Change the window's size through a button (flickers)

[Leon_2001]

Hello everyone,

I have written a Component "Resize.qml", which provides a button resizing a window/Pane/Rectangle ... attached to it.
Logic seems to work fine as it works as exspected with a Pane in a ApplicationWindow. But actually I made it to resize the ApplicationWindo itself, which also does work in general, but flickers while resizing.

main.qml 

import QtQuick 2.10
import QtQuick.Controls 2.3

ApplicationWindow {
  id: root
  width: 800;  height:  600
  visible: true

  Resize {
    width: 18
    height: 18
    anchors.horizontalCenter: parent.right
    anchors.verticalCenter: parent.top

    corner: Resize.Corner.TopRightCorner
    source: "verkleinern.png"
    target: root
  }
}

Resize.qml

import QtQuick 2.10

Item {
  id: root

  enum Corner {
    TopLeftCorner,
    TopRightCorner,
    BottomLeftCorner
  }

  property alias source: buttonIcon.source
  property int corner : Resize.Corner.TopLeftCorner
  property var target: null

  Image {
    id: buttonIcon
    anchors.fill: parent
  }

  MouseArea {
    anchors.fill: parent
    drag.target: root

    onPositionChanged: {
      if(drag.active) {
        switch(corner) {
          case Resize.Corner.TopLeftCorner: {
            root.target.width -= mouseX;
            root.target.x += mouseX;

            root.target.height -= mouseY;
            root.target.y += mouseY;
            break;
          }
          case Resize.Corner.TopRightCorner: {
            root.target.width += mouseX;

            root.target.height -= mouseY;
            root.target.y += mouseY;
            break;
          }
        }
      }
    }
  }
}

If you drag the Button in the upper right corner around, the window's size follows it. It only works perfect if you drag the button really really slow, in the other case it flickers a lot, which I haven't noticed in a nested window.

Does anyone have a solution for this?

[Jarrod]

I'm getting the same flickering with basically the same approach. Would like to know if there is a way to get a smooth resizing.

[GrecKo]

Use https://doc.qt.io/qt-6/qwindow.html#startSystemResize instead. You can call it from QML.