TraceCanvas QML Type

A specialized Canvas type for rendering Trace objects. More...

• List of all members, including inherited members

Properties

• autoDestroy : bool
• autoDestroyDelay : int
• renderFunction : var
• trace : var

Methods

• renderSmoothedLine()

Detailed Description

This type provides capabilities for rendering Trace objects on the screen.

To make the Trace rendering available in the keyboard, this type must be declared as the KeyboardStyle.traceCanvasDelegate component.

traceCanvasDelegate: TraceCanvas {
}

Custom drawing attributes can be initialized in the Canvas.available signal. For example:

onAvailableChanged: {
    if (!available)
        return;
    var ctx = getContext("2d")
    ctx.lineWidth = 8 * scaleHint
    ctx.lineCap = "round"
    ctx.strokeStyle = Qt.rgba(0xFF, 0xFF, 0xFF)
    ctx.fillStyle = ctx.strokeStyle
}

The type offers built-in options for Trace rendering. Currently the following rendering options are available:

• renderSmoothedLine Renders smoothed line with round corners (the default)

The rendering function can be changed with the renderFunction property.

renderFunction: renderSmoothedLine

Custom rendering function is also supported. Consider the following example:

renderFunction: renderCustomLine

function renderCustomLine() {
    getContext("2d")
    var points = trace.points()

    ...
}

Property Documentation

Method Documentation