Canvas event handling

Canvas - the FlightGear 2D drawing API
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Tutorials
Howto:Getting started with Canvas Howto: Canvas Troubleshooting Howto:Adding a canvas to a GUI dialog (PUI!) Howto:Creating a Canvas GUI dialog file (New) Howto:Dynamic Liveries via Canvas (new) Howto:Creating a Canvas GUI Widget Howto:Add a 2D canvas instrument to your aircraft Howto:Parsing 2D Instruments using the Canvas Howto:Creating fullscreen Canvas applications Howto:Use SVG inside a Canvas Howto:Extend the Canvas SVG module Howto:Serializing a Canvas to SVG Howto:Canvas applications as Nasal submodules Howto:Using raster images and nested canvases Canvas HUD Howto:Project 3D to 2D coordinates on desktop canvas
Reference
Canvas Element Group Image Map Path Text Canvas Nasal API MessageBox Layout System Canvas GUI API Canvas draw library Event Handling
Related
Canvas Properties Unifying the 2D rendering backend via canvas Howto:Use a Camera View in an Instrument Howto:Extending Canvas to support rendering 3D models Howto:Extending Canvas to support MathGL
To be ported
Navigation display Map FGCanvas Canvas Nasal/JavaScript Subset
Deprecated by Canvas
Complex Glass Cockpit Avionics
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The Canvas event handling system is heavily inspired by the DOM Event Model. If you have already worked with events in HTML and JavaScript most concepts of the Canvas event system should be already familiar to you.

canvas.addEventListener("<type>", <func>);
canvas_element.addEventListener("<type>", <func>);

Event classes

var Event = {
  # Name of event type [read-only]
  type: <typename>,

  # Target element [read-only]
  target: <target-element>,

  # Stop further propagation of event (stop
  # bubbling up to its parents)
  stopPropagation: func()
};

var MouseEvent = {
  parents: [Event],

  # Position in screen coordinates [read-only]
  screenX: <screen-x>,
  screenY: <screen-y>,

  # Position in window/canvas coordinates [read-only]
  clientX: <client-x>,
  clientY: <client-y>,

  # Distance to position of previous event [read-only]
  deltaX: <delta-x>,
  deltaY: <delta-y>,

  # Current click count (number of clicks within a certain
  # time limit. max. 3) [read-only]
  click_count: <click-count>
};

Event types

Type	Description	DOM equivalent event	Notes
mousedown	Mouse button pressed	mousedown
mouseup	Mouse button released	mouseup
click	mousedown + mouseup have been triggered for this element without moving more than a certain maximum distance	click
dblclick	Two click events have been triggered for this element without moving more than a certain maximum distance and time limit	dblclick
drag	The mouse has been moved with a button down. After dragging has started above an element, all consecutive drag events are send to this element even if the mouse leaves its area
wheel	Mouse wheel rotated (see deltaY for direction)	wheel
mouseover	TODO	mouseover
mouseout	TODO	mouseout
mouseleave	TODO	mouseleave