The Tor Browser: accessible/src/jsat/ContentControl.jsm@b8a032363ba2 (annotated)

accessible/src/jsat/ContentControl.jsm@b8a032363ba2 (annotated)

accessible/src/jsat/ContentControl.jsm

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* 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/. */
 let Ci = Components.interfaces;
 let Cu = Components.utils;
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, 'Services',
   'resource://gre/modules/Services.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Utils',
   'resource://gre/modules/accessibility/Utils.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Logger',
   'resource://gre/modules/accessibility/Utils.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Roles',
   'resource://gre/modules/accessibility/Constants.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'TraversalRules',
   'resource://gre/modules/accessibility/TraversalRules.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Presentation',
   'resource://gre/modules/accessibility/Presentation.jsm');
 this.EXPORTED_SYMBOLS = ['ContentControl'];
 const MOVEMENT_GRANULARITY_CHARACTER = 1;
 const MOVEMENT_GRANULARITY_WORD = 2;
 const MOVEMENT_GRANULARITY_PARAGRAPH = 8;
 this.ContentControl = function ContentControl(aContentScope) {
   this._contentScope = Cu.getWeakReference(aContentScope);
   this._vcCache = new WeakMap();
   this._childMessageSenders = new WeakMap();
 };
 this.ContentControl.prototype = {
   messagesOfInterest: ['AccessFu:MoveCursor',
                        'AccessFu:ClearCursor',
                        'AccessFu:MoveToPoint',
                        'AccessFu:AutoMove',
                        'AccessFu:Activate',
                        'AccessFu:MoveCaret',
                        'AccessFu:MoveByGranularity'],
   start: function cc_start() {
     let cs = this._contentScope.get();
     for (let message of this.messagesOfInterest) {
       cs.addMessageListener(message, this);
     }
   },
   stop: function cc_stop() {
     let cs = this._contentScope.get();
     for (let message of this.messagesOfInterest) {
       cs.removeMessageListener(message, this);
     }
   },
   get document() {
     return this._contentScope.get().content.document;
   },
   get window() {
     return this._contentScope.get().content;
   },
   get vc() {
     return Utils.getVirtualCursor(this.document);
   },
   receiveMessage: function cc_receiveMessage(aMessage) {
     Logger.debug(() => {
       return ['ContentControl.receiveMessage',
         aMessage.name,
         JSON.stringify(aMessage.json)];
     });
     try {
       let func = this['handle' + aMessage.name.slice(9)]; // 'AccessFu:'.length
       if (func) {
         func.bind(this)(aMessage);
       } else {
         Logger.warning('ContentControl: Unhandled message:', aMessage.name);
       }
     } catch (x) {
       Logger.logException(
         x, 'Error handling message: ' + JSON.stringify(aMessage.json));
     }
   },
   handleMoveCursor: function cc_handleMoveCursor(aMessage) {
     let origin = aMessage.json.origin;
     let action = aMessage.json.action;
     let vc = this.vc;
     if (origin != 'child' && this.sendToChild(vc, aMessage)) {
       // Forwarded succesfully to child cursor.
       return;
     }
     let moved = vc[action](TraversalRules[aMessage.json.rule]);
     if (moved) {
       if (origin === 'child') {
         // We just stepped out of a child, clear child cursor.
         Utils.getMessageManager(aMessage.target).sendAsyncMessage(
           'AccessFu:ClearCursor', {});
       } else {
         // We potentially landed on a new child cursor. If so, we want to
         // either be on the first or last item in the child doc.
         let childAction = action;
         if (action === 'moveNext') {
           childAction = 'moveFirst';
         } else if (action === 'movePrevious') {
           childAction = 'moveLast';
         }
         // Attempt to forward move to a potential child cursor in our
         // new position.
         this.sendToChild(vc, aMessage, { action: childAction});
       }
     } else if (!this._childMessageSenders.has(aMessage.target)) {
       // We failed to move, and the message is not from a child, so forward
       // to parent.
       this.sendToParent(aMessage);
     }
   },
   handleMoveToPoint: function cc_handleMoveToPoint(aMessage) {
     let [x, y] = [aMessage.json.x, aMessage.json.y];
     let rule = TraversalRules[aMessage.json.rule];
     let vc = this.vc;
     let win = this.window;
     let dpr = win.devicePixelRatio;
     this.vc.moveToPoint(rule, x * dpr, y * dpr, true);
     let delta = Utils.isContentProcess ?
       { x: x - win.mozInnerScreenX, y: y - win.mozInnerScreenY } : {};
     this.sendToChild(vc, aMessage, delta);
   },
   handleClearCursor: function cc_handleClearCursor(aMessage) {
     let forwarded = this.sendToChild(this.vc, aMessage);
     this.vc.position = null;
     if (!forwarded) {
       this._contentScope.get().sendAsyncMessage('AccessFu:CursorCleared');
     }
   },
   handleAutoMove: function cc_handleAutoMove(aMessage) {
     this.autoMove(null, aMessage.json);
   },
   handleActivate: function cc_handleActivate(aMessage) {
     let activateAccessible = (aAccessible) => {
       Logger.debug(() => {
         return ['activateAccessible', Logger.accessibleToString(aAccessible)];
       });
       try {
         if (aMessage.json.activateIfKey &&
           aAccessible.role != Roles.KEY) {
           // Only activate keys, don't do anything on other objects.
           return;
         }
       } catch (e) {
         // accessible is invalid. Silently fail.
         return;
       }
       if (aAccessible.actionCount > 0) {
         aAccessible.doAction(0);
       } else {
         let control = Utils.getEmbeddedControl(aAccessible);
         if (control && control.actionCount > 0) {
           control.doAction(0);
         }
         // XXX Some mobile widget sets do not expose actions properly
         // (via ARIA roles, etc.), so we need to generate a click.
         // Could possibly be made simpler in the future. Maybe core
         // engine could expose nsCoreUtiles::DispatchMouseEvent()?
         let docAcc = Utils.AccRetrieval.getAccessibleFor(this.document);
         let docX = {}, docY = {}, docW = {}, docH = {};
         docAcc.getBounds(docX, docY, docW, docH);
         let objX = {}, objY = {}, objW = {}, objH = {};
         aAccessible.getBounds(objX, objY, objW, objH);
         let x = Math.round((objX.value - docX.value) + objW.value / 2);
         let y = Math.round((objY.value - docY.value) + objH.value / 2);
         let node = aAccessible.DOMNode || aAccessible.parent.DOMNode;
         for (let eventType of ['mousedown', 'mouseup']) {
           let evt = this.document.createEvent('MouseEvents');
           evt.initMouseEvent(eventType, true, true, this.window,
             x, y, 0, 0, 0, false, false, false, false, 0, null);
           node.dispatchEvent(evt);
         }
       }
       if (aAccessible.role !== Roles.KEY) {
         // Keys will typically have a sound of their own.
         this._contentScope.get().sendAsyncMessage('AccessFu:Present',
           Presentation.actionInvoked(aAccessible, 'click'));
       }
     };
     let focusedAcc = Utils.AccRetrieval.getAccessibleFor(
       this.document.activeElement);
     if (focusedAcc && focusedAcc.role === Roles.ENTRY) {
       let accText = focusedAcc.QueryInterface(Ci.nsIAccessibleText);
       let oldOffset = accText.caretOffset;
       let newOffset = aMessage.json.offset;
       let text = accText.getText(0, accText.characterCount);
       if (newOffset >= 0 && newOffset <= accText.characterCount) {
         accText.caretOffset = newOffset;
       }
       this.presentCaretChange(text, oldOffset, accText.caretOffset);
       return;
     }
     let vc = this.vc;
     if (!this.sendToChild(vc, aMessage)) {
       activateAccessible(vc.position);
     }
   },
   handleMoveByGranularity: function cc_handleMoveByGranularity(aMessage) {
     // XXX: Add sendToChild. Right now this is only used in Android, so no need.
     let direction = aMessage.json.direction;
     let granularity;
     switch(aMessage.json.granularity) {
       case MOVEMENT_GRANULARITY_CHARACTER:
         granularity = Ci.nsIAccessiblePivot.CHAR_BOUNDARY;
         break;
       case MOVEMENT_GRANULARITY_WORD:
         granularity = Ci.nsIAccessiblePivot.WORD_BOUNDARY;
         break;
       default:
         return;
     }
     if (direction === 'Previous') {
       this.vc.movePreviousByText(granularity);
     } else if (direction === 'Next') {
       this.vc.moveNextByText(granularity);
     }
   },
   presentCaretChange: function cc_presentCaretChange(
     aText, aOldOffset, aNewOffset) {
     if (aOldOffset !== aNewOffset) {
       let msg = Presentation.textSelectionChanged(aText, aNewOffset, aNewOffset,
         aOldOffset, aOldOffset, true);
       this._contentScope.get().sendAsyncMessage('AccessFu:Present', msg);
     }
   },
   handleMoveCaret: function cc_handleMoveCaret(aMessage) {
     let direction = aMessage.json.direction;
     let granularity = aMessage.json.granularity;
     let accessible = this.vc.position;
     let accText = accessible.QueryInterface(Ci.nsIAccessibleText);
     let oldOffset = accText.caretOffset;
     let text = accText.getText(0, accText.characterCount);
     let start = {}, end = {};
     if (direction === 'Previous' && !aMessage.json.atStart) {
       switch (granularity) {
         case MOVEMENT_GRANULARITY_CHARACTER:
           accText.caretOffset--;
           break;
         case MOVEMENT_GRANULARITY_WORD:
           accText.getTextBeforeOffset(accText.caretOffset,
             Ci.nsIAccessibleText.BOUNDARY_WORD_START, start, end);
           accText.caretOffset = end.value === accText.caretOffset ?
             start.value : end.value;
           break;
         case MOVEMENT_GRANULARITY_PARAGRAPH:
           let startOfParagraph = text.lastIndexOf('\n', accText.caretOffset - 1);
           accText.caretOffset = startOfParagraph !== -1 ? startOfParagraph : 0;
           break;
       }
     } else if (direction === 'Next' && !aMessage.json.atEnd) {
       switch (granularity) {
         case MOVEMENT_GRANULARITY_CHARACTER:
           accText.caretOffset++;
           break;
         case MOVEMENT_GRANULARITY_WORD:
           accText.getTextAtOffset(accText.caretOffset,
                                   Ci.nsIAccessibleText.BOUNDARY_WORD_END, start, end);
           accText.caretOffset = end.value;
           break;
         case MOVEMENT_GRANULARITY_PARAGRAPH:
           accText.caretOffset = text.indexOf('\n', accText.caretOffset + 1);
           break;
       }
     }
     this.presentCaretChange(text, oldOffset, accText.caretOffset);
   },
   getChildCursor: function cc_getChildCursor(aAccessible) {
     let acc = aAccessible || this.vc.position;
     if (Utils.isAliveAndVisible(acc) && acc.role === Roles.INTERNAL_FRAME) {
       let domNode = acc.DOMNode;
       let mm = this._childMessageSenders.get(domNode, null);
       if (!mm) {
         mm = Utils.getMessageManager(domNode);
         mm.addWeakMessageListener('AccessFu:MoveCursor', this);
         this._childMessageSenders.set(domNode, mm);
       }
       return mm;
     }
     return null;
   },
   sendToChild: function cc_sendToChild(aVirtualCursor, aMessage, aReplacer) {
     let mm = this.getChildCursor(aVirtualCursor.position);
     if (!mm) {
       return false;
     }
     // XXX: This is a silly way to make a deep copy
     let newJSON = JSON.parse(JSON.stringify(aMessage.json));
     newJSON.origin = 'parent';
     for (let attr in aReplacer) {
       newJSON[attr] = aReplacer[attr];
     }
     mm.sendAsyncMessage(aMessage.name, newJSON);
     return true;
   },
   sendToParent: function cc_sendToParent(aMessage) {
     // XXX: This is a silly way to make a deep copy
     let newJSON = JSON.parse(JSON.stringify(aMessage.json));
     newJSON.origin = 'child';
     aMessage.target.sendAsyncMessage(aMessage.name, newJSON);
   },
   /**
    * Move cursor and/or present its location.
    * aOptions could have any of these fields:
    * - delay: in ms, before actual move is performed. Another autoMove call
    *    would cancel it. Useful if we want to wait for a possible trailing
    *    focus move. Default 0.
    * - noOpIfOnScreen: if accessible is alive and visible, don't do anything.
    * - forcePresent: present cursor location, whether we move or don't.
    * - moveToFocused: if there is a focused accessible move to that. This takes
    *    precedence over given anchor.
    * - moveMethod: pivot move method to use, default is 'moveNext',
    */
   autoMove: function cc_autoMove(aAnchor, aOptions = {}) {
     let win = this.window;
     win.clearTimeout(this._autoMove);
     let moveFunc = () => {
       let vc = this.vc;
       let acc = aAnchor;
       let rule = aOptions.onScreenOnly ?
         TraversalRules.SimpleOnScreen : TraversalRules.Simple;
       let forcePresentFunc = () => {
         if (aOptions.forcePresent) {
           this._contentScope.get().sendAsyncMessage(
             'AccessFu:Present', Presentation.pivotChanged(
               vc.position, null, Ci.nsIAccessiblePivot.REASON_NONE,
               vc.startOffset, vc.endOffset));
         }
       };
       if (aOptions.noOpIfOnScreen &&
         Utils.isAliveAndVisible(vc.position, true)) {
         forcePresentFunc();
         return;
       }
       if (aOptions.moveToFocused) {
         acc = Utils.AccRetrieval.getAccessibleFor(
           this.document.activeElement) || acc;
       }
       let moved = false;
       let moveMethod = aOptions.moveMethod || 'moveNext'; // default is moveNext
       let moveFirstOrLast = moveMethod in ['moveFirst', 'moveLast'];
       if (!moveFirstOrLast || acc) {
         // We either need next/previous or there is an anchor we need to use.
         moved = vc[moveFirstOrLast ? 'moveNext' : moveMethod](rule, acc, true);
       }
       if (moveFirstOrLast && !moved) {
         // We move to first/last after no anchor move happened or succeeded.
         moved = vc[moveMethod](rule);
       }
       let sentToChild = this.sendToChild(vc, {
         name: 'AccessFu:AutoMove',
         json: aOptions
       });
       if (!moved && !sentToChild) {
         forcePresentFunc();
       }
     };
     if (aOptions.delay) {
       this._autoMove = win.setTimeout(moveFunc, aOptions.delay);
     } else {
       moveFunc();
     }
   },
   QueryInterface: XPCOMUtils.generateQI([Ci.nsISupportsWeakReference,
     Ci.nsIMessageListener
   ])
 };

The Tor Browser / annotate

accessible/src/jsat/ContentControl.jsm@b8a032363ba2 (annotated)

accessible/src/jsat/ContentControl.jsm