dom/events/ContentEventHandler.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_ContentEventHandler_h_
   7 #define mozilla_ContentEventHandler_h_
   8
   9 #include "mozilla/EventForwards.h"
  10 #include "nsCOMPtr.h"
  11 #include "nsISelection.h"
  12 #include "nsRange.h"
  13
  14 class nsPresContext;
  15
  16 struct nsRect;
  17
  18 namespace mozilla {
  19
  20 enum LineBreakType
  21 {
  22   LINE_BREAK_TYPE_NATIVE,
  23   LINE_BREAK_TYPE_XP
  24 };
  25
  26 /*
  27  * Query Content Event Handler
  28  *   ContentEventHandler is a helper class for EventStateManager.
  29  *   The platforms request some content informations, e.g., the selected text,
  30  *   the offset of the selected text and the text for specified range.
  31  *   This class answers to NS_QUERY_* events from actual contents.
  32  */
  33
  34 class MOZ_STACK_CLASS ContentEventHandler
  35 {
  36 public:
  37   ContentEventHandler(nsPresContext* aPresContext);
  38
  39   // NS_QUERY_SELECTED_TEXT event handler
  40   nsresult OnQuerySelectedText(WidgetQueryContentEvent* aEvent);
  41   // NS_QUERY_TEXT_CONTENT event handler
  42   nsresult OnQueryTextContent(WidgetQueryContentEvent* aEvent);
  43   // NS_QUERY_CARET_RECT event handler
  44   nsresult OnQueryCaretRect(WidgetQueryContentEvent* aEvent);
  45   // NS_QUERY_TEXT_RECT event handler
  46   nsresult OnQueryTextRect(WidgetQueryContentEvent* aEvent);
  47   // NS_QUERY_EDITOR_RECT event handler
  48   nsresult OnQueryEditorRect(WidgetQueryContentEvent* aEvent);
  49   // NS_QUERY_CONTENT_STATE event handler
  50   nsresult OnQueryContentState(WidgetQueryContentEvent* aEvent);
  51   // NS_QUERY_SELECTION_AS_TRANSFERABLE event handler
  52   nsresult OnQuerySelectionAsTransferable(WidgetQueryContentEvent* aEvent);
  53   // NS_QUERY_CHARACTER_AT_POINT event handler
  54   nsresult OnQueryCharacterAtPoint(WidgetQueryContentEvent* aEvent);
  55   // NS_QUERY_DOM_WIDGET_HITTEST event handler
  56   nsresult OnQueryDOMWidgetHittest(WidgetQueryContentEvent* aEvent);
  57
  58   // NS_SELECTION_* event
  59   nsresult OnSelectionEvent(WidgetSelectionEvent* aEvent);
  60
  61 protected:
  62   nsPresContext* mPresContext;
  63   nsCOMPtr<nsIPresShell> mPresShell;
  64   nsCOMPtr<nsISelection> mSelection;
  65   nsRefPtr<nsRange> mFirstSelectedRange;
  66   nsCOMPtr<nsIContent> mRootContent;
  67
  68   nsresult Init(WidgetQueryContentEvent* aEvent);
  69   nsresult Init(WidgetSelectionEvent* aEvent);
  70
  71   nsresult InitBasic();
  72   nsresult InitCommon();
  73
  74 public:
  75   // FlatText means the text that is generated from DOM tree. The BR elements
  76   // are replaced to native linefeeds. Other elements are ignored.
  77
  78   // Get the offset in FlatText of the range. (also used by IMEContentObserver)
  79   static nsresult GetFlatTextOffsetOfRange(nsIContent* aRootContent,
  80                                            nsINode* aNode,
  81                                            int32_t aNodeOffset,
  82                                            uint32_t* aOffset,
  83                                            LineBreakType aLineBreakType);
  84   static nsresult GetFlatTextOffsetOfRange(nsIContent* aRootContent,
  85                                            nsRange* aRange,
  86                                            uint32_t* aOffset,
  87                                            LineBreakType aLineBreakType);
  88   // Computes the native text length between aStartOffset and aEndOffset of
  89   // aContent.  Currently, this method supports only text node or br element
  90   // for aContent.
  91   static uint32_t GetNativeTextLength(nsIContent* aContent,
  92                                       uint32_t aStartOffset,
  93                                       uint32_t aEndOffset);
  94   // Get the native text length of a content node excluding any children
  95   static uint32_t GetNativeTextLength(nsIContent* aContent,
  96                                       uint32_t aMaxLength = UINT32_MAX);
  97 protected:
  98   static uint32_t GetTextLength(nsIContent* aContent,
  99                                 LineBreakType aLineBreakType,
 100                                 uint32_t aMaxLength = UINT32_MAX);
 101   static LineBreakType GetLineBreakType(WidgetQueryContentEvent* aEvent);
 102   static LineBreakType GetLineBreakType(WidgetSelectionEvent* aEvent);
 103   static LineBreakType GetLineBreakType(bool aUseNativeLineBreak);
 104   // Returns focused content (including its descendant documents).
 105   nsIContent* GetFocusedContent();
 106   // Returns true if the content is a plugin host.
 107   bool IsPlugin(nsIContent* aContent);
 108   // QueryContentRect() sets the rect of aContent's frame(s) to aEvent.
 109   nsresult QueryContentRect(nsIContent* aContent,
 110                             WidgetQueryContentEvent* aEvent);
 111   // Make the DOM range from the offset of FlatText and the text length.
 112   // If aExpandToClusterBoundaries is true, the start offset and the end one are
 113   // expanded to nearest cluster boundaries.
 114   nsresult SetRangeFromFlatTextOffset(nsRange* aRange,
 115                                       uint32_t aOffset,
 116                                       uint32_t aLength,
 117                                       LineBreakType aLineBreakType,
 118                                       bool aExpandToClusterBoundaries,
 119                                       uint32_t* aNewOffset = nullptr);
 120   // Find the first textframe for the range, and get the start offset in
 121   // the frame.
 122   nsresult GetStartFrameAndOffset(nsRange* aRange,
 123                                   nsIFrame** aFrame,
 124                                   int32_t* aOffsetInFrame);
 125   // Convert the frame relative offset to the root view relative offset.
 126   nsresult ConvertToRootViewRelativeOffset(nsIFrame* aFrame,
 127                                            nsRect& aRect);
 128   // Expand aXPOffset to the nearest offset in cluster boundary. aForward is
 129   // true, it is expanded to forward.
 130   nsresult ExpandToClusterBoundary(nsIContent* aContent, bool aForward,
 131                                    uint32_t* aXPOffset);
 132 };
 133
 134 } // namespace mozilla
 135
 136 #endif // mozilla_ContentEventHandler_h_