forked from mirrors/gecko-dev
		
	
		
			
				
	
	
		
			86 lines
		
	
	
	
		
			3.4 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			86 lines
		
	
	
	
		
			3.4 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| /* This Source Code Form is subject to the terms of the Mozilla Public
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|  * License, v. 2.0. If a copy of the MPL was not distributed with this
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|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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| 
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| this.EXPORTED_SYMBOLS = [
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|   "onSpellCheck",
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| ];
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| 
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| const SPELL_CHECK_ENDED_TOPIC = "inlineSpellChecker-spellCheck-ended";
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| const SPELL_CHECK_STARTED_TOPIC = "inlineSpellChecker-spellCheck-started";
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| 
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| const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
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| 
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| /**
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|  * Waits until spell checking has stopped on the given element.
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|  *
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|  * When a spell check is pending, this waits indefinitely until the spell check
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|  * ends.  When a spell check is not pending, it waits a small number of turns of
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|  * the event loop: if a spell check begins, it resumes waiting indefinitely for
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|  * the end, and otherwise it stops waiting and calls the callback.
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|  *
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|  * This this can therefore trap spell checks that have not started at the time
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|  * of calling, spell checks that have already started, multiple consecutive
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|  * spell checks, and the absence of spell checks altogether.
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|  *
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|  * @param editableElement  The element being spell checked.
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|  * @param callback         Called when spell check has completed or enough turns
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|  *                         of the event loop have passed to determine it has not
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|  *                         started.
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|  */
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| function onSpellCheck(editableElement, callback) {
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|   let editor = editableElement.editor;
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|   if (!editor) {
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|     let win = editableElement.ownerGlobal;
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|     editor = win.QueryInterface(Ci.nsIInterfaceRequestor).
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|                  getInterface(Ci.nsIWebNavigation).
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|                  QueryInterface(Ci.nsIInterfaceRequestor).
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|                  getInterface(Ci.nsIEditingSession).
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|                  getEditorForWindow(win);
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|   }
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|   if (!editor)
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|     throw new Error("Unable to find editor for element " + editableElement);
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| 
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|   try {
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|     // False is important here.  Pass false so that the inline spell checker
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|     // isn't created if it doesn't already exist.
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|     var isc = editor.getInlineSpellChecker(false);
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|   }
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|   catch (err) {
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|     // getInlineSpellChecker throws if spell checking is not enabled instead of
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|     // just returning null, which seems kind of lame.  (Spell checking is not
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|     // enabled on Android.)  The point here is only to determine whether spell
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|     // check is pending, and if getInlineSpellChecker throws, then it's not
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|     // pending.
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|   }
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|   let waitingForEnded = isc && isc.spellCheckPending;
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|   let count = 0;
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| 
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|   function observe(subj, topic, data) {
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|     if (subj != editor)
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|       return;
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|     count = 0;
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|     let expectedTopic = waitingForEnded ? SPELL_CHECK_ENDED_TOPIC :
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|                         SPELL_CHECK_STARTED_TOPIC;
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|     if (topic != expectedTopic)
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|       Cu.reportError("Expected " + expectedTopic + " but got " + topic + "!");
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|     waitingForEnded = !waitingForEnded;
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|   }
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| 
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|   let os = Cc["@mozilla.org/observer-service;1"].
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|            getService(Ci.nsIObserverService);
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|   os.addObserver(observe, SPELL_CHECK_STARTED_TOPIC);
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|   os.addObserver(observe, SPELL_CHECK_ENDED_TOPIC);
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| 
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|   let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
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|   timer.init(function tick() {
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|     // Wait an arbitrarily large number -- 50 -- turns of the event loop before
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|     // declaring that no spell checks will start.
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|     if (waitingForEnded || ++count < 50)
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|       return;
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|     timer.cancel();
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|     os.removeObserver(observe, SPELL_CHECK_STARTED_TOPIC);
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|     os.removeObserver(observe, SPELL_CHECK_ENDED_TOPIC);
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|     callback();
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|   }, 0, Ci.nsITimer.TYPE_REPEATING_SLACK);
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| };
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