Open code, practice, and notes →
Download source with English comments · for reading
GSAP · 28 Motion Design and Verification
Series contents · Technology map
Stage: Motion system verification · Editable example · Storage ID: gsap-03
Goals and learning outcomes
- Learning outcome: explain the role of Information Hierarchy. Input case: keyboard·10 rapid inputs·5 remounts.
- Deliverable: an input·accessibility·cleanup·frame verification report. Explain the rationale for handling Combined Verification, connecting it to the code.
Prerequisites
Prepare the exercise results on Resource Inventory and Repeated Disposal from Unit 27, “Cleanup on Failure Paths”.
Key concepts and explanations
Information Hierarchy
Motion should indicate the current step and next action. Reduce it if it interferes with reading or input.
Combined Verification
Keyboard and reduced-motion tests find different failures. Explain design choices with measurement and cleanup records.
Practice setup
The existing gsap-01·02·03 are starting examples. Write new units in a separate local GSAP project. The gsap-02 preview uses native scroll events; install and register ScrollTrigger in an external project. Preserve CSP and iframe isolation.
The linked example is a starting point. It does not implement every task below. Complete work beyond its supported scope in a separate project.
Practice tasks
- In src/day-28.js of a separate practice project, use the existing gsap-03 as a starting point to complete a learning-step motion system and report. Refer to the existing Unit 1·14·28 examples only as starting points.
- Input conditions: keyboard·10 rapid inputs·5 remounts. Baseline: default distance. Run under baseline conditions, then record observations and errors in notes/day-28.md.
- Variable: Motion; changed value: distance 0. Run again using the same input path. Deliverable to save: an input·accessibility·cleanup·frame verification report. Hypothesis to check: Functionality, content, and focus are preserved. Compare with the actual results and record whether they agree and the causes of any differences.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| Motion | default distance | distance 0 | Functionality, content, and focus are preserved. |
Predictions in this table are not measured results. Change one condition at a time and record why the actual result differs.
Completion criteria
- Required deliverable: an input·accessibility·cleanup·frame verification report. Include results for both baseline and changed conditions so that a total of 2 conditions can be compared, and record the inputs and execution environment together.
- Connect all of these concepts in the explanation of the difference between the two conditions: Information Hierarchy, Combined Verification. For items that differ from expectations, give at least 1 cause or reason they remain unresolved.
Self-check
- Which processing stage does Information Hierarchy affect in this exercise? Input case: keyboard·10 rapid inputs·5 remounts.
- Variable: Motion. Hypothesis to check: Functionality, content, and focus are preserved. Did the actual results match the hypothesis? Explain the evidence in terms of Combined Verification.
Official references
Linked example and execution scope
Example source · Runtime environments and limits
Source code and records are not overwritten automatically. Resetting an existing example also preserves your notes.