shutter 0.2.2

Renders a Flutter project's widget previews to PNG, reusing the ones it already has, and diffs two runs pixel by pixel into before and after images of a change.

Changelog

0.2.2

One image per change: before, diff and after on a single sheet.

• shutter diff --composite writes <id>-composite.png per entry into .dart_tool/shutter/diffs/<diff-id>/, next to what --images writes: the before, diff and after panels on the union canvas of the two shots, each under a caption naming it and, when the two sides differ in size, its own size. The entry points at it as composite.
• --direction horizontal puts the three panels side by side, vertical stacks them, and the default auto puts a portrait shot side by side and a landscape one stacked, so that all three stay in one view whatever the subject's shape. The panels are never scaled; --images stays the 1:1 view of the marked diff.
• An entry with an image on one side only gets a sheet too, its absent panel left as background and its diff panel all red: a widget the edit broke, or one whose id the edit changed, is shown rather than left out. An entry whose two PNGs are identical gets none.
• --title <text> draws a line of text above the panels. It is rendered through the engine rather than drawn from a bundled bitmap font, so any script the host has a font for works, and it is laid out in exactly the room each size of sheet leaves between its gutters, at the size of that sheet's captions. A title that did not fit one line is reported on stderr with the width of the sheets it did not fit.
• --title is the only part of diff that needs a Flutter SDK, and costs one flutter test run per distinct sheet size. Without it, diff stays pure Dart.
• The diff directory is created, and reported as diff, for either --images or --composite.

0.2.1

The layout of a screen while its on-screen keyboard is up.

• shutter shot --keyboard <height> (experimental) lays every preview out as a device does while its on-screen keyboard is up: the view reports a bottom inset of that many logical pixels (MediaQuery.viewInsets) from the first frame. A Scaffold, or any layout reading the inset, makes room for the keyboard; the keyboard itself is not drawn. There is no default height.
• shot prints the height, manifest.json records it, and diff prints both runs' when they differ. It is not part of shot ids.

0.2.0

States that come from a gesture or typing, and what opens above a preview.

• shutter shot --tap and --enter <target>=<text> (repeatable, run in the order given), then one of --press, --hover, or --focus, act on every preview before the capture. A target is key:<value>, text:<string>, label:<semantics label> (a text field's label or hint, a button's text), or type:<Widget>; a target that matches no widget, several, or cannot be reached makes the shot an error. Each action is followed by --settle milliseconds drawn in 16 ms frames; shutter agent suggests --settle 700 for the state after a tap, once its ink is over, and another --settle for another point of an animation.
• shutter shot --capture screen captures the whole viewport, with the shell's surface and the menus, dialogs, bottom sheets, and tooltips the app draws above the preview; --viewport <width>x<height> sets the viewport, the preview at its top left.
• shot prints the run's actions and capture, manifest.json records them, and diff prints both runs' when they differ. They are not part of shot ids.
• The shutter-visual-check skill also covers pressed, hovered, focused, opened, and typed states.

0.1.1

Documentation and package metadata; the tool behaves as in 0.1.0.

• The package description, the README, and shutter --help open on what shutter produces, a change to a widget expressed as before and after images, instead of on the agent that drives it.
• The ai topic is replaced by cli: shutter is a command-line tool an agent can drive, not an AI package.
• README lists when to reach for shutter: a change going up for review, a refactor that should change nothing on screen, a widget that might break on screen, a dependency just added or upgraded.
• shutter agent says what shot --widget answers, a look at a widget before the call site exists, names the commands that upload an image to a pull or merge request, and states that --import reaches only what the project's pubspec.yaml resolves.
• Flutter's previewer is called by its name, the Flutter Widget Previewer.

0.1.0

Initial release: a CLI, shaped for AI agents, that renders Flutter widgets to PNG and compares two runs.

• shutter shot renders the @Preview functions of the named files, or one --widget expression, to PNG through flutter test. The target project gains no dependency.
• shutter diff compares two runs by shot id as changed, added, removed, or unchanged; --images marks the differing pixels.
• shutter init writes the shell that wraps every shot, and shutter doctor checks the setup.
• shutter agent and shutter manual print the playbook and the reference; the shutter-visual-check skill points agents at them.
• Requires Flutter 3.47+ (Dart 3.13+) in the target project.

Experimental (specification not settled):

• The default shell generated for the design library the project uses.
• A preview's theme, through Flutter's unstable PreviewThemeData interface.
• google_fonts, downloaded once into .dart_tool/shutter/fonts/google_fonts/ and served as bundled assets.