Lasso Select Mode ⭐

Lasso Select Mode ⭐

Lasso Select Mode allows you to select multiple layers on your map by drawing a freehand shape around them. This feature enables quick and intuitive selection of layers for further manipulation or analysis.

You can enable Lasso Select Mode on a map like this:

// enable Lasso Select Mode
map.pm.enableGlobalLassoMode();

// disable Lasso Select Mode
map.pm.disableGlobalLassoMode();

The following methods are available on map.pm:

Method	Returns	Description
enableGlobalLassoMode(options)	-	Enables global Lasso Select Mode with optional configuration.
disableGlobalLassoMode()	-	Disables global Lasso Select Mode.
toggleGlobalLassoMode()	-	Toggles global Lasso Select Mode.
globalLassoModeEnabled()	Boolean	Returns true if global Lasso Select Mode is enabled, false if not.
setLassoMode(mode)	-	Sets the Lasso mode (APPEND, SUBTRACT, or RESET).
getLassoMode()	String	Returns the current Lasso mode.
setLassoSelectMode(mode)	-	Sets the Lasso select mode (CONTAIN or INTERSECT).
getLassoSelectMode()	String	Returns the current Lasso select mode.

Lasso Select Options

When enabling Lasso Select Mode, you can pass options to configure its behavior:

map.pm.enableGlobalLassoMode({
  mode: map.pm.Draw.Lasso.APPEND_MODE,
  selectMode: map.pm.Draw.Lasso.INTERSECT_SELECT_MODE,
  color: 'red',
});

Available options include:

Option	Values	Description
mode	APPEND_MODE, SUBTRACT_MODE, RESET_MODE	Determines how selections are handled.
selectMode	CONTAIN_SELECT_MODE, INTERSECT_SELECT_MODE	Determines how layers are selected.
color	Any valid color value	Sets the color of the lasso line while drawing.

Lasso Modes

Lasso Select Mode has three main modes that determine how selections are handled:

1. APPEND_MODE: Adds new selections to existing ones.
2. SUBTRACT_MODE: Removes selections from existing ones.
3. RESET_MODE: Clears existing selections before making new ones.

You can set these modes using the setLassoMode() method or when enabling the mode:

map.pm.setLassoAppendMode();
map.pm.setLassoSubtractMode();
map.pm.setLassoResetMode();

Select Modes

There are two select modes that determine how layers are selected:

1. CONTAIN_SELECT_MODE: Selects only layers fully contained within the lasso.
2. INTERSECT_SELECT_MODE: Selects layers that intersect with the lasso.

Set these modes using the setLassoSelectMode() method or when enabling the mode:

map.pm.setLassoContainSelectMode();
map.pm.setLassoIntersectSelectMode();

Events

The following events are available on a map instance:

Event	Params	Description	Output
pm:globallassomodetoggled	e	Fired when Lasso Select Mode is toggled.	enabled, map
pm:lassofinish	e	Fired when a lasso selection is completed.	layers, selection

Example Usage

// Enable Lasso Select Mode with APPEND mode and INTERSECT select mode
map.pm.enableGlobalLassoMode({
  mode: map.pm.Draw.Lasso.APPEND_MODE,
  selectMode: map.pm.Draw.Lasso.INTERSECT_SELECT_MODE,
});

// Listen for selection changes
map.on('pm:lassofinish', (e) => {
  console.log('Selected layers:', e.layers);
  console.log('Current selection:', e.selection);
});

// Get currently selected layers
const selectedLayers = map.pm.getSelectedLayers();

// Clear all selections
map.pm.Draw.Lasso.cleanupSelection();

Lasso Select Mode Button in the Toolbar

You can enable/disable a button in the toolbar to toggle Lasso Select Mode. Enable it by setting lassoMode to true in the addControls options:

map.pm.addControls({ 
  lassoMode: true, 
});

Notes

• Layers can be excluded from lasso selection by setting the lassoSelectable option to false on the layer's pm options.
• Holding the Ctrl key while using Lasso Select Mode in RESET mode will temporarily switch to APPEND mode, allowing for non-contiguous selections.
• Lasso Select Mode works with various layer types including markers, circles, polygons, polylines, and rectangles.

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