Makepad Screenshot Skill

Automated screenshot debugging for Makepad GUI applications

Trigger Words

• /screenshot - Capture current running Makepad app
• /screenshot <app-name> - Capture specific app
• /run-and-capture <package> - Build, run and capture
• "截图", "看看UI", "查看界面", "capture makepad"

Features

Automates visual debugging workflow for Makepad apps:

1. Bring app window to front
2. Capture screenshot
3. Analyze screenshot with Read tool
4. Report UI issues or confirm correct rendering

Usage

1. Capture Current Running App

/screenshot

Auto-detects and captures windows containing "makepad" or current project name.

2. Capture Specific App

/screenshot a2ui-demo

Captures app with window name containing "a2ui".

3. Build, Run and Capture

/run-and-capture a2ui-demo

Full workflow: cargo build → cargo run → wait for startup → capture.

Implementation Steps

Step 1: Detect Running App

# Find Makepad-related processes
ps aux | grep -E "(makepad|cargo.*run)" | grep -v grep

Step 2: Bring Window to Front (macOS)

# Generic pattern - match by process name
osascript -e 'tell application "System Events" to set frontmost of (first process whose name contains "APP_NAME") to true'

# Example
osascript -e 'tell application "System Events" to set frontmost of (first process whose name contains "a2ui") to true'

Step 3: Capture to Scratchpad

# Silent capture (-x suppresses shutter sound)
screencapture -x $SCRATCHPAD/screenshot.png

Step 4: View with Read Tool

Read $SCRATCHPAD/screenshot.png

Claude's Read tool supports image files and can directly analyze screenshot content.

Complete Automation Script

Capture Current App

APP_NAME="${1:-makepad}"
SCRATCHPAD="${SCRATCHPAD_DIR:-/tmp}"
SCREENSHOT="$SCRATCHPAD/makepad_screenshot_$(date +%H%M%S).png"

# Bring to front
osascript -e "tell application \"System Events\" to set frontmost of (first process whose name contains \"$APP_NAME\") to true" 2>/dev/null

sleep 0.5

# Capture
screencapture -x "$SCREENSHOT"

echo "$SCREENSHOT"

Build, Run and Capture

PACKAGE="$1"
SCRATCHPAD="${SCRATCHPAD_DIR:-/tmp}"
SCREENSHOT="$SCRATCHPAD/${PACKAGE}_$(date +%H%M%S).png"

# Kill old process
pkill -f "$PACKAGE" 2>/dev/null

# Build and run
cargo build -p "$PACKAGE" && \
(cargo run -p "$PACKAGE" 2>&1 &) && \
sleep 5 && \
osascript -e "tell application \"System Events\" to set frontmost of (first process whose name contains \"$PACKAGE\") to true" && \
sleep 1 && \
screencapture -x "$SCREENSHOT"

echo "$SCREENSHOT"

Claude Execution Flow

When user says "截图" or "/screenshot":

1. Detect App

``bash ps aux | grep -E "cargo.*run|makepad" | grep -v grep | head -1 ``

1. Determine App Name

- Extract from process list - Or use current project's package name

1. Execute Screenshot

``bash osascript -e 'tell application "System Events" to set frontmost of (first process whose name contains "APP") to true' sleep 0.5 screencapture -x /path/to/scratchpad/screenshot.png ``

1. Read and Analyze

`` Read /path/to/scratchpad/screenshot.png ``

1. Report Results

- Describe visible UI elements - Point out any issues (layout, colors, missing components) - Confirm functionality

Notes

• macOS Only - Uses screencapture and osascript
• Permission Required - osascript needs accessibility permission
• Window Occlusion - Must bring to front first
• Startup Time - Need to sleep after cargo run to wait for window
• Scratchpad - Use session-specific scratchpad directory for screenshots

Example Interactions

Example 1: Quick Screenshot

User: 截图看看现在的 UI

Claude:
1. Detected running a2ui-demo
2. Execute screenshot command
3. Read screenshot file
4. Analysis: "UI displays normally, TextField shows input '你好', product list rendered 3 cards..."

Example 2: Build Run and Capture

User: /run-and-capture a2ui-demo

Claude:
1. pkill old process
2. cargo build -p a2ui-demo
3. cargo run -p a2ui-demo &
4. sleep 5 wait for startup
5. Capture and analyze

Example 3: Verify Two-way Binding

User: I entered "Hello😊" in TextField, help me verify two-way binding with screenshot

Claude:
1. Execute screenshot, save to scratchpad
2. Read screenshot, analyze UI
3. Output verification report:

   ┌────────────────────────────────────────┐
   │ A2UI Demo - Product Catalog           │
   ├────────────────────────────────────────┤
   │ [Search Products]                      │
   │ ┌──────────────────────────────────┐  │
   │ │ Hello😊                          │  │ ← TextField shows input
   │ └──────────────────────────────────┘  │
   │ Hello😊                               │ ← Text (caption) synced
   │                                        │
   │ Products (Template Rendering)          │
   │ ┌──────────────────────────────────┐  │
   │ │ Premium Headphones | $99.99 | +  │  │
   │ └──────────────────────────────────┘  │
   └────────────────────────────────────────┘

   ✅ Two-way binding verification successful:
   | Component | Binding Path | Display Content |
   |-----------|--------------|-----------------|
   | TextField | /search/query | Hello😊 |
   | Text (caption) | /search/query | Hello😊 |

UI Analysis Report Format

After screenshot, Claude should provide structured analysis:

Basic Report

## Screenshot Analysis

**Application**: a2ui-demo
**Time**: 2026-02-01 14:30:00
**Window State**: Normal display

### UI Elements

| Element | Type | Content/State |
|---------|------|---------------|
| Title | Label | "A2UI Demo - Product Catalog" |
| Search Box | TextField | Empty/Has input |
| Product List | PortalList | 3 cards |

### Issue Detection

- ✅ Layout normal
- ✅ Text rendering normal
- ⚠️ Image not loaded (network image)

Function Verification Report

## Function Verification: TextField Two-way Binding

**Test Scenario**: User enters content in TextField, verify data model sync

### Verification Result

| Component | Binding Path | Expected | Actual | Status |
|-----------|--------------|----------|--------|--------|
| TextField | /search/query | Hello😊 | Hello😊 | ✅ |
| Text (caption) | /search/query | Hello😊 | Hello😊 | ✅ |

### Conclusion

✅ **Two-way binding works correctly**
- Unicode Chinese characters: ✅
- Emoji characters: ✅
- Real-time sync: ✅

Common Issue Troubleshooting

Window Cannot Be Brought to Front

# Check if process is running
ps aux | grep -E "a2ui|makepad" | grep -v grep

# Try using process ID
osascript -e 'tell application "System Events" to set frontmost of (first process whose unix id is PID) to true'

Screenshot is Black Screen

Possible causes:

1. Window occluded by other windows - bring to front first
2. App still starting - increase sleep time
3. GPU rendering delay - wait 1-2 seconds before capture

App Name Matching Issues

Makepad compiled app names are usually package names (underscores to hyphens):

• a2ui-demo → process name contains a2ui or a2ui-demo
• myapp → process name contains myapp or my-app

Related Skills

• makepad-basics - Makepad fundamentals
• makepad-widgets - Widget usage
• memory-skills - Memory system

Context: For automated visual debugging of Makepad GUI applications Tags: makepad, screenshot, debugging, gui, automation, macos