QML TextArea奇怪的填充

Question

I have a TextArea. If I set padding constantly padding working normally.

import QtQuick 2.9
import QtQuick.Controls 2.2

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    TextArea{
        font.pixelSize: 20
        anchors.fill: parent
        wrapMode: TextArea.Wrap
        leftPadding: 100 //*parent.width/640
        rightPadding: 100 //*parent.width/640
    }
}

If I uncomment lines above then I have strange behavior. What am I doing wrong?

Screenshot

Answer 1

It seems to be a bug, probably some updates are missing, when setting up the width of the contentItem of the ApplicationWindow , so the line lengths are not calculated properly.

If you write:

leftPadding: {
    console.log(parent, parent.width)
    return 100 * parent.width/640
}

You can see, that the parent.width is initially set to 0 and then changes to 640. When this change happens, there must be something going wrong with the signals.

A resize of the window will update the line lengths, so the proper layout is restored. You might try to file a bugreport on http://bugreports.qt.io to have it fixed.

Other than that, you may give an ID to your ApplicationWindow and use this instead of parent

import QtQuick 2.7
import QtQuick.Controls 2.0

ApplicationWindow {
    id: win
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    TextArea{
        font.pixelSize: 20
        anchors.fill: parent
        wrapMode: TextArea.Wrap
        leftPadding: 100 * win.width/640
        rightPadding: 100 * win.width/640
    }
}