QtWebEngine BaseApp

This base application provides Qt's WebEngine module, which is missing from the KDE runtime, and makes it possible to quickly and easily package applications that depend on this module.

If you just found this base application, then you might also be interested in the PyQt base application.

To help improving this documentation, open a pull request against the wiki branch.

Supported branches

Any branch based on a non-EOL base runtime should be supported. Branches are considered end-of-life when the base branch is EOL. The current list of supported branches is:

Baseapp branch	Base branch	Qt Webengine version
branch/5.15-23.08	5.15-23.08	5.15.x-lts
branch/6.6	6.6	6.6.x
branch/6.7	6.7	6.7.x

Features

Included libraries

• QtWebEngine
• QtWebView
• krb5: Just the minimal needed for Kerberos authentication with Chromium
• libevent
• minizip
• pciutils: libpci without utilities
• re2
• snappy

Dictionaries

QtWebEngine dictionaries are built from the Hunspell dictionaries and included in this base application.
When building a Flatpak application with this base application, these dictionaries will be packaged in the generated locale extensions, will not be bundled with the application itself, and that's as long as the maintainer didn't disable locale extensions by setting the separate-locales property.

Applications are expected to set the environment variable QTWEBENGINE_DICTIONARIES_PATH to /app/qtwebengine_dictionaries.

Sandboxing support (Qt6 only)

Support for spawning sandboxed Flatpak instances is included, and will be used by QtWebEngine to sandbox Chromium's render processes.

During build process, if an application needs a running QtWebengine process sandboxing must be disabled:

build-options:
  env:
    QTWEBENGINE_DISABLE_SANDBOX: '1'
  # Or alternatively
    QTWEBENGINE_CHROMIUM_FLAGS: --no-sandbox

Flatpak sandboxing support for Chromium was developed by Ryan Gonzalez for the Chromium Flatpak application.

QML

QML modules for Qt Pdf, Webengine and Webview are located in /app/qml. If you rely on those you should add QML_IMPORT_PATH=/app/qml as an environment variable in your application manifest.

Pkgconfig files

Qt webengine installs some pkgconfig files in /app/lib/$(gcc --print-multiarch)/pkgconfig which is not in the PKG_CONFIG_PATH set by flatpak-builder. If your program relies on them at build time you need to use append-pkg-config-path or prepend-pkg-config-path in the manifest.

build-options:
  arch:
    aarch64:
      prepend-pkg-config-path: /app/lib/aarch64-linux-gnu/pkgconfig
    x86_64:
      prepend-pkg-config-path: /app/lib/x86_64-linux-gnu/pkgconfig

Cleanup

Please make sure to cleanup development files from the BaseApp, in the application

cleanup-commands:
  - /app/cleanup-BaseApp.sh

Example QtWebEngine Application

id: org.kde.QtWebEngine.SampleApplication
runtime: org.kde.Platform
runtime-version: '6.6'
sdk: org.kde.Sdk
base: io.qt.qtwebengine.BaseApp
base-version: '6.6'
command: qtwebengine-sample-application
finish-args:
  - --device=dri
  - --env=QTWEBENGINEPROCESS_PATH=/app/bin/QtWebEngineProcess
  - --share=ipc
  - --share=network
  - --socket=fallback-x11
  - --socket=pulse
  - --socket=wayland
cleanup-commands:
  - /app/cleanup-BaseApp.sh
modules:
  - name: sample-application
  ...