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      1 /*
      2  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
      3  * Copyright (C) 2010 Apple Inc. All rights reserved.
      4  *
      5  * This library is free software; you can redistribute it and/or
      6  * modify it under the terms of the GNU Library General Public
      7  * License as published by the Free Software Foundation; either
      8  * version 2 of the License, or (at your option) any later version.
      9  *
     10  * This library is distributed in the hope that it will be useful,
     11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13  * Library General Public License for more details.
     14  *
     15  * You should have received a copy of the GNU Library General Public License
     16  * along with this library; see the file COPYING.LIB.  If not, write to
     17  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     18  * Boston, MA 02110-1301, USA.
     19  */
     20 
     21 #ifndef EditingBehavior_h
     22 #define EditingBehavior_h
     23 
     24 #include "core/editing/EditingBehaviorTypes.h"
     25 
     26 namespace WebCore {
     27 class KeyboardEvent;
     28 
     29 class EditingBehavior {
     30 
     31 public:
     32     explicit EditingBehavior(EditingBehaviorType type)
     33         : m_type(type)
     34     {
     35     }
     36 
     37     // Individual functions for each case where we have more than one style of editing behavior.
     38     // Create a new function for any platform difference so we can control it here.
     39 
     40     // When extending a selection beyond the top or bottom boundary of an editable area,
     41     // maintain the horizontal position on Windows and Android but extend it to the boundary of
     42     // the editable content on Mac and Linux.
     43     bool shouldMoveCaretToHorizontalBoundaryWhenPastTopOrBottom() const
     44     {
     45         return m_type != EditingWindowsBehavior && m_type != EditingAndroidBehavior;
     46     }
     47 
     48     // On Windows, selections should always be considered as directional, regardless if it is
     49     // mouse-based or keyboard-based.
     50     bool shouldConsiderSelectionAsDirectional() const { return m_type != EditingMacBehavior; }
     51 
     52     // On Mac, when revealing a selection (for example as a result of a Find operation on the Browser),
     53     // content should be scrolled such that the selection gets certer aligned.
     54     bool shouldCenterAlignWhenSelectionIsRevealed() const { return m_type == EditingMacBehavior; }
     55 
     56     // On Mac, style is considered present when present at the beginning of selection. On other platforms,
     57     // style has to be present throughout the selection.
     58     bool shouldToggleStyleBasedOnStartOfSelection() const { return m_type == EditingMacBehavior; }
     59 
     60     // Standard Mac behavior when extending to a boundary is grow the selection rather than leaving the base
     61     // in place and moving the extent. Matches NSTextView.
     62     bool shouldAlwaysGrowSelectionWhenExtendingToBoundary() const { return m_type == EditingMacBehavior; }
     63 
     64     // On Mac, when processing a contextual click, the object being clicked upon should be selected.
     65     bool shouldSelectOnContextualMenuClick() const { return m_type == EditingMacBehavior; }
     66 
     67     // On Mac and Windows, pressing backspace (when it isn't handled otherwise) should navigate back.
     68     bool shouldNavigateBackOnBackspace() const
     69     {
     70         return m_type != EditingUnixBehavior && m_type != EditingAndroidBehavior;
     71     }
     72 
     73     // On Mac, selecting backwards by word/line from the middle of a word/line, and then going
     74     // forward leaves the caret back in the middle with no selection, instead of directly selecting
     75     // to the other end of the line/word (Unix/Windows behavior).
     76     bool shouldExtendSelectionByWordOrLineAcrossCaret() const { return m_type != EditingMacBehavior; }
     77 
     78     // Based on native behavior, when using ctrl(alt)+arrow to move caret by word, ctrl(alt)+left arrow moves caret to
     79     // immediately before the word in all platforms, for example, the word break positions are: "|abc |def |hij |opq".
     80     // But ctrl+right arrow moves caret to "abc |def |hij |opq" on Windows and "abc| def| hij| opq|" on Mac and Linux.
     81     bool shouldSkipSpaceWhenMovingRight() const { return m_type == EditingWindowsBehavior; }
     82 
     83     // On Mac, undo of delete/forward-delete of text should select the deleted text. On other platforms deleted text
     84     // should not be selected and the cursor should be placed where the deletion started.
     85     bool shouldUndoOfDeleteSelectText() const { return m_type == EditingMacBehavior; }
     86 
     87     // Support for global selections, used on platforms like the X Window
     88     // System that treat selection as a type of clipboard.
     89     bool supportsGlobalSelection() const
     90     {
     91         return m_type != EditingWindowsBehavior && m_type != EditingMacBehavior;
     92     }
     93 
     94     // Convert a KeyboardEvent to a command name like "Copy", "Undo" and so on.
     95     // If nothing, return empty string.
     96     const char* interpretKeyEvent(const KeyboardEvent&) const;
     97 
     98     bool shouldInsertCharacter(const KeyboardEvent&) const;
     99 private:
    100     EditingBehaviorType m_type;
    101 };
    102 
    103 } // namespace WebCore
    104 
    105 #endif // EditingBehavior_h
    106