📐 Advanced Line

Available from v1.0.1

The Professional Line Tool is an advanced QGIS plugin that provides enhanced line drawing capabilities with precise measurement, angle control, and circle creation features. It's designed for surveyors, engineers, and GIS professionals who need accurate geometric drawing tools.

🚀 Getting Started

✅ Prerequisites

• QGIS with an active, editable vector layer (line geometry)
• Layer must be in edit mode

🔧 Installation & Activation

1. Click on Advanced line Icon in the toolbar
2. The tool will be activated on your map canvas

🎮 Basic Controls

⌨️ Quick Reference - All Keyboard Shortcuts

Key	🎯 Function	📝 Description
L	📏 Length/Parameters	Open parameter dialog for precise length/angle input
O	📐 Ortho Mode	Toggle orthogonal drawing (constrains to 45° increments)
A	🔒 Angle Lock	Cycle: 90° Lock → 180° Lock → Off (double-tap to cancel)
R	⭕ Circle Mode	Toggle between line drawing and circle drawing modes
Q	📊 Units Cycle	Switch between: Meters → Metric Links → Gunter Links → Feet → Yards
S	🎯 Snap Toggle	Enable/disable snapping to layers and vertices
U	↩️ Undo Point	Remove the last placed point from current line
C	🔄 Close Line	Connect current line back to start point (close polygon)
Enter	✅ Finish Line	Complete and save the current line to layer
Return	✅ Finish Line	Same as Enter - complete current line
Escape	❌ Cancel	Cancel current operation or exit preview mode

🖱️ Mouse Controls

Action	Function
Left Click	Add point / Start line / Confirm action
Right Click	Finish line / Open parameter dialog
Mouse Move	Preview line / Update cursor info

📏 Drawing Modes

🖊️ Standard Line Drawing

1. Start: Left-click to place first point
2. Continue: Move mouse and left-click to add more points
3. Press L to enter precise Length
4. Finish: Right-click or press Enter to complete line

Visual Feedback:

• 🟢 Green markers show placed points
• 🧲 Pink marker indicates snap points
• 📏 Live length and angle display in cursor info

⭕ Circle Drawing Mode

Press R to enter circle mode.

Method 1: Center-Radius

1. Left-click to set circle center
2. Move mouse to desired radius
3. Left-click to create circle

Method 2: Center + Precise Radius

1. Left-click to set circle center
2. Press L to enter precise radius
3. Enter radius value and click Apply

🎯 Advanced Features

🔒 Angle Lock System

Press A to cycle through angle lock modes:

1. First Press: 🔒 90° Lock

   • Constrains lines to 90° increments from previous segment
   • For first segment: locks to cardinal directions (N, E, S, W)

2. Second Press: 🔒 180° Lock

   • Constrains lines to 180° (parallel/perpendicular)
   • For first segment: locks to N-S or E-W axes

3. Third Press: ❌ Cancel Lock

   • Returns to free drawing

Double-tap A: Quick cancel of current lock

📐 Orthogonal Mode

Press O to toggle ortho mode:

• Constrains all lines to 45° increments
• Works independently of angle lock
• Visual indicator in cursor info

📏 Parameter Dialog (Press L)

Enter precise measurements:

Length Input:

• 🔢 Precise length value
• 🔄 Auto-converts between units
• 📊 Supports 5 unit types

Angle Input:

• ☑️ Enable "Use Angle" checkbox
• 🎯 Enter angle in degrees (0° = North, clockwise)
• 🎮 Quick angle buttons: 0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°

📊 Unit System

Press Q to cycle through supported units:

Unit	Name	Symbol	Conversion Factor
m	Meters	m	1.0
mli	Metric Links	Metric	0.2
li	Gunter Links	Gunter	0.201168
ft	Feet	ft	0.3048
yd	Yards	yd	0.9144

Features:

• 🔄 Automatic conversion between units
• 💾 Values preserved when switching units
• 📊 Live display in cursor info

🎯 Enhanced Snapping

The tool provides intelligent snapping:

QGIS Layer Snapping:

• 🎯 Respects project snapping settings
• 🔧 Toggle with S key

Custom Vertex Snapping:

• 🟢 Automatically snaps to your drawn points
• 🎯 Only active when QGIS snapping is enabled
• 🧲 Pink marker indicates snap target

📋 Cursor Information Display

The live cursor info shows:

• 📏 Length: Current segment length in selected units
• 📐 Angle: Direction in degrees (N=0° clockwise)
• 🎮 Mode: Current drawing mode/state
• 🎯 Snap Status: ON/OFF + Vertex indication
• 📊 Unit: Currently selected unit

Auto-scaling Display:

• Values < 1: Show 4 decimal places
• Values < 1000: Show 3 decimal places
• Values ≥ 1000m: Auto-convert to kilometers

📝 Workflow Examples

🏗️ Example 1: Property Boundary Survey

1. Set units to feet: Press Q until "Feet" is selected
2. Start at corner: Left-click first point
3. Enter precise distance: Press L, enter "150 ft", Apply
4. Move mouse to direction and click to confirm
5. Use angle lock: Press A for 90° constraint
6. Continue adding segments with precise measurements
7. Close boundary: Press C to connect back to start

🏗️ Example 2: Building Layout

1. Enable ortho mode: Press O
2. Start at building corner: Left-click
3. Draw first wall: Move mouse east, left-click
4. Use angle lock: Press A for 90° increments
5. Continue around building perimeter
6. Use parameter dialog: Press L for precise room dimensions
7. Finish: Press Enter when complete

🏗️ Example 3: Circular Features

1. Enter circle mode: Press R
2. Click center point of circular feature
3. For precise radius: Press L, enter radius value
4. For visual radius: Move mouse and click at desired edge
5. Return to line mode: Press R again

⚠️ Troubleshooting

🔴 Common Issues

Tool won't activate:

• ✅ Ensure you have an active vector layer
• ✅ Layer must have line geometry type
• ✅ Layer must be in edit mode

No cursor info display:

• 🖱️ Move mouse over the canvas
• 🔄 Tool activates on canvas focus

Snapping not working:

• 🎯 Check QGIS project snapping settings
• 🔧 Press S to toggle tool snapping
• ⚙️ Verify layer snapping configuration

Parameter dialog issues:

• 📏 Ensure positive length values
• 🔄 Check unit conversions are reasonable
• ✅ Click Apply button to confirm

💡 Tips for Best Results

1. 🎯 Accuracy: Use parameter dialog (L) for precise measurements
2. ⚡ Speed: Use angle lock (A) for repetitive geometric patterns
3. 🔧 Workflow: Enable ortho mode (O) for architectural drawings
4. 📊 Units: Set appropriate units before starting complex drawings
5. 💾 Save Often: Remember to save your edits regularly

🎨 Visual Indicators

Color	Meaning
Green Box	Placed vertex points
Pink Box	Active snap point
Gray Dashed	Preview line