When the iframe is attached to the DOM, its content is reloaded (invaliding the resize listener) so make sure to install the handler after the iframe is loaded. Optimize resize events by throttling resize process until the next animation frame. Rewrite the unit test "waitForResize" method, the previous one (timeout) was too weak and most tests was failing on FF.
Add support for creating a chart from the canvas id and prevent exceptions, at construction time, when the given item doesn't provide a valid CanvasRenderingContext2D or when the getContext API is not accessible (e.g. undefined by add-ons to prevent fingerprinting). New jasmine matcher to verify chart validity.
Solve weird animation issues with the tooltip. The optimization in Chart.Element.transition when the animation finishes to set `_view = _model` caused problems during update because we were using `helpers.extend` all over the place.
I changed to code so that we regenerate the model variable rather than continuously extending the old version. I also removed unnecessary tooltip reinitializations from the controller which should improve overall performance during interaction.
In order to simulate real-time chart updates (i.e. horizontal animation), it's necessary to distinguish a removed or added value from a simple update. The dataset controller now hooks array methods that alter the data array length to synchronize metadata accordingly. Also remove the duplicate calls of updateBezierControlPoints() for line and radar charts.
Responsiveness is currently based on the use of an iframe, however this method causes performance issues and could be troublesome when used with ad blockers. So make sure that the user is still able to create a chart without iframe when responsive is false.
CanvasRenderingContext2D.fillText() accepts a fourth parameter called maxWidth that sets the maximum width of the drawn text, enforced by scaling the entire line.
This commit uses the title element's layout dimensions to set maxWidth and avoid overflow outside of the canvas.
When responsive is false and no canvas height explicitly set, the aspectRatio option wasn't applied because of the canvas default height. Prevent the retinaScale method to change the canvas display size since this method is called for none responsive charts, but instead make the resize() responsible of these changes. Also, as discussed some time ago, moved most of the core.js logic into core.controller.js. Clean up the destroy process and make sure that initial canvas values are properly saved and restored.
Ensure that the hidden iframe is stretched vertically in order to detect height changes. Remove the classlist check/call since it was incorrectly spelled (should be classList), but also useless since the iframe has just been generated. Also remove the callback check: addResizeListener should never be called w/o a valid callback.
Add "onHover" to the legend options that will hold a user defined function (default is null) and called when a "mousemove" event is registered on top of a label item, with same parameters as the "onClick" option.
Also introduced logic that determines if the type of event passed to the legend "handleEvent" function is one we can handle. Currently allowing "click" and "mousemove" events. If the event is not one of those we stop the function execution (this is for the sake of reusing the legend hitbox calculations).
Change the linter in gulp tasks to be consistent with Code Climate results which are based on ESLint using .eslintrc options. However, defaults Code Climate rules are too strict, so turn as warnings the 'complexity' and 'max-statements' rules (other errors has been fixed). Note that the Gulp task name has been changed for `gulp lint`.
* Added borderDash support for grid lines (#3136)
* Save and restore context to prevent border dash being applied to other elements
* Adds support for borderDashOffset, checks for setLineDash (IE9/IE10)
* Fixes tests
