diff options
Diffstat (limited to 'include/vcl/vcllayout.hxx')
| -rw-r--r-- | include/vcl/vcllayout.hxx | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/include/vcl/vcllayout.hxx b/include/vcl/vcllayout.hxx new file mode 100644 index 0000000000..7c7a179b9b --- /dev/null +++ b/include/vcl/vcllayout.hxx @@ -0,0 +1,131 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * 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/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#pragma once + +#include <basegfx/point/b2dpoint.hxx> +#include <basegfx/polygon/b2dpolypolygon.hxx> +#include <i18nlangtag/languagetag.hxx> +#include <tools/gen.hxx> +#include <tools/degree.hxx> + +#include <vcl/glyphitem.hxx> +#include <vcl/dllapi.h> + +class LogicalFontInstance; +namespace vcl::text { class ImplLayoutArgs; } +namespace vcl::font { class PhysicalFontFace; } +class SalGraphics; +class GlyphItem; + +// 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 + basegfx::B2DPoint& DrawBase() { return maDrawBase; } + const basegfx::B2DPoint& DrawBase() const { return maDrawBase; } + Point& DrawOffset() { return maDrawOffset; } + const Point& DrawOffset() const { return maDrawOffset; } + basegfx::B2DPoint GetDrawPosition( const basegfx::B2DPoint& rRelative = basegfx::B2DPoint(0,0) ) const; + + virtual bool LayoutText( vcl::text::ImplLayoutArgs&, const SalLayoutGlyphsImpl* ) = 0; // first step of layouting + virtual void AdjustLayout( vcl::text::ImplLayoutArgs& ); // adjusting after fallback etc. + virtual void InitFont() const {} + virtual void DrawText( SalGraphics& ) const = 0; + + Degree10 GetOrientation() const { return mnOrientation; } + + void SetSubpixelPositioning(bool bSubpixelPositioning) + { + mbSubpixelPositioning = bSubpixelPositioning; + } + + bool GetSubpixelPositioning() const + { + return mbSubpixelPositioning; + } + + // methods using string indexing + virtual sal_Int32 GetTextBreak(double nMaxWidth, double nCharExtra, int nFactor) const = 0; + virtual double FillDXArray( std::vector<double>* pDXArray, const OUString& rStr ) const = 0; + virtual double GetTextWidth() const { return FillDXArray( nullptr, {} ); } + virtual void GetCaretPositions( std::vector<double>& rCaretPositions, const OUString& rStr ) const = 0; + virtual bool IsKashidaPosValid ( int /*nCharPos*/, int /*nNextCharPos*/ ) const = 0; // i60594 + + // methods using glyph indexing + virtual bool GetNextGlyph(const GlyphItem** pGlyph, basegfx::B2DPoint& rPos, int& nStart, + const LogicalFontInstance** ppGlyphFont = nullptr) const = 0; + virtual bool GetOutline(basegfx::B2DPolyPolygonVector&) const; + bool GetBoundRect(tools::Rectangle&) const; + + virtual SalLayoutGlyphs GetGlyphs() const; + +protected: + // used by layout engines + SalLayout(); + +private: + SalLayout(const SalLayout&) = delete; + SalLayout& operator=(const SalLayout&) = delete; + +protected: + int mnMinCharPos; + int mnEndCharPos; + LanguageTag maLanguageTag; + + Degree10 mnOrientation; + + mutable Point maDrawOffset; + basegfx::B2DPoint maDrawBase; + + bool mbSubpixelPositioning; +}; + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |