Custom QWidget Keyboard first time click issue.

[Arvind K]

For a General Application we have login form with on screen custom keyboard. Keyboard is designed with QWidget. When we try to enter a value with on screen keyboard , at first time it's not taking any input(i.e. button click) afterwards all buttons are working fine. We have tried to set a focus programmatically but its not working. Please give a solution for the same.
We observed that keyboard is working fine if we call on Pushbutton click, but its not working with QLineEdit.

[dheerendra]

Event not received indicates that event is taken some other object and processed before it reaches keyboard widget. Did try running the program with H/W keyboard ? Which platform did you try this ?

[Arvind K]

@dheerendra
For our Application we don't want to use H/W keyboard.
We are using Ubuntu 16.04 , 64bit system with Touchscreen display.

[mrjj]

@Arvind-K
Hi
since you are showing no code, i wont speculate on what error might be.

Anyway, try using QGuiApplication::focusObject();
and see what widget has the focus.

For my widget keyboard, i have all buttons set to NoFocus for focusPolicy as else they
steal focus on first shown, unless i control it very tight.

[Arvind K]

----------------- Login widget Code -------------------------------

frmlogin.h

#include <QWidget>
#include "keyboard/keyboard.h"
#include "messagebox.h"

namespace Ui {
class FrmLogin;
}

class FrmLogin : public QWidget
{
Q_OBJECT

public:
Ui::FrmLogin *ui;
explicit FrmLogin(QWidget *parent = 0);
~FrmLogin();

private slots:
void run_keyboard_lineEdit();
void on_BtnCancel_clicked();

protected:
void showEvent(QShowEvent *event);

private:
Keyboard *lineEditkeyboard;
};

---

frmlogin.cpp

FrmLogin::FrmLogin(QWidget *parent) :
QWidget(parent),
ui(new Ui::FrmLogin)
{

ui->setupUi(this);
setGeometry(QStyle::alignedRect(Qt::LeftToRight,Qt::AlignCenter,size(),
                                qApp->desktop()->availableGeometry()
                                )
            );
setWindowFlags ( Qt::CustomizeWindowHint | Qt::WindowTitleHint);
lineEditkeyboard = new Keyboard();

connect(ui->txt_Pass ,SIGNAL(selectionChanged()),this,SLOT(run_keyboard_lineEdit()));
connect(ui->txt_user ,SIGNAL(selectionChanged()),this,SLOT(run_keyboard_lineEdit()));

}

void FrmLogin::run_keyboard_lineEdit()
{
Qt::WindowFlags flags = windowFlags();

QLineEdit *line = (QLineEdit *)sender();
lineEditkeyboard->setLineEdit(line);
lineEditkeyboard->ui->lineEdit->setText(line->text());
if(line->objectName()=="txt_Pass")
{
    lineEditkeyboard->ui->lineEdit->setEchoMode(QLineEdit::EchoMode::Password);
}
else
{
    lineEditkeyboard->ui->lineEdit->setEchoMode(QLineEdit::EchoMode::Normal);
}

lineEditkeyboard->setWindowModality(Qt::ApplicationModal);
lineEditkeyboard->setWindowState(Qt::WindowActive);
lineEditkeyboard->raise();
lineEditkeyboard->show();

}

-------------- Keyboard Widget Code -----------------------------------

Keyboard.h

#include <QWidget>
#include <QtGui>
#include <QLineEdit>
#include <QPushButton>

namespace Ui {
class Keyboard;
}

class Keyboard : public QWidget
{
Q_OBJECT

public:
bool IsOnlyCharVar=false;
explicit Keyboard(QWidget *parent = 0);
void setLineEdit(QLineEdit * );
~Keyboard();
QPushButton *enterButton;
Ui::Keyboard *ui;

private slots:
void keyboardHandler();
void on_enterButton_clicked();
void on_lineEdit_returnPressed();

private:

QString outputText;
QLineEdit *outputLineEdit;   

};

Keyboard.cpp

#include "keyboard.h"
#include "ui_keyboard.h"
#include <QtGui>
#include "QToolTip"

Keyboard::Keyboard(QWidget *parent) :
QWidget(parent),
ui(new Ui::Keyboard)
{
ui->setupUi(this);

this->setWindowFlags(Qt::WindowStaysOnTopHint);   

connect ( ui->Buttona, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );
connect ( ui->Buttonb, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );
connect ( ui->Buttonc, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );
connect ( ui->Buttond, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );
connect ( ui->Buttone, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );
connect ( ui->Buttonf, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );
connect ( ui->Buttong, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );
connect ( ui->Buttonh, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );
connect ( ui->Buttoni, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );    

connect ( ui->space, SIGNAL( clicked() ), this, SLOT( keyboardHandler() ) );

outputText = "";
ui->lineEdit->setFocus();

}

void Keyboard::keyboardHandler()
{
QPushButton *button = (QPushButton *)sender();
QString inputText = button->text();

QToolTip::showText(button->mapToGlobal(QPoint()),inputText,button,button->rect(),300);

if (inputText == "Space")
{
    outputText += " ";
}
else if(inputText == "&&")
{
    outputText += "&";
}
else if(inputText == "\\")
{
    outputText += ui->Buttona->text() ;
}
else
{      
    {
        outputText += inputText;
    }
}
ui->lineEdit->setText(outputText);

}

void Keyboard::setLineEdit(QLineEdit * line)
{
outputLineEdit = line;
}

Keyboard::~Keyboard()
{
delete ui;
}

void Keyboard::on_shift_clicked()
{
if(shift == true)
{
shift = false;
ui->shift->setStyleSheet("background-color: rgb(248, 248, 248);");

    ui->Buttona->setText("a");
    ui->Buttons->setText("b");
    ui->Buttond->setText("c");
    ui->Buttonf->setText("d");
    ui->Buttong->setText("e");
    ui->Buttonh->setText("F");
    ui->Buttonj->setText("g");
    ui->Buttonk->setText("h");
    ui->Buttonl->setText("i");
}
else
{
    shift = true;
    ui->shift->setStyleSheet("background-color: rgb(121, 121, 255);");
    ui->Buttona->setText("A");
    ui->Buttons->setText("B");
    ui->Buttond->setText("C");
    ui->Buttonf->setText("D");
    ui->Buttong->setText("E");
    ui->Buttonh->setText("F");
    ui->Buttonj->setText("G");
    ui->Buttonk->setText("H");
    ui->Buttonl->setText("I");
}

}

void Keyboard::on_clear_clicked()
{
outputText="";
ui->lineEdit->setText(outputText);
}

void Keyboard::on_enterButton_clicked()
{
//qDebug() << "enter";
outputLineEdit->setText(outputText);
outputText="";
ui->lineEdit->setText(outputText);
close();
}

void Keyboard::on_backButton_clicked()
{
//outputText.remove(outputText.length()-1,outputText.length());
outputText.remove(outputText.length()-1,1);
ui->lineEdit->setText(outputText);
}

[Arvind K]

Any Updates??
Please feel free to ask any questions on above code.

[mrjj]

@Arvind-K
Hi
What did
qDebug() << "focus widget " << qApp->focusObject();
report ?
in the case where it dont type.

[Arvind K]

@mrjj

i used qDebug() << "focus widget " << qApp->focusObject(); at button click event.

it doesn't fire at first time . but at second time click on Button "a" i get "focus widget QPushButton(0x26bbc00, name= "Buttona")" log .

i think at first time my keyboard widget doesn't get activate. after click on widget anywhere it gets activate and after that it works proper.

how to solve this issue.?

[J.Hilk]

Hi,

from my experience, this behaviour comes from the focus shift,

you click a button and than it gets the focus a and only than the clicked mechanimn works.

IIRC, you can change that a couple of different ways.

the following comes to my mind:

• Chaning the signal from clicked to released
• Subclassing QPushButton and manually emitting the pressed signal during focus in event

[Arvind K]

@J.Hilk

Thank you for your reply.

1. At the first time my Push button click event is not getting fired so released event is also not working.
2. I have implemented focus in event but at first time its also not getting emitting.

[mrjj]

@Arvind-K
Hi
for my keyboard, I find it needed to have
NoFocus for focusPolicy on the buttons or they steal focus from Lineedit.

[Arvind K]

still, the issue is pending. Please provide a solution.

[deleted372]

It may be a silly question, does it happen with all the buttons of your keyboard?
Are you sure that the first time you push on a button of your keyboard the slot keyboardHandler() gets called?

[Arvind K]

@JoZCaVaLLo

Yes, it happens with all the buttons of a keyboard. slot keyboardHandler() does not get called for the first time. another thing I observed that when I called a keyboard on QPushbutton clicked event then keyboard works properly. this issue happens with QlineEdit Only.

[deleted372]

I would call lineEditkeyboard->setLineEdit(line) only when the lineEdit gets the focus.
In addition, in the setLineEdit(), I would call this->setFocusProxy(line). In order to avoid your keyboard to steal the focus from your linedit.

[Arvind K]

@JoZCaVaLLo
@mrjj
@J-Hilk
@dheerendra
one more thing to share when I called keyboard widget with a show() like
lineEditkeyboard->setLineEdit(line);
lineEditkeyboard->show();

the keyboard works properly but when I called Keyboard like

lineEditkeyboard->setLineEdit(line);
lineEditkeyboard->setWindowModality(Qt::ApplicationModal);
lineEditkeyboard->show();

then I face the same issue of the first click.

[mrjj]

@Arvind-K
hi, we need to find out what is happening.
please do
qDebug() << "focus widget " << qApp->focusObject();
which tells us when you open the keyboard, who has focus.
Meaning who will get the keys if u type.
I think you have something that steals keyboard focus when u open the
lineEditkeyboard

[Arvind K]

@mrjj

as you said I have done same when keyboard widget is shown.
output is

DBG default: focus widget QLineEdit(0x227ca90, name = "lineEdit")

lineEdit is Nothing but the QLineEdit on Keyboard widget.

[mrjj]

@Arvind-K
Ok so it does have the focus when first click is not registered?

[Arvind K]

@mrjj

Yes.
after that when I click on Anywhere on Widget Nothing happen or no Any event gets called.