QgsMultiRenderChecker Class Reference

This class allows checking rendered images against comparison images. More...

#include <qgsmultirenderchecker.h>

Public Member Functions
	QgsMultiRenderChecker ()=default
	Constructor for QgsMultiRenderChecker. More...
virtual	~QgsMultiRenderChecker ()=default
QString	controlImagePath () const
	Returns the path to the control images. More...
QString	report () const
	Returns a report for this test. More...
bool	runTest (const QString &testName, unsigned int mismatchCount=0)
	Test using renderer to generate the image to be compared. More...
void	setColorTolerance (unsigned int colorTolerance)
	Set tolerance for color components used by runTest() Default value is 0. More...
void	setControlName (const QString &name)
	Base directory name for the control image (with control image path suffixed) the path to the image will be constructed like this: controlImagePath + '/' + mControlName + '/' + mControlName + '.png'. More...
void	setControlPathPrefix (const QString &prefix)
void	setMapSettings (const QgsMapSettings &mapSettings)
	Set the map settings to use to render the image. More...
void	setRenderedImage (const QString &renderedImagePath)
	Set the path to the rendered image. More...
void	setSizeTolerance (int xTolerance, int yTolerance)
	Sets the largest allowable difference in size between the rendered and the expected image. More...

Static Public Member Functions
static void	drawBackground (QImage *image)
	Draws a checkboard pattern for image backgrounds, so that opacity is visible without requiring a transparent background for the image. More...

Detailed Description

This class allows checking rendered images against comparison images.

Its main purpose is for the unit testing framework.

It will either

• take an externally rendered image (setRenderedImage())
• render the image based on provided mapSettings (setMapSettings())

This image will then be compared against one or several images in a folder inside the control directory (tests/testdata/control_images/{controlName}).

There are modes for single and for multiple reference images.

• If there are no subfolders in the control directory, it will assume an image with the name {controlImage}.png in the control directory itself.

• If there are subfolders inside the control directory, it will search for images with the name {controlImage}.png in every subfolder.

For every control image there may be one or several randomly named anomaly images defining allowed anomalies. For every control image, the allowed mismatch and color tolerance values will be calculated individually.

Since

QGIS 2.8

Definition at line 56 of file qgsmultirenderchecker.h.

Constructor & Destructor Documentation

QgsMultiRenderChecker()

QgsMultiRenderChecker::QgsMultiRenderChecker ( )

default

Constructor for QgsMultiRenderChecker.

~QgsMultiRenderChecker()

virtual QgsMultiRenderChecker::~QgsMultiRenderChecker ( )

virtualdefault

Member Function Documentation

controlImagePath()

QString QgsMultiRenderChecker::controlImagePath

(

)

const

Returns the path to the control images.

Definition at line 98 of file qgsmultirenderchecker.cpp.

drawBackground()

static void QgsMultiRenderChecker::drawBackground ( QImage *  image )

inlinestatic

Draws a checkboard pattern for image backgrounds, so that opacity is visible without requiring a transparent background for the image.

Definition at line 137 of file qgsmultirenderchecker.h.

report()

QString QgsMultiRenderChecker::report ( ) const

inline

Returns a report for this test.

Definition at line 126 of file qgsmultirenderchecker.h.

runTest()

bool QgsMultiRenderChecker::runTest	(	const QString &	testName,
		unsigned int	mismatchCount = 0
	)

Test using renderer to generate the image to be compared.

Parameters

testName	- to be used as the basis for writing a file to e.g. /tmp/theTestName.png
mismatchCount	- defaults to 0 - the number of pixels that are allowed to be different from the control image. In some cases rendering may be non-deterministic. This parameter allows you to account for that by providing a tolerance.

Note

make sure to call setExpectedImage and setMapSettings first

Definition at line 35 of file qgsmultirenderchecker.cpp.

setColorTolerance()

void QgsMultiRenderChecker::setColorTolerance ( unsigned int  colorTolerance )

inline

Set tolerance for color components used by runTest() Default value is 0.

Parameters

colorTolerance

The maximum difference for each color component including alpha to be considered correct.

Definition at line 98 of file qgsmultirenderchecker.h.

setControlName()

void QgsMultiRenderChecker::setControlName

(

const QString &

name

)

Base directory name for the control image (with control image path suffixed) the path to the image will be constructed like this: controlImagePath + '/' + mControlName + '/' + mControlName + '.png'.

Definition at line 20 of file qgsmultirenderchecker.cpp.

setControlPathPrefix()

void QgsMultiRenderChecker::setControlPathPrefix

(

const QString &

prefix

)

Definition at line 25 of file qgsmultirenderchecker.cpp.

setMapSettings()

void QgsMultiRenderChecker::setMapSettings

(

const QgsMapSettings &

mapSettings

)

Set the map settings to use to render the image.

Parameters

mapSettings

The map settings

Definition at line 30 of file qgsmultirenderchecker.cpp.

setRenderedImage()

void QgsMultiRenderChecker::setRenderedImage ( const QString &  renderedImagePath )

inline

Set the path to the rendered image.

If this is not set or set to null QString, an image will be rendered based on the provided mapsettings

Parameters

renderedImagePath

A path to the rendered image with which control images will be compared

Definition at line 82 of file qgsmultirenderchecker.h.

setSizeTolerance()

void QgsMultiRenderChecker::setSizeTolerance ( int  xTolerance, int  yTolerance  )

inline

Sets the largest allowable difference in size between the rendered and the expected image.

Parameters

xTolerance	x tolerance in pixels
yTolerance	y tolerance in pixels

Since

QGIS 3.0

Definition at line 106 of file qgsmultirenderchecker.h.

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The documentation for this class was generated from the following files:

• /build/qgis-3.20.0+99unstable/src/core/qgsmultirenderchecker.h
• /build/qgis-3.20.0+99unstable/src/core/qgsmultirenderchecker.cpp