зеркало из https://github.com/mozilla/gecko-dev.git
97 строки
2.8 KiB
C++
97 строки
2.8 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* 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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#ifndef mozilla_a11y_TextUpdater_h__
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#define mozilla_a11y_TextUpdater_h__
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#include "AccEvent.h"
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#include "HyperTextAccessible.h"
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namespace mozilla {
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namespace a11y {
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/**
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* Used to find a difference between old and new text and fire text change
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* events.
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*/
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class TextUpdater
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{
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public:
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/**
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* Start text of the text leaf update.
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*/
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static void Run(DocAccessible* aDocument, TextLeafAccessible* aTextLeaf,
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const nsAString& aNewText);
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private:
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TextUpdater(DocAccessible* aDocument, TextLeafAccessible* aTextLeaf) :
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mDocument(aDocument), mTextLeaf(aTextLeaf), mHyperText(nullptr),
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mTextOffset(-1) { }
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~TextUpdater()
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{ mDocument = nullptr; mTextLeaf = nullptr; mHyperText = nullptr; }
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/**
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* Update text of the text leaf accessible, fire text change and value change
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* (if applicable) events for its container hypertext accessible.
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*/
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void DoUpdate(const nsAString& aNewText, const nsAString& aOldText,
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uint32_t aSkipStart);
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private:
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TextUpdater();
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TextUpdater(const TextUpdater&);
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TextUpdater& operator=(const TextUpdater&);
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/**
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* Fire text change events based on difference between strings.
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*/
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void ComputeTextChangeEvents(const nsAString& aStr1,
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const nsAString& aStr2,
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uint32_t* aEntries,
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nsTArray<RefPtr<AccEvent> >& aEvents);
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/**
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* Helper to create text change events for inserted text.
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*/
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inline void FireInsertEvent(const nsAString& aText, uint32_t aAddlOffset,
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nsTArray<RefPtr<AccEvent> >& aEvents)
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{
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RefPtr<AccEvent> event =
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new AccTextChangeEvent(mHyperText, mTextOffset + aAddlOffset,
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aText, true);
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aEvents.AppendElement(event);
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}
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/**
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* Helper to create text change events for removed text.
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*/
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inline void FireDeleteEvent(const nsAString& aText, uint32_t aAddlOffset,
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nsTArray<RefPtr<AccEvent> >& aEvents)
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{
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RefPtr<AccEvent> event =
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new AccTextChangeEvent(mHyperText, mTextOffset + aAddlOffset,
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aText, false);
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aEvents.AppendElement(event);
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}
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/**
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* The constant used to skip string difference calculation in case of long
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* strings.
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*/
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const static uint32_t kMaxStrLen = 1 << 6;
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private:
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DocAccessible* mDocument;
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TextLeafAccessible* mTextLeaf;
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HyperTextAccessible* mHyperText;
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int32_t mTextOffset;
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};
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} // namespace a11y
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} // namespace mozilla
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#endif
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