tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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image_load_helpers.js (3395B)

      1 /*
      2 * Helper structures to track callbacks from image and channel loads.
      3 */
      4 
      5 // START_REQUEST and STOP_REQUEST are used by ChannelListener, and
      6 // stored in ChannelListener.requestStatus.
      7 const START_REQUEST = 0x01;
      8 const STOP_REQUEST = 0x02;
      9 const DATA_AVAILABLE = 0x04;
     10 
     11 // One bit per callback that imageListener below implements. Stored in
     12 // ImageListener.state.
     13 const SIZE_AVAILABLE = 0x01;
     14 const FRAME_UPDATE = 0x02;
     15 const FRAME_COMPLETE = 0x04;
     16 const LOAD_COMPLETE = 0x08;
     17 const DECODE_COMPLETE = 0x10;
     18 
     19 // Safebrowsing requires that the profile dir is set.
     20 do_get_profile();
     21 
     22 // An implementation of imgIScriptedNotificationObserver with the ability to
     23 // call specified functions on onStartRequest and onStopRequest.
     24 function ImageListener(start_callback, stop_callback) {
     25  this.sizeAvailable = function onSizeAvailable(aRequest) {
     26    Assert.ok(!this.synchronous);
     27 
     28    this.state |= SIZE_AVAILABLE;
     29 
     30    if (this.start_callback) {
     31      this.start_callback(this, aRequest);
     32    }
     33  };
     34  this.frameComplete = function onFrameComplete() {
     35    Assert.ok(!this.synchronous);
     36 
     37    this.state |= FRAME_COMPLETE;
     38  };
     39  this.decodeComplete = function onDecodeComplete() {
     40    Assert.ok(!this.synchronous);
     41 
     42    this.state |= DECODE_COMPLETE;
     43  };
     44  this.loadComplete = function onLoadcomplete(aRequest) {
     45    Assert.ok(!this.synchronous);
     46 
     47    this.state |= LOAD_COMPLETE;
     48 
     49    if (this.stop_callback) {
     50      this.stop_callback(this, aRequest);
     51    }
     52  };
     53  this.frameUpdate = function onFrameUpdate() {};
     54  this.isAnimated = function onIsAnimated() {};
     55 
     56  // Initialize the synchronous flag to true to start. This must be set to
     57  // false before exiting to the event loop!
     58  this.synchronous = true;
     59 
     60  // A function to call when onStartRequest is called.
     61  this.start_callback = start_callback;
     62 
     63  // A function to call when onStopRequest is called.
     64  this.stop_callback = stop_callback;
     65 
     66  // The image load/decode state.
     67  // A bitfield that tracks which callbacks have been called. Takes the bits
     68  // defined above.
     69  this.state = 0;
     70 }
     71 
     72 function NS_FAILED(val) {
     73  return !!(val & 0x80000000);
     74 }
     75 
     76 function ChannelListener() {
     77  this.onStartRequest = function onStartRequest(aRequest) {
     78    if (this.outputListener) {
     79      this.outputListener.onStartRequest(aRequest);
     80    }
     81 
     82    this.requestStatus |= START_REQUEST;
     83  };
     84 
     85  this.onDataAvailable = function onDataAvailable(
     86    aRequest,
     87    aInputStream,
     88    aOffset,
     89    aCount
     90  ) {
     91    if (this.outputListener) {
     92      this.outputListener.onDataAvailable(
     93        aRequest,
     94        aInputStream,
     95        aOffset,
     96        aCount
     97      );
     98    }
     99 
    100    this.requestStatus |= DATA_AVAILABLE;
    101  };
    102 
    103  this.onStopRequest = function onStopRequest(aRequest, aStatusCode) {
    104    if (this.outputListener) {
    105      this.outputListener.onStopRequest(aRequest, aStatusCode);
    106    }
    107 
    108    // If we failed (or were canceled - failure is implied if canceled),
    109    // there's no use tracking our state, since it's meaningless.
    110    if (NS_FAILED(aStatusCode)) {
    111      this.requestStatus = 0;
    112    } else {
    113      this.requestStatus |= STOP_REQUEST;
    114    }
    115  };
    116 
    117  // A listener to pass the notifications we get to.
    118  this.outputListener = null;
    119 
    120  // The request's status. A bitfield that holds one or both of START_REQUEST
    121  // and STOP_REQUEST, according to which callbacks have been called on the
    122  // associated request.
    123  this.requestStatus = 0;
    124 }