, QWidget * parent = 0) :
QSpinBox(parent),
mValues(values),
mIndex(0)
{
qSort(mValues);
setMinimum(mValues.at(0));
setMaximum(mValues.at(mValues.size() - 1));
setValue(mValues.at(0));
}
protected:
void stepBy(int steps) // re-implementaion
{
mIndex += steps;
mIndex = qBound(0, mIndex, mValues.size() - 1);
setValue(mValues.at(mIndex));
}
private:
QVector<int> mValues;
int mIndex;
};
I Would suggest writing your own class to do it by sub-classing QAbstractSpinBox.
Maybe take a look at the accepted answer on this question:
How to subclass QSpinBox so it could have int64 values as maxium and minimum
QSpinBox emit another valueChanged after I call its setValue, resulting in an infinite loop (until my QVector explodes).
You can prevent this by using QObject::blockSignals(). Make sure to unblock signals afterwards.
I still have to find a way to keep track of Index, depending on which of the QSpinBox arrows was clicked (up or down... I don't even think this is possible).
Well, I suppose you can store the old value in a member variable, and when QSpinBox emits valueChanged(), you can compare the new to the old value to figure out whether the up or the down arrow was pressed.
That said, I don't know if that's enough to make QSpinBox behave like you want, correcting the value after it was changed once is a bit hacky. Subclassing QAbstractSpinbox might be better indeed.
During runtime I have inserted QCombobox in my QTreeWidget like this:
//global defines
#define COLUMN_1 (0)
#define COLUMN_2 (1)
//Init QComboBox to QTreeWidget - works fine.
QTreeWidgetItem *item = new QTreeWidgetItem(_myTreeWidget);
item->setText(COLUMN_1,"testing");
QComboBox *box = new QComboBox();
box->addItem("select1");
box->addItem("select2");
box->addItem("select3");
_myTreeWidget->setItemWidget(item, 1, box);
The above code works, but I also want to read the data text in these columns. Eg. get the strings "testing" & "select2" from code above. The problem is that I can't figure out how to read the "QComboBox::currentText()" in the comboboxes.
I have tried:
QTreeWidgetItemIterator it(_myTreeWidget);
while(*it)
{
QTreeWidgetItem *item = *it;
QVariant first = item->text(COLUMN_1);
QString firstStr = loggerName.toString(); //this works
QComboBox *box = (QComboBox*)item->data(COLUMN_2, 0);
QString boxValStr = box->text().toString(); //this doesn't works, always empty string
//... more code to handle strings...
it++;
}
Feels like the "item->data(COLUMN_2, 0)" is wrong way to go cause it returns a QVariant.
Solution on this problem?
QComboBox *box = (QComboBox*)item->data(COLUMN_2, 0);
When I read this code, I went into panic mode. Look at the signature:
QVariant QTreeWidgetItem::data ( int column, int role ) const
As you used setItemWidget, you should probably use
QWidget * QTreeWidget::itemWidget ( QTreeWidgetItem * item, int column ) const
ps: If you want to cast, use C++ casts. Much better, use qobject_cast<SubtypeofQObjectPtr> for QObject. It returns null when the cast is invalid.
Indeed, I mean retrieve the combobox using a call similar to :
QComboBox* box = qobject_cast<QComboBox*>(treeWidget->itemWidget(item, column));
Solved it thanks to the help from #Umnyobe and #Zaiborg above. Here is a total working example:
Init QTreeWidget with text in column1 and QComboBox in column2:
//global defines
#define COLUMN_1 (0)
#define COLUMN_2 (1)
QTreeWidgetItem *item = new QTreeWidgetItem(_myTreeWidgetPtr);//item to put in tree
item->setText(COLUMN_1,"animal"); //item for column 1 in the tree.
QComboBox *box = new QComboBox();
box->addItem("mouse"); //adds selections for comboboxes
box->addItem("cat");
box->addItem("dog");
_myTreeWidgetPtr->setItemWidget(item, COLUMN_2, box); //insert items in tree.
Read values from tree:
QTreeWidgetItemIterator it(_myTreeWidgetPtr);
while(*it)
{
QTreeWidgetItem *item = *it;
//Init pointer to current combobox
QComboBox* box = qobject_cast<QComboBox*>(_myTreeWidgetPtr->itemWidget(item, COLUMN_2));
//Get data from QTreeWidget
QString col1Str = item->text(COLUMN_LOGGER);
QString col2Str = box->currentText();
it++;
}
hope it can help someone :)
use the QSignalMapper class to collect the different boxes in the treewidget.
then connect the QSignalMapper::mapped() signal to some slot and use the combobox
edit:
QSignalMapper* mapper = new QSignalMapper(this);
QComboBox *box = new QComboBox();
connect( box, SLOT(/*whatever*/), mapper, SLOT( map() ) );
mapper->setMapping( box );
myTreeWidget->setItemWidget(item, 1, comboBox);
For anyone who is looking for a Python solution,
(PySide / PyQt QComboBox in QTreeWidget), here is it:
item = QTreeWidgetItem(self.treeWidgetAnimals)
item.setText(0, "animal")
combo_box = QComboBox()
combo_box.addItem('mouse')
combo_box.addItem('cat')
combo_box.addItem('dog')
self.treeWidgetAnimals.setItemWidget(item, 1, combo_box)
I was looking for hours but no other forum like pass reference "parent" like a "delegation":
item = QTreeWidgetItem (self.myTreeWidgetItemObject)
if you do not pass the parent, error ir not returned but the ComboBox not appears in display TreeWidget.
I used Qt Creator to make a "keyboard" window with sixty QPushButtons and one QLineEdit. How can I make the buttons to add characters into QLineEdit text box? If I press a QPushButton with the label 'Q' on it, I want the program to add the Unicode character 'Q' on the text box.
One way to do this would be to just connect the 'clicked' signal from all the buttons to a slot, and then handle the adding of the character there.
For example, if the all keyboard buttons are inside a layout called 'buttonLayout', in your MainWindow constructor you can do this:
for (int i = 0; i < ui->buttonLayout->count(); ++i)
{
QWidget* widget = ui->buttonLayout->itemAt( i )->widget();
QPushButton* button = qobject_cast<QPushButton*>( widget );
if ( button )
{
connect( button, SIGNAL(clicked()), this, SLOT(keyboardButtonPressed()) );
}
}
Then in the slot implementation, you can use QObject::sender(), which returns the object that sent the signal:
void MainWindow::keyboardButtonPressed()
{
QPushButton* button = qobject_cast<QPushButton*>( sender() );
if ( button )
{
ui->lineEdit->insert( button->text() );
}
}
OPTION 1 - Multiple signals and slots
Connect all pushbuttons clicked() signal to a slot
// Let button01 be the A
connect(ui->button01, SIGNAL(clicked()), this, SLOT(buttonClicked()));
...
// Let button 60 be the Q
connect(ui->button60, SIGNAL(clicked()), this, SLOT(buttonClicked()));
In the buttonClicked() slot you have to figure out which button was clicked and append the corresponding letter to the line edit.
void buttonClicked()
{
QObject* callingButton = QObject::sender();
if (callingButton == button01)
ui->lineEdit->setText(ui->lineEdit->text()+ "A");
...
else if (callingButton == button60)
ui->lineEdit->setText(ui->lineEdit->text()+ "Q");
}
OPTION 2 - Subclass QPushButton
You could subclass QPushButton in order to avoid the multiple ifs. In your subclass just catch the mouse release event and emit a new signal which will contain the button's text
void KeyboardButton::mouseReleaseEvent(QMouseEvent* event)
{
emit clicked(buttonLetter); // Where button letter a variable of every item of your subclass
}
Similarly connect the clicked(QString) signal with a slot
connect(ui->button01, SIGNAL(clicked(QString)), this, SLOT(buttonClicked(QString)));
...
connect(ui->button60, SIGNAL(clicked(QString)), this, SLOT(buttonClicked(QString)));
void buttonClicked(QString t)
{
ui->lineEdit->setText(ui->lineEdit->text()+ t);
}
I have created an application with a similar issue, trying to convert the qpushbutton text to the qlineedit itself. The key is how you initialize the buttons and to use polymorphism in your function. To create an emit signal wont work for individual characters. The .digitValue will work if the case if for numerics (which the buttons would be of type int), but qt doesnt have a character value (I should say after 6hrs of reading qt doc and another 4 of trying different combinations it would not work), I think it has to do with how many bits it takes to store each variable type in an array. I even tried converting the button->text to QString to use with the emit function as a signal prototyped.
I do not know what your button layout is, but I will give you a synopsis of what I did. I first created a global, static const char array containing all the letters needed e.g.
static const char vowelarray[] = "AEIOU";
Then initialized the QPushButtons with in the MainWindow function, using iteration, setting a for loop's terminating condition equal to the size char array (in your case 60?). This all depends on your button layout though. I personally created a void function (setLocation) for the button->setGeometry of each button and iterated the setGeometry, and then passed the function to the MainWindow Function, at end of fucntion. The following code was used to initialize the buttons, connect signals to slots, and use polymorphism to connect to lineedit.
for (int i = 0; i < 26; i++){
characterButton[i] = new QPushButton(chararry[i], this); `
characterButton[i] -> setStyleSheet("QPushButton{background: grey; color: brown}");
connect(characterButton[i],SIGNAL(released(),this,SLOT(characterPushed()));
}
setLocation();
Then created a void function (e.g. void MainWindow::characterPuched()) where the following code was used:
void MainWindow::characterPushed(){
QPushButton *characterButton = (QPushButton*) sender();
if (characterButton )
{
lineEdit -> setText(letters.insert(letters.size(), characterButton -> text()));
}
lineEdit -> setText(letters);
}
of course letters was a global variable as well as:
QString letters = "";
and of course the QPushButtons and the function were prototype in the header file as a private variables and slots, e.g.
private:
QPushButton *characterButton[26];
the variable 'letters' was used to extract and input text to and from the line edit for further functions throughout the application.
Best Luck!!``