gecko-dev/mobile/xul/chrome/content/AnimatedZoom.js

118 строки
3.5 KiB
JavaScript

// -*- Mode: js2; tab-width: 2; indent-tabs-mode: nil; js2-basic-offset: 2; js2-skip-preprocessor-directives: t; -*-
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Responsible for zooming in to a given view rectangle
*/
const AnimatedZoom = {
startScale: null,
/** Starts an animated zoom to zoomRect. */
animateTo: function(aZoomRect) {
if (!aZoomRect)
return;
this.zoomTo = aZoomRect.clone();
if (this.animationDuration === undefined)
this.animationDuration = Services.prefs.getIntPref("browser.ui.zoom.animationDuration");
Browser.hideSidebars();
Browser.hideTitlebar();
Browser.forceChromeReflow();
this.start();
// Check if zooming animations were occuring before.
if (!this.zoomRect) {
this.updateTo(this.zoomFrom);
mozRequestAnimationFrame(this);
let event = document.createEvent("Events");
event.initEvent("AnimatedZoomBegin", true, true);
window.dispatchEvent(event);
}
},
start: function start() {
this.tab = Browser.selectedTab;
this.browser = this.tab.browser;
this.bcr = this.browser.getBoundingClientRect();
this.zoomFrom = this.zoomRect || this.getStartRect();
this.startScale = this.browser.scale;
this.beginTime = mozAnimationStartTime;
},
/** Get the visible rect, in device pixels relative to the content origin. */
getStartRect: function getStartRect() {
let browser = this.browser;
let scroll = browser.getRootView().getPosition();
return new Rect(scroll.x, scroll.y, this.bcr.width, this.bcr.height);
},
/** Update the visible rect, in device pixels relative to the content origin. */
updateTo: function(nextRect) {
let zoomRatio = this.bcr.width / nextRect.width;
let scale = this.startScale * zoomRatio;
let scrollX = nextRect.left * zoomRatio;
let scrollY = nextRect.top * zoomRatio;
this.browser.fuzzyZoom(scale, scrollX, scrollY);
this.zoomRect = nextRect;
},
/** Stop animation, zoom to point, and clean up. */
finish: function() {
this.updateTo(this.zoomTo || this.zoomRect);
// Check whether the zoom limits have changed since the animation started.
let browser = this.browser;
let finalScale = this.tab.clampZoomLevel(browser.scale);
if (browser.scale != finalScale)
browser.scale = finalScale; // scale= calls finishFuzzyZoom.
else
browser.finishFuzzyZoom();
Browser.hideSidebars();
Browser.hideTitlebar();
this.beginTime = null;
this.zoomTo = null;
this.zoomFrom = null;
this.zoomRect = null;
this.startScale = null;
let event = document.createEvent("Events");
event.initEvent("AnimatedZoomEnd", true, true);
window.dispatchEvent(event);
browser._updateCSSViewport();
},
isZooming: function isZooming() {
return this.beginTime != null;
},
sample: function(aTimeStamp) {
try {
let tdiff = aTimeStamp - this.beginTime;
let counter = tdiff / this.animationDuration;
if (counter < 1) {
// update browser to interpolated rectangle
let rect = this.zoomFrom.blend(this.zoomTo, counter);
this.updateTo(rect);
mozRequestAnimationFrame(this);
} else {
// last cycle already rendered final scaled image, now clean up
this.finish();
}
} catch(e) {
this.finish();
throw e;
}
}
};