iOS keyboard doesn't activate when TextField receives focus

J.Hilk

if your QML is inside a QQuickWidget or a QQuickView, than that is a well known, but infixed bug

https://bugreports.qt.io/browse/QTBUG-63157

My, very hackish, workaround for iOS is to create an offscreen QLineEdit that I set the focus on manually and forward the textChanged signal to QML.

I hate it, but it works.

patrickkidd

@J.Hilk said in iOS keyboard doesn't activate when TextField receives focus:

Hi @patrickkidd

if your QML is inside a QQuickWidget or a QQuickView, than that is a well known, but infixed bug

https://bugreports.qt.io/browse/QTBUG-63157

My, very hackish, workaround for iOS is to create an offscreen QLineEdit that I set the focus on manually and forward the textChanged signal to QML.

I hate it, but it works.

Do you have a code snippet? How do you detect the QML Item kb focus? Then how do you forward the kb events to the QML component?

J.Hilk

@patrickkidd like I said, this code is nearly 2 years old, when I did my baby steps in QML x) so its convoluted

TextInput{
            id:nameEdit
            anchors.fill: parent
            font.pixelSize: Manager.fontSize

            enabled: !root.reactToClicked

            activeFocusOnPress: true

            Keys.onReturnPressed:{
                deselect()
                Qt.inputMethod.hide();
                parent.forceActiveFocus()
            }

            horizontalAlignment: Qt.AlignHCenter
            verticalAlignment: Qt.AlignVCenter
        }

        MouseArea{
            id:iosNameEdit
            anchors.fill: nameEdit

            visible: Qt.platform.os === "ios" && !root.reactToClicked

            property string uuid: Manager.newUuid()
            onClicked: {
                Manager.initLineEdit(nameEdit.text,iosNameEdit.uuid,false);
                root.moveUp()
            }

            Connections{
                target: Manager
                onCurrentTextChanged:{
                    if(uuid === iosNameEdit.uuid ) {
                        nameEdit.text = text
                    }
                }
                onEditingFinished:{
                    if(uuid === iosNameEdit.uuid ) {
                        root.moveDown()
                    }
                }
            }
        }

The relevant part of Manager instance:

Q_INVOKABLE QString newUuid(){return QUuid::createUuid().toString();}

 Q_INVOKABLE void initLineEdit(const QString &text, const QString &uuid, bool useTimeRestiction) {
        if(iosLineEdit)
            iosLineEdit->initLineEdit(text,uuid,useTimeRestiction);
    }

//Manager constructor
iosLineEdit = new iOSLineEdit(qobject_cast<QWidget*>(parent));
    iosLineEdit->show();
    iosLineEdit->lower();
    connect(iosLineEdit, &iOSLineEdit::currentTextChanged, this, &Manager::currentTextChanged);
    connect(iosLineEdit, &iOSLineEdit::currentEditFinsihed, this, &Manager::editingFinished);

//iosLineEdit.h
class QRegExpValidator;
class iOSLineEdit : public QLineEdit
{
    Q_OBJECT
public:
    explicit iOSLineEdit(QWidget *parent = nullptr);

public slots:
    void initLineEdit(const QString &text, const QString &uuid, bool useTimeRestiction);

signals:
    void currentTextChanged(const QString &uuid, const QString &text);
    void currentEditFinsihed(const QString &uuid);

protected:
    QString m_Uuid;
    QRegExpValidator *m_Validator;
};

//iosLineEdit.cpp
#include "ioslineedit.h"
#include <QRegExpValidator>
#include <QDebug>

iOSLineEdit::iOSLineEdit(QWidget *parent) : QLineEdit (parent)
{
    setMaximumSize(QSize(0,0));
    connect(this, &QLineEdit::textChanged, this, [=](const QString &text)->void{
        if( !m_Uuid.isEmpty()) {
            emit currentTextChanged(m_Uuid, text);
        }
    });
    connect(this, &QLineEdit::editingFinished, this, [=]()->void{
        if(!m_Uuid.isEmpty())
            emit currentEditFinsihed(m_Uuid);
        m_Uuid.clear();
        clear();
        setEnabled(false);
        hide();
    });

    m_Validator = new QRegExpValidator(QRegExp("/^(?:(?:([0-9]?\d|2[0-3]):)?([0-5]?\d):)?([0-5]?\d)$/"),this);
    lower();
    hide();
}

void iOSLineEdit::initLineEdit(const QString &text, const QString &uuid, bool useTimeRestiction)
{
    qDebug() << Q_FUNC_INFO;
    m_Uuid.clear();

    if(useTimeRestiction) {
        setInputMask(QString("99:99:99"));
        setValidator(m_Validator);
    } else {
        setInputMask(QString());
        setValidator(nullptr);
    }

    setText(text);

    m_Uuid = uuid;
    setEnabled(true);
    show();
    setFocus();
}

J.Hilk

@patrickkidd
Ignore the above post.

I took the time to refine my original fix.

You can find a working GitHub example here:
https://github.com/DeiVadder/IosTextFieldWorkaround

patrickkidd

@J.Hilk said in iOS keyboard doesn't activate when TextField receives focus:

@patrickkidd
Ignore the above post.

I took the time to refine my original fix.

You can find a working GitHub example here:
https://github.com/DeiVadder/IosTextFieldWorkaround

I tried this concept out in my app and it does work. Of course, there is quite a lot of features that need to be added, for example showing cursor position, allowing the selection of text, things like that.

Let's hope this bug gets fixed.

J.Hilk

@patrickkidd I think, once the keyboard is up, you could transfer the focus back to the textfield and the keyboard input would actually go to the textfield.

But I haven't tested that thoroughly

patrickkidd

@J.Hilk said in iOS keyboard doesn't activate when TextField receives focus:

@patrickkidd I think, once the keyboard is up, you could transfer the focus back to the textfield and the keyboard input would actually go to the textfield.

But I haven't tested that thoroughly

Negative. Setting focus outside an accepted text input control is the event that hides the iOS keyboard again.

J.Hilk

@patrickkidd yes, but textInput is an accepted text input control, just that the keyboard call event isn't forwarded outside the quickwidget.

Thats at least what I read out of the bug report

patrickkidd

@J.Hilk said in iOS keyboard doesn't activate when TextField receives focus:

@patrickkidd yes, but textInput is an accepted text input control, just that the keyboard call event isn't forwarded outside the quickwidget.

Thats at least what I read out of the bug report

How exactly would you transfer focus back to the TextField? I tried setting the keyboard focus back to the TextInput item like the following pseudo-snippet and the keyboard was hidden again. Is that what you were thinking about?

def beginFocus(self, text, textInputQQuickItem):
    quickWidget = QApplication.focusWidget()
    lineEdit.setFocus(Qt.MouseFocusReason)
    quickWidget.setFocus(Qt.MouseFocusReason)
    textInputQQuickItem.setFocus(True, Qt.MouseFocusReason)

J.Hilk

@patrickkidd

if you take my example and only change the content of IosLineEdit.qml

to this

import QtQuick 2.12
import QtQuick.Controls 2.12

import QLineEdit 1.0

TextInput {
    id:root
    onEditingFinished: parent.forceActiveFocus()

    QLineEdit{
        id:backend

        onTextChanged: root.text = text
        onEditingFinished: root.parent.forceActiveFocus()
    }

    MouseArea{
        anchors.fill: parent
        visible: Qt.platform.os === "ios" && !root.activeFocus

        onClicked: {
            backend.init(root.text)
            shiftFocus.start()
        }

        Timer{
            id:shiftFocus
            interval: 10
            running: false
            repeat: false
            onTriggered: root.forceActiveFocus()
        }
    }
}

then the keyboard is called, focus shifted and text input has again all functionality

have to change my repo I guess ;)

patrickkidd

@J.Hilk said in iOS keyboard doesn't activate when TextField receives focus:

@patrickkidd

if you take my example and only change the content of IosLineEdit.qml
then the keyboard is called, focus shifted and text input has again all functionality

have to change my repo I guess ;)

Calling QQuickItem::forceActiveFocus(Qt.MouseFocusReason) still does not help for me in my app. The keyboard does not appear for me in your example using the iOS Simulator either.

Below is my own nearly complete drop-in solution that retains focus on the QLineEdit and has extra (and crucial) support for cursor positions and selection areas. It should be all the code you need. Note there is no mouse area, which causes problems in some cases where the TextInput is a child.

class LineEditBackEnd(QLineEdit, Debug):

    def __init__(self, parent):
        super().__init__(parent)
        self.setMaximumSize(QSize(0, 0))
        self.move(-10, -10)
        self.lower()
        self.hide()

    # prevent a seg fault from calling `text` as property from qml                                                                                                                                              
    @pyqtSlot(result=str)
    def getText(self):
        return self.text()

    @pyqtSlot(str, int, int, int)
    def beginFocus(self, text, cursorPos, selectionStart, selectionEnd):
        if self.parent() is None:
            self.setParent(QApplication.activeWindow())
        self.blockSignals(True)
        self.setText(text)
        self.setCursorPosition(cursorPos)
        super().setSelection(selectionStart, selectionEnd-selectionStart)
        self.setFocus(Qt.MouseFocusReason)
        self.blockSignals(False)
        self.show()
        item.forceActiveFocus(Qt.MouseFocusReason)

    @pyqtSlot(str, int, int)
    def do_setSelection(self, text, start, end):
        self.blockSignals(True)
        if text != self.text():
            self.setText(text)
        super().setSelection(start, end-start)
        self.blockSignals(False)

    @pyqtSlot(int, int, int)
    def do_setCursorPosition(self, pos, start, end):
        self.blockSignals(True)
        super().setCursorPosition(pos)
        super().setSelection(start, end-start)
        self.blockSignals(False)

    @pyqtSlot(result=int)
    def getCursorPosition(self):
        return self.cursorPosition()

    @pyqtSlot(result=int)
    def selectionStart(self):
        return super().selectionStart()

    @pyqtSlot(result=int)
    def selectionEnd(self):
        return super().selectionEnd()

qmlRegisterType(LineEditBackEnd, 'LineEditBackEnd', 1, 0, 'LineEditBackEnd')

import QtQuick 2.12
import QtQuick.Controls 2.5
import QtQuick.Layouts 1.12
import LineEditBackEnd 1.0

// maybe a better text input that actually raises the kb on iOS                                                                                                                                                 

TextInput {

    id: root

    LineEditBackEnd { id: backend }

    property bool syncing: false
    property bool ios: Qt.platform.os == 'ios'

    onFocusChanged: {
        if(ios && !syncing) {
            syncing = true
            backend.beginFocus(text, cursorPosition, selectionStart, selectionEnd)
            syncing = false
        }
    }

    onSelectionStartChanged: {
        if(ios && !syncing) {
            syncing = true
            backend.do_setSelection(text, selectionStart, selectionEnd)
            syncing = false
        }
    }
    onSelectionEndChanged: {
	if(ios && !syncing) {
            syncing = true
            backend.do_setSelection(text, selectionStart, selectionEnd)
            syncing = false
	}
    }


    onCursorPositionChanged: {
	if(ios && !syncing) {
            syncing = true
            backend.do_setCursorPosition(cursorPosition, selectionStart, selectionEnd)
            syncing = false
	}
    }

    Connections {
	target: backend

	onTextChanged: {
            if(ios && !syncing) {
		syncing = true
		root.text = backend.getText()
		root.cursorPosition = backend.getCursorPosition()
                syncing = false
            }
        }

        onCursorPositionChanged: function(_old, _new) {
            if(ios && !syncing) {
                syncing = true
                cursorPosition = _new
                syncing = false
            }
        }
        onSelectionChanged: {
            if(ios && !syncing) {
                syncing = true
                select(backend.selectionStart(), backend.selectionEnd())
                syncing = false
            }
        }

        onEditingFinished: root.parent.forceActiveFocus()
    }

}

patrickkidd

@J.Hilk Scratch that, your solution may have better support for cursors and selection areas after all. Could be an error on my end. I'll do some more checking.

patrickkidd

@patrickkidd said in iOS keyboard doesn't activate when TextField receives focus:

@J.Hilk Scratch that, your solution may have better support for cursors and selection areas after all. Could be an error on my end. I'll do some more checking.

Hmm, I don't know. I wasn't able to port your solution into my project. The TextInput does not receive text events, or sometimes crashes when setting the text property, and does not support selection behavior. Not sure why. I guess I'll stick with mine which uses the default QtQuick selection behavior, until the Qt bug is fixed.