Function VideoRecorder

test/lib/testHelper.js:3360–3420

(chart)

    }

    function VideoRecorder(chart) {
        this.start = startRecording;
        this.stop = stopRecording;

        var recorder = null;

        var oldRefreshImmediately = chart.getZr().refreshImmediately;

        function startRecording() {
            // Normal resolution or high resolution?
            var compositeCanvas = document.createElement('canvas');
            var width = chart.getWidth();
            var height = chart.getHeight();
            compositeCanvas.width = width;
            compositeCanvas.height = height;
            var compositeCtx = compositeCanvas.getContext('2d');

            chart.getZr().refreshImmediately = function () {
                var ret = oldRefreshImmediately.apply(this, arguments);
                var canvasList = chart.getDom().querySelectorAll('canvas');
                compositeCtx.fillStyle = '#fff';
                compositeCtx.fillRect(0, 0, width, height);
                for (var i = 0; i < canvasList.length; i++) {
                    compositeCtx.drawImage(canvasList[i], 0, 0, width, height);
                }
                return ret;
            }

            var stream = compositeCanvas.captureStream(25);
            recorder = new MediaRecorder(stream, { mimeType: 'video/webm' });

            var videoData = [];
            recorder.ondataavailable = function (event) {
                if (event.data && event.data.size) {
                    videoData.push(event.data);
                }
            };

            recorder.onstop = function () {
                var url = URL.createObjectURL(new Blob(videoData, { type: 'video/webm' }));

                var a = document.createElement('a');
                a.href = url;
                a.download = 'recording.webm';
                a.click();

                setTimeout(function () {
                    window.URL.revokeObjectURL(url);
                }, 100);
            };

            recorder.start();
        }

        function stopRecording() {
            if (recorder) {
                chart.getZr().refreshImmediately = oldRefreshImmediately;
                recorder.stop();