lock touch screen

[imhs]

Hello, everyone.
I have coded a gui using qml and deploy it rpi3b+. there is a touch screen to interact with the user. I need to have lock screen functionality. However, I couldn't find a solution to do this!
is there any way?
any suggestion is greatly appreciated.
Regards

[jsulm]

@imhs By "lock" you mean disable touch? Do you want to disable it permanently or when needed and then enable it again? What is the use case for that?

[J.Hilk]

@imhs
you mean, you want to start the systems screen lock, so that the user has to reenter his Password ?

You can't do that from qt, maybe there's a native c lib that allows you to do it, but I'm not aware of it.

[imhs]

@jsulm said in lock touch screen:

@imhs By "lock" you mean disable touch? Do you want to disable it permanently or when needed and then enable it again? What is the use case for that?

@jsulm
Thanks for your response.

In fact, I want to disable all the buttons when the screen is locked to prevent accidental touch (since this UI controls some hardware) and enable them again when I toggle off the lock switch.

[imhs]

@J-Hilk said in lock touch screen:

@imhs
you mean, you want to start the systems screen lock, so that the user has to reenter his Password ?

You can't do that from qt, maybe there's a native c lib that allows you to do it, but I'm not aware of it.

I don't need a password to be entered again. Just a simple lock to block touch events.

[jsulm]

@imhs You can call https://doc.qt.io/qt-5/qwidget.html#setDisabled on your central widget or main window.

[imhs]

@jsulm said in lock touch screen:

@imhs You can call https://doc.qt.io/qt-5/qwidget.html#setDisabled on your central widget or main window.

Thanks for your response. But if I am not wrong, it is for Qwidget applications. I have used qml.
Is there any similar function in qml?
regards.

[J.Hilk]

@imhs
enabled = false (on the root element of your application)

[imhs]

@J-Hilk said in lock touch screen:

@imhs
enabled = false (on the root element of your application)

There is no property "enabled" in my root element which is "window".
here is the first lines of my code

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.VirtualKeyboard 2.4
import QtQuick.Controls 2.5
//import QtQuick.Controls 2.13
//import QtQuick.Controls 1.4
import QtQuick.Layouts 1.3
import Modbus.Backend 1.0
import QtQuick.Extras 1.4
import QtQuick.Controls.Styles 1.4
import Qt.labs.settings 1.0
import QtQuick.Window 2.3
import QtQuick.Dialogs 1.3

//import "delayfunc.js" as Mydelay

//import "content"
//import "content"

Window {

    id: window
    visible: true
    width: 800
    height: 480
    title: qsTr("Process Control")
  ....
}

other elements are inside this.

[J.Hilk]

@imhs
ah Window is special, I forgot

A hacky way could be a simply MouseArea to capture the input ?

MouseArea{
id:blockAllInput
anchors.fill: parent
enabled: false
z:100 //to make sure, its above it siblings
}

enable the MouseAre to capture all input disable it for normal function...

[imhs]

@J-Hilk said in lock touch screen:

@imhs
ah Window is special, I forgot

A hacky way could be a simply MouseArea to capture the input ?

MouseArea{
id:blockAllInput
anchors.fill: parent
enabled: false
z:100 //to make sure, its above it siblings
}

enable the MouseAre to capture all input disable it for normal function...

Thanks a lot. It works.
But is also prevent me to touch my lock switch again to disable it.

[J.Hilk]

@imhs
if the lock switch is also in main.qml, simply give it a z of > 100
😉

[imhs]

@J-Hilk said in lock touch screen:

@imhs
if the lock switch is also in main.qml, simply give it a z of > 100
😉

It is in the main.qml but it is not a child of the root (window). I tried it before my last post but it doesn't work.

[J.Hilk]

@imhs mmh,
can you show that part of the main.qml ?

[imhs]

please find the code below:

 GroupBox {
        id: buttons
        y:3
        //title: "Row layout"
        anchors.left: parent.left
        width: parent.width
        height: 40
        background: Rectangle {
            anchors.fill: parent
            opacity: 0.1
            color: "black"
            radius: 10

        }
        Rectangle{
            anchors.fill:parent

            color: "transparent"
            //            MouseArea{
            //                anchors.fill: parent
            //                cursorShape: Qt.BlankCursor
            //            }
            Switch{
                id:runStop_switch
                //text: qsTr("Switch")
                x:3//temp_box.x
                y: -5//temp_box.y
                checked: false
                signal mytoggle
                //onMytoggle:

                indicator: Rectangle {
                    implicitWidth: 40
                    implicitHeight: 20
                    x:runStop_switch.leftPadding
                    y:parent.height / 2 - height / 2+2
                    radius: 13
                    opacity: 0.9
                    color: runStop_switch.checked ? "yellow" : "#ffffff"
                    border.color: runStop_switch.checked ? "#17a81a" : "#cccccc"

                    Rectangle {
                        x: runStop_switch.checked ? parent.width - width : 0
                        y:0
                        width: 20
                        height: 20
                        radius: 23
                        color: runStop_switch.down ? "#cccccc" : "#ffffff"
                        border.color: runStop_switch.checked ? (runStop_switch.down ? "#17a81a" : "#21be2b") : "#999999"
                    }
                }

                contentItem: Text {
                    text: runStop_switch.text
                    font: runStop_switch.font
                    opacity: enabled ? 1.0 : 0.3
                    color: runStop_switch.down ? "#17a81a" : "#21be2b"
                    verticalAlignment: Text.AlignVCenter
                    leftPadding: runStop_switch.indicator.width + runStop_switch.spacing
                }
                //onToggled:   {


                onCheckedChanged:   {
                    if (runStop_switch.checked==true){
                         rusStop_label.text="Run";

                        modbus_connection.Read();
                      setpoint_slider_value.running=true
                        if (setpoint_slider.value0!=setpoint_slider.value){
                      modbus_connection.setStPnt(textField_setPnt.value/100)
                        }
                        temp_switch.checked=false
                        temp_switch.toggle()

                        motor0_switch.checked=false
                        motor0_switch.toggle()
                        motor1_switch.checked=false
                        motor1_switch.toggle()
                        motor2_switch.checked=false
                        motor2_switch.toggle()
                        motor3_switch.checked=false
                        motor3_switch.toggle()
                        motor4_switch.checked=false
                        motor4_switch.toggle()
                        motor5_switch.checked=false
                        motor5_switch.toggle()
                        motor6_switch.checked=false
                        motor6_switch.toggle()
                        if(motor0_switch.checked==true){
                            motor0.value=motor0.mymotor0_val
                            modbus_connection.setCell0(motor0.value)

                        }
                        if(motor1_switch.checked==true){
                            motor1.value=motor1.mymotor1_val
                            modbus_connection.setCell1(motor1.value)

                        }
                        if(motor2_switch.checked==true){
                            motor2.value=motor2.mymotor2_val
                            modbus_connection.setCell2(motor2.value)

                        }
                        if(motor3_switch.checked==true){
                            motor3.value=motor3.mymotor3_val
                            modbus_connection.setDuall_cell(motor3.value)

                        }
                        if(motor4_switch.checked==true){
                            motor4.value=motor4.mymotor4_val
                            modbus_connection.setCell4(motor4.value)

                        }
                        if(motor5_switch.checked==true){
                            motor5.value=motor5.mymotor5_val
                            modbus_connection.setCell5(motor5.value)

                        }
                        if(motor6_switch.checked==true){
                            motor6.value=motor6.mymotor6_val
                            modbus_connection.setCell6(motor6.value)

                        }


                        pump_switch.checked=false
                        pump_switch.toggle()
                        if(pump_switch.checked==true){
                            if (pump.mypump_val<150)
                                 pump.value=150
                            else
                            pump.value=pump.mypump_val
                            modbus_connection.setPump(pump.value)

                        }

                        status_timer.stop()
                        modbus_connection.setStatus("System is running")
                        status_bar_text.counter=3
                        status_timer.start()
                        modbus_connection.setStatus(" ")


                    }
                    else{

                        // modbus_connection.setStatus(" ")
                        modbus_connection.Disconect();
                        temp_switch.checked=true
//                        cooling_label.visible=false;
//                        heating_label.visible=false;
                        setpoint_slider_value.running=false
                        temp_switch.toggle()

                        motor0_switch.checked=true
                        motor0_switch.toggle()
                        if(motor0_switch.checked==false){
                            motor0.value=0

                        }
                        motor1_switch.checked=true
                        motor1_switch.toggle()

                        if(motor1_switch.checked==false){
                            motor1.value=0

                        }
                        motor2_switch.checked=true
                        motor2_switch.toggle()

                        if(motor2_switch.checked==false){
                            motor2.value=0

                        }
                        motor3_switch.checked=true
                        motor3_switch.toggle()

                        if(motor3_switch.checked==false){
                            motor3.value=0

                        }
                        motor4_switch.checked=true
                        motor4_switch.toggle()

                        if(motor4_switch.checked==false){
                            motor4.value=0

                        }
                        motor5_switch.checked=true
                        motor5_switch.toggle()

                        if(motor5_switch.checked==false){
                            motor5.value=0

                        }
                        motor6_switch.checked=true
                        motor6_switch.toggle()

                        if(motor6_switch.checked==false){
                            motor6.value=0

                        }


                        pump_switch.checked=true
                        pump_switch.toggle()
                        if(pump_switch.checked==false){
                            pump.value=0

                        }

                        status_bar_text.counter=3
                        status_timer.start()

                        rusStop_label.text="Stop"
                        status_timer.stop()
                        modbus_connection.setStatus("System has been stopped")
                        status_timer.stop()
                      //  console.log("Stop")
                    }


                }

            }
            Label {
                id:rusStop_label
                width: 40
                x:runStop_switch.x+2
                y:runStop_switch.y-5
                visible: true
                color: "white"
                horizontalAlignment: Text.AlignHCenter
                text: "Stop"
                font.pixelSize: 12
            }



            Label{
                id: state_title
                x: heating_cooling.x+20
                y:30
                text:"State"
                color: "white"
                font.bold: true
                font.pixelSize: 12
            }

            Switch{
                id:lock_switch
                //text: qsTr("Unlock")
                x:725//temp_box.x
                y: -5//temp_box.y
                checked: false

                indicator: Rectangle {
                    implicitWidth: 40
                    implicitHeight: 20
                    x:lock_switch.leftPadding
                    y:parent.height / 2 - height / 2+2
                    radius: 13
                    opacity: 0.9
                    color: lock_switch.checked ? "yellow" : "#ffffff"
                    border.color: lock_switch.checked ? "#17a81a" : "#cccccc"

                    Rectangle {
                        x: lock_switch.checked ? parent.width - width : 0
                        y:0
                        width: 20
                        height: 20
                        radius: 23
                        color: lock_switch.down ? "#cccccc" : "#ffffff"
                        border.color: lock_switch.checked ? (lock_switch.down ? "#17a81a" : "#21be2b") : "#999999"
                    }
                }

                contentItem: Text {
                    text: lock_switch.text
                    font: lock_switch.font
                    opacity: enabled ? 1.0 : 0.3
                    color: lock_switch.down ? "#17a81a" : "#21be2b"
                    verticalAlignment: Text.AlignVCenter
                    leftPadding: lock_switch.indicator.width + lock_switch.spacing
                }
                onCheckedChanged: {
//                onToggled:   {

                    if (lock_switch.checked==true){
                        lock_label.text="Locked"
                        date.enabled=false
                        rdioBut_external.enabled=false
                        rdioBut_internal.enabled=false
                        temp_switch.enabled=false
                        motor0_switch.enabled=false
                        motor1_switch.enabled=false
                        motor2_switch.enabled=false
                        motor3_switch.enabled=false
                        motor4_switch.enabled=false
                        motor5_switch.enabled=false
                        motor6_switch.enabled=false
                        pump_switch.enabled=false
                        pwm_slider.enabled=false
                        setpoint_slider.enabled=false
                        rdioBut_motor0.enabled=false
                        rdioBut_motor1.enabled=false
                        rdioBut_motor2.enabled=false
                        rdioBut_motor3.enabled=false
                        rdioBut_motor4.enabled=false
                        rdioBut_motor5.enabled=false
                        rdioBut_motor6.enabled=false
                        rdioBut_pump.enabled=false
                        pump_select.enabled=false
                        motor0_select.enabled=false
                        motor1_select.enabled=false
                        motor2_select.enabled=false
                        motor3_select.enabled=false
                        motor4_select.enabled=false
                        motor5_select.enabled=false
                        motor6_select.enabled=false
                        runStop_switch.enabled=false
                        textField_setPnt.enabled=false
                        pwm_slider_spinbox.enabled=false
                         modbus_connection.setStatus(" ")
                        status_timer.stop()
                        modbus_connection.setStatus("Screen is locked")
                        status_bar_text.counter=5
                        status_timer.start()
                       //


                       // console.log("Screen is locked ")
                    }
                    else{
                        lock_label.text="Unlocked"
                        date.enabled=true
                        rdioBut_external.enabled=true
                        rdioBut_internal.enabled=true
                        temp_switch.enabled=true
                        motor0_switch.enabled=true
                        motor1_switch.enabled=true
                        motor2_switch.enabled=true
                        motor3_switch.enabled=true
                        motor4_switch.enabled=true
                        motor5_switch.enabled=true
                        motor6_switch.enabled=true
                        pump_switch.enabled=true
                        pwm_slider.enabled=true
                        setpoint_slider.enabled=true
                        rdioBut_motor0.enabled=true
                        rdioBut_motor1.enabled=true
                        rdioBut_motor2.enabled=true
                        rdioBut_motor3.enabled=true
                        rdioBut_motor4.enabled=true
                        rdioBut_motor5.enabled=true
                        rdioBut_motor6.enabled=true
                        rdioBut_pump.enabled=true
                        pump_select.enabled=true
                        motor0_select.enabled=true
                        motor1_select.enabled=true
                        motor2_select.enabled=true
                        motor3_select.enabled=true
                        motor4_select.enabled=true
                        motor5_select.enabled=true
                        motor6_select.enabled=true
                        runStop_switch.enabled=true
                        textField_setPnt.enabled=true
                        pwm_slider_spinbox.enabled=true
                        modbus_connection.setStatus(" ")
                        status_timer.stop()
                        modbus_connection.setStatus("Screen is unlocked")
                        status_bar_text.counter=5
                        status_timer.start()
                       //

                      //  console.log("Screen is unlocked")
                    }


                }

            }
            Label {
                id:lock_label
                width: 40
                x:lock_switch.x+2
                y:lock_switch.y-5
                visible: true
                color: "white"
                text: "Unlocked"
                horizontalAlignment: Text.AlignHCenter
                font.pixelSize: 12
            }


        }


    }

[J.Hilk]

@imhs
ah yes runStop_switch is not a sibling of the mouse area, as it's a child of buttons the z property only effects the siblings hierarchy

try:

MouseArea{
        id:blockAllInput
        anchors.fill: parent
       z: 100
        onPressed: {
            var adjusted = mapToItem(blockAllInput, runStop_switch.x, runStop_switch.y)
            if(mouseX > adjusted.x && mouseX < adjusted.x + runStop_switch.width)
                if(mouseY > adjusted.y && mouseY < adjusted.y + runStop_switch.height)
                    mouse.accepted = false
        }
    }

that should let the pressed signal through, but not the release, so clicked will not be emitted 🤔
You'll have to adjust that

[imhs]

@J-Hilk said in lock touch screen:

MouseArea{
id:blockAllInput
anchors.fill: parent
z: 100
onPressed: {
var adjusted = mapToItem(blockAllInput, runStop_switch.x, runStop_switch.y)
if(mouseX > adjusted.x && mouseX < adjusted.x + runStop_switch.width)
if(mouseY > adjusted.y && mouseY < adjusted.y + runStop_switch.height)
mouse.accepted = false
}
}

Thank you so much. You gave me the clue. I appreciate your kind help.