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/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
// Helper file for shared image functionality
//
// Note that this is use by tests elsewhere in the source tree. When in doubt,
// check mxr before removing or changing functionality.
// Helper function to clear both the content and chrome image caches
function clearAllImageCaches() {
var tools = SpecialPowers.Cc["@mozilla.org/image/tools;1"].getService(
SpecialPowers.Ci.imgITools
);
var imageCache = tools.getImgCacheForDocument(window.document);
imageCache.clearCache(true); // true=chrome
imageCache.clearCache(false); // false=content
}
// Helper function to clear the image cache of content images
function clearImageCache() {
var tools = SpecialPowers.Cc["@mozilla.org/image/tools;1"].getService(
SpecialPowers.Ci.imgITools
);
var imageCache = tools.getImgCacheForDocument(window.document);
imageCache.clearCache(false); // true=chrome, false=content
}
// Helper function to determine if the frame is decoded for a given image id
function isFrameDecoded(id) {
return !!(
getImageStatus(id) & SpecialPowers.Ci.imgIRequest.STATUS_FRAME_COMPLETE
);
}
// Helper function to determine if the image is loaded for a given image id
function isImageLoaded(id) {
return !!(
getImageStatus(id) & SpecialPowers.Ci.imgIRequest.STATUS_LOAD_COMPLETE
);
}
// Helper function to get the status flags of an image
function getImageStatus(id) {
// Get the image
var img = SpecialPowers.wrap(document.getElementById(id));
// Get the request
var request = img.getRequest(
SpecialPowers.Ci.nsIImageLoadingContent.CURRENT_REQUEST
);
// Return the status
return request.imageStatus;
}
// Forces a synchronous decode of an image by drawing it to a canvas. Only
// really meaningful if the image is fully loaded first
function forceDecode(id) {
// Get the image
var img = document.getElementById(id);
// Make a new canvas
var canvas = document.createElement("canvas");
// Draw the image to the canvas. This forces a synchronous decode
var ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0);
}
// Functions to facilitate getting/setting various image-related prefs
//
// If you change a pref in a mochitest, Don't forget to reset it to its
// original value!
//
// Null indicates no pref set
const DISCARD_ENABLED_PREF = {
name: "discardable",
branch: "image.mem.",
type: "bool",
};
const DECODEONDRAW_ENABLED_PREF = {
name: "decodeondraw",
branch: "image.mem.",
type: "bool",
};
const DISCARD_TIMEOUT_PREF = {
name: "min_discard_timeout_ms",
branch: "image.mem.",
type: "int",
};
function setImagePref(pref, val) {
var prefService = SpecialPowers.Services.prefs;
var branch = prefService.getBranch(pref.branch);
if (val != null) {
switch (pref.type) {
case "bool":
branch.setBoolPref(pref.name, val);
break;
case "int":
branch.setIntPref(pref.name, val);
break;
default:
throw new Error("Unknown pref type");
}
} else if (branch.prefHasUserValue(pref.name)) {
branch.clearUserPref(pref.name);
}
}
function getImagePref(pref) {
var prefService = SpecialPowers.Services.prefs;
var branch = prefService.getBranch(pref.branch);
if (branch.prefHasUserValue(pref.name)) {
switch (pref.type) {
case "bool":
return branch.getBoolPref(pref.name);
case "int":
return branch.getIntPref(pref.name);
default:
throw new Error("Unknown pref type");
}
} else {
return null;
}
}
// JS implementation of imgIScriptedNotificationObserver with stubs for all of its methods.
function ImageDecoderObserverStub() {
this.sizeAvailable = function sizeAvailable() {};
this.frameComplete = function frameComplete() {};
this.decodeComplete = function decodeComplete() {};
this.loadComplete = function loadComplete() {};
this.frameUpdate = function frameUpdate() {};
this.discard = function discard() {};
this.isAnimated = function isAnimated() {};
this.hasTransparency = function hasTransparency() {};
}