class QDesktopServices

The QDesktopServices class provides methods for accessing common desktop services. More…

Added in version 4.2.

Synopsis

Static functions

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Many desktop environments provide services that can be used by applications to perform common tasks, such as opening a web page, in a way that is both consistent and takes into account the user’s application preferences.

This class contains functions that provide simple interfaces to these services that indicate whether they succeeded or failed.

The openUrl() function is used to open files located at arbitrary URLs in external applications. For URLs that correspond to resources on the local filing system (where the URL scheme is “file”), a suitable application will be used to open the file; otherwise, a web browser will be used to fetch and display the file.

The user’s desktop settings control whether certain executable file types are opened for browsing, or if they are executed instead. Some desktop environments are configured to prevent users from executing files obtained from non-local URLs, or to ask the user’s permission before doing so.

URL Handlers

The behavior of the openUrl() function can be customized for individual URL schemes to allow applications to override the default handling behavior for certain types of URLs.

The dispatch mechanism allows only one custom handler to be used for each URL scheme; this is set using the setUrlHandler() function. Each handler is implemented as a slot which accepts only a single QUrl argument.

The existing handlers for each scheme can be removed with the unsetUrlHandler() function. This returns the handling behavior for the given scheme to the default behavior.

This system makes it easy to implement a help system, for example. Help could be provided in labels and text browsers using help://myapplication/mytopic URLs, and by registering a handler it becomes possible to display the help text inside the application:

class MyHelpHandler(QObject):

    Q_OBJECT
# public
    # ...
# public slots
    def showHelp(url):
QDesktopServices.setUrlHandler("help", helpInstance, "showHelp")

If inside the handler you decide that you can’t open the requested URL, you can just call openUrl() again with the same argument, and it will try to open the URL using the appropriate mechanism for the user’s desktop environment.

Combined with platform specific settings, the schemes registered by the openUrl() function can also be exposed to other applications, opening up for application deep linking or a very basic URL-based IPC mechanism.

See also

QSystemTrayIconQProcessQStandardPaths

static openUrl(url)
Parameters:

url – QUrl

Return type:

bool

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Opens the given url in the appropriate Web browser for the user’s desktop environment, and returns true if successful; otherwise returns false.

If the URL is a reference to a local file (i.e., the URL scheme is “file”) then it will be opened with a suitable application instead of a Web browser.

The following example opens a file on the Windows file system residing on a path that contains spaces:

QDesktopServices.openUrl(QUrl("file:///C:/Program Files", QUrl.TolerantMode))

If a mailto URL is specified, the user’s e-mail client will be used to open a composer window containing the options specified in the URL, similar to the way mailto links are handled by a Web browser.

For example, the following URL contains a recipient (user@foo.com), a subject (Test), and a message body (Just a test):

mailto:user@foo.com?subject=Testbody=Just a test

Warning

Although many e-mail clients can send attachments and are Unicode-aware, the user may have configured their client without these features. Also, certain e-mail clients (e.g., Lotus Notes) have problems with long URLs.

Warning

A return value of true indicates that the application has successfully requested the operating system to open the URL in an external application. The external application may still fail to launch or fail to open the requested URL. This result will not be reported back to the application.

Warning

URLs passed to this function on iOS will not load unless their schemes are listed in the LSApplicationQueriesSchemes key of the application’s Info.plist file. For more information, see the Apple Developer Documentation for canOpenURL:. For example, the following lines enable URLs with the HTTPS scheme:

<key>LSApplicationQueriesSchemes</key>
<array>
    <string>https</string>
</array>

Note

For Android Nougat (SDK 24) and above, URLs with a file scheme are opened using FileProvider which tries to obtain a shareable content scheme URI first. For that reason, Qt for Android defines a file provider with the authority ${applicationId}.qtprovider, with applicationId being the app’s package name to avoid name conflicts. For more information, also see Setting up file sharing .

See also

setUrlHandler()

static setUrlHandler(scheme, receiver, method)
Parameters:

  • scheme – str

  • receiver – QObject

  • method – str

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Sets the handler for the given scheme to be the handler method provided by the receiver object.

This function provides a way to customize the behavior of openUrl() . If openUrl() is called with a URL with the specified scheme then the given method on the receiver object is called instead of QDesktopServices launching an external application.

The provided method must be implemented as a slot that only accepts a single QUrl argument.

class MyHelpHandler(QObject):

    Q_OBJECT
# public
    # ...
# public slots
    def showHelp(url):

If setUrlHandler() is used to set a new handler for a scheme which already has a handler, the existing handler is simply replaced with the new one. Since QDesktopServices does not take ownership of handlers, no objects are deleted when a handler is replaced.

Note that the handler will always be called from within the same thread that calls openUrl() .

You must call unsetUrlHandler() before destroying the handler object, so the destruction of the handler object does not overlap with concurrent invocations of openUrl() using it.

iOS and macOS

To use this function for receiving data from other apps on iOS/macOS you also need to add the custom scheme to the CFBundleURLSchemes list in your Info.plist file:

<key>CFBundleURLTypes</key>
<array>
    <dict>
        <key>CFBundleURLSchemes</key>
        <array>
            <string>myapp</string>
        </array>
    </dict>
</array>

For more information, see the Apple Developer Documentation for Defining a Custom URL Scheme for Your App.

Warning

It is not possible to claim support for some well known URL schemes, including http and https. This is only allowed for Universal Links.

To claim support for http and https the above entry in the Info.plist file is not allowed. This is only possible when you add your domain to the Entitlements file:

<key>com.apple.developer.associated-domains</key>
<array>
    <string>applinks:your.domain.com</string>
</array>

iOS/macOS will search for /.well-known/apple-app-site-association on your domain, when the application is installed. If you want to listen to https://your.domain.com/help?topic=ABCDEF you need to provide the following content there:

"applinks": {
    "apps": [],
    "details": [{
        "appIDs" : [ "ABCDE12345.com.example.app" ],
        "components": [{
            "/": "/help",
            "?": { "topic": "?*"}
        }]
    }]

For more information, see the Apple Developer Documentation for Supporting Associated Domains.

Android

To use this function for receiving data from other apps on Android, you need to add one or more intent filter to the activity in your app manifest:

<intent-filter>
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    <data android:scheme="https" android:host="your.domain.com" android:port="1337" android:path="/help"/>
</intent-filter>

For more information, see the Android Developer Documentation for Create Deep Links to App Content.

To immediately open the corresponding content in your Android app, without requiring the user to select the app, you need to verify your link. To enable the verification, add an additional parameter to your intent filter:

<intent-filter android:autoVerify="True">

Android will look for https://your.domain.com/.well-known/assetlinks.json, when the application is installed. If you want to listen to https://your.domain.com:1337/help, you need to provide the following content there:

[{
  "relation": ["delegate_permission/common.handle_all_urls"],
  "target": {
    "namespace": "android_app",
    "package_name": "com.example.app",
    "sha256_cert_fingerprints":
    ["14:6D:E9:83:C5:73:06:50:D8:EE:B9:95:2F:34:FC:64:16:A0:83:42:E6:1D:BE:A8:8A:04:96:B2:3F:CF:44:E5"]

}]

For more information, see the Android Developer Documentation for Verify Android App Links.

static unsetUrlHandler(scheme)
Parameters:

scheme – str

Removes a previously set URL handler for the specified scheme.

Call this function before the handler object that was registered for scheme is destroyed, to prevent concurrent openUrl() calls from continuing to call the destroyed handler object.

See also

setUrlHandler()