draw-io

draw.io Diagram Skill

1. Basic Rules

• Edit only .drawio files
• Do not directly edit .drawio.png files
• Use auto-generated .drawio.png by pre-commit hook in slides

2. Font Settings

For diagrams used in Quarto slides, specify defaultFontFamily in mxGraphModel tag:

<mxGraphModel defaultFontFamily="Noto Sans JP" ...>

Also explicitly specify fontFamily in each text element's style attribute:

style="text;html=1;fontSize=27;fontFamily=Noto Sans JP;"

3. Conversion Commands

See conversion script at scripts/convert-drawio-to-png.sh.

# Convert all .drawio files
mise exec -- pre-commit run --all-files
 
# Convert specific .drawio file
mise exec

Internal command used:

4. Layout Adjustment

4.1. Coordinate Adjustment Steps

1. Open .drawio file in text editor (plain XML format)
2. Find mxCell for element to adjust (search by value attribute for text)
3. Adjust coordinates in mxGeometry tag
   • x: Position from left
   • y: Position from top
   • width: Width
   • height: Height
4. Run conversion and verify

4.2. Coordinate Calculation

• Element center coordinate = y + (height / 2)
• To align multiple elements, calculate and match center coordinates

5. Design Principles

5.1. Basic Principles

• Clarity: Create simple, visually clean diagrams
• Consistency: Unify colors, fonts, icon sizes, line thickness
• Accuracy: Do not sacrifice accuracy for simplification

5.2. Element Rules

• Label all elements
• Use arrows to indicate direction (prefer 2 unidirectional arrows over bidirectional)
• Use latest official icons
• Add legend to explain custom symbols

5.3. Accessibility

• Ensure sufficient color contrast
• Use patterns in addition to colors

5.4. Progressive Disclosure

Separate complex systems into staged diagrams:

5.5. Metadata

Include title, description, last updated, author, and version in diagrams.

6. Best Practices

6.1. Background Color

• Remove background="#ffffff"
• Transparent background adapts to various themes

6.2. Font Size

• Use 1.5x standard font size (around 18px) for PDF readability

6.3. Japanese Text Width

• Allow 30-40px per character
• Insufficient width causes unintended line breaks

6.4. Arrow Placement

• Always place arrows at back (position in XML right after Title)
• Position arrows to avoid overlapping with labels
• Keep arrow start/end at least 20px from label bottom edge

6.5. Arrow Connection to Text Labels

For text elements, exitX/exitY don't work, so use explicit coordinates:

6.6. edgeLabel Offset Adjustment

Adjust offset attribute to distance arrow labels from arrows:

6.7. Remove Unnecessary Elements

• Remove decorative icons irrelevant to context
• Example: If ECR exists, separate Docker icon is unnecessary

6.8. Labels and Headings

• Service name only: 1 line
• Service name + supplementary info: 2 lines with line break
• Redundant notation (e.g., ECR Container Registry): shorten to 1 line
• Use <br> tag for line breaks

6.9. Background Frame and Internal Element Placement

When placing elements inside background frames (grouping boxes), ensure sufficient margin.

• YOU MUST: Internal elements must have at least 30px margin from frame boundary
• YOU MUST: Account for rounded corners (rounded=1) and stroke width
• YOU MUST: Always visually verify PNG output for overflow

Coordinate calculation verification:

Bad example (may overflow):

Good example (sufficient margin):

7. Reference

• Layout Guidelines
• AWS Icons
• AWS Icon Search Script

AWS icon search examples:

8. Checklist

• No background color set (page="0")
• Font size appropriate (larger recommended)
• Arrows placed at back layer
• Arrows not overlapping labels (verify in PNG)
• Arrow start/end sufficiently distant from labels (at least 20px)
• Arrows not penetrating boxes or icons (verify in PNG)
• Internal elements not overflowing background frame (verify in PNG)
• 30px+ margin between background frame and internal elements
• AWS service names are official names/correct abbreviations
• AWS icons are latest version (mxgraph.aws4.*)
• No unnecessary elements remaining
• Visually verified PNG conversion

9. Image Display in reveal.js Slides

Add auto-stretch: false to YAML header:

This ensures correct image display on mobile devices.*