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✍️ Freehand Adjuster

Available from v2.0.0

This advanced tool allows you to interactively edit line and polygon geometries with exceptional control. You can either drag vertices freely or use a precision panel to set exact side lengths. It fully supports snapping and topological editing.

✅ Prerequisites​

  • You must have a Line or Polygon layer selected.
  • The layer must be in editing mode (pencil icon ✏️ activated).

🔄 Tool Workflow Overview​

  1. Activate the tool.
  2. Left-click a line or polygon feature to select it.
  3. The tool displays vertices and side lengths.
  4. Choose your action:
    • Drag a vertex: Click and drag any vertex to a new position.
    • Open Length Panel: Ctrl+Left-click a vertex to open a dialog for precise length input.
  5. Apply the changes.
  6. Right-click to reset and select a new feature.

🧭 Step-by-Step Instructions​

🟩 Step 1: Activate the Tool​

  • From your tool panel, click on Free Adjuster to activate the Freehand Adjuster.
  • A message will appear:

    “Click feature → drag vertex or Ctrl+click for length dialog...”

🟩 Step 2: Select a Feature​

  • Left-click anywhere on a line or polygon feature.
  • The tool will select the feature and display its geometry details:
    • 🔴 Red circle markers will appear on every vertex.
    • White length labels (with a black halo) will show the length of each segment.

🟩 Step 3: Choose Your Adjustment Method​

Once a feature is selected, you can modify it in two ways:

Method A: Freehand Dragging​

  1. Hover over a vertex marker.
  2. Click and hold the left mouse button.
  3. Drag the vertex to its new location. A red rubber band will show a live preview of the change.
  4. Release the mouse button to finalize the vertex position.
  5. If topological editing is on, any shared vertices from adjacent features will also move.

Method B: Precise Length Panel (Ctrl+Click)​

  1. Hold the Ctrl key on your keyboard.
  2. Left-click on the vertex you wish to adjust.
  3. The Length Adjustment Panel will open.

🟩 Step 4: Using the Length Adjustment Panel​

This dialog gives you precise numerical control over the connected side lengths.

  1. Select Units: Choose your desired measurement unit from the dropdown (Meters, Feet, etc.).
  2. Enter Lengths: Input the new, exact length(s) for the sides connected to the vertex.
  3. Show Preview: Check this box to see a red rubber band preview of your changes on the map before applying them.
  4. Auto-Adjust (for Triangles): If you are editing a vertex with two connected sides, this option prevents errors. If you enter a length for one side that makes the triangle invalid, it will automatically calculate a valid length for the other side.
  5. Click Apply to confirm the new lengths and close the dialog.

🟩 Step 5: Cycle Units (Optional)​

  • While the tool is active, press the Q key on your keyboard.
  • The displayed length units on the map labels will cycle through Meters, Feet, Yards, and Links.

🟩 Step 6: Finish or Reset​

  • After an adjustment, the tool is ready to edit another vertex on the same feature.
  • To deselect the current feature and choose a new one, right-click anywhere on the map.

🎨 Visual Cues Guide​

ElementAppearanceMeaning
Vertex Markers🔴 Red CirclesShows all editable vertices on the selected feature.
Length LabelsWhite text with black outlineDisplays the length of each segment in the current unit.
Preview Rubber BandThin red lineShows a live preview of the geometry as you drag or input lengths.
Snap IndicatorMagenta cross (default QGIS style)Appears when your cursor is snapping to a vertex or segment.

❗ Error Messages & Hints​

MessageMeaning / Suggestion
"No layer selected" / "Select a vector layer"The tool was activated without a valid layer. Select a line or polygon layer.
"Point layers not supported"The active layer is a point layer. The tool only works on lines and polygons.
"Layer is not editable"The layer is not in editing mode. Click the pencil icon ✏️ to enable editing.
"Invalid Triangle" / "Sides too short"The lengths entered in the panel cannot form a valid triangle. Adjust the values or check "Auto-adjust".

💡 Best Practices​

  • For best results with shared boundaries, enable snapping and topological editing in your QGIS project settings.
  • Zoom in close for better accuracy when selecting and dragging vertices.
  • Press Q to match the tool's units to your project or survey data units.
  • Remember to save your layer edits in QGIS when you are finished!

🛑 To Exit the Tool​

  • Select any other tool from the QGIS toolbars.
  • Press the Esc key to cancel a drag-in-progress.

📌 The Freehand Adjuster offers an unparalleled combination of speed and precision, making it the go-to tool for fine-tuning vector geometries with confidence. 🗺️✍️