lemmings/mouse.js

80 lines
3.7 KiB
JavaScript

/* Interactive elements
* Copyright 2016 Harmen de Weerd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
function addMouseTracker(elem) {
elem.mouse = {x : 0, y : 0, buttons : 0, targetElement : null, hasFocus: false};
elem.mouse.interactiveElements = [];
elem.getInteractiveElement = findElement;
elem.addEventListener("mousedown",
elem.mouse.downListener = function(event) {
this.mouse.buttons = event.buttons;
this.mouse.x = event.offsetX;
this.mouse.y = event.offsetY;
this.mouse.targetElement = this.getInteractiveElement(event.offsetX, event.offsetY);
if (this.mouse.targetElement != null) {
this.mouse.targetElement.startAction(event);
}
});
elem.addEventListener("mouseup",
elem.mouse.upListener = function(event) {
this.mouse.buttons = event.buttons;
if (this.mouse.targetElement != null) {
this.mouse.targetElement.endAction(event);
this.mouse.targetElement = null;
}
});
elem.addEventListener("mousemove",
elem.mouse.moveListener = function(event) {
this.mouse.hasFocus = true;
this.mouse.x = event.offsetX;
this.mouse.y = event.offsetY;
if (this.mouse.targetElement != null) {
this.mouse.targetElement.continueAction(event);
} else {
var interactiveElement = this.getInteractiveElement(event.offsetX, event.offsetY);
if (interactiveElement != null) {
this.style.cursor = interactiveElement.getActionLabel(event.offsetX - interactiveElement.x, event.offsetY - interactiveElement.y);
} else {
this.style.cursor = "initial";
}
}
});
elem.addEventListener("mouseout",
elem.mouse.outListener = function(event) {
this.mouse.hasFocus = false;
});
elem.addInteractiveElement = function(obj) {
if (!obj.mouseHit) obj.mouseHit = mouseHit
this.mouse.interactiveElements.push(obj);
elem.removeMouseTracker = function() {
elem.removeEventListener("mousedown", this.mouse.downListener)
elem.removeEventListener("mouseup", this.mouse.upListener)
elem.removeEventListener("mousemove", this.mouse.moveListener)
elem.removeEventListener("mouseout", this.mouse.outListener)
delete elem.mouse
}
};
}
function mouseHit(x, y) {
return (x < this.x + this.getWidth() && x > this.x &&
y < this.y + this.getHeight() && y > this.y)
}
function findElement(x, y) {
return this.mouse.interactiveElements.find(elem => elem.mouseHit(x, y))
}