Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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
#ifndef mozilla_a11y_SelectionManager_h__
#define mozilla_a11y_SelectionManager_h__
#include "nsISelectionController.h"
#include "nsISelectionListener.h"
#include "mozilla/WeakPtr.h"
namespace mozilla {
class PresShell;
namespace dom {
class AbstractRange;
class Element;
class Selection;
} // namespace dom
namespace a11y {
class AccEvent;
class HyperTextAccessible;
/**
* This special accessibility class is for the caret and selection management.
* There is only 1 visible caret per top level window. However, there may be
* several visible selections.
*
* The important selections are the one owned by each document, and the one in
* the currently focused control.
*
* On Windows this class is used to move an invisible system caret that
* shadows the Mozilla caret. Windows will also automatically map this to
* the MSAA caret accessible object (via OBJID_CARET) (as opposed to the root
* accessible tree for a window which is retrieved with OBJID_CLIENT).
*
* For ATK and IAccessible2, this class is used to fire caret move and
* selection change events.
*/
struct SelData;
class SelectionManager : public nsISelectionListener {
public:
// nsISupports
// implemented by derived nsAccessibilityService
// nsISelectionListener
NS_DECL_NSISELECTIONLISTENER
// SelectionManager
void Shutdown() { ClearControlSelectionListener(); }
/**
* Listen to selection events on the focused control.
*
* Note: only one control's selection events are listened to at a time. This
* will remove the previous control's selection listener.
*/
void SetControlSelectionListener(dom::Element* aFocusedElm);
/**
* Stop listening to selection events on the control.
*/
void ClearControlSelectionListener();
/**
* Listen to selection events on the document.
*/
void AddDocSelectionListener(PresShell* aPresShell);
/**
* Stop listening to selection events for a given document
*/
void RemoveDocSelectionListener(PresShell* aPresShell);
/**
* Process delayed event, results in caret move and text selection change
* events.
*/
void ProcessTextSelChangeEvent(AccEvent* aEvent);
/**
* Gets the current caret offset/hypertext accessible pair. If there is no
* current pair, then returns -1 for the offset and a nullptr for the
* accessible.
*/
inline HyperTextAccessible* AccessibleWithCaret(int32_t* aCaret) {
if (aCaret) *aCaret = mCaretOffset;
return mAccWithCaret;
}
/**
* Update caret offset when it doesn't go through a caret move event.
*/
inline void UpdateCaretOffset(HyperTextAccessible* aItem, int32_t aOffset) {
mAccWithCaret = aItem;
mCaretOffset = aOffset;
}
inline void ResetCaretOffset() {
mCaretOffset = -1;
mAccWithCaret = nullptr;
}
/**
* Called by DOM when a selection range is added/removed.
* We need this because nsISelectionListener isn't sufficient for spelling
* errors, etc., since it only tells us that there was a change, not which
* range changed. We don't want to unnecessarily push a cache update for all
* Accessibles in the entire selection.
* Returns false if these notifications aren't required for this selection
* type at this time.
*/
static bool SelectionRangeChanged(SelectionType aType,
const dom::AbstractRange& aRange);
~SelectionManager();
protected:
SelectionManager();
/**
* Process DOM selection change. Fire selection and caret move events.
*/
void ProcessSelectionChanged(SelData* aSelData);
private:
// Currently focused control.
int32_t mCaretOffset;
HyperTextAccessible* mAccWithCaret;
WeakPtr<dom::Selection> mCurrCtrlNormalSel;
};
} // namespace a11y
} // namespace mozilla
#endif