I have MyWindow class which pops up a blank window, which accepts a mouse click, I need to unit test the mouse click event
Code snippet:
void TestGui::testGUI_data()
{
QTest::addColumn<QTestEventList>("events");
QTest::addColumn<QTestEventList>("expected");
Mywindow mywindow;
QSize editWidgetSize = mywindow.size();
QPoint clickPoint(editWidgetSize.rwidth()-2, editWidgetSize.rheight()-2);
QTestEventList events, expected;
events.addMouseClick( Qt::LeftButton, 0, clickPoint);
expected.addMouseClick( Qt::LeftButton, 0, clickPoint);
QTest::newRow("mouseclick") << events << expected ;
}
void TestGui::testGUI()
{
QFETCH(QTestEventList, events);
QFETCH(QTestEventList, expected);
Mywindow mywindow;
mywindow.show();
events.simulate(&mywindow);
QCOMPARE(events, expected); } // prints FAIL! : TestGui::testGUI(mouseclick) Compared values are not the same
...
}
How to test the mouse click on mywindow. is there any better approach to unit test mouse events?
Thanks,
vels
Take a look on QTest namespace documentation. There is QTest::mouseClick function which allows you to emulate mouse click on the given position of your widget (there is even no necessity to show the widget).
As far as I remember QCOMPARE uses "operator==" for the arguments given and if it returns false then it tries to print it using "QTest::toString<T>(const T& t)" function. If there is no implementation for a type of QCOMPARE arguments then it will just print that values are different. Again take a look on the QTest namespace documentation for details how to reimplement "QTest::toString<T> (const T& t)" for the type you need.
Related
I am getting this error with connect function
QTimer timer;
QObject::connect(&timer, &QTimer::timeout,this, &MainWindow::draw);
timer.start(1000);
both timeout and draw are predefined functions.
How can I solve this?
Even If I use a different function like
Sprite *sprite = new Sprite(this);
QTimer timer;
QObject::connect(&timer, &QTimer::timeout,sprite, &Sprite::drawNextBall);
timer.start(1000);
void Sprite::drawNextBall(QPainter &painter)
{
qDebug() <<"Sprite::drawNextBall() called";
painter.drawEllipse(x, y, 15, 15);
}
As stated by the error message, signal and slot arguments should match. This is definitely not the case in your example as QTimer::timeout has not a QPainter& as its first argument:
The signature of a signal must match the signature of the receiving slot. (In fact a slot may have a shorter signature than the signal it receives because it can ignore extra arguments.) [1]
Secondly, QPainter should only be used to draw on a QWidget inside a QWidget::paintEvent:
Warning: When the paintdevice is a widget, QPainter can only be used inside a paintEvent() function or in a function called by paintEvent(). [2]
What you probably want is connecting the QTimer::timeout signal to the QWidget::update (MainWindow::update or Sprite::update).
Relevant reading material
Signals & Slots
QPainter - Detailed description
Is it possible for QTextLayout to render several characters, but to process/handle it as one character. For example rendering a code point like: [U+202e], and when moving the caret/calculating positions, it is treated as one character.
Edited:
Please check this following issue, were I explain what I'm trying to do. It for the edbee Qt component. It's using QTextLayout for line rendering.
https://github.com/edbee/edbee-lib/issues/127
Possibly it isn't possible with QTextLayout, the documentation is quite limited.
According to Qt docs:
"The class has a rather low level API and unless you intend to implement your own text rendering for some specialized widget, you probably won't need to use it directly." - https://doc.qt.io/qt-5/qtextlayout.html#details
You should probably use a QLineEdit or a QTextEdit (each has a method called setReadOnly(bool)).
Before answering the question, I will point out that the CursorMode enum (https://doc.qt.io/qt-5/qtextlayout.html#CursorMode-enum) seems very promising for this problem, but to me, the documentation isn't clear on how to use it or set it.
Now to answer your question in regards to QLineEdit or QTextEdit, it's a bit complicated, but it's the same for QLineEdit and QTextEdit, so lets look at QTextEdit.
Firstly, mouse clicks: QTextEdit has a signal called cursorPositionChanged(), which will be helpful here. You'll want to connect that to a custom slot, which can make use of the function moveCursor(QTextCursor::MoveOperation operation, QTextCursor::MoveMode mode = QTextCursor::MoveAnchor) (https://doc.qt.io/qt-5/qtextedit.html#moveCursor). Notice that there are very helpful enumeration values for you here in QTextCursor::MoveOperation regarding word hopping (https://doc.qt.io/qt-5/qtextcursor.html#MoveOperation-enum). How do we put all of this together? Well, probably the right way to do it is to determine the width of the chars to the left of the cursor's position and the width of the chars to the right of the cursor's position when the cursorPositionChanged() signal is emitted and go to the side of the word that has less width. However, I'm not sure how to do that. At this point I'd settle with checking the number of chars to the left and right and going to the side with less.
Secondly, keyboard presses: This goes a bit out of my knowledge, but almost everything drawable and iteractable inherits from QWidget. Take a look at https://doc.qt.io/qt-5/qwidget.html#keyPressEvent and it's possible that overriding that in your own implementation of QTextEdit is necessary to get the left arrow and right arrow keypresses to jump words (once you get that part it's pretty easy, just use the same function as last section for moving the cursor, or in the case of QLineEdit, cursorWordForward()/cursorWordBackward()).
All this being said, I've so far been assuming that you're not deleting anything or selecting anything. Selection can be a real pain depending on if you allow multiple selections, but the functions are all there in the documentation to implement those things.
Example of mouse click impl:
myclass.hpp
#include <QTextEdit>
#include <QTextCursor>
#include <QObject>
#include <QString>
int distance_to_word_beginning_or_end(const QString &str, int index, bool beginning);
class MyClass {
MyClass();
~MyClass();
private:
QTextEdit *text_edit;
public slots:
void text_edit_changed_cursor_location();
};
myclass.cpp
#include "myclass.hpp"
int distance_to_word_beginning_or_end(const QString &str, int index, bool beginning)
{
// return the distance from the beginning or end of the word from the index given
int inc_or_dec = (beginning) ? -1 : 1;
int distance = 0;
while (index >= 0 && index < str.length())
{
if (str.at(index) == ' ' || str.at(index) == '\n' || str.at(index) == '\t')
{
return distance;
}
distance++;
index += inc_or_dec;
}
return --distance;
}
MyClass::MyClass()
{
text_edit = new QTextEdit();
QObject::connect(text_edit, &QTextEdit::cursorPositionChanged, this, &MyClass::text_edit_changed_cursor_location);
}
MyClass::~MyClass()
{
delete text_edit;
}
void MyClass::text_edit_changed_cursor_location()
{
QString text_edit_string = text_edit->text();
QTextCursor text_edit_cursor = text_edit->textCursor();
auto current_position = text_edit_cursor.position();
QTextCursor new_text_cursor;
int distance_to_beginning = distance_to_word_beginning_or_end(text_edit_string, current_position, true);
int distance_to_end = distance_to_word_beginning_or_end(text_edit_string, current_position, false);
auto movement_type;
if (distance_to_beginning > distance_to_end)
{
new_text_cursor.setPosition(current_position + distance_to_end);
} else {
new_text_cursor.setPosition(current_position - distance_to_beginning);
}
text_edit->setTextCursor(new_text_cursor);
}
I didn't find a proper solution to this problem, so I hope somebody can give me an answer to my problem:
I am using a normal QTreeWidget, but as items I use an own subclass of QTreeWidgetItem (because I needed to store some other information in the item). Now I want to use the itemClicked() signal by the QTreeWidget, but I think my slot doesn't get any signal and I think it has to do with the signature of itemClicked(), since it sends a QTreeWidgetItem and of course not my own subclass.
Is it possible that QTreeWidget doesn't detect a click on my own subclass items?
Here is my connection:
connect(treeWidget, SIGNAL(itemClicked(QTreeWidgetItem *)), this, SLOT(displayTransformData(QTreeWidgetItem*)));
And here is my slot:
void GUI::displayTransformData(QTreeWidgetItem* item) {
cout << "test" endl;
Q_actorTreeWidgetItem* actor_item = dynamic_cast<Q_actorTreeWidgetItem*>(item);
vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor = actor_item->getActorReference();
double* position = new double[3];
position = actor->GetOrigin();
x_loc->setText(QString(std::to_string( position[0]).c_str() ));
}
I'm already trying to cast the item that I could get from the signal into my own subclass, but the slot function is never called, because the test from my cout line doesn't appear in the console.
I'm very grateful for every help!
The problem is your incorrect SIGNAL specification,
SIGNAL(itemClicked(QTreeWidgetItem *))
You should probably see a warning message at the console along the lines of:
QObject::connect: No such signal
tree_widget::itemClicked(QTreeWidgetItem *) in ...
From the documentation the actual signal spec is
void QTreeWidget::itemClicked(QTreeWidgetItem *item, int column)
So, using the old Qt4 syntax you need
connect(treeWidget, SIGNAL(itemClicked(QTreeWidgetItem *, int)),
this, SLOT(displayTransformData(QTreeWidgetItem*)));
If possible, however, you should make use of the newer Qt5 signal/slot syntax
connect(treeWidget, &QTreeWidget::itemClicked, this, &GUI::displayTransformData);
We know that for drawing on an image in qt, qpainter is used. Recently, I used drawLine() function to draw whatever an user is scribbling. This was done by passing the lastPoint and currentPoint from the mouseMoveEvent to a custom function which implements drawLine(). I have passed the arguments for that custom function as given below:
void myPaint::mouseMoveEvent(QMouseEvent *event) {
qDebug() << event->pos();
if ((event->buttons() & Qt::LeftButton) && scribbling) {
pixelList.append(event->pos());
drawLineTo(event->pos());
lastPoint = event->pos();
}
}
Now with the help of qDebug() I noticed that some pixels are missed while drawing but the drawing is precise. I looked up the source of qt-painting where I saw that drawLine() was calling drawLines() which was making use of qpainterPath to have a shape drawn on the image.
My question is that, is there anyway to track these "missed" pixels or any approach to find all the pixels which have been drawn?
Thanks!
void myPaint::drawLineTo(const QPoint &endPoint) {
QPainter painter(image); //image is initialized in the constructor of myPaint
painter.setRenderHint(QPainter::Antialiasing);
painter.setPen(QPen(Qt::blue, myPenWidth, Qt::SolidLine, Qt::RoundCap,Qt::RoundJoin));
painter.drawLine(lastPoint, endPoint);
modified = true;
lastPoint = endPoint; //at the mousePressEvent, the event->pos() will be stored as
// lastPoint
update();
}
For a start, don't draw in a mouseEvent(). Actually handling a mouseevent should be done as quick as possible. Also, it is not a good idea to look at the Qt source, it can be confusing. Rather assume that what Qt gives you work, and first try to answer "What I am doing wrong?". As I said drawing in a mouse event is definitely wrong.
Your description is really subjective, maybe an image of your output is better. Are you trying to emulate a pen (like in windows paint)? In this case do the mouse button has to be down ? is that the purpose of your variable scribbling?
There is more. following the documentation, QMouseEvent::buttons() always return a combination of all buttons for mouse move event. Which make sense : the mouse movements are independent of the buttons. It means
if ((event->buttons() & Qt::LeftButton)
will always be true.
Let's assume you want to draw the path of your mouse when the left button is pressed. Then you use something like :
void myPaint::mousePressEvent(QMouseEvent *event){
scribbling = true;
pixelList.clear();
}
void myPaint::mouseReleaseEvent(QMouseEvent *event){
scribbling = false;
}
void myPaint::mouseMoveEvent(QMouseEvent *event) {
if ( scribbling) {
pixelList.append(event->pos());
}
}
void myPaint::paintEvent(){
QPainter painter(this)
//some painting here
if ( scribbling) {
painter.setRenderHint(QPainter::Antialiasing);
painter.setPen(QPen(Qt::blue, myPenWidth, Qt::SolidLine, Qt::RoundCap,Qt::RoundJoin));
// here draw your path
// for example if your path can be made of lines,
// or you just put the points if they are close from each other
}
//other painting here
}
If after all of this you don't have a good rendering, try using float precision (slower), ie QMouseEvent::posF() instead of QMouseEvent::pos().
EDIT :
"I want to know whether there is any way to calculate all the sub-pixels between any two pixels that we send as arguments to drawLine"
Yes there is. I don't know why you need to do such thing but is really simple. A line can be characterized with the equation
y = ax + b
Both of the endpoints of the line p0 = (x0, y0) and p1 = (x1, y1) satisfy this equation so you can easily find a and b. Now all you need to do is increment from x0 to x1 by the amount of
pixels you want (say 1), and to compute the corresponding y value, each time saving point(x,y).
So will go over all of the points saved in pixelList and repeat this process for any two consecutive points.
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!!``