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86fa46c5eb
This is a fix for bug 15130102 "Language name for Hebrew displayed the wrong way around on keyboard". This patch extends the previous BiDi support (when the direction for the entire string was given by the caller) to run the BiDi algorithm (provided by ICU) over the string to break it into BiDi runs. Thus, it handles mixed LTR and RTL strings in a single layout, and also respects heuristics for inferring the paragraph direction from the string. Change-Id: Ia4b869de3c139c5a7d16b8ce7766870b98a815ea (cherry picked from commit 4b3a941128454e55893d65433a835e78a9e9781d)
119 lines
3.7 KiB
C++
119 lines
3.7 KiB
C++
/*
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* Copyright (C) 2013 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef MINIKIN_LAYOUT_H
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#define MINIKIN_LAYOUT_H
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#include <hb.h>
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#include <vector>
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#include <minikin/CssParse.h>
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#include <minikin/FontCollection.h>
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#include <minikin/MinikinFontFreeType.h>
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namespace android {
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// The Bitmap class is for debugging. We'll probably move it out
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// of here into a separate lightweight software rendering module
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// (optional, as we'd hope most clients would do their own)
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class Bitmap {
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public:
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Bitmap(int width, int height);
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~Bitmap();
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void writePnm(std::ofstream& o) const;
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void drawGlyph(const GlyphBitmap& bitmap, int x, int y);
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private:
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int width;
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int height;
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uint8_t* buf;
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};
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struct LayoutGlyph {
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// index into mFaces and mHbFonts vectors. We could imagine
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// moving this into a run length representation, because it's
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// more efficient for long strings, and we'll probably need
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// something like that for paint attributes (color, underline,
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// fake b/i, etc), as having those per-glyph is bloated.
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int font_ix;
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unsigned int glyph_id;
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float x;
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float y;
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};
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// Lifecycle and threading assumptions for Layout:
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// The object is assumed to be owned by a single thread; multiple threads
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// may not mutate it at the same time.
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// The lifetime of the FontCollection set through setFontCollection must
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// extend through the lifetime of the Layout object.
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class Layout {
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public:
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~Layout();
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void dump() const;
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void setFontCollection(const FontCollection* collection);
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void doLayout(const uint16_t* buf, size_t nchars);
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void draw(Bitmap*, int x0, int y0) const;
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void setProperties(const std::string css);
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// This must be called before any invocations.
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// TODO: probably have a factory instead
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static void init();
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// public accessors
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size_t nGlyphs() const;
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// Does not bump reference; ownership is still layout
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MinikinFont *getFont(int i) const;
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unsigned int getGlyphId(int i) const;
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float getX(int i) const;
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float getY(int i) const;
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float getAdvance() const;
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// Get advances, copying into caller-provided buffer. The size of this
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// buffer must match the length of the string (nchars arg to doLayout).
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void getAdvances(float* advances);
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void getBounds(MinikinRect* rect);
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private:
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// Find a face in the mFaces vector, or create a new entry
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int findFace(MinikinFont* face, MinikinPaint* paint);
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// Lay out a single bidi run
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void doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
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bool isRtl, FontStyle style, MinikinPaint& paint);
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CssProperties mProps; // TODO: want spans
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std::vector<LayoutGlyph> mGlyphs;
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std::vector<float> mAdvances;
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// In future, this will be some kind of mapping from the
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// identifier used to represent font-family to a font collection.
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// But for the time being, it should be ok to have just one
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// per layout.
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const FontCollection* mCollection;
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std::vector<MinikinFont *> mFaces;
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std::vector<hb_font_t *> mHbFonts;
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float mAdvance;
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MinikinRect mBounds;
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};
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} // namespace android
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#endif // MINIKIN_LAYOUT_H
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