blob: 8a6891cdc273694557935c91c807b255c95b6635 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
/*
* screen.js
* Part of Pointless Viewer, a Beamer presentation viewer
* Copyright 2018 Pacien TRAN-GIRARD
* License: GNU GPL v3
*/
"use strict";
class Screen {
constructor(window, secondary=false) {
this.window = window;
this.secondary = secondary;
this.canvas = window.document.getElementById("screen");
this.context = this.canvas.getContext("2d");
this.page = null;
var self = this;
this.window.addEventListener("resize", function() {
self._refreshPage();
});
}
setPage(page) {
this.page = page;
this._refreshPage();
}
_resizeScreen(ratio) {
var windowRatio = this.window.innerWidth / this.window.innerHeight;
var scaleFactor = ratio / windowRatio;
this.canvas.width = this.window.innerWidth * Math.min(scaleFactor, 1);
this.canvas.height = this.window.innerHeight / Math.max(scaleFactor, 1);
}
_setOffset() {
var xOffset = this.secondary ? -this.canvas.width : 0;
this.context.transform(1, 0, 0, 1, xOffset, 0);
}
_paintPage() {
var renderRatio = this.canvas.height / this.page.getViewport(1).height;
var renderViewport = this.page.getViewport(renderRatio);
var renderContext = { canvasContext: this.context, viewport: renderViewport };
this.page.render(renderContext);
}
_refreshPage() {
if (this.page == null) return;
var viewport = this.page.getViewport(1);
var ratio = (viewport.width / 2) / viewport.height;
this._resizeScreen(ratio);
this._setOffset();
this._paintPage();
}
}
|