summaryrefslogtreecommitdiffstats
path: root/accessible/base/TextUpdater.h
diff options
context:
space:
mode:
authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /accessible/base/TextUpdater.h
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
downloadUXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar
UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.gz
UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.lz
UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.xz
UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.zip
Add m-esr52 at 52.6.0
Diffstat (limited to 'accessible/base/TextUpdater.h')
-rw-r--r--accessible/base/TextUpdater.h96
1 files changed, 96 insertions, 0 deletions
diff --git a/accessible/base/TextUpdater.h b/accessible/base/TextUpdater.h
new file mode 100644
index 000000000..06df3890d
--- /dev/null
+++ b/accessible/base/TextUpdater.h
@@ -0,0 +1,96 @@
+/* -*- Mode: C++; tab-width: 2; 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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_a11y_TextUpdater_h__
+#define mozilla_a11y_TextUpdater_h__
+
+#include "AccEvent.h"
+#include "HyperTextAccessible.h"
+
+namespace mozilla {
+namespace a11y {
+
+/**
+ * Used to find a difference between old and new text and fire text change
+ * events.
+ */
+class TextUpdater
+{
+public:
+ /**
+ * Start text of the text leaf update.
+ */
+ static void Run(DocAccessible* aDocument, TextLeafAccessible* aTextLeaf,
+ const nsAString& aNewText);
+
+private:
+ TextUpdater(DocAccessible* aDocument, TextLeafAccessible* aTextLeaf) :
+ mDocument(aDocument), mTextLeaf(aTextLeaf), mHyperText(nullptr),
+ mTextOffset(-1) { }
+
+ ~TextUpdater()
+ { mDocument = nullptr; mTextLeaf = nullptr; mHyperText = nullptr; }
+
+ /**
+ * Update text of the text leaf accessible, fire text change and value change
+ * (if applicable) events for its container hypertext accessible.
+ */
+ void DoUpdate(const nsAString& aNewText, const nsAString& aOldText,
+ uint32_t aSkipStart);
+
+private:
+ TextUpdater();
+ TextUpdater(const TextUpdater&);
+ TextUpdater& operator=(const TextUpdater&);
+
+ /**
+ * Fire text change events based on difference between strings.
+ */
+ void ComputeTextChangeEvents(const nsAString& aStr1,
+ const nsAString& aStr2,
+ uint32_t* aEntries,
+ nsTArray<RefPtr<AccEvent> >& aEvents);
+
+ /**
+ * Helper to create text change events for inserted text.
+ */
+ inline void FireInsertEvent(const nsAString& aText, uint32_t aAddlOffset,
+ nsTArray<RefPtr<AccEvent> >& aEvents)
+ {
+ RefPtr<AccEvent> event =
+ new AccTextChangeEvent(mHyperText, mTextOffset + aAddlOffset,
+ aText, true);
+ aEvents.AppendElement(event);
+ }
+
+ /**
+ * Helper to create text change events for removed text.
+ */
+ inline void FireDeleteEvent(const nsAString& aText, uint32_t aAddlOffset,
+ nsTArray<RefPtr<AccEvent> >& aEvents)
+ {
+ RefPtr<AccEvent> event =
+ new AccTextChangeEvent(mHyperText, mTextOffset + aAddlOffset,
+ aText, false);
+ aEvents.AppendElement(event);
+ }
+
+ /**
+ * The constant used to skip string difference calculation in case of long
+ * strings.
+ */
+ const static uint32_t kMaxStrLen = 1 << 6;
+
+private:
+ DocAccessible* mDocument;
+ TextLeafAccessible* mTextLeaf;
+ HyperTextAccessible* mHyperText;
+ int32_t mTextOffset;
+};
+
+} // namespace a11y
+} // namespace mozilla
+
+#endif