gecko/image/test/unit/image_load_helpers.js
Joe Drew 5fd88749b5 Bug 716140 - Create a clone imgStatusTracker on every asynchronous decoding event, and replay the difference between that imgStatusTracker and the image's current status tracker when decoding completes. r=seth
* * *
[mq]: test-fixes
* * *
[mq]: undefer-on-remove
* * *
imported patch notify-in-sequence

--HG--
extra : rebase_source : 01a495a64cb4b6a8076a3550c254ddd804f53e80
2013-01-18 16:47:18 -05:00

126 lines
3.4 KiB
JavaScript

/*
* Helper structures to track callbacks from image and channel loads.
*/
// START_REQUEST and STOP_REQUEST are used by ChannelListener, and
// stored in ChannelListener.requestStatus.
const START_REQUEST = 0x01;
const STOP_REQUEST = 0x02;
const DATA_AVAILABLE = 0x04;
// One bit per callback that imageListener below implements. Stored in
// ImageListener.state.
const SIZE_AVAILABLE = 0x01;
const FRAME_UPDATE = 0x02;
const FRAME_COMPLETE = 0x04;
const LOAD_COMPLETE = 0x08;
const DECODE_COMPLETE = 0x10;
// An implementation of imgIScriptedNotificationObserver with the ability to
// call specified functions on onStartRequest and onStopRequest.
function ImageListener(start_callback, stop_callback)
{
this.sizeAvailable = function onSizeAvailable(aRequest)
{
do_check_false(this.synchronous);
this.state |= SIZE_AVAILABLE;
if (this.start_callback)
this.start_callback(this, aRequest);
}
this.frameComplete = function onFrameComplete(aRequest)
{
do_check_false(this.synchronous);
this.state |= FRAME_COMPLETE;
}
this.decodeComplete = function onDecodeComplete(aRequest)
{
do_check_false(this.synchronous);
this.state |= DECODE_COMPLETE;
}
this.loadComplete = function onLoadcomplete(aRequest)
{
do_check_false(this.synchronous);
try {
aRequest.requestDecode();
} catch (e) {
do_print("requestDecode threw " + e);
}
this.state |= LOAD_COMPLETE;
if (this.stop_callback)
this.stop_callback(this, aRequest);
}
this.frameUpdate = function onFrameUpdate(aRequest)
{
}
this.isAnimated = function onIsAnimated()
{
}
// Initialize the synchronous flag to true to start. This must be set to
// false before exiting to the event loop!
this.synchronous = true;
// A function to call when onStartRequest is called.
this.start_callback = start_callback;
// A function to call when onStopRequest is called.
this.stop_callback = stop_callback;
// The image load/decode state.
// A bitfield that tracks which callbacks have been called. Takes the bits
// defined above.
this.state = 0;
}
function NS_FAILED(val)
{
return !!(val & 0x80000000);
}
function ChannelListener()
{
this.onStartRequest = function onStartRequest(aRequest, aContext)
{
if (this.outputListener)
this.outputListener.onStartRequest(aRequest, aContext);
this.requestStatus |= START_REQUEST;
}
this.onDataAvailable = function onDataAvailable(aRequest, aContext, aInputStream, aOffset, aCount)
{
if (this.outputListener)
this.outputListener.onDataAvailable(aRequest, aContext, aInputStream, aOffset, aCount);
this.requestStatus |= DATA_AVAILABLE;
}
this.onStopRequest = function onStopRequest(aRequest, aContext, aStatusCode)
{
if (this.outputListener)
this.outputListener.onStopRequest(aRequest, aContext, aStatusCode);
// If we failed (or were canceled - failure is implied if canceled),
// there's no use tracking our state, since it's meaningless.
if (NS_FAILED(aStatusCode))
this.requestStatus = 0;
else
this.requestStatus |= STOP_REQUEST;
}
// A listener to pass the notifications we get to.
this.outputListener = null;
// The request's status. A bitfield that holds one or both of START_REQUEST
// and STOP_REQUEST, according to which callbacks have been called on the
// associated request.
this.requestStatus = 0;
}