Class QAccelPlot::PlotExporter¶

ClassList > QAccelPlot > PlotExporter

Exports a plot as a raster image: to a file, to the clipboard, or as a QImage .More...

#include <PlotExporter.hpp>

Inherits the following classes: QObject

Inheritance diagram¶

flowchart TB
  classQAccelPlot_1_1PlotExporter["QAccelPlot::PlotExporter"]

  external_base_classQAccelPlot_1_1PlotExporter_1["QObject"]
  external_base_classQAccelPlot_1_1PlotExporter_1 --> classQAccelPlot_1_1PlotExporter

Public Properties¶

Type	Name
property bool	busy True from a request until its `finished()` signal.
property qreal	dpi Resolution stored in saved files, in dots per inch; 0 stores 96 times the effective scale. Default: 0.
property PlotView *	plot Plot to export; null once the plot is destroyed.
property int	quality Encoder quality from 0 to 100 passed to `QImageWriter` ; -1 uses the format's default. Default: -1.
property qreal	scale Image pixels per logical pixel; 0 uses the window's device pixel ratio. Default: 0.
property bool	transparentBackground Leaves out the plot's `axesAreaColor` and`plotAreaColor` backgrounds. Default: false.

Public Signals¶

Type	Name
signal void	busyChanged Emitted when the busy property changes.
signal void	dpiChanged Emitted when the dpi property changes.
signal void	finished (bool ok, const QString & path, const QString & error) Emitted when a request ends; path is the saved file, empty for other requests.
signal void	imageReady (const QImage & image) Emitted with the captured image before`finished()` for a`grabImage()` request.
signal void	plotChanged Emitted when the plot property changes.
signal void	qualityChanged Emitted when the quality property changes.
signal void	scaleChanged Emitted when the scale property changes.
signal void	transparentBackgroundChanged Emitted when the transparentBackground property changes.

Public Functions¶

Type	Name
	PlotExporter (QObject * parent=nullptr) Constructs an exporter without a plot.
	PlotExporter (const PlotExporter &) = delete
	PlotExporter (PlotExporter &&) = delete
bool	busy () const Returns true while a request is in progress.
Q_INVOKABLE bool	copyToClipboard () Copies the plot image to the clipboard; returns false when the request fails immediately.
qreal	dpi () const Returns the resolution stored in saved files; 0 means 96 times the effective scale.
Q_INVOKABLE bool	grabImage () Captures the plot and emits `imageReady()` ; returns false when the request fails immediately.
PlotExporter &	operator= (const PlotExporter &) = delete
PlotExporter &	operator= (PlotExporter &&) = delete
PlotView *	plot () const Returns the plot to export.
int	quality () const Returns the encoder quality.
Q_INVOKABLE bool	save (const QString & path) Saves the plot to path in the format its suffix names.
qreal	scale () const Returns the image pixels per logical pixel; 0 means the window's device pixel ratio.
void	setDpi (qreal dpi) Sets the stored resolution; negative and nonfinite values are ignored with a warning.
void	setPlot (PlotView * plot) Sets the plot to export; a request in progress keeps its plot.
void	setQuality (int quality) Sets the encoder quality; values outside -1 to 100 are ignored with a warning.
void	setScale (qreal scale) Sets the image pixels per logical pixel; negative and nonfinite values are ignored with a warning.
void	setTransparentBackground (bool transparent) Sets whether the image leaves out the plot's backgrounds.
bool	transparentBackground () const Returns whether the image leaves out the plot's backgrounds.
	~PlotExporter () override Restores the plot's appearance if a capture is in progress.

Public Static Functions¶

Type	Name
Q_INVOKABLE QStringList	supportedFormats () Returns the lowercase file suffixes `save()` accepts on this system, such as`png` and`jpg` .

Detailed Description¶

The capture contains the plot item and everything drawn inside its bounds, as on screen: series, axes, legend, overlays, and any child items. Children outside the bounds are clipped. The plot must be visible in a window that is shown, not minimized, and renders through a hardware scene graph backend.

Every request is asynchronous and ends with exactly one finished() signal, except one made while busy: it returns false with a warning and leaves finished() to the request in progress. A request for a plot another exporter is capturing fails. The capture is taken on the next frame, and fails when the window is hidden, minimized, or destroyed first; encoding and writing a file run on a worker thread.

** **

PlotExporter {
    id: exporter
    plot: myPlot
    scale: 2
    onFinished: (ok, path, error) => console.log(ok ? "Saved " + path : error)
}
Button { text: "Save"; onClicked: exporter.save("plot.png") }

See also: PlotView

Public Properties Documentation¶

property busy¶

True from a request until its finished() signal.

bool QAccelPlot::PlotExporter::busy;

property dpi¶

Resolution stored in saved files, in dots per inch; 0 stores 96 times the effective scale. Default: 0.

qreal QAccelPlot::PlotExporter::dpi;

The default makes documents place the image at its on-screen size.

property plot¶

Plot to export; null once the plot is destroyed.

PlotView* QAccelPlot::PlotExporter::plot;

property quality¶

Encoder quality from 0 to 100 passed to QImageWriter ; -1 uses the format's default. Default: -1.

int QAccelPlot::PlotExporter::quality;

Lossy formats (JPEG, WebP) trade file size for artifacts. PNG stays lossless and only trades file size for encoding time. Other formats ignore it.

property scale¶

Image pixels per logical pixel; 0 uses the window's device pixel ratio. Default: 0.

qreal QAccelPlot::PlotExporter::scale;

At a device pixel ratio other than 1, Qt 6.3 and later cannot render every image size, so a side can be a pixel shorter or longer than the plot's size times the scale.

property transparentBackground¶

Leaves out the plot's axesAreaColor andplotAreaColor backgrounds. Default: false.

bool QAccelPlot::PlotExporter::transparentBackground;

Grid, series, axes, and child items such as the legend are drawn as usual. Formats without an alpha channel, such as JPEG, composite the image over white. The plot shows no background for the frame it is captured in.

Public Signals Documentation¶

signal busyChanged¶

Emitted when the busy property changes.

void QAccelPlot::PlotExporter::busyChanged;

signal dpiChanged¶

Emitted when the dpi property changes.

void QAccelPlot::PlotExporter::dpiChanged;

signal finished¶

Emitted when a request ends; path is the saved file, empty for other requests.

void QAccelPlot::PlotExporter::finished;

ok is false when the request failed, and error describes why.

signal imageReady¶

Emitted with the captured image beforefinished() for agrabImage() request.

void QAccelPlot::PlotExporter::imageReady;

signal plotChanged¶

Emitted when the plot property changes.

void QAccelPlot::PlotExporter::plotChanged;

signal qualityChanged¶

Emitted when the quality property changes.

void QAccelPlot::PlotExporter::qualityChanged;

signal scaleChanged¶

Emitted when the scale property changes.

void QAccelPlot::PlotExporter::scaleChanged;

signal transparentBackgroundChanged¶

Emitted when the transparentBackground property changes.

void QAccelPlot::PlotExporter::transparentBackgroundChanged;

Public Functions Documentation¶

function PlotExporter¶

Constructs an exporter without a plot.

explicit QAccelPlot::PlotExporter::PlotExporter (
    QObject * parent=nullptr
)

function PlotExporter¶

QAccelPlot::PlotExporter::PlotExporter (
    const PlotExporter &
) = delete

function PlotExporter¶

QAccelPlot::PlotExporter::PlotExporter (
    PlotExporter &&
) = delete

function busy¶

Returns true while a request is in progress.

bool QAccelPlot::PlotExporter::busy () const

function copyToClipboard¶

Copies the plot image to the clipboard; returns false when the request fails immediately.

Q_INVOKABLE bool QAccelPlot::PlotExporter::copyToClipboard ()

function dpi¶

Returns the resolution stored in saved files; 0 means 96 times the effective scale.

qreal QAccelPlot::PlotExporter::dpi () const

function grabImage¶

Captures the plot and emits imageReady() ; returns false when the request fails immediately.

Q_INVOKABLE bool QAccelPlot::PlotExporter::grabImage ()

function operator=¶

PlotExporter & QAccelPlot::PlotExporter::operator= (
    const PlotExporter &
) = delete

function operator=¶

PlotExporter & QAccelPlot::PlotExporter::operator= (
    PlotExporter &&
) = delete

function plot¶

Returns the plot to export.

PlotView * QAccelPlot::PlotExporter::plot () const

function quality¶

Returns the encoder quality.

int QAccelPlot::PlotExporter::quality () const

function save¶

Saves the plot to path in the format its suffix names.

Q_INVOKABLE bool QAccelPlot::PlotExporter::save (
    const QString & path
)

path may be a local file path or a file: URL. An existing file is replaced only when the new one is written completely. Returns false when the request fails immediately, after emitting finished() unless the exporter is busy.

function scale¶

Returns the image pixels per logical pixel; 0 means the window's device pixel ratio.

qreal QAccelPlot::PlotExporter::scale () const

function setDpi¶

Sets the stored resolution; negative and nonfinite values are ignored with a warning.

void QAccelPlot::PlotExporter::setDpi (
    qreal dpi
)

function setPlot¶

Sets the plot to export; a request in progress keeps its plot.

void QAccelPlot::PlotExporter::setPlot (
    PlotView * plot
)

function setQuality¶

Sets the encoder quality; values outside -1 to 100 are ignored with a warning.

void QAccelPlot::PlotExporter::setQuality (
    int quality
)

function setScale¶

Sets the image pixels per logical pixel; negative and nonfinite values are ignored with a warning.

void QAccelPlot::PlotExporter::setScale (
    qreal scale
)

function setTransparentBackground¶

Sets whether the image leaves out the plot's backgrounds.

void QAccelPlot::PlotExporter::setTransparentBackground (
    bool transparent
)

function transparentBackground¶

Returns whether the image leaves out the plot's backgrounds.

bool QAccelPlot::PlotExporter::transparentBackground () const

function ~PlotExporter¶

Restores the plot's appearance if a capture is in progress.

QAccelPlot::PlotExporter::~PlotExporter () override

Public Static Functions Documentation¶

function supportedFormats¶

Returns the lowercase file suffixes save() accepts on this system, such aspng andjpg .

static Q_INVOKABLE QStringList QAccelPlot::PlotExporter::supportedFormats ()

The documentation for this class was generated from the following file QAccelPlot/src/QAccelPlot/export/PlotExporter.hpp