[lyx.git] / src / insets / Inset.h

// -*- C++ -*-
/**
 * \file Inset.h
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Alejandro Aguilar Sierra
 * \author Jürgen Vigna
 * \author Lars Gullik Bjønnes
 * \author Matthias Ettrich
 *
 * Full author contact details are available in file CREDITS.
 */

#ifndef INSETBASE_H
#define INSETBASE_H

#include "ColorCode.h"
#include "InsetCode.h"
#include "InsetLayout.h"
#include "LayoutEnums.h"
#include "OutputEnums.h"

#include "support/strfwd.h"
#include "support/types.h"

#include <climits>


namespace lyx {

class BiblioInfo;
class Buffer;
class BufferView;
class Change;
class CompletionList;
class Cursor;
class CursorSlice;
class Dimension;
class DocIterator;
class FuncRequest;
class FuncStatus;
class InsetArgument;
class InsetCollapsable;
class InsetCommand;
class InsetIterator;
class InsetLayout;
class InsetList;
class InsetMath;
class InsetTabular;
class InsetText;
class LaTeXFeatures;
class Lexer;
class MathAtom;
class MetricsInfo;
class OutputParams;
class PainterInfo;
class ParConstIterator;
class ParIterator;
class Text;
class TocBackend;
class TocList;
class XHTMLStream;
class otexstream;

namespace graphics { class PreviewLoader; }


/// returns the InsetCode corresponding to the \c name.
/// Eg, insetCode("branch") == BRANCH_CODE
InsetCode insetCode(std::string const & name);
/// returns the Inset name corresponding to the \c InsetCode.
/// Eg, insetName(BRANCH_CODE) == "branch"
std::string insetName(InsetCode);
/// returns the Inset name corresponding to the \c InsetCode.
/// Eg, insetDisplayName(BRANCH_CODE) == _("Branch")
docstring insetDisplayName(InsetCode);
///
static int const TOC_ENTRY_LENGTH = 120;

/// Common base class to all insets

// Do not add _any_ (non-static) data members as this would inflate
// everything storing large quantities of insets. Mathed e.g. would
// suffer.

class Inset {
public:
        ///
        enum EntryDirection {
                ENTRY_DIRECTION_IGNORE,
                ENTRY_DIRECTION_RIGHT,
                ENTRY_DIRECTION_LEFT
        };
        ///
        typedef ptrdiff_t  difference_type;
        /// short of anything else reasonable
        typedef size_t     size_type;
        /// type for cell indices
        typedef size_t     idx_type;
        /// type for cursor positions
        typedef ptrdiff_t  pos_type;
        /// type for row numbers
        typedef size_t     row_type;
        /// type for column numbers
        typedef size_t     col_type;

        /// virtual base class destructor
        virtual ~Inset() {}

        /// change associated Buffer
        virtual void setBuffer(Buffer & buffer);
        /// reset associated Buffer to null value
        virtual void resetBuffer();
        /// retrieve associated Buffer
        Buffer & buffer();
        Buffer const & buffer() const;
        /// Returns true if buffer_ actually points to a Buffer that has
        /// been loaded into LyX and is still open. Note that this will
        /// always return false for cloned Buffers. If you want to allow
        /// for the case of cloned Buffers, use isBufferValid().
        bool isBufferLoaded() const;
        /// Returns true if this is a loaded buffer or a cloned buffer.
        bool isBufferValid() const;

        /// initialize view for this inset.
        /**
          * This is typically used after this inset is created interactively.
          * Intented purpose is to sanitize internal state with regard to current
          * Buffer. 
          **/
        virtual void initView() {}
        /// \return true if this inset is labeled.
        virtual bool isLabeled() const { return false; }

        /// identification as math inset
        virtual InsetMath * asInsetMath() { return 0; }
        /// identification as math inset
        virtual InsetMath const * asInsetMath() const { return 0; }
        /// true for 'math' math inset, but not for e.g. mbox
        virtual bool inMathed() const { return false; }
        /// is this inset based on the InsetText class?
        virtual InsetText * asInsetText() { return 0; }
        /// is this inset based on the InsetText class?
        virtual InsetText const * asInsetText() const { return 0; }
        /// is this inset based on the InsetCollapsable class?
        virtual InsetCollapsable * asInsetCollapsable() { return 0; }
        /// is this inset based on the InsetCollapsable class?
        virtual InsetCollapsable const * asInsetCollapsable() const { return 0; }
        /// is this inset based on the InsetTabular class?
        virtual InsetTabular * asInsetTabular() { return 0; }
        /// is this inset based on the InsetTabular class?
        virtual InsetTabular const * asInsetTabular() const { return 0; }
        /// is this inset based on the InsetCommand class?
        virtual InsetCommand * asInsetCommand() { return 0; }
        /// is this inset based on the InsetCommand class?
        virtual InsetCommand const * asInsetCommand() const { return 0; }
        /// is this inset based on the InsetArgument class?
        virtual InsetArgument const * asInsetArgument() const { return nullptr; }

        /// the real dispatcher
        void dispatch(Cursor & cur, FuncRequest & cmd);
        /**
         * \returns true if this function made a definitive decision on
         * whether the inset wants to handle the request \p cmd or not.
         * The result of this decision is put into \p status.
         *
         * Every request that is enabled in this method needs to be handled
         * in doDispatch(). Normally we have a 1:1 relationship between the
         * requests handled in getStatus() and doDispatch(), but there are
         * some exceptions:
         * - A request that is disabled in getStatus() does not need to
         *   appear in doDispatch(). It is guaranteed that doDispatch()
         *   is never called with this request.
         * - A few requests are en- or disabled in Inset::getStatus().
         *   These need to be handled in the doDispatch() methods of the
         *   derived insets, since Inset::doDispatch() has not enough
         *   information to handle them.
         * - LFUN_MOUSE_* need not to be handled in getStatus(), because these
         *   are dispatched directly
         */
        virtual bool getStatus(Cursor & cur, FuncRequest const & cmd,
                FuncStatus & status) const;

        /// cursor enters
        virtual void edit(Cursor & cur, bool front, 
                EntryDirection entry_from = ENTRY_DIRECTION_IGNORE);
        /// cursor enters
        /// Note: this method must preserve the selection status. See:
        /// https://www.mail-archive.com/lyx-devel@lists.lyx.org/msg199001.html
        virtual Inset * editXY(Cursor & cur, int x, int y);

        /// compute the size of the object returned in dim
        virtual void metrics(MetricsInfo & mi, Dimension & dim) const = 0;
        /// draw inset and update (xo, yo)-cache
        virtual void draw(PainterInfo & pi, int x, int y) const = 0;
        /// draw inset selection if necessary
        virtual void drawSelection(PainterInfo &, int, int) const {}
        /// draw inset background if the inset has an own background and a
        /// selection is drawn by drawSelection.
        virtual void drawBackground(PainterInfo &, int, int) const;
        ///
        virtual bool editing(BufferView const * bv) const;
        ///
        virtual bool showInsetDialog(BufferView *) const;

        /// draw two angular markers
        void drawMarkers(PainterInfo & pi, int x, int y) const;
        /// draw four angular markers
        void drawMarkers2(PainterInfo & pi, int x, int y) const;
        /// add space for markers
        void metricsMarkers(Dimension & dim, int framesize = 1) const;
        /// add space for markers
        void metricsMarkers2(Dimension & dim, int framesize = 1) const;
        /// draw inset decoration if necessary.
        /// This can use \c drawMarkers() for example.
        virtual void drawDecoration(PainterInfo &, int, int) const {}

        /// last metrics computed for the inset
        Dimension const dimension(BufferView const &) const;
        /// last drawn position for 'important' insets
        int xo(BufferView const & bv) const;
        /// last drawn position for 'important' insets
        int yo(BufferView const & bv) const;
        /// do we cover screen position x/y?
        bool covers(BufferView const & bv, int x, int y) const;
        /// get the screen positions of the cursor (see note in Cursor.cpp)
        virtual void cursorPos(BufferView const & bv,
                CursorSlice const & sl, bool boundary, int & x, int & y) const;

        /// Allow multiple blanks
        virtual bool isFreeSpacing() const;
        /// Don't eliminate empty paragraphs
        virtual bool allowEmpty() const;
        /// Force inset into LTR environment if surroundings are RTL
        virtual bool forceLTR() const;
        /// whether to include this inset in the strings generated for the TOC
        virtual bool isInToc() const;

        /// Where should we go when we press the up or down cursor key?
        virtual bool idxUpDown(Cursor & cur, bool up) const;
        /// Move one cell backwards
        virtual bool idxBackward(Cursor &) const { return false; }
        /// Move one cell forward
        virtual bool idxForward(Cursor &) const { return false; }

        /// Move to the next cell
        virtual bool idxNext(Cursor &) const { return false; }
        /// Move to the previous cell
        virtual bool idxPrev(Cursor &) const { return false; }

        /// Target pos when we enter the inset while moving forward
        virtual bool idxFirst(Cursor &) const { return false; }
        /// Target pos when we enter the inset while moving backwards
        virtual bool idxLast(Cursor &) const { return false; }

        /// Delete a cell and move cursor
        virtual bool idxDelete(idx_type &) { return false; }
        /// pulls cell after pressing erase
        virtual void idxGlue(idx_type) {}
        /// returns list of cell indices that are "between" from and to for
        /// selection purposes
        virtual bool idxBetween(idx_type idx, idx_type from, idx_type to) const;

        /// to which column belongs a cell with a given index?
        virtual col_type col(idx_type) const { return 0; }
        /// to which row belongs a cell with a given index?
        virtual row_type row(idx_type) const { return 0; }
        /// cell index corresponding to row and column;
        virtual idx_type index(row_type row, col_type col) const;
        /// number of embedded cells
        virtual size_t nargs() const { return 0; }
        /// number of rows in gridlike structures
        virtual size_t nrows() const { return 0; }
        /// number of columns in gridlike structures
        virtual size_t ncols() const { return 0; }
        /// Is called when the cursor leaves this inset.
        /// Returns true if cursor is now invalid, e.g. if former 
        /// insets in higher cursor slices of \c old do not exist 
        /// anymore.
        /// \c old is the old cursor, the last slice points to this.
        /// \c cur is the new cursor. Use the update flags to cause a redraw.
        virtual bool notifyCursorLeaves(Cursor const & /*old*/, Cursor & /*cur*/)
                { return false; }
        /// Is called when the cursor enters this inset.
        /// Returns true if cursor is now invalid, e.g. if former 
        /// insets in higher cursor slices of \c old do not exist 
        /// anymore.
        /// \c cur is the new cursor, some slice points to this. Use the update
        /// flags to cause a redraw.
        virtual bool notifyCursorEnters(Cursor & /*cur*/)
                { return false; }
        /// is called when the mouse enters or leaves this inset
        /// return true if this inset needs a repaint
        virtual bool setMouseHover(BufferView const *, bool) const
                { return false; }
        /// return true if this inset is hovered (under mouse)
        /// This is by now only used by mathed to draw corners 
        /// (Inset::drawMarkers() and Inset::drawMarkers2()).
        /// Other insets do not have to redefine this function to 
        /// return the correct status of mouseHovered.
        virtual bool mouseHovered(BufferView const *) const { return false; }

        /// request "external features"
        virtual void validate(LaTeXFeatures &) const {}

        /// Validate LFUN_INSET_MODIFY argument.
        virtual bool validateModifyArgument(docstring const &) const { return true; }

        /// describe content if cursor inside
        virtual void infoize(odocstream &) const {}
        /// describe content if cursor behind
        virtual void infoize2(odocstream &) const {}

        enum { PLAINTEXT_NEWLINE = 10000 };

        /// plain text output in ucs4 encoding
        /// return the number of characters; in case of multiple lines of
        /// output, add PLAINTEXT_NEWLINE to the number of chars in the last line
        virtual int plaintext(odocstringstream &, OutputParams const &,
                              size_t max_length = INT_MAX) const = 0;
        /// docbook output
        virtual int docbook(odocstream & os, OutputParams const &) const;
        /// XHTML output
        /// the inset is expected to write XHTML to the XHTMLStream
        /// \return any "deferred" material that should be written outside the
        /// normal stream, and which will in fact be written after the current
        /// paragraph closes. this is appropriate e.g. for floats.
        virtual docstring xhtml(XHTMLStream & xs, OutputParams const &) const;

        /// Writes a string representation of the inset to the odocstream.
        /// This one should be called when you want the whole contents of
        /// the inset.
        virtual void toString(odocstream &) const {}
        /// Appends a potentially abbreviated version of the inset to
        /// \param str. Intended for use by the TOC.
        virtual void forOutliner(docstring & str,
                                                         size_t const maxlen = TOC_ENTRY_LENGTH,
                                                         bool const shorten = true) const;

        /// can the contents of the inset be edited on screen ?
        // true for InsetCollapsables (not ButtonOnly) (not InsetInfo), InsetText
        virtual bool editable() const;
        /// has the Inset settings that can be modified in a dialog ?
        virtual bool hasSettings() const;
        /// can we go further down on mouse click?
        // true for InsetCaption, InsetCollapsables (not ButtonOnly), InsetTabular
        virtual bool descendable(BufferView const &) const { return false; }
        /// is this an inset that can be moved into?
        /// FIXME: merge with editable()
        // true for InsetTabular & InsetText
        virtual bool isActive() const { return nargs() > 0; }
        /// can we click at the specified position ?
        virtual bool clickable(BufferView const &, int, int) const { return false; }
        /// Move one cell backwards
        virtual bool allowsCaptionVariation(std::string const &) const { return false; }
        // true for insets that have a table structure (InsetMathGrid, InsetTabular)
        virtual bool isTable() const { return false; }

        /// does this contain text that can be change track marked in DVI?
        virtual bool canTrackChanges() const { return false; }
        /// Will this inset paint its own change tracking status (in the parent
        /// paragraph) or will it let RowPainter handle it?
        virtual bool canPaintChange(BufferView const &) const { return false; }
        /// return true if the inset should be removed automatically
        virtual bool autoDelete() const;

        /// Returns true if the inset supports completions.
        virtual bool completionSupported(Cursor const &) const { return false; }
        /// Returns true if the inset supports inline completions at the
        /// cursor position. In this case the completion might be stored
        /// in the BufferView's inlineCompletion property.
        virtual bool inlineCompletionSupported(Cursor const & /*cur*/) const 
                { return false; }
        /// Return true if the inline completion should be automatic.
        virtual bool automaticInlineCompletion() const { return true; }
        /// Return true if the popup completion should be automatic.
        virtual bool automaticPopupCompletion() const { return true; }
        /// Return true if the cursor should indicate a completion.
        virtual bool showCompletionCursor() const { return true; }
        /// Returns completion suggestions at cursor position. Return an
        /// null pointer if no completion is a available or possible.
        /// The caller is responsible to free the returned object!
        virtual CompletionList const * createCompletionList(Cursor const &) const 
                { return 0; }
        /// Returns the completion prefix to filter the suggestions for completion.
        /// This is only called if completionList returned a non-null list.
        virtual docstring completionPrefix(Cursor const &) const;
        /// Do a completion at the cursor position. Return true on success.
        /// The completion does not contain the prefix. If finished is true, the
        /// completion is final. If finished is false, completion might only be
        /// a partial completion.
        virtual bool insertCompletion(Cursor & /*cur*/, 
                docstring const & /*completion*/, bool /*finished*/) 
                { return false; }
        /// Get the completion inset position and size
        virtual void completionPosAndDim(Cursor const &, int & /*x*/, int & /*y*/, 
                Dimension & /*dim*/) const {}

        /// returns true if the inset can hold an inset of given type
        virtual bool insetAllowed(InsetCode) const { return false; }
        /// should this inset use the empty layout by default rather than 
        /// the standard layout? (default: only if that is forced.)
        virtual bool usePlainLayout() const { return forcePlainLayout(); }
        /// if this inset has paragraphs should they be forced to use the
        /// empty layout?
        virtual bool forcePlainLayout(idx_type = 0) const { return false; }
        /// if this inset has paragraphs should the user be allowed to
        /// customize alignment, etc?
        virtual bool allowParagraphCustomization(idx_type = 0) const
                { return true; }
        /// Is the width forced to some value?
        virtual bool hasFixedWidth() const { return false; }
        /// if this inset has paragraphs should they be forced to use a
        /// local font language switch?
        virtual bool forceLocalFontSwitch() const { return false; }

        /// Is the content of this inset part of the output document?
        virtual bool producesOutput() const { return true; }
        /// Is the content of this inset part of the immediate (visible) text sequence?
        virtual bool isPartOfTextSequence() const { return producesOutput(); }

        /// \return Tool tip for this inset.
        /// This default implementation returns an empty string. This can be
        /// either plain text or Qt html, and formatToolTip will be called
        /// on it before display in both cases.
        virtual docstring toolTip(BufferView const & bv, int x, int y) const;
        
        /// \return Context menu identifier. This function determines
        /// whose Inset's menu should be shown for the given position.
        virtual std::string contextMenu(BufferView const & bv, int x, int y) const;

        /// \return Context menu identifier for this inset.
        /// This default implementation returns an empty string.
        virtual std::string contextMenuName() const;


        virtual docstring layoutName() const;
        ///
        virtual InsetLayout const & getLayout() const;
        ///
        virtual bool isPassThru() const { return getLayout().isPassThru(); }
        /// Is this inset's layout defined in the document's textclass?
        bool undefined() const;
        /// should this inset be handled like a normal character?
        /// (a character can be a letter or punctuation)
        virtual bool isChar() const { return false; }
        /// is this equivalent to a letter?
        /// (a letter is a character that is considered part of a word)
        virtual bool isLetter() const { return false; }
        /// is this equivalent to a space (which is BTW different from
        /// a line separator)?
        virtual bool isSpace() const { return false; }
        /// does this inset try to use all available space (like \\hfill does)?
        virtual bool isHfill() const { return false; }

        enum DisplayType {
                Inline = 0,
                AlignLeft,
                AlignCenter,
                AlignRight
        };

        /// should we have a non-filled line before this inset?
        virtual DisplayType display() const { return Inline; }
        /// indentation before this inset (only needed for displayed hull insets with fleqn option)
        virtual int indent(BufferView const &) const { return 0; }
        ///
        virtual LyXAlignment contentAlignment() const { return LYX_ALIGN_NONE; }
        /// should we break lines after this inset?
        virtual bool isLineSeparator() const { return false; }
        /// should paragraph indendation be ommitted in any case?
        virtual bool neverIndent() const { return false; }
        /// dumps content to lyxerr
        virtual void dump() const;
        /// write inset in .lyx format
        virtual void write(std::ostream &) const {}
        /// read inset in .lyx format
        virtual void read(Lexer &) {}
        /** Export the inset to LaTeX.
         *  Don't use a temporary stringstream if the final output is
         *  supposed to go to a file.
         *  \sa Buffer::writeLaTeXSource for the reason.
         */
        virtual void latex(otexstream &, OutputParams const &) const {}
        /// returns true to override begin and end inset in file
        virtual bool directWrite() const;
        ///
        virtual bool allowSpellCheck() const { return false; }

        /// if this insets owns text cells (e.g. InsetText) return cell num
        virtual Text * getText(int /*num*/) const { return 0; }

        /** Adds a LaTeX snippet to the Preview Loader for transformation
         *  into a bitmap image. Does not start the laoding process.
         *
         *  Most insets have no interest in this capability, so the method
         *  defaults to empty.
         */
        virtual void addPreview(DocIterator const &,
                graphics::PreviewLoader &) const {}

        /** Classifies the unicode characters appearing in a math inset
         *  depending on whether they are to be translated as latex
         *  math/text commands or used as math symbols without translation.
         *
         *  Only math insets have interest in this classification, so the
         *  method defaults to empty.
         */
        virtual void initUnicodeMath() const {}

        /// Add an entry to the TocList
        /// Pass a DocIterator that points at the paragraph containing
        /// the inset
        ///
        /// \param output_active : is the inset active or is it in an inactive
        /// branch or a note?
        ///
        /// \param utype : is the toc being generated for use by the output
        /// routines?
        ///
        /// \param tocbackend : where to add the toc information.
        virtual void addToToc(DocIterator const & /* di */,
                                                  bool /* output_active */,
                              UpdateType /* utype*/,
                              TocBackend & /* tocbackend */) const {}
        /// Collect BibTeX information
        virtual void collectBibKeys(InsetIterator const &) const {}
        /// Update the counters of this inset and of its contents.
        /// The boolean indicates whether we are preparing for output, e.g.,
        /// of XHTML.
        virtual void updateBuffer(ParIterator const &, UpdateType) {}

        /// Updates the inset's dialog
        virtual Buffer const * updateFrontend() const;

public:
        /// returns LyX code associated with the inset. Used for TOC, ...)
        virtual InsetCode lyxCode() const { return NO_CODE; }

        ///
        enum mode_type {UNDECIDED_MODE, TEXT_MODE, MATH_MODE};
        /// return text or mathmode if that is possible to determine
        virtual mode_type currentMode() const { return UNDECIDED_MODE; }
        /// returns whether changing mode during latex export is forbidden
        virtual bool lockedMode() const { return false; }
        /// returns whether only ascii chars are allowed during latex export
        virtual bool asciiOnly() const { return false; }
        /// returns whether this inset is allowed in other insets of given mode
        virtual bool allowedIn(mode_type) const { return true; }
        /**
         * The font is inherited from the parent for LaTeX export if this
         * method returns true. No open font changes are closed in front of
         * the inset for LaTeX export, and the font is inherited for all other
         * exports as well as on screen.
         * If this method returns false all open font changes are closed in
         * front of the inset for LaTeX export. The default font is used
         * inside the inset for all exports and on screen.
         */
        virtual bool inheritFont() const { return true; }
        /**
         * If this method returns true all explicitly set font attributes
         * are reset during editing operations.
         * For copy/paste operations the language is never changed, since
         * the language of a given text never changes if the text is
         * formatted differently, while other font attribues like size may
         * need to change if the text is copied from one environment to
         * another one.
         * If this method returns false no font attribute is reset.
         * The default implementation returns true if the resetFont layout
         * tag is set and otherwise the negation of inheritFont(),
         * since inherited inset font attributes do not need to be changed,
         * and non-inherited ones need to be set explicitly.
         */
        virtual bool resetFontEdit() const;

        /// set the change for the entire inset
        virtual void setChange(Change const &) {}
        /// accept the changes within the inset
        virtual void acceptChanges() {}
        /// reject the changes within the inset
        virtual void rejectChanges() {}

        ///
        virtual ColorCode backgroundColor(PainterInfo const &) const;
        ///
        virtual ColorCode labelColor() const;
        //
        enum { TEXT_TO_INSET_OFFSET = 4 };

        /// Determine the action of backspace and delete: do we select instead of
        /// deleting if not already selected?
        virtual bool confirmDeletion() const { return false; }

protected:
        /// Constructors
        Inset(Buffer * buf) : buffer_(buf) {}
        Inset(Inset const &) : buffer_(0) {}

        /// replicate ourselves
        friend class InsetList;
        friend class MathAtom;
        virtual Inset * clone() const = 0;

        /** The real dispatcher.
         *  Gets normally called from Cursor::dispatch(). Cursor::dispatch()
         *  assumes the common case of 'LFUN handled, need update'.
         *  This has to be overriden by calling Cursor::undispatched() or
         *  Cursor::noScreenUpdate() if appropriate.
         *  If you need to call the dispatch method of some inset directly
         *  you may have to explicitly request an update at that place. Don't
         *  do it in doDispatch(), since that causes nested updates when
         *  called from Cursor::dispatch(), and these can lead to crashes.
         *  \sa getStatus
         */
        virtual void doDispatch(Cursor & cur, FuncRequest & cmd);

        Buffer * buffer_;
};

} // namespace lyx

#endif