import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

accessible/base/SelectionManager.h

@@ -0,0 +1,133 @@
+/* -*- 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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_a11y_SelectionManager_h__
+#define mozilla_a11y_SelectionManager_h__
+
+#include "nsIFrame.h"
+#include "nsISelectionListener.h"
+
+class nsIPresShell;
+
+namespace mozilla {
+
+namespace dom {
+class Element;
+}
+
+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(nsIPresShell* aPresShell);
+
+  /**
+   * Stop listening to selection events for a given document
+   */
+  void RemoveDocSelectionListener(nsIPresShell* aShell);
+
+  /**
+   * 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;
+  }
+
+protected:
+
+  SelectionManager();
+
+  /**
+   * Process DOM selection change. Fire selection and caret move events.
+   */
+  void ProcessSelectionChanged(SelData* aSelData);
+
+private:
+  int32_t mCaretOffset;
+  HyperTextAccessible* mAccWithCaret;
+  // Currently focused controls.
+  nsWeakPtr mCurrCtrlNormalSel;
+  nsWeakPtr mCurrCtrlSpellSel;
+};
+
+} // namespace a11y
+} // namespace mozilla
+
+#endif