erste Studie zur Verwendung von tldraw
This commit is contained in:
mistangl
304
doc/tldraw_technologie.md
Normal file
304
doc/tldraw_technologie.md
Normal file
@@ -0,0 +1,304 @@
|
||||
# Technologie-Zusammenfassung: iPad Skizzen-Tool mit Symbolbibliothek
|
||||
|
||||
**Datum:** 09. April 2026
|
||||
**Thema:** Hybride iPad-Anwendung für technische Skizzen (Schienen/Weichen/Kreisel) mit Snap-to-Grid, Symbolbibliothek und JSON/SVG-Export
|
||||
|
||||
---
|
||||
|
||||
## 1. Anforderungen
|
||||
|
||||
- iPad als Eingabegerät (Bleistift-Look)
|
||||
- ~10 Grundsymbole (Weichen, Kreisel, etc.) aus Katalog
|
||||
- Snap-to-Grid
|
||||
- Output: **JSON + SVG**
|
||||
- Symbole parametrisch veränderbar (z.B. Kreiselab stand)
|
||||
|
||||
---
|
||||
|
||||
## 2. Gewählte Architektur: Option C (Hybrid)
|
||||
|
||||
```
|
||||
iPad (PWA/Safari) Hetzner Server
|
||||
───────────────── ──────────────
|
||||
tldraw (Canvas) FastAPI (Python)
|
||||
rough.js (Bleistift) │
|
||||
Custom Shapes ├── GET /symbols → Bibliothek ausliefern
|
||||
│ ├── POST /normalize → Skizze → SVG
|
||||
│ JSON (Shapes + Meta) └── POST /export → finales JSON/SVG
|
||||
└──────────────────────────────────────►
|
||||
```
|
||||
|
||||
**Warum Hybrid:**
|
||||
- iPad nur für Eingabe + lokales Snap/Rendering (kein App Store, kein Swift)
|
||||
- Server für Bibliotheksverwaltung, Normalisierung und Export (Python/FastAPI)
|
||||
- PWA läuft direkt im Safari, gehostet auf Hetzner via nginx
|
||||
|
||||
---
|
||||
|
||||
## 3. Kerntechnologien
|
||||
|
||||
| Schicht | Technologie | Zweck |
|
||||
|---|---|---|
|
||||
| iPad-Frontend | **tldraw** (PWA) | Canvas, Snap-to-Grid, SVG-Export |
|
||||
| Bleistift-Look | **rough.js** | Skizzenhafter Renderstil |
|
||||
| Symbolbibliothek | **JSON + SVG-Pfade** | Katalog mit Metadaten |
|
||||
| Backend | **FastAPI (Python)** | Bibliothek, Normalisierung, Export |
|
||||
| Output | **SVG + JSON** | Weiterverarbeitung / CAD |
|
||||
|
||||
---
|
||||
|
||||
## 4. Symbolbibliothek-Format (JSON)
|
||||
|
||||
```json
|
||||
{
|
||||
"symbols": [
|
||||
{
|
||||
"id": "weiche_links_r300",
|
||||
"label": "Weiche links R300",
|
||||
"type": "weiche",
|
||||
"radius": 300,
|
||||
"direction": "left",
|
||||
"svg_path": "M 0,0 L 100,0 Q 150,0 200,50",
|
||||
"snap_points": [[0,0], [100,0], [200,50]],
|
||||
"ports": ["in", "out_gerade", "out_abzweig"]
|
||||
},
|
||||
{
|
||||
"id": "kreisel_standard",
|
||||
"label": "Kreisel",
|
||||
"type": "kreisel",
|
||||
"geometry": {
|
||||
"circle_top_r": 40,
|
||||
"circle_bottom_r": 40,
|
||||
"straight_length": 80
|
||||
},
|
||||
"svg_path": "...",
|
||||
"snap_points": [[0,0], [0,160]]
|
||||
}
|
||||
]
|
||||
}
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
## 5. Metadaten an tldraw-Shapes anhängen
|
||||
|
||||
### Option A: `meta`-Feld (schnell, für Prototypen)
|
||||
|
||||
```typescript
|
||||
editor.createShape({
|
||||
type: 'geo',
|
||||
x: 100,
|
||||
y: 200,
|
||||
props: {
|
||||
geo: 'rectangle',
|
||||
w: 80,
|
||||
h: 40,
|
||||
},
|
||||
meta: {
|
||||
symbol_id: 'weiche_links_r300',
|
||||
symbol_type: 'weiche',
|
||||
radius: 300,
|
||||
direction: 'left',
|
||||
ports: ['in', 'out_gerade', 'out_abzweig'],
|
||||
catalog_version: '1.2'
|
||||
}
|
||||
})
|
||||
```
|
||||
|
||||
### Option B: Custom Shape Type (produktiv, empfohlen)
|
||||
|
||||
```typescript
|
||||
const WeicheShapeUtil = defineShape({
|
||||
type: 'weiche',
|
||||
props: {
|
||||
radius: T.number,
|
||||
direction: T.string,
|
||||
ports: T.arrayOf(T.string),
|
||||
svg_path: T.string,
|
||||
},
|
||||
component(shape) {
|
||||
return (
|
||||
<SVGContainer>
|
||||
<path d={shape.props.svg_path} stroke="black" fill="none" />
|
||||
</SVGContainer>
|
||||
)
|
||||
},
|
||||
getBounds(shape) { /* ... */ }
|
||||
})
|
||||
```
|
||||
|
||||
**JSON-Export einer Custom Shape:**
|
||||
|
||||
```json
|
||||
{
|
||||
"id": "shape:abc123",
|
||||
"type": "weiche",
|
||||
"x": 100,
|
||||
"y": 200,
|
||||
"props": {
|
||||
"radius": 300,
|
||||
"direction": "left",
|
||||
"ports": ["in", "out_gerade", "out_abzweig"],
|
||||
"svg_path": "M 0,0 L 100,0 Q 150,0 200,50"
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
## 6. Parametrische Shapes: Kreisel-Beispiel
|
||||
|
||||
Ziel: Nutzer kann nur den **Abstand der zwei Kreise** verändern, alles andere ist gesperrt.
|
||||
|
||||
### 6.1 Shape-Definition mit eingeschränkten Props
|
||||
|
||||
```typescript
|
||||
const KreiselShapeUtil = defineShape({
|
||||
type: 'kreisel',
|
||||
props: {
|
||||
abstand: T.number, // ← einziger veränderbarer Parameter
|
||||
radius: T.number, // fest (aus Katalog)
|
||||
},
|
||||
```
|
||||
|
||||
### 6.2 Custom Handle (nur vertikale Bewegung)
|
||||
|
||||
```typescript
|
||||
getHandles(shape) {
|
||||
return {
|
||||
mitte: {
|
||||
id: 'mitte',
|
||||
type: 'vertex',
|
||||
x: 0,
|
||||
y: shape.props.abstand / 2, // Handle mittig zwischen den Kreisen
|
||||
canBind: false,
|
||||
}
|
||||
}
|
||||
},
|
||||
|
||||
onHandleDrag(shape, { handle, delta }) {
|
||||
return {
|
||||
props: {
|
||||
// Nur abstand ändern, x-Bewegung ignorieren, Minimum erzwingen
|
||||
abstand: Math.max(20, shape.props.abstand + delta.y * 2)
|
||||
}
|
||||
}
|
||||
},
|
||||
```
|
||||
|
||||
### 6.3 Resize einschränken (nur Höhe)
|
||||
|
||||
```typescript
|
||||
onResize(shape, info) {
|
||||
return {
|
||||
props: {
|
||||
abstand: Math.max(20, info.newPoint.y * 2)
|
||||
}
|
||||
}
|
||||
},
|
||||
|
||||
getResizeSnapGeometry(shape) {
|
||||
return { points: [[0, 0], [0, shape.props.abstand]] }
|
||||
},
|
||||
```
|
||||
|
||||
### 6.4 SVG-Rendering (reagiert auf `abstand`)
|
||||
|
||||
```typescript
|
||||
component(shape) {
|
||||
const { abstand, radius } = shape.props
|
||||
const r = radius
|
||||
|
||||
return (
|
||||
<SVGContainer>
|
||||
{/* Oberer Kreis */}
|
||||
<circle cx={0} cy={0} r={r} stroke="black" fill="none" />
|
||||
|
||||
{/* Unterer Kreis – position hängt von abstand ab */}
|
||||
<circle cx={0} cy={abstand} r={r} stroke="black" fill="none" />
|
||||
|
||||
{/* Zwei vertikale Verbindungslinien */}
|
||||
<line x1={-r} y1={0} x2={-r} y2={abstand} stroke="black" />
|
||||
<line x1={ r} y1={0} x2={ r} y2={abstand} stroke="black" />
|
||||
</SVGContainer>
|
||||
)
|
||||
}
|
||||
```
|
||||
|
||||
### 6.5 Freiheitsgrade im Überblick
|
||||
|
||||
| Aktion | Erlaubt |
|
||||
|---|---|
|
||||
| Kreisel verschieben | ✓ |
|
||||
| Abstand der Kreise ändern | ✓ (Handle mittig) |
|
||||
| Breite / Radius ändern | ✗ gesperrt |
|
||||
| Drehen | konfigurierbar |
|
||||
| Im JSON-Export | `"abstand": 120` |
|
||||
|
||||
---
|
||||
|
||||
## 7. FastAPI-Backend (3 Endpunkte)
|
||||
|
||||
```python
|
||||
from fastapi import FastAPI
|
||||
from pydantic import BaseModel
|
||||
|
||||
app = FastAPI()
|
||||
|
||||
# 1. Symbolbibliothek ausliefern
|
||||
@app.get("/symbols")
|
||||
async def get_symbols():
|
||||
with open("catalog/symbols.json") as f:
|
||||
return json.load(f)
|
||||
|
||||
# 2. Koordinaten normalisieren / bereinigen
|
||||
class SketchPayload(BaseModel):
|
||||
shapes: list[dict]
|
||||
grid_size: int = 10
|
||||
|
||||
@app.post("/normalize")
|
||||
async def normalize(payload: SketchPayload):
|
||||
# Snap-Koordinaten auf Grid runden, SVG-Pfade normalisieren
|
||||
...
|
||||
return {"svg": normalized_svg, "shapes": cleaned_shapes}
|
||||
|
||||
# 3. Finales Projektfile exportieren
|
||||
@app.post("/export")
|
||||
async def export(payload: SketchPayload):
|
||||
return {
|
||||
"json": build_project_json(payload.shapes),
|
||||
"svg": build_final_svg(payload.shapes)
|
||||
}
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
## 8. Umsetzungsplan (Phasen)
|
||||
|
||||
| Phase | Inhalt | Aufwand |
|
||||
|---|---|---|
|
||||
| 1 | tldraw als PWA auf Hetzner (nginx + Docker) | 1 Tag |
|
||||
| 2 | Symbolbibliothek JSON + SVG-Pfade für 10 Symbole | 1–2 Tage |
|
||||
| 3 | Custom Shape Types in tldraw registrieren | 1 Tag |
|
||||
| 4 | FastAPI-Backend mit 3 Endpunkten | 1 Tag |
|
||||
| 5 | Parametrische Handles (Kreisel etc.) | 1 Tag |
|
||||
| 6 | Export → JSON + SVG finalisieren | 1 Tag |
|
||||
|
||||
**Geschätzter Gesamtaufwand Prototyp: ~1 Woche**
|
||||
|
||||
---
|
||||
|
||||
## 9. Entscheidungsmatrix: `meta` vs. Custom Shape
|
||||
|
||||
| Kriterium | `meta`-Feld | Custom Shape Type |
|
||||
|---|---|---|
|
||||
| Implementierungsaufwand | minimal | mittel |
|
||||
| Eigenes SVG-Rendering | ✗ | ✓ |
|
||||
| Typvalidierung der Props | ✗ | ✓ |
|
||||
| Parametrische Handles | ✗ | ✓ |
|
||||
| Im JSON-Export enthalten | ✓ | ✓ |
|
||||
| Empfehlung | Prototyp Phase 1 | Produktiv ab Phase 3 |
|
||||
|
||||
---
|
||||
|
||||
*Erstellt mit Claude (Anthropic) – Technologiegespräch vom 09.04.2026*
|
||||
Reference in New Issue
Block a user