Class: QgsMultiRenderChecker¶
- class qgis.core.QgsMultiRenderChecker¶
Bases:
sip.wrapper
Constructor for QgsMultiRenderChecker.
QgsMultiRenderChecker(
QgsMultiRenderChecker
)This class allows checking rendered images against comparison images.
Its main purpose is for the unit testing framework.
It will either <ul> <li>take an externally rendered image (
setRenderedImage()
)</li> <li>render the image based on provided mapSettings (setMapSettings()
)</li> </ul>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. <ul> <li>If there are no subfolders in the control directory, it will assume an image with the name {controlImage}.png in the control directory itself.</li>
<li>If there are subfolders inside the control directory, it will search for images with the name {controlImage}.png in every subfolder.</li> </ul>
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.
Methods
Returns the path to the control images.
Draws a checkboard pattern for image backgrounds, so that opacity is visible without requiring a transparent background for the image
Returns a report for this test
Test using renderer to generate the image to be compared.
Set tolerance for color components used by
runTest()
Default value is 0.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’
- param prefix
Set the map settings to use to render the image
Set the path to the rendered image.
Sets the largest allowable difference in size between the rendered and the expected image.
- controlImagePath(self) → str¶
Returns the path to the control images.
- Return type
str
- drawBackground(image: QImage)¶
Draws a checkboard pattern for image backgrounds, so that opacity is visible without requiring a transparent background for the image
- Parameters
image (QImage) –
- report(self) → str¶
Returns a report for this test
- Return type
str
- runTest(self, testName: str, mismatchCount: int = 0) → bool¶
Test using renderer to generate the image to be compared.
- Parameters
testName (str) –
to be used as the basis for writing a file to
e.g. /tmp/theTestName.png
mismatchCount (int = 0) –
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
- Return type
bool
- setColorTolerance(self, colorTolerance: int)¶
Set tolerance for color components used by
runTest()
Default value is 0.- Parameters
colorTolerance (int) – The maximum difference for each color component including alpha to be considered correct.
- setControlName(self, name: str)¶
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’
- Parameters
name (str) –
- setControlPathPrefix(self, prefix: str)¶
- Parameters
prefix (str) –
- setMapSettings(self, mapSettings: QgsMapSettings)¶
Set the map settings to use to render the image
- Parameters
mapSettings (QgsMapSettings) – The map settings
- setRenderedImage(self, renderedImagePath: str)¶
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 (str) – A path to the rendered image with which control images will be compared
- setSizeTolerance(self, xTolerance: int, yTolerance: int)¶
Sets the largest allowable difference in size between the rendered and the expected image.
- Parameters
xTolerance (int) – x tolerance in pixels
yTolerance (int) – y tolerance in pixels
New in version 3.0.