gecko-dev/dom/events/ContentEventHandler.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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_ContentEventHandler_h_
#define mozilla_ContentEventHandler_h_
#include "mozilla/EventForwards.h"
#include "mozilla/dom/Selection.h"
#include "nsCOMPtr.h"
#include "nsIFrame.h"
#include "nsINode.h"
#include "nsISelectionController.h"
#include "nsRange.h"
class nsPresContext;
struct nsRect;
namespace mozilla {
enum LineBreakType
{
LINE_BREAK_TYPE_NATIVE,
LINE_BREAK_TYPE_XP
};
/*
* Query Content Event Handler
* ContentEventHandler is a helper class for EventStateManager.
* The platforms request some content informations, e.g., the selected text,
* the offset of the selected text and the text for specified range.
* This class answers to NS_QUERY_* events from actual contents.
*/
class MOZ_STACK_CLASS ContentEventHandler
{
public:
typedef dom::Selection Selection;
explicit ContentEventHandler(nsPresContext* aPresContext);
// Handle aEvent in the current process.
nsresult HandleQueryContentEvent(WidgetQueryContentEvent* aEvent);
// eQuerySelectedText event handler
nsresult OnQuerySelectedText(WidgetQueryContentEvent* aEvent);
// eQueryTextContent event handler
nsresult OnQueryTextContent(WidgetQueryContentEvent* aEvent);
// eQueryCaretRect event handler
nsresult OnQueryCaretRect(WidgetQueryContentEvent* aEvent);
// eQueryTextRect event handler
nsresult OnQueryTextRect(WidgetQueryContentEvent* aEvent);
// eQueryTextRectArray event handler
nsresult OnQueryTextRectArray(WidgetQueryContentEvent* aEvent);
// eQueryEditorRect event handler
nsresult OnQueryEditorRect(WidgetQueryContentEvent* aEvent);
// eQueryContentState event handler
nsresult OnQueryContentState(WidgetQueryContentEvent* aEvent);
// eQuerySelectionAsTransferable event handler
nsresult OnQuerySelectionAsTransferable(WidgetQueryContentEvent* aEvent);
// eQueryCharacterAtPoint event handler
nsresult OnQueryCharacterAtPoint(WidgetQueryContentEvent* aEvent);
// eQueryDOMWidgetHittest event handler
nsresult OnQueryDOMWidgetHittest(WidgetQueryContentEvent* aEvent);
// NS_SELECTION_* event
nsresult OnSelectionEvent(WidgetSelectionEvent* aEvent);
protected:
nsPresContext* mPresContext;
nsCOMPtr<nsIPresShell> mPresShell;
// mSelection is typically normal selection but if OnQuerySelectedText()
// is called, i.e., handling eQuerySelectedText, it's the specified selection
// by WidgetQueryContentEvent::mInput::mSelectionType.
RefPtr<Selection> mSelection;
// mFirstSelectedRange is the first selected range of mSelection. If
// mSelection is normal selection, this must not be nullptr if Init()
// succeed. Otherwise, this may be nullptr if there are no selection
// ranges.
RefPtr<nsRange> mFirstSelectedRange;
nsCOMPtr<nsIContent> mRootContent;
nsresult Init(WidgetQueryContentEvent* aEvent);
nsresult Init(WidgetSelectionEvent* aEvent);
nsresult InitBasic();
nsresult InitCommon(SelectionType aSelectionType = SelectionType::eNormal);
/**
* InitRootContent() computes the root content of current focused editor.
*
* @param aNormalSelection This must be a Selection instance whose type is
* SelectionType::eNormal.
*/
nsresult InitRootContent(Selection* aNormalSelection);
public:
// FlatText means the text that is generated from DOM tree. The BR elements
// are replaced to native linefeeds. Other elements are ignored.
// NodePosition stores a pair of node and offset in the node.
// When mNode is an element and mOffset is 0, the start position means after
// the open tag of mNode.
// This is useful to receive one or more sets of them instead of nsRange.
struct NodePosition
{
nsCOMPtr<nsINode> mNode;
int32_t mOffset;
// Only when mNode is an element node and mOffset is 0, mAfterOpenTag is
// referred.
bool mAfterOpenTag;
NodePosition()
: mOffset(-1)
, mAfterOpenTag(true)
{
}
NodePosition(nsINode* aNode, int32_t aOffset)
: mNode(aNode)
, mOffset(aOffset)
, mAfterOpenTag(true)
{
}
explicit NodePosition(const nsIFrame::ContentOffsets& aContentOffsets)
: mNode(aContentOffsets.content)
, mOffset(aContentOffsets.offset)
, mAfterOpenTag(true)
{
}
protected:
NodePosition(nsINode* aNode, int32_t aOffset, bool aAfterOpenTag)
: mNode(aNode)
, mOffset(aOffset)
, mAfterOpenTag(aAfterOpenTag)
{
}
public:
bool operator==(const NodePosition& aOther) const
{
return mNode == aOther.mNode &&
mOffset == aOther.mOffset &&
mAfterOpenTag == aOther.mAfterOpenTag;
}
bool IsValid() const
{
return mNode && mOffset >= 0;
}
bool OffsetIsValid() const
{
return IsValid() && static_cast<uint32_t>(mOffset) <= mNode->Length();
}
bool IsBeforeOpenTag() const
{
return IsValid() && mNode->IsElement() && !mOffset && !mAfterOpenTag;
}
bool IsImmediatelyAfterOpenTag() const
{
return IsValid() && mNode->IsElement() && !mOffset && mAfterOpenTag;
}
nsresult SetToRangeStart(nsRange* aRange) const
{
nsCOMPtr<nsIDOMNode> domNode(do_QueryInterface(mNode));
return aRange->SetStart(domNode, mOffset);
}
nsresult SetToRangeEnd(nsRange* aRange) const
{
nsCOMPtr<nsIDOMNode> domNode(do_QueryInterface(mNode));
return aRange->SetEnd(domNode, mOffset);
}
nsresult SetToRangeEndAfter(nsRange* aRange) const
{
nsCOMPtr<nsIDOMNode> domNode(do_QueryInterface(mNode));
return aRange->SetEndAfter(domNode);
}
};
// NodePositionBefore isn't good name if mNode isn't an element node nor
// mOffset is not 0, though, when mNode is an element node and mOffset is 0,
// this is treated as before the open tag of mNode.
struct NodePositionBefore final : public NodePosition
{
NodePositionBefore(nsINode* aNode, int32_t aOffset)
: NodePosition(aNode, aOffset, false)
{
}
};
// Get the flatten text length in the range.
// @param aStartPosition Start node and offset in the node of the range.
// @param aEndPosition End node and offset in the node of the range.
// @param aRootContent The root content of the editor or document.
// aRootContent won't cause any text including
// line breaks.
// @param aLength The result of the flatten text length of the
// range.
// @param aLineBreakType Whether this computes flatten text length with
// native line breakers on the platform or
// with XP line breaker (\n).
// @param aIsRemovingNode Should be true only when this is called from
// nsIMutationObserver::ContentRemoved().
// When this is true, aStartPosition.mNode should
// be the root node of removing nodes and mOffset
// should be 0 and aEndPosition.mNode should be
// same as aStartPosition.mNode and mOffset should
// be number of the children of mNode.
static nsresult GetFlatTextLengthInRange(const NodePosition& aStartPosition,
const NodePosition& aEndPosition,
nsIContent* aRootContent,
uint32_t* aLength,
LineBreakType aLineBreakType,
bool aIsRemovingNode = false);
// Computes the native text length between aStartOffset and aEndOffset of
// aContent. aContent must be a text node.
static uint32_t GetNativeTextLength(nsIContent* aContent,
uint32_t aStartOffset,
uint32_t aEndOffset);
// Get the native text length of aContent. aContent must be a text node.
static uint32_t GetNativeTextLength(nsIContent* aContent,
uint32_t aMaxLength = UINT32_MAX);
// Get the native text length which is inserted before aContent.
// aContent should be an element.
static uint32_t GetNativeTextLengthBefore(nsIContent* aContent,
nsINode* aRootNode);
protected:
// Get the text length of aContent. aContent must be a text node.
static uint32_t GetTextLength(nsIContent* aContent,
LineBreakType aLineBreakType,
uint32_t aMaxLength = UINT32_MAX);
// Get the text length of a given range of a content node in
// the given line break type.
static uint32_t GetTextLengthInRange(nsIContent* aContent,
uint32_t aXPStartOffset,
uint32_t aXPEndOffset,
LineBreakType aLineBreakType);
// Get the contents in aContent (meaning all children of aContent) as plain
// text. E.g., specifying mRootContent gets whole text in it.
// Note that the result is not same as .textContent. The result is
// optimized for native IMEs. For example, <br> element and some block
// elements causes "\n" (or "\r\n"), see also ShouldBreakLineBefore().
nsresult GenerateFlatTextContent(nsIContent* aContent,
nsAFlatString& aString,
LineBreakType aLineBreakType);
// Get the contents of aRange as plain text.
nsresult GenerateFlatTextContent(nsRange* aRange,
nsAFlatString& aString,
LineBreakType aLineBreakType);
// Get offset of start of aRange. Note that the result includes the length
// of line breaker caused by the start of aContent because aRange never
// includes the line breaker caused by its start node.
nsresult GetStartOffset(nsRange* aRange,
uint32_t* aOffset,
LineBreakType aLineBreakType);
// Check if we should insert a line break before aContent.
// This should return false only when aContent is an html element which
// is typically used in a paragraph like <em>.
static bool ShouldBreakLineBefore(nsIContent* aContent,
nsINode* aRootNode);
// Get the line breaker length.
static inline uint32_t GetBRLength(LineBreakType aLineBreakType);
static LineBreakType GetLineBreakType(WidgetQueryContentEvent* aEvent);
static LineBreakType GetLineBreakType(WidgetSelectionEvent* aEvent);
static LineBreakType GetLineBreakType(bool aUseNativeLineBreak);
// Returns focused content (including its descendant documents).
nsIContent* GetFocusedContent();
// Returns true if the content is a plugin host.
bool IsPlugin(nsIContent* aContent);
// QueryContentRect() sets the rect of aContent's frame(s) to aEvent.
nsresult QueryContentRect(nsIContent* aContent,
WidgetQueryContentEvent* aEvent);
// Make the DOM range from the offset of FlatText and the text length.
// If aExpandToClusterBoundaries is true, the start offset and the end one are
// expanded to nearest cluster boundaries.
nsresult SetRangeFromFlatTextOffset(nsRange* aRange,
uint32_t aOffset,
uint32_t aLength,
LineBreakType aLineBreakType,
bool aExpandToClusterBoundaries,
uint32_t* aNewOffset = nullptr,
nsIContent** aLastTextNode = nullptr);
// If the aRange isn't in text node but next to a text node, this method
// modifies it in the text node. Otherwise, not modified.
nsresult AdjustCollapsedRangeMaybeIntoTextNode(nsRange* aCollapsedRange);
// Find the first frame for the range and get the start offset in it.
nsresult GetStartFrameAndOffset(const nsRange* aRange,
nsIFrame*& aFrame,
int32_t& aOffsetInFrame);
// Convert the frame relative offset to be relative to the root frame of the
// root presContext (but still measured in appUnits of aFrame's presContext).
nsresult ConvertToRootRelativeOffset(nsIFrame* aFrame,
nsRect& aRect);
// Expand aXPOffset to the nearest offset in cluster boundary. aForward is
// true, it is expanded to forward.
nsresult ExpandToClusterBoundary(nsIContent* aContent, bool aForward,
uint32_t* aXPOffset);
typedef nsTArray<mozilla::FontRange> FontRangeArray;
static void AppendFontRanges(FontRangeArray& aFontRanges,
nsIContent* aContent,
int32_t aBaseOffset,
int32_t aXPStartOffset,
int32_t aXPEndOffset,
LineBreakType aLineBreakType);
nsresult GenerateFlatFontRanges(nsRange* aRange,
FontRangeArray& aFontRanges,
uint32_t& aLength,
LineBreakType aLineBreakType);
nsresult QueryTextRectByRange(nsRange* aRange,
LayoutDeviceIntRect& aRect,
WritingMode& aWritingMode);
// Returns a node and position in the node for computing text rect.
NodePosition GetNodePositionHavingFlatText(const NodePosition& aNodePosition);
NodePosition GetNodePositionHavingFlatText(nsINode* aNode,
int32_t aNodeOffset);
struct MOZ_STACK_CLASS FrameAndNodeOffset final
{
// mFrame is safe since this can live in only stack class and
// ContentEventHandler doesn't modify layout after
// ContentEventHandler::Init() flushes pending layout. In other words,
// this struct shouldn't be used before calling
// ContentEventHandler::Init().
nsIFrame* mFrame;
// offset in the node of mFrame
int32_t mOffsetInNode;
FrameAndNodeOffset()
: mFrame(nullptr)
, mOffsetInNode(-1)
{
}
FrameAndNodeOffset(nsIFrame* aFrame, int32_t aStartOffsetInNode)
: mFrame(aFrame)
, mOffsetInNode(aStartOffsetInNode)
{
}
nsIFrame* operator->() { return mFrame; }
const nsIFrame* operator->() const { return mFrame; }
operator nsIFrame*() { return mFrame; }
operator const nsIFrame*() const { return mFrame; }
bool IsValid() const { return mFrame && mOffsetInNode >= 0; }
};
// Get first frame after the start of the given range for computing text rect.
// This returns invalid FrameAndNodeOffset if there is no content which
// should affect to computing text rect in the range. mOffsetInNode is start
// offset in the frame.
FrameAndNodeOffset GetFirstFrameInRangeForTextRect(nsRange* aRange);
// Get last frame before the end of the given range for computing text rect.
// This returns invalid FrameAndNodeOffset if there is no content which
// should affect to computing text rect in the range. mOffsetInNode is end
// offset in the frame.
FrameAndNodeOffset GetLastFrameInRangeForTextRect(nsRange* aRange);
struct MOZ_STACK_CLASS FrameRelativeRect final
{
// mRect is relative to the mBaseFrame's position.
nsRect mRect;
nsIFrame* mBaseFrame;
FrameRelativeRect()
: mBaseFrame(nullptr)
{
}
explicit FrameRelativeRect(nsIFrame* aBaseFrame)
: mBaseFrame(aBaseFrame)
{
}
FrameRelativeRect(const nsRect& aRect, nsIFrame* aBaseFrame)
: mRect(aRect)
, mBaseFrame(aBaseFrame)
{
}
bool IsValid() const { return mBaseFrame != nullptr; }
// Returns an nsRect relative to aBaseFrame instead of mBaseFrame.
nsRect RectRelativeTo(nsIFrame* aBaseFrame) const;
};
// Returns a rect for line breaker before the node of aFrame (If aFrame is
// a <br> frame or a block level frame, it causes a line break at its
// element's open tag, see also ShouldBreakLineBefore()). Note that this
// doesn't check if aFrame should cause line break in non-debug build.
FrameRelativeRect GetLineBreakerRectBefore(nsIFrame* aFrame);
// Returns a line breaker rect after aTextContent as there is a line breaker
// immediately after aTextContent. This is useful when following block
// element causes a line break before it and it needs to compute the line
// breaker's rect. For example, if there is |<p>abc</p><p>def</p>|, the
// rect of 2nd <p>'s line breaker should be at right of "c" in the first
// <p>, not the start of 2nd <p>. The result is relative to the last text
// frame which represents the last character of aTextContent.
FrameRelativeRect GuessLineBreakerRectAfter(nsIContent* aTextContent);
// Returns a guessed first rect. I.e., it may be different from actual
// caret when selection is collapsed at start of aFrame. For example, this
// guess the caret rect only with the content box of aFrame and its font
// height like:
// +-aFrame----------------- (border box)
// |
// | +--------------------- (content box)
// | | I
// ^ guessed caret rect
// However, actual caret is computed with more information like line-height,
// child frames of aFrame etc. But this does not emulate actual caret
// behavior exactly for simpler and faster code because it's difficult and
// we're not sure it's worthwhile to do it with complicated implementation.
FrameRelativeRect GuessFirstCaretRectIn(nsIFrame* aFrame);
// Make aRect non-empty. If width and/or height is 0, these methods set them
// to 1. Note that it doesn't set nsRect's width nor height to one device
// pixel because using nsRect::ToOutsidePixels() makes actual width or height
// to 2 pixels because x and y may not be aligned to device pixels.
void EnsureNonEmptyRect(nsRect& aRect) const;
void EnsureNonEmptyRect(LayoutDeviceIntRect& aRect) const;
};
} // namespace mozilla
#endif // mozilla_ContentEventHandler_h_