(function() {(function() {Luv.Mouse = Luv.Class('Luv.Mouse', {This function creates a mouse handler for a mouse game.
It is usually instantiated directly by the main Luv() function,
you will probably not need to call Luv.Mouse() yourself:
var luv = Luv();
luv.mouse // Already instantiated mouse handler init: function(el) {
var mouse = this;
mouse.x = 0;
mouse.y = 0;
mouse.pressedButtons = {};
mouse.wheelTimeOuts = {};The mouse module works by attaching several event listeners to the given el element. That's how mouse position, button presses and wheel state are detected.
var handlePress = function(button) {
mouse.pressedButtons[button] = true;
mouse.onPressed(mouse.x, mouse.y, button);
};
var handleRelease = function(button) {
mouse.pressedButtons[button] = false;
mouse.onReleased(mouse.x, mouse.y, button);
};
var handleWheel = function(evt) {
evt.preventDefault();
var button = getWheelButtonFromEvent(evt);The 'wheel has stopped scrolling' event is triggered via setTimeout, since browsers don't provide a native 'stopped scrolling' event
clearTimeout(mouse.wheelTimeOuts[button]);
mouse.wheelTimeOuts[button] = setTimeout(function() {
handleRelease(button);
}, Luv.Mouse.WHEEL_TIMEOUT * 1000);
handlePress(button);
};mousemove is particularly laggy in Chrome. I'd love to find a better solution
el.addEventListener('mousemove', function(evt) {
var rect = el.getBoundingClientRect();
mouse.x = evt.pageX - rect.left;
mouse.y = evt.pageY - rect.top;
mouse.onMoved(mouse.x, mouse.y);
});
el.addEventListener('mousedown', function(evt) {
handlePress(getButtonFromEvent(evt));
});
el.addEventListener('mouseup', function(evt) {
handleRelease(getButtonFromEvent(evt));
});
el.addEventListener('DOMMouseScroll', handleWheel); // firefox
el.addEventListener('mousewheel', handleWheel); // everyone else
},Returns the x coordinate where the mouse is (relative to the DOM element)
getX: function() { return this.x; },Returns the x coordinate where the mouse is (relative to the DOM element)
getY: function() { return this.y; },Returns both the x and y coordinates of the mouse, as an object of the form `{x: 100, y:200}
getPosition: function() {
return {x: this.x, y: this.y};
},onPressed is an overridable callback that is called when any of the mouse
buttons is pressed.
button is a string representing a button name ("l" for left, "m" for middle,
"r" for right).
var luv = Luv();
luv.mouse.onPressed = function(x,y,button) {
console.log("Mouse button " + button + " was pressed in " + x + ", " + y);
} onPressed: function(x,y,button) {},Works the same as onPressed, but is called when a button stops being pressed.
onReleased: function(x,y,button) {},
onMoved: function(x,y) {},Returns true if a button is pressed, false otherwhise. Usually used inside the update loop:
var luv = Luv();
luv.update = function(dt) {
if(luv.mouse.isPressed('l')) {
console.log('Left mouse button pressed');
}
}; isPressed: function(button) {
return !!this.pressedButtons[button];
}
});The mouse considers it has stopped scrolling after 20ms
Luv.Mouse.WHEEL_TIMEOUT = 0.02;Internal variable + function to transform DOM event magic numbers into human button names (left, middle, right)
var mouseButtonNames = {1: "l", 2: "m", 3: "r"};
var getButtonFromEvent = function(evt) {
return mouseButtonNames[evt.which];
};Internal function to determine the mouse weel direction
var getWheelButtonFromEvent = function(evt) {
var delta = Math.max(-1, Math.min(1, (evt.wheelDelta || -evt.detail)));
return delta === 1 ? 'wu' : 'wd';
};
}());