GridLayout {
        columns: 2
        width: window.width
        height: window.height

        Rectangle {
            Layout.preferredWidth: 250
            Layout.preferredHeight: parent.height
            color: "orange"
        }

        ColumnLayout {
            Layout.fillWidth: true
            Layout.fillHeight: true

            RowLayout {
                Layout.fillWidth: true
                Layout.preferredHeight: 40

                Rectangle {
                    Layout.preferredWidth: 40
                    Layout.preferredHeight: parent.height
                    color: "red"

                    MouseArea {
                        anchors.fill: parent
                    }
                }

                Rectangle {
                    Layout.preferredWidth: parent.width * 0.80
                    Layout.preferredHeight: parent.height
                    color: "blue"
                }

                Rectangle {
                    Layout.fillWidth: true
                    Layout.preferredHeight: parent.height
                    color: "green"
                }
            }
            Rectangle {
                Layout.fillWidth: true
                Layout.fillHeight: true
                color: "pink"
            }
        }
    }