third_party/WebKit/Source/core/editing/EditingBehavior.h

   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/CoreExport.h"
  25 #include "core/editing/EditingBehaviorTypes.h"
  26 #include "wtf/Allocator.h"
  27
  28 namespace blink {
  29 class KeyboardEvent;
  30
  31 class CORE_EXPORT EditingBehavior {
  32     STACK_ALLOCATED();
  33 public:
  34     explicit EditingBehavior(EditingBehaviorType type)
  35         : m_type(type)
  36     {
  37     }
  38
  39     // Individual functions for each case where we have more than one style of editing behavior.
  40     // Create a new function for any platform difference so we can control it here.
  41
  42     // When extending a selection beyond the top or bottom boundary of an editable area,
  43     // maintain the horizontal position on Windows and Android but extend it to the boundary of
  44     // the editable content on Mac and Linux.
  45     bool shouldMoveCaretToHorizontalBoundaryWhenPastTopOrBottom() const
  46     {
  47         return m_type != EditingWindowsBehavior && m_type != EditingAndroidBehavior;
  48     }
  49
  50     // On Windows, selections should always be considered as directional, regardless if it is
  51     // mouse-based or keyboard-based.
  52     bool shouldConsiderSelectionAsDirectional() const { return m_type != EditingMacBehavior; }
  53
  54     // On Mac, when revealing a selection (for example as a result of a Find operation on the Browser),
  55     // content should be scrolled such that the selection gets certer aligned.
  56     bool shouldCenterAlignWhenSelectionIsRevealed() const { return m_type == EditingMacBehavior; }
  57
  58     // On Mac, style is considered present when present at the beginning of selection. On other platforms,
  59     // style has to be present throughout the selection.
  60     bool shouldToggleStyleBasedOnStartOfSelection() const { return m_type == EditingMacBehavior; }
  61
  62     // Standard Mac behavior when extending to a boundary is grow the selection rather than leaving the base
  63     // in place and moving the extent. Matches NSTextView.
  64     bool shouldAlwaysGrowSelectionWhenExtendingToBoundary() const { return m_type == EditingMacBehavior; }
  65
  66     // On Mac, when processing a contextual click, the object being clicked upon should be selected.
  67     bool shouldSelectOnContextualMenuClick() const { return m_type == EditingMacBehavior; }
  68
  69     // On Mac and Windows, pressing backspace (when it isn't handled otherwise) should navigate back.
  70     bool shouldNavigateBackOnBackspace() const
  71     {
  72         return m_type != EditingUnixBehavior && m_type != EditingAndroidBehavior;
  73     }
  74
  75     // On Mac, selecting backwards by word/line from the middle of a word/line, and then going
  76     // forward leaves the caret back in the middle with no selection, instead of directly selecting
  77     // to the other end of the line/word (Unix/Windows behavior).
  78     bool shouldExtendSelectionByWordOrLineAcrossCaret() const { return m_type != EditingMacBehavior; }
  79
  80     // Based on native behavior, when using ctrl(alt)+arrow to move caret by word, ctrl(alt)+left arrow moves caret to
  81     // immediately before the word in all platforms, for example, the word break positions are: "|abc |def |hij |opq".
  82     // But ctrl+right arrow moves caret to "abc |def |hij |opq" on Windows and "abc| def| hij| opq|" on Mac and Linux.
  83     bool shouldSkipSpaceWhenMovingRight() const { return m_type == EditingWindowsBehavior; }
  84
  85     // On Mac, undo of delete/forward-delete of text should select the deleted text. On other platforms deleted text
  86     // should not be selected and the cursor should be placed where the deletion started.
  87     bool shouldUndoOfDeleteSelectText() const { return m_type == EditingMacBehavior; }
  88
  89     // Support for global selections, used on platforms like the X Window
  90     // System that treat selection as a type of clipboard.
  91     bool supportsGlobalSelection() const
  92     {
  93         return m_type != EditingWindowsBehavior && m_type != EditingMacBehavior;
  94     }
  95
  96     // Convert a KeyboardEvent to a command name like "Copy", "Undo" and so on.
  97     // If nothing, return empty string.
  98     const char* interpretKeyEvent(const KeyboardEvent&) const;
  99
 100     bool shouldInsertCharacter(const KeyboardEvent&) const;
 101 private:
 102     EditingBehaviorType m_type;
 103 };
 104
 105 } // namespace blink
 106
 107 #endif // EditingBehavior_h