- Jump To … +
  ./demo/canvas-001.js ./demo/canvas-002.js ./demo/canvas-003.js ./demo/canvas-004.js ./demo/canvas-005.js ./demo/canvas-006.js ./demo/canvas-007.js ./demo/canvas-008.js ./demo/canvas-009.js ./demo/canvas-010.js ./demo/canvas-011.js ./demo/canvas-012.js ./demo/canvas-013.js ./demo/canvas-014.js ./demo/canvas-015.js ./demo/canvas-015a.js ./demo/canvas-016.js ./demo/canvas-017.js ./demo/canvas-018.js ./demo/canvas-019.js ./demo/canvas-019a.js ./demo/canvas-020.js ./demo/canvas-021.js ./demo/canvas-022.js ./demo/canvas-023.js ./demo/canvas-024.js ./demo/canvas-025.js ./demo/canvas-026.js ./demo/canvas-027.js ./demo/canvas-028.js ./demo/canvas-029.js ./demo/canvas-030.js ./demo/canvas-031.js ./demo/canvas-032.js ./demo/canvas-033.js ./demo/canvas-034.js ./demo/canvas-035.js ./demo/canvas-036.js ./demo/canvas-037.js ./demo/canvas-038.js ./demo/canvas-039.js ./demo/canvas-040.js ./demo/canvas-041.js ./demo/canvas-042.js ./demo/canvas-043.js ./demo/canvas-044.js ./demo/canvas-045.js ./demo/canvas-046.js ./demo/canvas-047.js ./demo/canvas-048.js ./demo/canvas-049.js ./demo/canvas-050.js ./demo/canvas-051.js ./demo/canvas-052.js ./demo/canvas-053.js ./demo/canvas-054.js ./demo/canvas-055.js ./demo/canvas-056.js ./demo/canvas-058.js ./demo/canvas-059.js ./demo/canvas-060.js ./demo/canvas-061.js ./demo/canvas-062.js ./demo/canvas-063.js ./demo/canvas-064.js ./demo/core-001.js ./demo/delaunator-001.js ./demo/delaunator-002.js ./demo/dom-001.js ./demo/dom-002.js ./demo/dom-003.js ./demo/dom-004.js ./demo/dom-005.js ./demo/dom-006.js ./demo/dom-007.js ./demo/dom-008.js ./demo/dom-009.js ./demo/dom-010.js ./demo/dom-011.js ./demo/dom-012.js ./demo/dom-013.js ./demo/dom-015.js ./demo/dom-016.js ./demo/dom-017.js ./demo/dom-018.js ./demo/filters-001.js ./demo/filters-002.js ./demo/filters-002a.js ./demo/filters-003.js ./demo/filters-004.js ./demo/filters-005.js ./demo/filters-006.js ./demo/filters-007.js ./demo/filters-008.js ./demo/filters-009.js ./demo/filters-010.js ./demo/filters-011.js ./demo/filters-012.js ./demo/filters-013.js ./demo/filters-014.js ./demo/filters-015.js ./demo/filters-016.js ./demo/filters-017.js ./demo/filters-018.js ./demo/filters-019.js ./demo/filters-020.js ./demo/filters-021.js ./demo/filters-022.js ./demo/filters-023.js ./demo/filters-024.js ./demo/filters-025.js ./demo/filters-026.js ./demo/filters-027.js ./demo/filters-028.js ./demo/filters-101.js ./demo/filters-102.js ./demo/filters-103.js ./demo/filters-104.js ./demo/filters-105.js ./demo/filters-501.js ./demo/filters-502.js ./demo/filters-503.js ./demo/filters-504.js ./demo/filters-505.js ./demo/mediapipe-001.js ./demo/mediapipe-002.js ./demo/mediapipe-003.js ./demo/modules-001.js ./demo/modules-002.js ./demo/modules-003.js ./demo/modules-004.js ./demo/modules-005.js ./demo/modules-006.js ./demo/packets-001.js ./demo/packets-002.js ./demo/particles-001.js ./demo/particles-002.js ./demo/particles-003.js ./demo/particles-004.js ./demo/particles-005.js ./demo/particles-006.js ./demo/particles-007.js ./demo/particles-008.js ./demo/particles-009.js ./demo/particles-010.js ./demo/particles-011.js ./demo/particles-012.js ./demo/particles-013.js ./demo/particles-014.js ./demo/particles-015.js ./demo/particles-016.js ./demo/rapier-001.js ./demo/snippets-001.js ./demo/snippets-002.js ./demo/snippets-003.js ./demo/snippets-004.js ./demo/snippets-005.js ./demo/snippets-006.js ./demo/tensorflow-001.js ./demo/tensorflow-002.js ./demo/utilities.js

- §

  # Demo Canvas 033

  User preferences: prefers-color-scheme; prefers-reduced-motion

- §

  Run code

      import * as scrawl from '../source/scrawl.js';

      import { reportSpeed } from './utilities.js';

- §

  #### Scene setup

      const canvas = scrawl.library.canvas.mycanvas;

      const background_dark = '#404040',
          text_dark = '#c0ffc0',
          background_light = '#f0f0f0',
          text_light = '#408f40';

- §

  Create the demo Oval entity

      const track = scrawl.makeOval({

          name: 'loader-track',

          radiusX: '22%',
          radiusY: '12%',

          start: ['center', 'center'],
          handle: ['center', 'center'],

          strokeStyle: '#808080',
          lineWidth: 10,
          method: 'draw',

          delta: {
              roll: 0.2
          },

          useAsPath: true,
          precision: 0.1
      });

- §

  Create the three Phrase entitys that will animate around the oval

  - We give them their own group to make updating their attributes easier

      const textGroup = scrawl.makeGroup({

          name: 'text-group',
          host: canvas.base.name,
      });

      scrawl.makePhrase({

          name: 'loader-text-1',
          group: textGroup,

          weight: 'bold',

          text: 'Loading',
          size: '50px',
          justify: 'center',

          textPath: 'loader-track',
          handleY: '120%',

          delta: {
            textPathPosition: -0.002
          },

      }).clone({

          name: 'loader-text-2',
          textPathPosition: 0.333,

      }).clone({

          name: 'loader-text-3',
          textPathPosition: 0.667,
      });

- §

  #### prefers-color-scheme actions

  Setup the actions to take, to match the animation scene to the user’s preference for `dark` or `light` (default) color scheme

      canvas.setColorSchemeDarkAction(() => {

          canvas.set({ backgroundColor: background_dark});
          textGroup.setArtefacts({ fillStyle: text_dark});
      });

      canvas.setColorSchemeLightAction(() => {

          canvas.set({ backgroundColor: background_light});
          textGroup.setArtefacts({ fillStyle: text_light});
      });

- §

  #### Scene animation

  Function to display frames-per-second data, and other information relevant to the demo

      const report = reportSpeed('#reportmessage');

- §

  Create the Display cycle animation

      scrawl.makeRender({

          name: "demo-animation",
          target: canvas,
          afterShow: report,
      });

- §

  #### prefers-reduced-motion actions

      const checkE = (e) => {
          if (e) {
              if ("keydown" === e.type) {

- §

  spacebar

                  if (32 === e.keycode) return true;

- §

  enter key

                  if (13 === e.keycode) return true;
              }

- §

  mouse click

              if ("click" === e.type) return true;

- §

  tap

              if ("touchend" === e.type) return true;
          }
          return false;
      };

      const startAnimation = (e) => {
          if (e === "reduced-motion" || checkE(e)) {
              track.set({ noDeltaUpdates: false });
              textGroup.setArtefacts({ noDeltaUpdates: false });
          }
      };

      const stopAnimation = (e) => {
          if (e === "reduced-motion" || checkE(e)) {
              track.set({ noDeltaUpdates: true });
              textGroup.setArtefacts({ noDeltaUpdates: true });
          }
      };

      canvas.setReduceMotionAction(() => setTimeout(() => stopAnimation("reduced-motion"), 1000));

      canvas.setNoPreferenceMotionAction(() => startAnimation("reduced-motion"));

      scrawl.addNativeListener(['click', 'keydown', 'touchend'], startAnimation, '#play');

      scrawl.addNativeListener(['click', 'keydown', 'touchend'], stopAnimation, '#pause');

- §

  #### Development and testing

  In chrome browsers, open the inspector and enable the Rendering view - this includes selectors to emulate both `prefers-reduced-motion` and `prefers-color-scheme` user choices.

      console.log(scrawl.library);