Page rows and page stacks

Add flow to your application: Add, remove and replace pages in different ways

A row of pages

We have seen so far that one of the core components of a Kirigami window is a Kirigami.Page. A single page can envelop the whole screen of the application, or it can be shown together with other pages at the same time, if there is space.

Whenever a page gets added, or pushed, it appears to the right of the existing page(s), forming a row. This row of pages can be managed with the fittingly named Kirigami.PageRow.

A minimal page row with a single page could look like this:

import QtQuick
import org.kde.kirigami as Kirigami

Kirigami.ApplicationWindow {
    title: "Single Page"
    width: 500
    height: 200

    Kirigami.PageRow {
        anchors.fill: parent

        Kirigami.Page {
            id: mainPage
            anchors.fill: parent
            Rectangle {
                anchors.fill: parent
                color: "lightblue"
            }
        }
    }
}

A single page with light blue color to show the page's dimensions

There are two improvements that can be done here. The first is that, with initialPage, we can both set mainPage to be the first page that appears in the page row, and have its dimensions be managed by the page row instead of via manual anchors, positioners or layouts. The second is to have a toolbar, which can be set by defining a toolbar style with globalToolBar.style. There are a few styles we can choose from, but we'll go with Kirigami.ApplicationHeaderStyle.Auto for now.

import QtQuick
import org.kde.kirigami as Kirigami

Kirigami.ApplicationWindow {
    title: "With globalToolBar and initialPage"
    width: 500
    height: 200
    Kirigami.PageRow {
        anchors.fill: parent
        globalToolBar.style: Kirigami.ApplicationHeaderStyle.Auto
        initialPage: Kirigami.Page {
            Rectangle {
                anchors.fill: parent
                color: "lightblue"
            }
        }
    }
}

A single page with toolbar and light blue color to show the page's dimensions

There are only two ways of adding pages to a page row: by setting its initialPage (which can optionally take an array of pages) or by using push(). To delete a page from the page row, you should use pop(), whereas goBack() or goForward() can be used to navigate between pages.

import QtQuick
import QtQuick.Controls as Controls
import org.kde.kirigami as Kirigami

Kirigami.ApplicationWindow {
    title: "Multiple pages in a row"
    width: 700
    height: 300
    Kirigami.PageRow {
        id: mainRow
        anchors.fill: parent
        globalToolBar.style: Kirigami.ApplicationHeaderStyle.Auto
        initialPage: Kirigami.Page {
            id: firstPage
            Rectangle {
                anchors.fill: parent
                color: "lightblue"
                Controls.Button {
                    anchors.centerIn: parent
                    text: "Push!"
                    onClicked: mainRow.push(secondPage)
                }
            }
        }

        Component {
            id: secondPage
            Kirigami.Page {
                Rectangle {
                    anchors.fill: parent
                    color: "lightgreen"
                    Controls.Button {
                        anchors.centerIn: parent
                        text: "Pop!"
                        onClicked: mainRow.pop()
                    }
                }
            }
        }
    }
}

Initial page with light blue color

Upon clicking Push

The application's stack of pages

If a Kirigami.PageRow with a toolbar looks familiar to you, that is because you have seen it before. An ApplicationWindow.pageStack is nothing more than a very convenient, global page row. Every function available to a PageRow is also available to the pageStack.

The previous example can be reduced significantly with a pageStack, with the added bonus of navigation actions:

import QtQuick
import QtQuick.Controls as Controls
import org.kde.kirigami as Kirigami

Kirigami.ApplicationWindow {
    title: "Using the pageStack"
    width: 500
    height: 200
    pageStack.initialPage: Kirigami.Page {
            id: firstPage
            Rectangle {
                anchors.fill: parent
                color: "lightblue"
                Controls.Button {
                    anchors.centerIn: parent
                    text: "Push!"
                    onClicked: pageStack.push(secondPage)
                }
            }
        }
        Component {
            id: secondPage
            Kirigami.Page {
                Rectangle {
                    anchors.fill: parent
                    color: "lightgreen"
                    Controls.Button {
                        anchors.centerIn: parent
                        text: "Pop!"
                        onClicked: pageStack.pop()
                }
            }
        }
    }
}

In general you'll want to use a pageStack rather than implement your own PageRow, especially when your application gets bigger and you need your components living in separate files. If you create your window in your Main.qml using a Kirigami.ApplicationWindow, a component residing in another file can still directly invoke the global pageStack by means of a call to the applicationWindow():

// "Main.qml"
import org.kde.kirigami as Kirigami

Kirigami.ApplicationWindow {
    title: "Pushing a Page from a different QML file"
    width: 700
    height: 400
    pageStack.initialPage: BasicPage {}
}

and

// "BasicPage.qml"
import QtQuick
import QtQuick.Controls as Controls
import org.kde.kirigami as Kirigami

Kirigami.Page {
    Controls.Button {
        anchors.centerIn: parent
        text: "This pushes page1 from BasicPage\ninto the pageStack from Main.qml!"
        onClicked: {
            applicationWindow().pageStack.push(page1)
        }
        Component {
            id: page1
            Kirigami.Page {
                Controls.Label {
                    anchors.centerIn: parent
                    text: "page1 was pushed!"
                }
            }
        }
    }
}

Clicking the button pushes a new page with help of applicationWindow