System Services¶

PrismQML bundles a set of system-level service objects. On the Python side they are obtained through get_xxx() singletons; when using App or register_types(), identically named context properties are injected into QML and can be referenced directly.

Clipboard — ClipboardHelper¶

Method	Description
`copy(text)`	Copy text to the clipboard
`paste()`	Read clipboard text; returns `""` when empty

from prismqml import get_clipboard_helper

get_clipboard_helper().copy("copied text")

Fluent.Button {
    text: "Copy"
    onClicked: ClipboardHelper.copy("text")
}

QR Code — QRCodeGenerator¶

Depends on the optional qrcode package; available is False when it is not installed:

from prismqml import get_qrcode_generator

gen = get_qrcode_generator()
if gen.available:
    url = gen.getImageSource("https://example.com", 256, "#000000", "#ffffff", "M")

Member	Description
`available`	Whether the `qrcode` library is usable
`getImageSource(content, size, fgColor, bgColor, errorLevel)`	Returns an `image://qrcode/...` URL for a QML `Image`

size accepts 32–1024 (default 128); errorLevel is L / M / Q / H. QML can use the ready-made component instead:

Fluent.QRCode { content: "https://example.com" }

See Data for the component details.

SVG Rendering — SvgImageProvider¶

The image://svg image provider is registered automatically at App startup and renders SVG files at high quality through QSvgRenderer; sourceSize optionally selects the render size:

Image {
    source: "image://svg/path/to/icon.svg"
    sourceSize: Qt.size(128, 128)   // optional
}

Everything after image://svg/ is one QML URL component: reserved characters are percent-decoded exactly once, then file / qrc sources are resolved with Qt URL semantics.

Screen Eyedropper — ScreenEyedropperManager¶

Member	Description
`startPicking(is_dark)`	Show a cursor-following magnifier and start picking
`stopPicking()`	Stop picking
`colorPicked(QColor)`	Signal: a color was confirmed
`pickingStarted` / `pickingFinished` / `pickingCancelled`	Signals: picking lifecycle

from prismqml import get_screen_eyedropper_manager

picker = get_screen_eyedropper_manager()
picker.colorPicked.connect(lambda color: print(color.name()))
picker.startPicking(True)   # True = dark magnifier appearance

Left click or Enter confirms; right click, Esc, or losing focus cancels. The QML ColorPicker component already integrates this entry point.

Single Instance — SingleInstance¶

from prismqml import SingleInstance

instance = SingleInstance("com.example.myapp")
instance.activateRequested.connect(raise_main_window)
if not instance.try_lock():
    return  # another instance is running; this process sent the activate message
app.exec()
instance.unlock()

Windows locks through a named mutex (Local\\{app_id}); other platforms use QSharedMemory
When try_lock() fails, the second instance sends an activate message to the primary instance and returns False; the primary emits the activateRequested signal, which can raise the main window to the front
If the primary instance is unresponsive (a stale lock), the second instance takes over startup automatically
Prefer a reverse-domain app_id; a with SingleInstance("...") as instance: context manager is also supported