I am trying to compile a test application for an ARM embedded device. If I use my Desktop Qt SDK version of Qt, this header file compiles just fine. If I use my Linaro GCC for the Embedded target from within Qt Creator, I get the error "'QLCDNumber' does not name a type" on the line of the private declaration for lcdNumber. I've googled around but do not see any solutions that work for this.
Is the problem that my embedded version of qt is missing support for QLCDNumber?
If so, why doesn't it complain about the #include ?
Also, if this is the case, does anyone happen to know what I need to enable in ./configure to enable support for QLCDNumber?
#ifndef BATTERYMONITOR_H
#define BATTERYMONITOR_H
#include <QtGui>
#include <QWidget>
#include <QLabel>
#include <QRadioButton>
#include <QLCDNumber>
class BatteryMonitor : public QWidget
{
Q_OBJECT
public:
BatteryMonitor(QWidget *parent = 0);
public slots:
void clickedBatteryStatus();
private:
QRadioButton *temperature;
QRadioButton *voltage;
QRadioButton *current;
QRadioButton *relativeStateOfCharge;
QRadioButton *batteryStatus;
QRadioButton *runTimeToEmpty;
QLCDNumber *lcdNumber;
};
#endif // BATTERYMONITOR_H
Did it config with QT_NO_LCDNUMBER defined in your embedded Qt SDK? You can check it in file $QTDIR/include/QtCore/qconfig.h.
QLCDNumber and qlcdnumber.h are in the right include path of Qt SDK no matter macro QT_NO_LCDNUMBER defined or not. So there is nothing wrong about #include <QLCDNumber>.
Related
In our applications we are using customizable dialogs using exhaustively QSplitter, so that our customers can rearrange the dialogs to fit their needs.
(Sometimes we are also using QDockWidget, but this seems to be similar.)
Now, it is very annoying to rearrange the dialog every time it is opened again. Or even between different starts of the program.
After consulting the documentation I was able to restore the state and the geometry of a specific dialog containing one QSplitter.
#include <QApplication>
#include <QLabel>
#include <QDebug>
#include <QSplitter>
#include <QPushButton>
#include <QTextEdit>
#include <QDialog>
#include <QSettings>
#include <QHBoxLayout>
int main(int argc, char** args) {
QApplication app(argc, args);
app.setOrganizationName("Tech");
app.setOrganizationDomain("qt.us");
app.setApplicationName("RestoreLayout");
app.setApplicationVersion("1.0");
QDialog dialog;
dialog.setLayout(new QHBoxLayout);
auto splitter = new QSplitter;
splitter->addWidget(new QLabel("Left"));
splitter->addWidget(new QLabel("Right"));
dialog.layout()->addWidget(splitter);
auto accept = new QPushButton("Accept");
accept->connect(accept, &QPushButton::clicked, [&](){
dialog.accept();
});
splitter->addWidget(accept);
auto geom= QSettings().value("Geom").toByteArray();
auto splitterState = QSettings().value("State").toByteArray();
qDebug() << geom;
qDebug() << splitterState;
dialog.restoreGeometry(geom);
splitter->restoreState(splitterState);
dialog.show();
dialog.connect(&dialog, &QDialog::accepted, [&]() {
QSettings().setValue("Geom", dialog.saveGeometry());
QSettings().setValue("State", splitter->saveState());
app.quit();
});
app.exec();
}
Unfortunately, this seems to be an approach, which is not usable in general.
Assume, that there is some arbitrary dialog, that needs to restore its geometry and state. Even worser QSplitter and QDockWidget might be even used in a nested fashion, which is done in our applications.
How can an outside programmer restore the geometry and the state of a arbitrary dialog that might be easily applicable to all possible dialogs?
For saving states of QDockWidget each it must be named: dockWidgetN->setObjectName("dock-widget-N");
But you can save only QMainWindow state for saving states of docks in this window.
You can separatelly save states via QSettings (it's QByteArray) and use some one state for many windows.
See here: How to save state of a dialog in Qt?
I am trying to connect QTextEdit to QTextBrowser, so the text browser widget outputs what is entered in text edit widget. As a signal I used textChanged(), and as a slot I used setText(QString). And these two don't have same parameters.
If I used QLineEdit instead of QTextEdit, in that case there is textChanged(QString) function which is compatible with the slot,but I need to make it work with QTextEdit. Here is the code:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtWidgets>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
QWidget * mainWidget=new QWidget(this);
ui->setupUi(this);
QTextEdit * mainTextEdit=new QTextEdit();
QTextBrowser * textDisplay=new QTextBrowser();
connect(mainTextEdit,SIGNAL( textChanged() ),
textDisplay,SLOT( setText(QString) ) );
QHBoxLayout * Alayout=new QHBoxLayout();
Alayout->addWidget(mainTextEdit);
Alayout->addWidget(textDisplay);
mainWidget->setLayout(Alayout);
setCentralWidget(mainWidget);
}
MainWindow::~MainWindow()
{
delete ui;
}
Thankfully, the QTextEdit and QTextBrowser are views onto a QTextDocument model. So, you can simply set the editor's document on the browser. QTextBrowser::setDocument is semantically equivalent to QAbstractItemView::setModel:
textDisplay->setDocument(mainTextEdit->document());
In Qt, there are really two basic model classes: QAbstractItemModel and QTextDocument. A QTextDocument is a model in its own model-view framework. We simply set another view onto the document that the editor operates on. The editor allows modifications to the model, the browser doesn't. It's no different from using the same model on two QListViews, etc.
A QTextEditor is a view with a default model (document). You can replace that default model with one from another view, or even with one that you yourself provide. You could have multiple editors all displaying the same QTextDocument document and allowing editing of it, in parallel. You can also have multiple browsers doing the same.
Complete example:
#include <QApplication>
#include <QTextEdit>
#include <QTextBrowser>
#include <QHBoxLayout>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QWidget window;
QHBoxLayout layout(&window);
QTextEdit edit;
QTextBrowser browser;
layout.addWidget(&edit);
layout.addWidget(&browser);
browser.setDocument(edit.document());
window.show();
return a.exec();
}
I would do it in the following way:
Declare the pointers to the text edit and text browser widgets as member variables in the class,
Create a slot onTextChanged() in MainWindow class that will be called as soon as the text edit is changed and setup the connection as:
connect(mainTextEdit, SIGNAL(textChanged()), this, SLOT(onTextChanged()));
Implement the onTextChanged() slot in the following way:
MainWindow::onTextChanged()
{
QString text = mainTextEdit->toPlainText();
textDisplay->setPlainText(text);
}
I am running on ubuntu 13.10 64bit with installed Qt Creator also i have installed libphonon-dev
my code looks like this:
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <phonon/phonon> // yes directory /usr/include/phonon exists
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
Phonon::MediaObject *music = Phonon::createPlayer(Phonon::MusicCategory, Phonon::MediaSource("/home/erik/Downloads/Bob_Marley-No_Woman_No_Cry.mp3"));
music->play();
}
MainWindow::~MainWindow()
{
delete ui;
}
I am getting 10 same errors:
/usr/include/phonon/phonon:12: In file included from
/usr/include/phonon/phonon:12:0,
/home/erik/QtProjs/QtPlayer/mainwindow.cpp:3: from
../QtPlayer/mainwindow.cpp:3: /usr/include/phonon/effectwidget.h:28:
error: QtGui/QWidget: No such file or directory #include
<QtGui/QWidget> ^ /usr/include/phonon/effectwidget.h
any other project file is default (mainwindow.h, mainwindow.ui, main.cpp)
Yesterday i have made a simple text editor(not from example), but i cant get through this error.
Thankyou
Take a look at this question. It can be similar to your case if you're building a Qt 4 project with Qt 5.
I am just staring Qt, so hopefully is a rookie question. Working in Qt Creator 2.7.2, Qt 5, standard desktop app.
Currently my app is one window, with the main window entirely taken up by a console object, with is just a plain text edit, like this:
setCentralWidget(console);
Which of course takes up the entire window. So I added a frame using the UI editor, frame_2. How do I get the console to appear inside the frame, instead of taking up the whole window?
http://qt-project.org/doc/qt-4.8/designer-layouts.html
http://qt-project.org/doc/qt-4.8/layout.html
Your central widget is just QWidget, and then it needs a layout. You drag a layout into it, and there are some buttons across the top of Qt Designer for turning on and off the layout.
When setupUi is called, it already does the setCentralWidget call for you. If you call it yourself you lose all you gained from using Qt Designer.
ui->setupUi(this);
If you are using Qt Designer, you should not edit any generated files. If you edit the .ui file again, it may generate the ui_.h file for you again and fix the problem.
Here is an example of the generated file ui_mainwindow.h:
/********************************************************************************
** Form generated from reading UI file 'mainwindow.ui'
**
** Created: Wed Jul 10 15:48:32 2013
** by: Qt User Interface Compiler version 4.8.4
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/
#ifndef UI_MAINWINDOW_H
#define UI_MAINWINDOW_H
#include <QtCore/QVariant>
#include <QtGui/QAction>
#include <QtGui/QApplication>
#include <QtGui/QButtonGroup>
#include <QtGui/QHeaderView>
#include <QtGui/QMainWindow>
#include <QtGui/QMenuBar>
#include <QtGui/QStatusBar>
#include <QtGui/QToolBar>
#include <QtGui/QWidget>
QT_BEGIN_NAMESPACE
class Ui_MainWindow
{
public:
QMenuBar *menuBar;
QToolBar *mainToolBar;
QWidget *centralWidget;
QStatusBar *statusBar;
void setupUi(QMainWindow *MainWindow)
{
if (MainWindow->objectName().isEmpty())
MainWindow->setObjectName(QString::fromUtf8("MainWindow"));
MainWindow->resize(400, 300);
menuBar = new QMenuBar(MainWindow);
menuBar->setObjectName(QString::fromUtf8("menuBar"));
MainWindow->setMenuBar(menuBar);
mainToolBar = new QToolBar(MainWindow);
mainToolBar->setObjectName(QString::fromUtf8("mainToolBar"));
MainWindow->addToolBar(mainToolBar);
centralWidget = new QWidget(MainWindow);
centralWidget->setObjectName(QString::fromUtf8("centralWidget"));
// !!!!! NOTE !!!!! setCentralWidget gets called
MainWindow->setCentralWidget(centralWidget);
statusBar = new QStatusBar(MainWindow);
statusBar->setObjectName(QString::fromUtf8("statusBar"));
MainWindow->setStatusBar(statusBar);
retranslateUi(MainWindow);
QMetaObject::connectSlotsByName(MainWindow);
} // setupUi
void retranslateUi(QMainWindow *MainWindow)
{
MainWindow->setWindowTitle(QApplication::translate("MainWindow", "MainWindow", 0, QApplication::UnicodeUTF8));
} // retranslateUi
};
namespace Ui {
class MainWindow: public Ui_MainWindow {};
} // namespace Ui
QT_END_NAMESPACE
#endif // UI_MAINWINDOW_H
I also rambled about using Layouts on a previous post:
Add QRadioButton into QWidget without layout
Hope that helps.
I would like to execute a QMenu object at the position of text cursor in a QPlainTextEdit. My problem is that QTextCursor is only define by its position in the Text (index of the character).
How can I find global position of the QTextCursor? Should I use an other object than QTextCursor in order to find the position of the text cursor where I want to open my QMenu?
Thank you by advance.
I've never tried myself, but doesn't QPlainTextEdit::cursorRect() work? It should give you position of the cursor in viewport coordinates. You can then get the viewport using viewport() and map the local position to global using viewport()->mapToGlobal().
I have found similar query to your in some online forum and here's someone suggested the output as
Note: Reference from http://www.unix.com/unix-linux-applications/81388-read-position-mouse-cursor.html, Author of below posting is daggilli, registered user of UNIX online forums. Credit of below posting in its complete form goes to daggilli.
This is the complete code for a Qt application I threw together in about ten minutes (called crosshair) which displays the current mouse coordinates in a window. You might be able to pull enough out of it to be useful. This is Qt 3.1, but Qt 4 is not a great deal different. You will need the Qt development libraries, not just the runtimes. The code comprises two files, crosshair.h and crosshair.cpp.
crosshair.h:
Code:
#ifndef CROSSHAIR_H
#define CROSSHAIR_H
#include <qwidget.h>
#include <qstring.h>
#include <qlabel.h>
#include <qevent.h>
class Crosshair : public QLabel
{
Q_OBJECT
public:
Crosshair(QWidget *parent=0);
protected:
void mousePressEvent(QMouseEvent *);
private:
QTimer *timer;
private slots:
void timerfire();
};
#endif
crosshair.cpp:
Code:
#include <qapplication.h>
#include <qpushbutton.h>
#include <qtimer.h>
#include <qcursor.h>
#include <iostream>
#include "crosshair.h"
using namespace std;
int main(int argc,char **argv)
{
QApplication a(argc,argv);
Crosshair mousepos;
a.setMainWidget(&mousepos);
mousepos.show();
return a.exec();
}
Crosshair::Crosshair(QWidget *parent) : QLabel(parent)
{
setIndent(20);
resize(100,30);
move(1200,200);
setText("0,0");
timer=new QTimer(this);
connect(timer,SIGNAL(timeout()),this,SLOT(timerfire()));
timer->start(50,false);
}
void Crosshair::mousePressEvent(QMouseEvent *)
{
qApp->quit();
}
void Crosshair::timerfire()
{
QPoint p=QCursor::pos();
this->setText(QString().sprintf("%d,%d",p.x(),p.y()));
}
To build this, put both files in a directory called crosshair. cd to that directory and type
Code:
qmake -project
qmake
make
This does nothing more complex than inherit from a QLabel, set a timer to run 20x a second, grab the current cursor coordinates and write them into the label's text. Clicking in the window closes it. I use it for fixing up alignment bugs in JavaScript when I'm laying out objects.
You could open a file in the Crosshair class's constructor to store your data, and use gettimeofday(2) to get a timestamp. Nothing says Qt has to run in GUI mode (you can tell it explicitly not to in the QApplication constructor).
Qt from Trolltech: http://doc.trolltech.com