what am i doing wrong? Program runs and compiles but icon is not on tray.
My OS is Windows 7.
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow( QWidget * parent )
: QMainWindow( parent )
, ui( new Ui::MainWindow )
{
QMenu * trayIconMenu;
trayIconMenu = new QMenu();
QSystemTrayIcon tray;
QIcon icon( ":/ok.png" );
tray.setIcon( icon );
tray.setContextMenu( trayIconMenu );
tray.show();
ui->setupUi( this );
}
MainWindow::~MainWindow()
{
delete ui;
}
The problem is that your QSystemTrayIcon destroys as soon as the execution exists your MainWindow constructor. You should rather do this:
MainWindow::MainWindow( QWidget * parent )
: QMainWindow( parent ),
ui( new Ui::MainWindow )
{
QMenu * trayIconMenu = new QMenu();
QSystemTrayIcon *tray = new QSystemTrayIcon(QIcon( ":/ok.png" ), this);
tray->setContextMenu( trayIconMenu );
tray->show();
ui->setupUi( this );
}
Related
I have a qplaintextedit that is loaded dynamically with text contents, with QString.
I want to add an option to the menu that appears when we right click on the qplaintextedit. How can I do it programmatically so that I am able to add my own menu item to the default menu item? Any ideas would be appreciated.
You can sublcass QPlainTextEdit and reimplement the method contextMenuEvent(QContextMenuEvent *event). Alternatively you can add an event filter to a QPlainTextEdit and catch the QContextMenuEvent.
In your implementation, you can call QMenu *QPlainTextEdit::createStandardContextMenu(const QPoint &position) to create the default menu of the text edit and than add your custom items to it.
Example (subclass):
void MyTextEdit::contextMenuEvent(QContextMenuEvent *event)
{
QMenu* menu = createStandardContextMenu(event->pos());
QAction* clearAction = menu->addAction("Clear");
QAction* choosedAction = menu->exec(event->globalPos());
//...
delete menu;
}
See:
Event handlers
Event filters
QPlainTextEdit::contextMenuEvent
QPlainTextEdit::createStandardContextMenu
You have to reimplement the function : void QPlainTextEdit::contextMenuEvent(QContextMenuEvent *event)
More details in the doc here : http://doc.qt.io/qt-5/qplaintextedit.html#contextMenuEvent
It is not necessary to subclass QPlainTextEdit, nor to use an event filter. You can do it all in the main widget of your application. The following worked for me using Qt versions 4.7.4 and 4.8.5.
In the Designer:
You add a QPlainTextEdit widget whose name is "textbox".
In MainWindow.h:
// Auto generated from MainWindow.ui
#include "ui_MainWindow.h"
class MainWindow : public QMainWindow
{
Q_OBJECT
private:
/// The auto generated user interface.
Ui::MainWindowClass ui;
...
}
In MainWindow.cpp:
MainWindow::MainWindow( QWidget * pParent, Qt::WFlags flags )
: QMainWindow( pParent, flags )
, ui( )
{
ui.textbox->setContextMenuPolicy( Qt::CustomContextMenu );
connect( ui.textbox, SIGNAL( customContextMenuRequested( QPoint ) ),
this, SLOT( onTextboxCustomContextMenuRequested( QPoint ) ) );
}
void MainWindow::onTextboxCustomContextMenuRequested( QPoint p )
{
// Start with the standard menu.
QMenu * pMenu = ui.textbox->createStandardContextMenu();
QAction * pAction;
// Clear.
// Because QPlainTextEdit::clear() is a slot method, I can connect directly to it.
pAction = new QAction( "Clear", this );
connect( pAction, SIGNAL( triggered() ), ui.textbox, SLOT( clear() ) );
pMenu->addAction( pAction );
// Show the menu.
QPoint q = ui.textbox->mapToGlobal( p );
pMenu->exec( q );
// The menu's ownership is transferred to me, so I must destroy it.
delete pMenu;
}
I have a QScrollArea with some buttons in it, like shown on the picture.
The idea of the layout is:
1. The left and right button should be used for scrolling the buttons when they are too wide
2.The numbers of buttons in the scroll area can be changed dynamically
3. Any free space should be used to expand the scroll area as much as possible. If no such space exist navigation buttons should be used for scrolling.
With my current implementation when i increase the buttons i have this:
But there is free space on the right, so this should look like:
If i increase once more to 10 for example, then scrollbar should appear( because the layout is constained by the widget ).
I want to know if there is any other way aside from manual resizing of the widgets( because ui can be translated and buttons can change size hint also the real design is more complicated :(
Here is my implementation of the ScrollAreaTest widget:
#include "MainWidget.h"
#include <QLineEdit>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QScrollArea>
#include <QPushButton>
#include <QDebug>
#include "ButtonWidget.h"
#include "CheckableButtonGroup.h"
MainWidget::MainWidget(QWidget *parent)
: QWidget(parent),
m_scrollArea( 0 ),
m_lineEdit( 0 ),
m_buttons( 0 )
{
QVBoxLayout* mainLayout = new QVBoxLayout( this );
QWidget* firstRow = new QWidget;
QHBoxLayout* firstRowLayout = new QHBoxLayout( firstRow );
QPushButton* left = new QPushButton;
QPushButton* right = new QPushButton;
m_buttons = new CheckableButtonGroup( Qt::Horizontal );
m_buttons->setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Preferred );
m_buttons->setButtonsCount( 5 );
m_buttons->setStyleSheet( "border: none" );
QWidget* const buttonsContainer = new QWidget;
QHBoxLayout* const buttonsContainerLayout = new QHBoxLayout( buttonsContainer );
buttonsContainerLayout->setSpacing( 0 );
buttonsContainerLayout->setSizeConstraint( QLayout::SetMinAndMaxSize );
buttonsContainerLayout->setMargin( 0 );
buttonsContainerLayout->addWidget( m_buttons, 0, Qt::AlignLeft );
qDebug() << m_buttons->buttons()[ 0 ]->size();
m_scrollArea = new QScrollArea;
m_scrollArea->setContentsMargins( 0, 0, 0, 0 );
m_scrollArea->setWidget( buttonsContainer );
m_scrollArea->setWidgetResizable( true );
m_scrollArea->setStyleSheet( "border: 1px solid blue" );
m_scrollArea->setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Preferred );
firstRowLayout->addWidget( left , 0, Qt::AlignLeft );
firstRowLayout->addWidget( m_scrollArea, 1, Qt::AlignLeft );
firstRowLayout->addWidget( right , 0, Qt::AlignLeft );
m_lineEdit = new QLineEdit;
QPushButton* button = new QPushButton;
QHBoxLayout* secondRowLayout = new QHBoxLayout;
secondRowLayout->addWidget( m_lineEdit );
secondRowLayout->addWidget( button );
connect( button, SIGNAL(clicked()), SLOT(setButtonsCount()) );
mainLayout->addWidget( firstRow, 1, Qt::AlignLeft );
mainLayout->addLayout( secondRowLayout );
button->setText( "Set buttons count" );
buttonsContainer->resize( m_buttons->buttonsOptimalWidth(), buttonsContainer->height() );
m_buttons->resize( m_buttons->buttonsOptimalWidth(), m_buttons->height() );
//area->resize( 100, area->height() );
//area->setHorizontalScrollBarPolicy( Qt::ScrollBarAlwaysOff );
}
MainWidget::~MainWidget()
{
}
void MainWidget::setButtonsCount()
{
m_buttons->setButtonsCount( m_lineEdit->text().toInt() );
}
And here is the whole Qt project containing the problem:
https://drive.google.com/file/d/0B-mc4aKkzWlxQzlPMEVuNVNKQjg/edit?usp=sharing
The essential steps are:
The container widget that holds the buttons (your CheckableButtonGroup) must have a QLayout::SetMinAndMaxSize size constraint set. Then it will be exactly large enough to hold the buttons. Its size policy doesn't matter, since you're simply putting it into a QScrollArea, not into another layout.
The scroll area needs to set its maximum size according to the size of the widget it holds. The default implementation doesn't do it, so one has to implement it by spying on resize events of the embedded widget.
The code below is a minimal example that works under both Qt 4.8 and 5.2.
// https://github.com/KubaO/stackoverflown/tree/master/questions/scrollgrow-21253755
#include <QtGui>
#if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
#include <QtWidgets>
#endif
class ButtonGroup : public QWidget {
Q_OBJECT
QHBoxLayout m_layout{this};
public:
ButtonGroup(QWidget * parent = 0) : QWidget{parent} {
m_layout.setSizeConstraint(QLayout::SetMinAndMaxSize); // <<< Essential
}
Q_SLOT void addButton() {
auto n = m_layout.count();
m_layout.addWidget(new QPushButton{QString{"Btn #%1"}.arg(n+1)});
}
};
class AdjustingScrollArea : public QScrollArea {
bool eventFilter(QObject * obj, QEvent * ev) {
if (obj == widget() && ev->type() == QEvent::Resize) {
// Essential vvv
setMaximumWidth(width() - viewport()->width() + widget()->width());
}
return QScrollArea::eventFilter(obj, ev);
}
public:
AdjustingScrollArea(QWidget * parent = 0) : QScrollArea{parent} {}
void setWidget(QWidget *w) {
QScrollArea::setWidget(w);
// It happens that QScrollArea already filters widget events,
// but that's an implementation detail that we shouldn't rely on.
w->installEventFilter(this);
}
};
class Window : public QWidget {
QGridLayout m_layout{this};
QLabel m_left{">>"};
AdjustingScrollArea m_area;
QLabel m_right{"<<"};
QPushButton m_add{"Add a widget"};
ButtonGroup m_group;
public:
Window() {
m_layout.addWidget(&m_left, 0, 0);
m_left.setSizePolicy(QSizePolicy::Maximum, QSizePolicy::Preferred);
m_left.setStyleSheet("border: 1px solid green");
m_layout.addWidget(&m_area, 0, 1);
m_area.setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::Preferred);
m_area.setStyleSheet("QScrollArea { border: 1px solid blue }");
m_area.setWidget(&m_group);
m_layout.setColumnStretch(1, 1);
m_layout.addWidget(&m_right, 0, 2);
m_right.setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
m_right.setStyleSheet("border: 1px solid green");
m_layout.addWidget(&m_add, 1, 0, 1, 3);
connect(&m_add, SIGNAL(clicked()), &m_group, SLOT(addButton()));
}
};
int main(int argc, char *argv[])
{
QApplication a{argc, argv};
Window w;
w.show();
return a.exec();
}
#include "main.moc"
I have a MainWindow which calls the LoginWindow in the constructor. The LoginDialog has a button to create an account which will create a QDialog.
I wanted to hide the LoginDialog while the Dialog for the new account is showing but somehow it crashes.
When I remove the first and last line of the function which hides and shows the LoginDialog it's absolutely fine. Why does it crash with hide() and show() are called ?
void LoginDialog::createAccount()
{
// (-> will cause crash later) hide(); //Hides LoginDialog
QDialog dlg;
dlg.setGeometry( this->x(), this->y(), this->width(), this->height() );
QWidget* centralWidget = new QWidget( &dlg );
QVBoxLayout* l = new QVBoxLayout( centralWidget );
dlg.setLayout( l );
QLineEdit *dlgUser = new QLineEdit( centralWidget );
QLineEdit *dlgPass = new QLineEdit( centralWidget );
dlgPass->setEchoMode( QLineEdit::Password );
l->addWidget( new QLabel( tr("Username :"), centralWidget ) );
l->addWidget( dlgUser );
l->addWidget( new QLabel( tr("Password :"), centralWidget ) );
l->addWidget( dlgPass );
l->addWidget( new QDialogButtonBox( QDialogButtonBox::Ok | QDialogButtonBox::Cancel, Qt::Horizontal, centralWidget ) );
if( dlg.exec() != QDialog::Rejected )
{
;
}
delete centralWidget;
// (-> will cause crash later) show(); //Show LoginDialog again
}
There are no errors, it just crashes unexpectedly and sometimes it exits with code (0).
When analyzing with the debugger and really going through every single step it doesn't crash. The LoginDialog will be shown and it's not going to crash.
I don't get the purpose of your centralWidget in the dialog? I don't think it is needed at all, and you can assemble your widgets directly in the dialog. I would rewrite your code in this way:
void LoginDialog::createAccount()
{
QDialog dlg;
dlg.setGeometry( this->x(), this->y(), this->width(), this->height() );
QLineEdit *dlgUser = new QLineEdit( &dlg );
QLineEdit *dlgPass = new QLineEdit( &dlg );
dlgPass->setEchoMode( QLineEdit::Password );
QVBoxLayout* l = new QVBoxLayout;
l->addWidget( new QLabel( tr("Username :"), &dlg ) );
l->addWidget( dlgUser );
l->addWidget( new QLabel( tr("Password :"), &dlg ) );
l->addWidget( dlgPass );
l->addWidget( new QDialogButtonBox( QDialogButtonBox::Ok | QDialogButtonBox::Cancel, Qt::Horizontal, &dlg ) );
dlg.setLayout( l );
if( dlg.exec() != QDialog::Rejected )
{
// Do something.
}
}
I do this in Qt Creator. I want to change my QStackedLayout with only QPushButton, not QComboBox. Is this possible? Anybody has implemented this? I got many example from Qt Documentation but all examples use QComboBox (now QPushButton like I need). This is my code:
#mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
Dialog::Dialog()
{
QVBoxLayout *mainlayout = new QVBoxLayout;
QVBoxLayout *layouta = new QVBoxLayout;
QVBoxLayout *layoutb = new QVBoxLayout;
QPushButton *tombola = new QPushButton("A");
QPushButton *tombolb = new QPushButton("B");
QPushButton *tombolc = new QPushButton("C");
QFrame *framea = new QFrame;
QFrame *frameb = new QFrame;
QStackedLayout *stackia = new QStackedLayout;
layouta->addWidget(tombola);
layoutb->addWidget(tombolb);
framea->setLayout(layouta);
frameb->setLayout(layoutb);
framea->setMinimumSize(88,88);
frameb->setMinimumSize(88,88);
//building frame
framea->setFrameShape(QFrame::StyledPanel);
framea->setFrameShadow(QFrame::Raised);
frameb->setFrameShape(QFrame::StyledPanel);
frameb->setFrameShadow(QFrame::Raised);
//get c button smaller
tombolc->setMaximumWidth(33);
stackia->addWidget(framea);
stackia->addWidget(frameb);
stackia->addWidget(tombolc);
mainlayout->addLayout(stackia);
QPushButton *tombold = new QPushButton("D");
mainlayout->addWidget(tombold);
setLayout(mainlayout);
connect(tombold, SIGNAL(clicked()), stackia, SLOT(setCurrentIndex(1))); //CONNECTOR
}
RESULT
Qt Creator says:
Object::connect: No such slot QStackedLayout::setCurrentIndex(1)
What is my mistake?
At second chance after searching and asking for 4 days, I have changed my connect() and function code into:
CONNECTOR:
connect(tombold, SIGNAL(clicked()), stackia, SLOT(change_stack()));
FUNCTION:
void Dialog::change_stack()
{
stackia->setCurrentIndex(1);
}
RESULT
But Qt Creator says:
Object::connect: No such slot QStackedLayout::change_stack()
and immediately the window closed.
At my sight, my code has error. But I don't know what error so I can't change QStackLayout content/page into another page. What is my mistake? I believe this is actually quite simple but I just don't know where is the error.
Any suggestion?
You should add change_stack function to your Dialog class and connect to it like this:
class Dialog : public QWidget
{
...
private slots:
void change_stack();
private:
QStackedLayout *stackia;
}
Dialog::Dialog
{
...
connect(tombold, SIGNAL(clicked()), this, SLOT(change_stack()));
...
}
void Dialog::change_stack()
{
stackia->setCurrentIndex(1);
}
Concerning
connect(tombold, SIGNAL(clicked()), stackia, SLOT(setCurrentIndex(1)));
A slot can only have as many parameters or less parameters than a signal.
E.g. you can do
connect( sender , SIGNAL( somethingHappened( const QString& ) ),
receiver, SLOT ( doSomething ( const QString& ) ) );
and you can do
// connect signal and ignore the parameter
connect( sender , SIGNAL( somethingHappened( const QString& ) ),
receiver, SLOT ( doSomethingElse ( ) ) );
but you cannot do
// this will not work
connect( sender , SIGNAL( somethingElseHappened( ) ),
receiver, SLOT ( doSomething ( const QString& ) ) );
What you probably want is something like this:
Dialog::Dialog
{
...
// This must be a member variable
_stackia = new QStackedLayout();
tombola->setProperty( "tabpage", 1 );
tombolb->setProperty( "tabpage", 2 );
tombolc->setProperty( "tabpage", 3 );
connect( tombola, SIGNAL( clicked () ),
this , SLOT ( tombol_clicked() ) );
connect( tombolb, SIGNAL( clicked () ),
this , SLOT ( tombol_clicked() ) );
connect( tombolc, SIGNAL( clicked () ),
this , SLOT ( tombol_clicked() ) );
}
// This must be defined as slot in the header
void Dialog::tombol_clicked()
{
int index = sender()->property( "tabpage" ).toInt();
_stackia->setCurrentIndex( index );
}
It seems like this would be a common thing to do, but I can't find how.
I have a QTextEdit or QPlainTextEdit widget with a bunch of text. Enough that scrolling is necessary.
I want another widget to give some information about the currently visible text. To do this, I need to know
when the visible text changes
what's the text?
I see that QPlainTextEdit has the method firstVisibleBlock, but it's protected. This tells me that it's not really something I should be using in my application. I wouldn't otherwise need to subclass from the edit window.
I also see that there's the signal updateRequest but it's not clear what I do with the QRect.
How do I do it or where do I find a hint?
I've written a minimal program that as two QTextEdit fields. In the left field you write and the text you are writing is shown in the second text edit too. You get the text of a QTextEdit by using toPlainText() and the signal is textChanged().
I've tested it and what you write in m_pEdit_0 is shown in "real-time" in m_pEdit_1.
main_window.hpp
#ifndef __MAIN_WINDOW_H__
#define __MAIN_WINDOW_H__
#include <QtGui/QtGui>
#include <QtGui/QMainWindow>
#include <QtGui/QApplication>
class main_window : public QMainWindow
{
Q_OBJECT
public:
main_window( QWidget* pParent = 0 );
~main_window();
public Q_SLOTS:
void on_edit_0_text_changed();
private:
QHBoxLayout* m_pLayout;
QTextEdit* m_pEdit_0;
QTextEdit* m_pEdit_1;
};
#endif // !__MAIN_WINDOW_H__
main_window.cpp
#include "main_window.hpp"
main_window::main_window( QWidget *pParent ) : QMainWindow( pParent )
{
m_pEdit_0 = new QTextEdit( this );
m_pEdit_1 = new QTextEdit( this );
connect( m_pEdit_0, SIGNAL( textChanged() ), this, SLOT( on_edit_0_text_changed() ) );
m_pLayout = new QHBoxLayout;
m_pLayout->addWidget( m_pEdit_0 );
m_pLayout->addWidget( m_pEdit_1 );
QWidget* central_widget = new QWidget( this );
central_widget->setLayout( m_pLayout );
setCentralWidget( central_widget );
}
main_window::~main_window()
{
}
void main_window::on_edit_0_text_changed()
{
m_pEdit_1->setText( m_pEdit_0->toPlainText() );
}
main.cpp
#include "main_window.hpp"
int main( int argc, char* argv[] )
{
QApplication a(argc, argv);
main_window mw;
mw.show();
return a.exec();
}
Edit:
This would work too, but would lack in performance for huge documents:
void main_window::on_edit_0_text_changed()
{
QStringList text_in_lines = m_pEdit_0->toPlainText().split( "\n" );
m_pEdit_1->clear();
for( int i = 0; i < text_in_lines.count(); i++ )
{
m_pEdit_1->append( text_in_lines.at( i ) );
}
}