Subgroup: Multi
Class: QgsMultiRenderChecker¶
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class
qgis.core.
QgsMultiRenderChecker
¶ Bases:
sip.wrapper
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.
New in version 2.8: Methods
controlImagePath
controlImagePath drawBackground
Draws a checkboard pattern for image backgrounds, so that opacity is visible report
Returns a report for this test runTest
Test using renderer to generate the image to be compared. setColorTolerance
Set tolerance for color components used by runTest() Default value is 0. setControlName
Base directory name for the control image (with control image path setControlPathPrefix
setMapSettings
Set the map settings to use to render the image setRenderedImage
Set the path to the rendered image. setSizeTolerance
Sets the largest allowable difference in size between the rendered and the expected image. Attributes
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controlImagePath
(self) → str¶ controlImagePath
Returns:
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drawBackground
(image: QImage)¶ Draws a checkboard pattern for image backgrounds, so that opacity is visible without requiring a transparent background for the image
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report
(self) → str¶ Returns a report for this test
Returns: A report
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runTest
(self, testName: str, mismatchCount: int = 0) → bool¶ 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
Parameters: 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
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setColorTolerance
(self, colorTolerance: int)¶ 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.
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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’
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setControlPathPrefix
(self, prefix: str)¶
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setMapSettings
(self, mapSettings: QgsMapSettings)¶ Set the map settings to use to render the image
Parameters: mapSettings – The map settings
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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 – A path to the rendered image with which control images will be compared
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setSizeTolerance
(self, xTolerance: int, yTolerance: int)¶ 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
New in version 3.0.
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