Attempt to make easier the creation of unit tests that check the drawing output. Until now, this was done by checking calls on a 'fake' context, which is hard to maintain (need to update pixel values by hands) and also not reliable when optimizing code (i.e. different calls sequence but same result).
As of now, it's possible to define 'auto' tests based on JSON/PNG fixtures: chart is generated from the JSON file and compared to the associated PNG image. The image diff is done using `pixelmatch`. As an example (and in preparation of the `filler` plugin), add auto tests for the line element `fill` options.
`karma.conf.ci.js` has been merged into `karma.conf.js` for local testing consistency: `gulp unittestWatch` has been replaced by `gulp unittest --watch` and thus use exactly the same config file. Upgrade to latest jasmine and karma packages and remove deprecated `gulp-karma` dependency (directly use `karma.Server` in gulp).
Split `test/mockContext.js` into smaller `test/jasmine.*` modules to make easier unit tests maintenance and finally, move all `*.test.js` files under the `test/specs` folder.
Prevent attempt to remove the legend or title layout items if they haven't been created but also check if the item to remove is registered with the layout manager to avoid removing the wrong box `splice(-1, 1)`. Add ids to the legend and title plugins to allow to fully disable them (`options: {plugins: {legend: false, title: false}}`).
gridLines.circular is a new option that toggles circular lines. This allows radar charts with circular lines #3082
pointLabels.display is a new option that toggles the display of point labels.
The existing angleLines.display is used with the new pointLabels.display setting is used to trigger the radar like settings.
This required changing the default polar area config.
Animation callbacks now receives `animationObject` directly with a reference on the associated chart (`animation.chart`), which deprecates `animation.animationObject` and `animation.chartInstance`. Also fix missing `onComplete` animation argument and make sure that an animation object is passed even when animations are disabled.
If a value is set on the model after `pivot()` has been called, the view wasn't initialized and the animation started from 0. Now, `_start` and incomplete `_view` are initialized to the model value during the transition (no initial implicit transition).
Also remove exception handling when animating a string (color), which is faster when string are not valid colors (e.g. tooltip position). It requires to update `chartjs-color` to version 2.1.0.
In order to take full advantage of the new plugin hooks called before and after a dataset is drawn, all drawing operations must happen on stable meta data, so make sure that transitions are performed before.
Chart data can now be entirely replaced using `chart.data = {...}` thanks to the new property setter (instead of using `chart.config.data = {}`). Also update the documentation, as suggested by @ldaguise and @kennethkalmer, with a note about versions prior 2.6.
Make all `before` hooks cancellable (except `beforeInit`), meaning that if any plugin return explicitly `false`, the current action is not performed. Ensure that `init` hooks are called before `update` hooks and add associated calling order unit tests. Deprecate `Chart.PluginBase` in favor of `IPlugin` (no more an inheritable class) and document plugin hooks (also rename `extension` by `hook`).
Move base platform definition and logic in src/platform/platform.js and simplify the browser -> Chart.js event mapping by listing only different naming then fallback to the native type.
Replace `createEvent` by `add/removeEventListener` methods which dispatch Chart.js IEvent objects instead of native events. Move `add/removeResizeListener` implementation into the DOM platform which is now accessible via `platform.add/removeEventListener(chart, 'resize', listener)`.
Finally, remove `bindEvent` and `unbindEvent` from the helpers since the implementation is specific to the chart controller (and should be private).
Refactoring to put browser specific code in a new class, BrowserPlatform.
BrowserPlatform implements IPlatform. Chart.Platform is the constructor for the platform object that is attached to the chart instance.
Plugins are notified about the event using the `onEvent` call. The legend plugin was converted to use onEvent instead of the older private `handleEvent` method.
Wrote test to check that plugins are notified about events
Fix bar draw issue.
1. `Chart.elements.Rectangle.draw` function supports both horizontal and vertical bar.
2. Corrected bar position at minus.
3. Adjust bar size when `borderWidth` is set.
4. Adjust bar size when `borderSkipped` is set.
5. Adjust `borderWidth` with value near 0(base).
6. Update test.
