office-gobmx/include/vcl/vcllayout.hxx
Miklos Vajna c5dc042219 vcl: use SalLayoutGlyphs, not SalLayout for pre-computed layout
This means that the pre-computed glyph ids and positions are usable with
multiple dx array or draw base.

So the amount of cached data is smaller, but it can be used in more
situations, most importantly Writer's SwFntObj::DrawText() use-case
(which does GetTextArray() followed by a DrawTextArray(), with different
dx array arguments).

Change-Id: I3bcd1b7a015c2cf9921efa0f3f355f2c627fb652
Reviewed-on: https://gerrit.libreoffice.org/59207
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins
2018-08-16 23:39:04 +02:00

185 lines
7 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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#ifndef INCLUDED_VCL_VCLLAYOUT_HXX
#define INCLUDED_VCL_VCLLAYOUT_HXX
#include <memory>
#include <vector>
#include <basegfx/polygon/b2dpolypolygon.hxx>
#include <tools/gen.hxx>
#include <vcl/devicecoordinate.hxx>
#include <vcl/dllapi.h>
class ImplLayoutArgs;
class PhysicalFontFace;
class SalGraphics;
namespace vcl
{
class TextLayoutCache;
}
typedef sal_uInt16 sal_GlyphId;
struct VCL_DLLPUBLIC GlyphItem
{
int mnFlags;
int mnCharPos; // index in string
int mnCharCount; // number of characters making up this glyph
int mnOrigWidth; // original glyph width
int mnNewWidth; // width after adjustments
int mnXOffset;
sal_GlyphId maGlyphId;
Point maLinearPos; // absolute position of non rotated string
int mnFallbackLevel;
public:
GlyphItem(int nCharPos, int nCharCount, sal_GlyphId aGlyphId, const Point& rLinearPos,
long nFlags, int nOrigWidth, int nXOffset )
: mnFlags(nFlags)
, mnCharPos(nCharPos)
, mnCharCount(nCharCount)
, mnOrigWidth(nOrigWidth)
, mnNewWidth(nOrigWidth)
, mnXOffset(nXOffset)
, maGlyphId(aGlyphId)
, maLinearPos(rLinearPos)
, mnFallbackLevel(0)
{ }
enum {
IS_IN_CLUSTER = 0x001,
IS_RTL_GLYPH = 0x002,
IS_DIACRITIC = 0x004,
IS_VERTICAL = 0x008,
IS_SPACING = 0x010,
ALLOW_KASHIDA = 0x020,
IS_DROPPED = 0x040,
IS_CLUSTER_START = 0x080
};
bool IsInCluster() const { return ((mnFlags & IS_IN_CLUSTER) != 0); }
bool IsRTLGlyph() const { return ((mnFlags & IS_RTL_GLYPH) != 0); }
bool IsDiacritic() const { return ((mnFlags & IS_DIACRITIC) != 0); }
bool IsVertical() const { return ((mnFlags & IS_VERTICAL) != 0); }
bool IsSpacing() const { return ((mnFlags & IS_SPACING) != 0); }
bool AllowKashida() const { return ((mnFlags & ALLOW_KASHIDA) != 0); }
bool IsDropped() const { return ((mnFlags & IS_DROPPED) != 0); }
bool IsClusterStart() const { return ((mnFlags & IS_CLUSTER_START) != 0); }
};
typedef std::vector<GlyphItem> SalLayoutGlyphs;
// all positions/widths are in font units
// one exception: drawposition is in pixel units
// Unfortunately there is little documentation to help implementors of
// new classes derived from SalLayout ("layout engines"), and the code
// and data structures are far from obvious.
// For instance, I *think* the important virtual functions in the
// layout engines are called in this order:
// * InitFont()
// * LayoutText()
// * AdjustLayout(), any number of times (but presumably
// usually not at all or just once)
// * Optionally, DrawText()
// Functions that just return information like GetTexWidth() and
// FillDXArray() are called after LayoutText() and before DrawText().
// Another important questions is which parts of an ImplLayoutArgs can
// be changed by callers between LayoutText() and AdjustLayout()
// calls. It probably makes sense only if one assumes that the "string
// related inputs" part are not changed after LayoutText().
// But why use the same ImplLayoutArgs structure as parameter for both
// LayoutText() and AdjustLayout() in the first place? And why
// duplicate some of the fields in both SalLayout and ImplLayoutArgs
// (mnMinCharPos, mnEndCharPos, mnLayoutFlags==mnFlags,
// mnOrientation)? Lost in history...
class VCL_DLLPUBLIC SalLayout
{
public:
virtual ~SalLayout();
// used by upper layers
Point& DrawBase() { return maDrawBase; }
const Point& DrawBase() const { return maDrawBase; }
Point& DrawOffset() { return maDrawOffset; }
const Point& DrawOffset() const { return maDrawOffset; }
Point GetDrawPosition( const Point& rRelative = Point(0,0) ) const;
virtual bool LayoutText( ImplLayoutArgs&, const SalLayoutGlyphs* ) = 0; // first step of layouting
virtual void AdjustLayout( ImplLayoutArgs& ); // adjusting after fallback etc.
virtual void InitFont() const {}
virtual void DrawText( SalGraphics& ) const = 0;
int GetUnitsPerPixel() const { return mnUnitsPerPixel; }
int GetOrientation() const { return mnOrientation; }
// methods using string indexing
virtual sal_Int32 GetTextBreak(DeviceCoordinate nMaxWidth, DeviceCoordinate nCharExtra, int nFactor) const = 0;
virtual DeviceCoordinate FillDXArray( DeviceCoordinate* pDXArray ) const = 0;
virtual DeviceCoordinate GetTextWidth() const { return FillDXArray( nullptr ); }
virtual void GetCaretPositions( int nArraySize, long* pCaretXArray ) const = 0;
virtual bool IsKashidaPosValid ( int /*nCharPos*/ ) const { return true; } // i60594
// methods using glyph indexing
virtual bool GetNextGlyph(const GlyphItem** pGlyph, Point& rPos, int&,
const PhysicalFontFace** pFallbackFont = nullptr) const = 0;
virtual bool GetOutline( SalGraphics&, basegfx::B2DPolyPolygonVector& ) const;
virtual bool GetBoundRect( SalGraphics&, tools::Rectangle& ) const;
// used by glyph+font+script fallback
virtual void MoveGlyph( int nStart, long nNewXPos ) = 0;
virtual void DropGlyph( int nStart ) = 0;
virtual void Simplify( bool bIsBase ) = 0;
virtual std::shared_ptr<vcl::TextLayoutCache>
CreateTextLayoutCache(OUString const&) const;
virtual const SalLayoutGlyphs* GetGlyphs() const;
protected:
// used by layout engines
SalLayout();
private:
SalLayout( const SalLayout& ) = delete;
SalLayout& operator=( const SalLayout& ) = delete;
protected:
int mnMinCharPos;
int mnEndCharPos;
int mnUnitsPerPixel;
int mnOrientation;
mutable Point maDrawOffset;
Point maDrawBase;
};
#endif // INCLUDED_VCL_VCLLAYOUT_HXX
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */