46 lines
1.4 KiB
Python
46 lines
1.4 KiB
Python
# Generated by Finn Stutzenstein on 2019-11-22 11:42
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from django.db import migrations
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def calculate_aspect_ratios(apps, schema_editor):
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"""
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Assignes every projector one aspect ratio of the ones, that OS
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supported until this migration. If no matching ratio was found, the
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default of 16:9 is assigned.
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"""
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Projector = apps.get_model("core", "Projector")
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ratio_environment = 0.05
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aspect_ratios = {
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4 / 3: (4, 3),
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16 / 9: (16, 9),
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16 / 10: (16, 10),
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30 / 9: (30, 9),
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}
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for projector in Projector.objects.all():
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projector_ratio = projector.width / projector.height
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ratio = (16, 9) # default, if no matching aspect ratio was found.
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# Search ratio, that fits to the projector_ratio. Take first one found.
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for value, _ratio in aspect_ratios.items():
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if (
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value >= projector_ratio - ratio_environment
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and value <= projector_ratio + ratio_environment
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):
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ratio = _ratio
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break
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projector.aspect_ratio_numerator = ratio[0]
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projector.aspect_ratio_denominator = ratio[1]
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projector.save(skip_autoupdate=True)
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class Migration(migrations.Migration):
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dependencies = [
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("core", "0026_projector_size_1"),
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]
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operations = [
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migrations.RunPython(calculate_aspect_ratios),
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]
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