flex_seed_scheme 2.0.0

A more flexible and powerful version of Flutter's ColorScheme.fromSeed. Use multiple seed colors, custom chroma and tone mapping.

Changelog

All notable changes to the FlexSeedScheme (FSS) package are documented here.

2.0.0

May 14, 2024

This release adds support for the revised Material-3 ColorScheme released in Flutter version 3.22.0 and for seeded scheme variants, that will arrive in the Flutter stable release after 3.22.x.

• CHANGE

  • Bring the internal Material Color Utilities (MCU) library version to parity with its latest package release 0.11.1. Flutter SDK stable 3.22 still uses MCU 0.8.0, but the Flutter master channel already uses MCU 0.11.1.
  • The FlexPaletteType.extended tones got two new tones added, tone 2, and 24. It now has 27 tones.

• NEW

  • Support revised Material-3 ColorScheme with the new colors primaryFixed, primaryFixedDim, onPrimaryFixed, onPrimaryFixedVariant, secondaryFixed, secondaryFixedDim, onSecondaryFixed, onSecondaryFixedVariant, tertiaryFixed, tertiaryFixedDim, onTertiaryFixed, onTertiaryFixedVariant, surfaceDim, surfaceBright, surfaceContainerLowest, surfaceContainerLow, surfaceContainer, surfaceContainerHigh and surfaceContainerHighest.

  • New alternative way to specify the used seeding algorithm in SeedColorScheme.fromSeeds by providing new enum value FlexSchemeVariant to its variant property.

    • In addition to supporting selection of built-in FlexTones, the variant property also supports using Flutter SDK, MCU based scheme variants tonalSpot, monochrome, neutral, vibrant, expressive, content,rainbow and fruitSalad in by specifying them in property variant in SeedColorScheme.fromSeeds. In Flutter 3.22 only the default tonalSpot is available, but with FSS you can use any of the other variants as well already in Flutter 3.22. The other variants are not yet available in Flutter 3.22, but they are available in the ColorScheme API in the master channel and will be available in Flutter ColorScheme.fromSeed in the next stable release after 3.22. With FSS you can use them already starting from Flutter 3.22.0.
    • With the variants enum property you can also select built-in FlexTones that you could use before in SeedColorScheme.fromSeeds in tones. The FlexTones are still available and can be used as before, it has some advantages. With tones you can create customized seed extractions based on FlexTones and you can use tones surface quick modifiers, onMainsUseBW, onSurfacesUseBW and surfacesUseBW.
    • When using variants, if the variant is one of the Flutter SDK/MCU variants, it will not use more than one key color, the primary as seed color. The FlexSchemeVariant that have their property isFlutterScheme set to true are part of the Flutter SDK/MCU variants.
    • The Flutter SDK/MCU variants are tonalSpot, fidelity, monochrome, neutral, vibrant, expressive, content, rainbow and fruitSalad.
    • The other FlexSchemeVariant that have their property isFlutterScheme set to false are part of the FlexTones variants using the corresponding built-in FlexTones as seed extraction. The variants are material, material3Legacy, soft, vivid, vividSurfaces, highContrast, ultraContrast, jolly, vividBackground, oneHue, candyPop and chroma. The chroma option is similar to the new nice SDK/MCU one called fidelity, in that it follows chroma of seed color, with the added benefit that it can use a separate seed color for each tonal palette.
    • The APIs variant and tones are mutually exclusive, you can only use one of them in SeedColorScheme.fromSeeds. Both can be unspecified, but if you specify one, the other must be unspecified/null.

• A new FlexTones.material3Legacy was added. This FlexTones configuration preserves and provides access to the seed generation used by Flutter prior to Flutter version 3.22 and as used by FlexTones.materialin FlexSeedScheme before version 2.0.0. If you in Flutter 3.22 and FlexSeedScheme 2.0.0 need to replicate this style you can use this FlexTones in SeedColorScheme.fromSeeds property tones or the FlexSchemeVariant.material3Legacy in variants.

• BREAKING

  • The Material-3 ColorScheme colors background, onBackground and surfaceVariant have been deprecated since they are also deprecated in Flutter 3.22.
    • These deprecated colors are still supported in SeedColorScheme.fromSeeds and FlexTones, but they will be removed in a future release. They are replaced by surface, onSurface and surfaceContainerLowest. There are also many new surface colors, like surfaceDim, surfaceBright and surfaceContainerLowest in the new Material-3 ColorScheme in Flutter 3.22.
    • The fact that these deprecated colors are still referenced in the package will reduce its pub.dev score with 10 points, but they are kept for now to maintain FULL compatibility with Flutter 3.22 that also still provides values for these deprecated colors and uses them in code. This package needs to provide the same values to be fully compatible. The ColorScheme colors background, onBackground and surfaceVariant may only be fully removed when they have been removed from the Flutter SDK stable channel. If later tests show they can be removed without breaking any styles earlier, they will be removed in a future release of this package, even if they are still available in the Flutter SDK stable channel. A future dev version may also remove them to provide compatibility with the Flutter master channel when they are removed there.

• BREAKING STYLES

  • All built-in FlexTones now use the paletteType extended via FlexPaletteType.extended as default for additional tone fidelity. This is needed for compatibility with Flutter 3.22 and its revised ColorScheme.

  • The default tones for the built-in FlexTones have been adjusted to match the new Material-3 ColorScheme in Flutter 3.22. The new tones and default styles are marginally different but also better than in previous Flutter versions. If you need the result and style used in Flutter 3.19 and earlier, you can use the FlexTones.material3Legacy as tones in SeedColorScheme.fromSeeds to get the result FlexTones.material produced in FSS before version 2.0.0 and that was also the default in Flutter in version 3.19 and earlier.

  • The FlexSchemeVariant.tonalSpot is the variant that Flutter SDK uses from MCU in ColorScheme.fromSeed in Flutter 3.22 and later when you make seed generated color schemes with it. This generated scheme is different from the one ColorScheme.fromSeed generated in Flutter 3.19 and earlier. If you need the result and style used in Flutter 3.19 and earlier, you can use the material3Legacy as tones or variant in SeedColorScheme.fromSeeds to get the result FlexTones.material produced in FSS before version 2.0.0 and that was also the default in Flutter in version 3.19 and earlier when using ColorScheme.fromSeed.

  • The FlexTones.material has been updated and now produces the same result as tonalSpot in tests. There may be some edge cases where there are rounding differences. The material alternative can be used both in variant and tones. It provides the advantages over tonalSpot that since it is a FlexTones, it can use multiple seed colors and if used in tones, its results can be quick adjusted with onMainsUseBW, onSurfacesUseBW and surfacesUseBW. The tonalSpot is a Flutter SDK/MCU variant and does not support these customizations.

1.5.0

April 3, 2024

• NEW
  • Exposed Hct and ViewingConditions from the underlying Material Color Utilities (MCU) library. They are exposed for convenience, you no longer have to add and import (MCU) to use them.
  • Add CODE_OF_CONDUCT.md and CONTRIBUTING.md files for guidance on contributing to the package.

1.4.0

July 2, 2023

• NEW

  • Added support for new HCT tones used by updated Material3 color system, that were added during the first half of 2023 to the Material 3 color system specification. The added tones 4, 6, 12, 17, 22 are for new dark mode surfaces in revised Material 3 dark surface colors. Likewise, added tones 97, 96, 94, 92, 87 are for light mode surfaces in the updated Material 3 color system. For more information, see: https://m3.material.io/styles/color/the-color-system/color-roles.
    • The change and additions are none breaking. APIs that want and can use the extended tones can pass in an optional paletteType of FlexPaletteType and set it to FlexPaletteType.extended, by default its values FlexPaletteType.common resulting in the 15 tones [0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, 98, 99, 100] being produced as before.
    • The complete list of the 25 extended tones are [0, 4, 5, 6, 10, 12, 17, 20, 22, 30, 40, 50, 60, 70, 80, 87, 90, 92, 94, 95, 96, 97, 98, 99, 100].
    • None breaking Changed APIs that now support using paletteType of FlexPaletteTypeare:
      • FlexTonalPalette.of
      • FlexTonalPalette.fromList
      • FlexCorePalette.of
      • FlexCorePalette.fromHueChroma
      • FlexCorePalette.fromList
      • FlexCorePalette.fromSeeds
      • FlexTones
    • Flutter 3.10 and earlier do not yet use these new tones in its standard ColorScheme, but since they are in the Material 3 spec, they will arrive at some later point.
    • FlexTonalPalette, like MCU TonalPalette, caps chroma for tones higher than or equal to 90, to maximum chroma value of 40. In FlexTonalPalette this still applies when using FlexPaletteType.common, when you use the FlexPaletteType.extended, there is no chroma max cap on high tones, it uses fidelity mode for high tones. When using type FlexPaletteType.common the chroma of high tones (>= 90), is limited to maximum 40. This keeps the chromacity of tones 90 to 100, lower than 40. If the source uses has more chromacity than 40, there may be a sudden jump in chroma reduction at tone 90. This is the standard behavior for the original Material-3 tonal palette computation. The FlexPaletteType.common type is intended to be used when there is a need to follow strict M3's original palette design.
    • When using the FlexPaletteType.extended type tones, there are not only the new tones, but the chroma limit of tones >= 90 is also removed. This increases fidelity of higher tone when high chromacity is used.
  • Added two new pre-configured FlexToness, candyPop and chroma, they use the new FlexPaletteType.extended tonal palette.
  • Added new FlexTones modifier surfacesUseBW(). It can be used as a modifier to force any FlexTones seed strategy to use tone 100 (white) or tone 0 (black) as background and surface colors, depending on if they are dark or light

• CHANGE

  • Minor style breaking: To correct and improve produced themes, the tones primaryContainerTone and secondaryContainerTone for light mode FlexTones.highContrast and FlexTones.ultraContrast were both changed from 95 to 90. This produces brighter and more punchy themes for these two high-contrast themes in light mode.

• CHORE

  • Bump Dart SDK to >= 3.0.0 and Flutter SDK to >= 3.10.0. Fix lints for the bump.
  • Add all Material Color Utilities (MCU) updates from its Dart version to the internal bundled version.
    • This includes all PRs up to and including "PR: 28.6.2023 Change var back to double in Java." This equals Dart version 0.8.0 published on June 29, 2023, with its two new schemes fruit salad and rainbow.
    • At this time, Flutter master was using MCU version 0.5.0 and Flutter stable 3.10.0 still used the MCU version 0.2.0.
    • Since MCU is using zero semver and Flutter SDK, depends on it, any minor version number change is breaking and cannot be resolved across Flutter channels if a package also uses MCU. This is the reason why (FSS) for now does not use MCU directly. It bundles its own version of it for now. This also means FSS may sometimes use a newer version of MCU than Flutter stable, beta, and master. FSS may stop bundling MCU when it stops getting so many frequent breaking updates that cause dependency hell for a package that needs to depend on MCU and work on all Flutter channels.

• EXAMPLE

  • Major refactoring of the example app.
  • Use a theme controller and ListenableBuilder to rebuild the app theme when the theme controller changes.
  • Feature: Add showing generated tonal palettes to the example.
  • Feature: Separate controls for making on Main and on Surface colors black and white.
  • Feature: Change seed colors in the app with Color picker.
  • Feature: Add switching between showing common tones and extended tones.
  • Feature: Add selecting a custom color as key color for error palette.

1.3.0

May 11, 2023

INTERNAL CHANGE

• Removed the Material Color Utilities (MCU) dependency.

  • It is now included and maintained as a separate forked code base in FSS, while keeping MCU's original license in place for its parts. The included MCU library was only modified to abide by the much stricter lint rules used in FSS. More unit tests for better test coverage of MCU were added as well.

  • Why is MCU included as a forked version baked into FSS?

    The constant changes in MCU, with e.g. recent 3 different breaking-pinned zero-ver versions used in Flutter stable, beta and master channels, made it hopeless to depend on MCU. Using it caused repeated version conflicts with Flutter's own pinned dependency on different breaking versions of it, in different Flutter channels. FSS needs to be able to work across all Flutter channels without constant hassle caused by MCU and which exact version of it different version of Flutter repo itself is pinned to.

  • The included forked version will be kept in sync with the original and updated when needed. Currently included MCU version is 0.5.0, the latest one, which is what Flutter master channel currently uses. However, new Flutter stable 3.10 is still using MCU 0.2.0. If the MCU package stabilizes and improves its constant breaking changes, FSS may later again be changed to depend on the original package. Until then, it embeds the code for it in its package to avoid the version conflict hassles it has repeatedly caused. These changes are all internal to the FSS package and do not affect how it works.

NEW

• Exposed Blend, CorePalette and TonalPalette from MCU. Previously only Cam16 was exposed. These APIs from MCU are exposed because FlexColorScheme (FCS) uses them. By exposing these APIs from the included MCU in FSS, it also no longer has any dependency on the MCU package that Flutter depends on. This makes it easier for the latest release of FCS to also work on all current Flutter channels.

Future versions of FSS may expose a few more APIs from MCU, but more likely it will offer a few new alternative ones with its own twist. Like it is for example, doing with SeedColorScheme.fromSeeds.

1.2.4

Apr 16, 2023

• Bumped Flutter sdk version constraint to >=2.19.0 <4.0.0 (from >=2.18.0 <3.0.0)
• Changed material_color_utilities version constraint to >=0.2.0 <0.4.0 from ^0.2.0.

These changes enable the package to be used on current Flutter stable 3.7 versions, as well as the latest 3.10.x versions on channels beta and master. It will also work with the next stable Flutter release after 3.7.

1.2.3

Mar 19, 2023

• FIX: Version 1.2.0 unintentionally introduced a lower level breaking API from version 1.1.0. This release relaxes the API and fixes the breakage.

1.2.2

Jan 30, 2023

• Add example screenshots to pubspec.yaml.

1.2.1

Jan 25, 2023

• Fix date on 1.2.0 changelog.

1.2.0

Jan 25, 2023

Requires minimum Flutter 3.7.0. Now support outlineVariant and scrim colors in ColorScheme in Flutter stable 3.7.0 and later.

This release also adds new features to allow customization of seed generation of error, neutral and neutral variant tonal palettes. All listed features are unchanged from the previous dev pre-release 1.2.0-dev.1.

NEW

• Adds support for outlineVariant and scrim colors in ColorScheme.

• Added support for customizing seed generation for error, neutral and neutral variant tonal palettes.

• To support the new features the SeedColorScheme.fromSeeds got the following new Color properties errorKey, neutralKey and neutralVariantKey.

• The FlexTones class got the following new double properties errorChroma, errorMinChroma, neutralMinChroma and neutralVariantMinChroma

• The FlexCorePalette.fromSeeds factory got the following new int properties error, neutral, neutralVariant and neutralVariantMinChroma. As well as new double properties errorChroma, errorMinChroma, neutralChroma, neutralMinChroma, neutralVariantChroma and neutralVariantMinChroma.

• The demo application got an About dialog. The demo app also shows the ColorScheme applied on common Material components.

1.2.0-dev.1

Dec 23, 2022

Requires minimum Flutter 3.7.0-1.2.pre (beta channel). This is a development pre-release to support outlineVariant and scrim colors in ColorScheme. It is used for development and testing against new Material 3 features in Flutter 3.7 beta and master channel. It will be released as a stable version when the new color properties land in the Flutter stable channel, most likely after January 25, 2023.

The release also adds new features to allow customization of seed generation of error, neutral and neutral variant tonal palettes.

NEW

• Adds support for outlineVariant and scrim colors in ColorScheme.

• Added support for customizing seed generation for error, neutral and neutral variant tonal palettes.

• To support the new features the SeedColorScheme.fromSeeds got the following new Color properties errorKey, neutralKey and neutralVariantKey.

• The FlexTones class got the following new double properties errorChroma, errorMinChroma, neutralMinChroma and neutralVariantMinChroma

• The FlexCorePalette.fromSeeds factory got the following new int properties error, neutral, neutralVariant and neutralVariantMinChroma. As well as new double properties errorChroma, errorMinChroma, neutralChroma, neutralMinChroma, neutralVariantChroma and neutralVariantMinChroma.

• The demo application got an About dialog. The demo app also shows the ColorScheme applied on common Material components.

1.1.0

Nov 17, 2022

NEW

• Added new FlexTones method onMainsUseBW, that can return a new instance of its configurations with tone mapping for its main *on colors set to tone, 0 (black) or 100 (white), depending on what is appropriate for its main color tones. The main colors are primary, secondary, tertiary, error and their containers. The method works on any configured FlexTones, also custom ones, not only the built-in ones.

• Added new FlexTones method onSurfacesUseBW, that can return a new instance of its configurations with tone mapping for its surface *on colors set to tone, 0 (black) or 100 (white), depending on what is appropriate for its surface color tones. Surface colors are background, surface, surfaceVariant and inverseSurface. The method works on any configured FlexTones, also custom ones, not only the built-in ones.

• To be able to support creating mono-hue seeded color schemes, the FlexCorePalette.fromSeeds got a new property tertiaryHueRotation. It controls the used hue rotation degrees from primary key color, that is used when a tertiary seed key color is not provided. The tertiaryHueRotation defaults 60 degrees, same as previously from Material 3 color system hard-coded value.

• Added two new FlexTones.

  • FlexTones.oneHue that set tertiaryHueRotation to 0, so we can create a mono hue palette if we only provide primary key color as seed.
  • FlexTones.vividBackground that is a copy of FlexTones.vividSurfaces but with tone mapping for background and surface swapped.

CHANGE

Tone mappings for some pre-configured FlexTones were slightly modified. They now produce improved and more usable color schemes. Most significantly, the mappings for FlexTones.vividSurfaces were modified to provide a more usable and improved vivid surfaces tinted color scheme, while still offering a slightly more tinted surface design than FlexTones.vivid. Tone mapping changes are as follows:

• The FlexTones.vivid, brightness light:
  • Tone surfaceTone was changed from 99 to 98.
• The FlexTones.vivid, brightness dark:
  • Tone onErrorContainerTone was changed from 90 to 80 (dark M3 default).
  • Tone backgroundTone was changed from 10 to 5.
• The FlexTones.vividSurfaces brightness light:
  • Tone onPrimaryTone was changed from 95 to 98.
  • Tone onSecondaryTone was changed from 95 to 98.
  • Tone onTertiaryTone was changed from 95 to 98.
  • Tone onErrorTone was changed from 95 to 98.
  • Tone primaryContainerTone was changed from 80 to 90 (light M3 default).
  • Tone secondaryContainerTone was changed from 80 to 90 (light M3 default).
  • Tone tertiaryContainerTone was changed from 80 to 90 (light M3 default).
  • Tone errorContainerTone was changed from 80 to 90 (light M3 default).
  • Tone surfaceVariantTone was changed from 80 to 90 (light M3 default).
  • Tone backgroundTone was changed from 90 to 98.
  • neutralChroma was changed from 8 to 5.
  • neutralVariantChroma was changed from 16 to 10.
• The FlexTones.vividSurfaces brightness dark:
  • Tone primaryContainerTone was changed from 40 to 20.
  • Tone tertiaryContainerTone was changed from 40 to 30 (dark M3 default).
  • Tone primaryContainerTone was changed from 40 to 30 (dark M3 default).
  • Tone onErrorTone was changed from 20 to 30 (dark M3 default).
  • Tone onErrorContainerTone was changed from 90 to 80 (dark M3 default).
  • Tone surfaceTone was changed from 10 to 20.
  • Tone surfaceVariantTone was changed from 40 to 30 (dark M3 default).
  • Tone backgroundTone was changed from 20 to 10.
  • Tone onSurfaceVariantTone was changed from 90 to 95.
  • Tone onInverseSurfaceTone was changed from 30 to 20 (dark M3 default).
  • neutralChroma was changed from 8 to 5.
  • neutralVariantChroma was changed from 16 to 10.
• The FlexTones.ultraContrast brightness light:
  • Tone primaryTone was changed from 30 to 20.
• The FlexTones.ultraContrast brightness dark:
  • Tone surfaceTone was changed from 10 to 5.
  • Tone backgroundTone was changed from 10 to 5.

1.0.1

Sep 2, 2022

DOCS

• Readme: Removed old notice about package being a beta release and using Flutter 3.3 beta.
• Readme: Described custom FlexTones config with an example.
• API doc improvements.

EXAMPLE

• Allow selection of example custom tones example and all built-in FlexTones options.
• Publish example app as a live web demo.

1.0.0

Aug 30, 2022

First stable release.

• Document updates.
• Updated minimum dependencies to Dart >=2.18.0 and Flutter >= 3.3.0.

0.2.0-dev.2

Aug 28, 2022

NEW

• From Material Color utilities export and show Cam16.

0.2.0-dev.1

Aug 27, 2022

NEW

• Add customization possibility of error tonal palette to the default FlexTonalPalette constructor.

BREAKING

• The FlexTonalPalette method asList and constructor fromList, now include the values of the error color in produced asList, and as required values in fromList.

0.1.0-dev.3

Aug 27, 2022

• Fix pub points.

0.1.0-dev.2

Aug 27, 2022

• Relax version constraint to make it work on beta 3.3.0-0.3.pre and later.
• Remove in Flutter beta 3.3.0 unsupported ColorScheme colors scrim and outlineVariant.

0.1.0-dev.1

Aug 26, 2022

• First dev release of the package.